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O K L A H O M A C O N S E R V A T I O N C O M M I S S I O N , W A T E R Q U A L I T Y D I V I S I O N The Water Quality Primer 2 3 Introduction This booklet is an introduction to water resources and pollution ecology. Many people feel that water pollution is an issue, but they do not necessarily know why various pollutants are a problem. The “Water Quality Primer” provides basic, up-to-date information to help citizens understand: Þ basic ecology of streams, rivers, lakes, wetlands, and groundwater Þ how healthy aquatic systems function Þ how pollutants are affecting our streams, rivers, lakes, wetlands, and groundwater Þ what are the sources of pollution Þ how do pollutants get in the water Þ why landuses are potential sources of pollution Þ how do pollutants affect life in the water Þ how do pollutants affect water needed by people Certain aquatic ecology concepts will be introduced in this primer, but it is not a course in aquatic ecology. There are many important concepts that are not covered here. The “Water Quality Primer” was created by the Oklahoma Conservation Commission’s Water Quality Division with funding from the federal Clean Water Act. The Oklahoma Conservation Commission is concerned with the suitability of water for agriculture, fish and wildlife, human enjoyment, and as a source of raw water for drinking water systems. The term “nonpoint source pollution” will be seen in this publication time and time again. Nonpoint source pollution is the “pollution for which the specific point of origin is not well-defined.” The Oklahoma Conservation Commission’s Water Quality Division is the lead technical agency for nonpoint source proje cts and concerns. Nonpoint source pollution offers special challenges because it tends to be a problem to which many people and activities contribute. Education offers one of the best solutions to this problem. A few examples of nonpoint source pollution are: Þ sediment from landclearing activities Þ fertilizer & pesticide runoff Þ animal waste runoff Þ gasoline & oil which enters waterbodies Þ grass clippings placed in streams or lakes For more information, please contact: Oklahoma Conservation Commission Water Quality Division 5225 North Shartel, Suite 102 Oklahoma City, Oklahoma 73118 405-810-1002 The Oklahoma Conservation Commission as authorized by Executive Director Mike Thralls issues this publication, printed by Action Printing of Norman, Oklahoma, with funding through a grant from the United States Environmental Protection Agency. Five hundred copies were prepared at a cost of $8.99 each. Copies have been deposited with the Publications Clearinghouse of the Oklahoma State De-partment of Libraries. All programs and services of the Oklahoma Conservation Commission and the Oklahoma Conservation Districts are offered on a nondiscriminatory basis without regard to race, color, national origin, religion, gender, marital status or disability. 4 Nonpoint Source Pollutants Often the first information people learn about water concerns pollutants. For most of us, the source of our drinking water is a water treatment plant. Here the water is tested and chemically treated before being piped to our homes, schools, and businesses. The water that flows in our streams receives no treatment. Yet this water provides a home for fish and a drinking source for wildlife. On downstream, this water may be impounded and used for drinking water. The Clean Water Act states that our waters will be “fishable and swimmable.” This means our waters will be clean enough for aquatic creatures to survive in, and clean enough so that people can safely wade and swim. The following pollutants can have an impact on Oklahoma waterbodies. 1. SOIL Soil reaches streams chiefly as a result of water erosion. Larger particles fill in pools and voids under rocks and other debris, resulting in loss of habitat. Smaller particles cover and kill the spawn of many aquatic species and reduce water clarity, making it difficult for site-feeding species to capture prey, and for aquatic plants to grow. Both of these effects render water less attractive to humans. Many other pollutants, such as phosphorous, pesticides, and heavy metals, attach to soil particles, and therefore can be reduced by eliminating soil erosion. Soil is the most common and important of the conventional pollutants in Oklahoma. 2. NUTRIENTS Nutrients include different forms of nitrogen and phosphorous. Excessive amounts of either stimulate the growth of algae, other aquatic plants, bacteria, and fungi. Only algae and other plants can grow on nutrients alone. Rampant growth of such life forms lower dissolved oxygen levels, reduce water clarity, and affect a waterbody’s aesthetic value. With the exception of ammonia, none of these are toxic at levels found in streams. They are considered pollutants because of their growth-stimulating properties. Major sources of nutrients in water include fertilizer that is washed from land before it can be taken up by terrestrial plants, nutrients contained in the soil that reaches water, and nutrients contained within animal waste that reaches the water. One other increasingly important source is atmospheric deposition of nitrogen, mainly from vehicle and power plant exhaust. “We abuse land because we regard it as a commodity belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect.” Aldo Leopold When people are aware of an environmental problem, they usually want to do their part to reduce pollution. Providing information is an important tool in pollution reduction. 5 3. CHLORIDE Chloride is present naturally in all streams, rivers, and lakes. In Oklahoma, chloride concentrations are highly variable but generally increase along an east/west gradient. Many eastern streams have less than 5 parts-per-million (ppm) of naturally occurring chloride while some western streams approach 1000 ppm. Petroleum production generates large amounts of chloride, that is a potential pollutant, and street de-icing activities that use salt also can increase chloride levels in water. Wintertime levels of chloride may temporarily rise to one or two-hundred ppm. Some of the more sensitive aquatic species are displaced at these levels, but many species will not be affected until the total concentration exceeds 300 - 400 ppm. Chloride can be used as a water pollution indicator, since it often appears in combination with other types of pollution, and is very stable in water and will remain there once introduced. 4. CHLORINE Free chlorine doesn’t occur naturally and its presence is always due to pollution, usually a leaking potable water pipe, a recently drained swimming pool, or sewage effluent that hasn’t been properly dechlorinated. Chlorine is used as a disinfectant to kill bacteria in water. In surface water, it also kills all other aquatic species. Most fish and invertebrates will die at concentrations less than 1 ppm. Chlorine is a gas and will vaporize out of the water within a few hours. If chlorine gets into the water, the effects will either be immediate or not at all. 5. ANIMAL WASTE Manure is a good source of nutrients, and in addition, also contains considerable organic matter, which provides food for bacteria and fungi. When supplied with both food and nutrients, bacteria and fungi grow rapidly and use up all of the oxygen in the water. When only nutrients are added to the water, bacteria and fungi can’t grow, but algae can, sometimes resulting in an algal bloom. Algae grow over a matter of days, not hours, and also manufacture quite a bit of oxygen, so oxygen does not get used up nearly as quickly as when bacteria are growing. Given equal amounts of nutrients, the organic matter contained in animal waste will cause a greater oxygen depletion than would the same nutrients contained in a portion of inorganic fertilizer. A fish kill can occur a few hours after a large amount of manure has entered a stream or pond. Animal waste is the perfect food for bacteria - which grow quickly and consume lots of dissolved oxygen. NOTES: ____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ 6 6. PESTICIDES Pesticides kill things, and many do so indiscriminately. Many pesticides are so toxic to aquatic life that streams can be impacted by the pesticides clinging to wind-blown soil particles from fields that were sprayed. Pesticides are varied in their uses, and range from milk house disinfectant to germination inhibitors to biological agents. The full range of pesticides vary in toxicity to aquatic life from non-toxic to ex-tremely toxic. In general, insecticides are the most toxic and herbicides the least toxic to aquatic life, but there are many exceptions. Frequently, several different pesticides are found in the same batch of polluted water. When this occurs, there are often several sub-lethal stresses that by themselves would cause no harm, but together add up to a lethal combination. 7. OTHER TOXIC CHEMICALS A large number of poisonous chemicals are used around the home, farm, and in industry. Examples include cleaning agents, paints, solvents, motor fuels, various metals, and a variety of other chemicals. When any of these chemicals are found in streams, it is usually because someone dumped them down a storm drain or ditch, or spilled them on the ground. There are so many toxic compounds that it would be impossible to afford testing for them all, so the impacts of toxic chemicals are often seen without knowing exactly what chemical caused the problem. Only when the problem is ongoing do we have the time and resources to identify the cause and source of the problem. One of the best solutions is to educate people on how to properly dispose of waste. The main pesticides seen in urban areas are chlorpyrifos-based, and are probably used by homeowners in an effort to control fleas, ticks, and grubs. Several of the streams in Oklahoma City and Tulsa are seriously affected by two closely related pesticides, dursban and diazinon. As shown in this photograph, pesticides are often associated with sediment. Oklahoma City, Tulsa, and several other “environmentally aware” cities sponsor household pollutant collection events to encourage the proper disposal of many household chemicals and products that have a great potential to pollute waterbodies. 7 8. ACIDITY pH is a measure of how acidic water is. Unpolluted water in much of Oklahoma tends to vary between pH 7 and 8.5. The most common cause of low pH is acid rain, which is not a serious problem in Oklahoma. The most common cause of high pH is excessive algal growth. It is important to measure pH because it affects the toxicity of many metals, ammonia, and other poisons to aquatic animals. Lower pH generally increases the toxicity of metals, while higher pH increases the toxicity of ammonia. Toxic levels of ammonia, for example, can cause a fish kill. Many pesticides also have pH-dependent toxicity. At very high or low pH values, proteins are destroyed and aquatic life can be affected directly by the acids or bases in the water. 9. TEMPERATURE Most, but not all, of the aquatic animals that reside in Oklahoma are able to withstand a wide range of temperatures and aren’t directly affected by warming or cooling of the water. This doesn’t mean that temperature isn’t important. Oxygen isn’t very soluble in water; its maximum concentration is around 15 ppm at 0 degrees Celsius (32 degrees F). By contrast, the air we breathe is around 200,000 ppm oxygen. As water warms, it holds less oxygen. At 20 degrees C (68 degrees Fahrenheit), saturation is 9 ppm, and at 35 degrees C (95 degrees F), saturation is 7 ppm. The most sensitive species in our area begin to die if dissolved oxygen (DO) concentrations fall below 6 ppm. Many of the common species suffer at concentrations below 5 ppm. Frequently during the summer, warm water barely holds enough dissolved oxygen to maintain healthy aquatic populations. If any oxygen-demanding substances are added to the water at this time - like manure - DO concentrations fall low enough that fish kills occur. Because of thermal pollution’s severe consequences, industries are not allowed to discharge heated water, although the water is otherwise unpolluted. Similarly, sewage treatment plants are allowed to discharge more waste in the winter than in the summer because cold water holds more oxygen and is better able to withstand the effects of pollutants. 10. EXOTIC SPECIES The introduction of any non-native species is called biological pollution and often has severe consequences. Dandelions, starlings, and Norway rats are exotic species with which most people are familiar. A well-known introduced fish is the common carp. This fish reduces water quality by muddying the water, and it has displaced many native fish. Introduced lake trout are displacing the native cutthroat trout in Yellowstone Lake. Zebra mussels and Asiatic clams are spreading across the nation, displacing many of our native clam species. The most common cause of thermal pollution is the removal of trees along the streambank. This can cause water temperatures to increase from 6 to 9 degrees C (10 - 15 degrees F), and the impact that this has on the dissolved oxygen level is often enough to cause the disappearance of sensitive aquatic species. 8 11. HYDROMODIFICATION Hydromodification is the human-caused modification of a stream’s natural flow regime. The Arkansas River in Tulsa is a good example of hydromodification. The Arkansas’ flow varies tremendously depending on activities at the Keystone Dam. Fluctuating water levels strand small fish on dry ground and cause the disappearance of fish that require extended periods of high water or long stretches of free flowing river in which to live and spawn. In urban areas, hydromodification is seen in watersheds where impervious surfaces such as roads, roofs, and parking lots increase the runoff and velocity of small streams. 12. PATHOGENS Pathogens are micro-organisms capable of causing diseases. Normally we’re concerned with human pathogens, which almost always enter the water through the introduction of human or animal waste. Pathogens are worrisome because of the diseases that can be caused when they are introduced into the body. Pathogen contamination most commonly takes place when animal waste reaches water and sewage pipes leak. Poorly functioning sewage treatment plants are a less common source. 13. TOXIC ALGAE The most common type of toxic algae are a special type of primitive algae, the Blue-Green algae, which are actually photosynthetic bacteria. Like other algae, toxic algae produce oxygen in light and use it at night, all the while using the nutrients nitrogen and phosphorous. Sometimes, however, for reasons we do not understand, they produce very deadly toxins. These episodes are rare but very serious. Usually toxic blooms of Blue-Green algae occur in small ponds and are discovered when cattle die. Other types of toxic algae are Dinoflagellates and Cryptomonads. Like the Blue-Greens, these algae only produce toxins some of the time, but their toxins are very poisonous. Dinoflagellates are responsible for red tides in the ocean and for massive fish kills and disorders of the central nervous system in humans. A very large outbreak of one type of toxic Dinoflagellate in North Carolina is thought to be tied to swine and human waste increases in the Neuse River. In the urban area, impervious surfaces cause increased volumes of water to enter streams in a great flush, stressing streambanks and making it difficult for plants and animals to become established. NOTES: ____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ 9 Watersheds What is a watershed? A watershed is an area of land that drains to a given point. This point can be a bridge over a stream, a property boundary, a dam, or just a mark on a map. All the pollutants discussed - and the land-uses and activ ities that created them - happen within watersheds. For example, the area of land that drains into the Grand Lake O’ the Cherokees is the entire area of land from which runoff will eventually reach Grand Lake. The watershed contains about 6,000,000 acres. Included in this watershed are the watersheds of every small pond and large lake that lie on the tributaries of the Neosho and Spring Rivers. Likewise, the watershed of Grand Lake lies within the Arkansas River watershed, which in turn lies within the Mississippi River watershed. When talking about a watershed, normally a specific point is designated, and the land area that impacts the stream, lake, pond, or wetland to that point is the watershed. However, varying statutory definitions for the term “watershed” exist which often leads to confusion. Although numerous defin i-tions exist, they do not change the scientific definition of a “watershed”. The definition provided in the Oklahoma Department of Environmental Quality statutes states that “a lake’s watershed is all the land within 600 feet of the high water mark.” The USDA Natural Resources Conservation Service, Oklahoma State Office, defines a watershed as “the topographically defined area drained by a river/ stream or system of connecting rivers/streams such that all outflow is discharged through a single outlet.” The Oklahoma Conservation Commission’s definition is “an area of land that drains to a given point.” As rain falls and moves over the land’s surface as runoff, it dissolves any water soluble substance it contacts, floats anything buoyant enough to float, and dislodges any particles small enough and loose enough to be kept in suspension. These dissolved, suspended, and floating particles all impact water quality if they reach a stream or pond. Everyone lives in a watershed. This is an important concept. Our lawns, driveways, and rooftops contribute runoff to nearby waterbodies. We as individuals impact water quality. Once we understand the concept of watersheds, that we impact our streams, rivers, lakes, and wetlands, we place ourselves in a position to care for our resources on a more personal level. Regardless of what any law states, a watershed is an area of land that drains to a particular point. Activities that take place within a watershed have an impact on water resources. Every square foot of land on this planet is part of a watershed. 10 Natural Background or Pollution....What’s the Difference? Unpolluted waterbodies have stable concentrations of dissolved, suspended, and floatable particles (and have had stable concentrations for thousands of years). Organisms that are adapted to these conditions thrive in the water. When human activities cause concentrations of any substance to increase beyond what the native organisms are adapted to, then their health suffers, and this water is considered polluted. Pollution-causing activities occur in watersheds everywhere and have an impact on water quality and habitat quality of streams. The closer these activities are to streams or ponds - or to a direct channel to these waterbodies - the greater the impact. Pictured on this page are some of the activities that can take place in a watershed that may have an impact on streams. Agriculture Industry Mining Urbanization Recreation 11 Streambank Erosion Extreme examples of streambank erosion can be seen throughout Oklahoma, in urban areas, out in the country, and in all of the small towns between. Streambank erosion problems affect many aspects of a stream, but because of the activities that tend to contribute to unstable banks, this section is being placed with the watershed portion of this primer. Eroding banks contribute to sediment in streams, threaten structures, and reduce habitat and crop production area. Bank erosion problems are accelerated when riparian vegetation is disturbed by: ¨ crops planted too close to a stream; ¨ cattle allowed unlimited access to streams; ¨ encroaching development; and ¨ landuse changes which cause greater flushes of water. Many of the problems faced by streams and rivers could be battled by leaving natural buffer zones along the stream. The area directly adjacent to the stream should remain undisturbed. No development should ever take place within 50 feet or so of a perennial stream. A larger buffer should be left in areas where the floodplain is greater. Agricultural activities also should leave stream and river riparian areas undisturbed, and, if possible, cattle should be allowed only limited access. The urban storm sewer system should be designed to release water into streams at a low rate of flow so that banks are not chewed up by massive flushes of water. Consider the urban area; streets, sidewalks, parking lots, driveways, and roofs. These impervious surfaces do not allow water to soak in, and are in fact usually designed to move water into our streams quickly. Multiply this modified hydrology by riparian area removal and you are almost assured of an unstable stream channel. Streambank erosion is a major problem throughout the state. Bridges and structures become endangered, productive grazing and cropland is lost, and habitat is destroyed. 12 Landuse Classes - Sources of Nonpoint Source Pollutants The pollutants discussed on the preceding pages began the journey to an understanding of aquatic pollution. The following section describes general classes of landuse that can generate pollutants. Urbanization Urban areas are concentrated collections of humans. Since human activities are usually the cause of pollution, many different types of pollutants come from cities and towns. Sewage treatment plants come to mind when considering urban pollution. Under the best of circumstances, sewage treatment plants do not release ideal water. However, billions of dollars have been spent in the United States to ensure that fish and other organisms can live in the waters below a sewage treatment plant. Because equipment wears out, populations grow, and accidents happen, sometimes water released from treatment plants is poorly treated. In extreme situations, untreated waste water flows into streams, usually after a rain. Stormwater runoff is another urban threat to stream health. Most urban areas have storm sewers that directly route water to a stream quickly and efficiently. Neighborhood activities — such as fertilizer and pesticide application, new home construction, etc. — can result in chemical- and soil-laden runoff entering urban streams via the storm sewer system, on a daily basis, particularly in the late spring, early summer, and fall, when rainfall is greatest. Keep in mind that all human activities in the urban area have the potential of impacting streams. In an effort to speedily route water away from neighborhoods, businesses, and streets, storm sewer systems are designed to send water to the nearest stream and away from town. This is quite different from many years ago - before urbanization - when water was allowed to make its way to the stream by gentle movement through the soil. The Clean Water Act has resulted in great success in bringing the effluent from community treatment plants up to grade. Concrete channels strip streams of their ability to provide habitat for plants and animals. This stream has no chance of meeting the Clean Water Act’s “fishable” goal. 13 Urban Landuses that can Impact Local Streams Earth moving activities - like this new residential development - will contribute sediment to local streams if the appropriate “best management practices” are not employed to reduce erosion and maintain sediment on site. Although proper lawn maintenance and pet care will drastically reduce flea and tick populations, many homeowners be-lieve they must dose their lawns regularly with pesticides. Automobile activities within cities contribute to nonpoint source pollution. Motor oil, gasoline, coolants, and by -products of tire and brake wear are a few of the transportation-related pollutants that have a negative impact on our water. All the impervious surfaces over which our stormwater flows allow little time and no place for the filtering of pollutants. High-maintenance lawns abound in urban areas. Many homeowners subscribe to lawn care services that systematically apply fertilizers and pesticides. Often these lawns have high moisture requirements, and the idea of “conservation” never comes into play. Down the drain and into a stream! The US EPA says that urban area runoff is the third largest source of impairment to surveyed lakes. 14 Industrial Facilities Industries generally are thought of as urban facilities, but many are locating more frequently in rural areas too. Many industries discharge treated wastewater, and like effluent from a sewage plant, if everything works accordin g to plan, major pollution problems are not caused. However, people make mistakes, equipment gets old and worn, and new processes are added that create new and different pollutants. The Oklahoma Department of Environmental Quality (the agency that regula tes industrial discharges) must stay vigilant to keep streams safe from industrial discharges. Industries can be large contributors to air pollution (as can cities), primarily through the burning of fossil fuels. Industrial atmospheric pollution is not nearly the problem it was a few years ago. It does, however, remain the major source of acid rain, and through rainfall, is an increasingly significant source of nitrate in water. Mining Mining and the associated extraction and processing of minerals or metals can have tremendous impacts on water quality. Fortunately for Oklahoma waters, there are no more large deposits of metals such as lead or zinc left in the state. Metals can generate very toxic by-products, as did the lead and zinc deposits of Ottawa County. Most present-day mining in Oklahoma focuses on rock, clay, and sand, with smaller but important amounts of coal and gypsum being extracted. The major pollutant generated by modern Oklahoma mining activities is sediment. Most sediment comes from small, loosely-regulated (or not regulated) borrow pits. The mining of gypsum generates silt but the gypsum itself is not a major pollutant. Waters in the gypsum-rich part of the state have a natural abundance of gypsum, and the life in these streams has adapted to it. Like cities and towns, industries, in addition to their wastewater treatment plant, must comply with a stormwater pollution prevention plan. The plan should prevent solvents, petroleum products, sediment, and an array of chemicals from entering streams. Industrial activities remain the leading cause of acid rain and contribute many other pollutants to waterways. As with all surface mines, sediment is potentially the major pollutant. 15 With a couple of notable exceptions, mining in present-day Oklahoma doesn’t create much of a problem (other than sediment) because it is a declining industry and modern mining operations go to much greater lengths to control pollution. Most of the stream health problems that stem from mining are the result of acid mine drainage from mines that were active in the first half of this century. State and federal agencies are slowly getting these problems under control, although the very worst ones may have to wait for Nature to clean up our mess. In Oklahoma, acid mine drainage occurs mainly in Pittsburgh, Ottawa, and Latimer counties, with some also in LeFlore, Craig, and McIntosh counties. Petroleum and Natural Gas Extraction As with mining, most of the environmental problems associated with the petroleum industry are due to past practices. Laws (and the pollution controlling efforts of the industry) were once much more lax. Although still a large industry in our state, oil production, like mining, is declining. Natural gas production remains high. Large volumes of sediment are still contributed by areas of land where vegetation and soil microor-ganisms were killed and soil was destabilized by brine waters produced during petroleum activities. In the past, many streams and ponds were also killed by crude oil that was allowed to flow into them from uncontrolled wells and overflowing tanks. Most of these problems have been slowly remedied by Mother Nature. The industry itself also funds cleanup and plugging of abandoned wells and sites. Today’s problems are mostly due to pipeline breaks that occur where streams wash out poorly-designed pipeline crossings or where very old collection lines corrode and begin discharging. In the oil and natural gas extraction industry, constant observation and prompt reporting of problems is a good way to control pollution. In some areas coal mining activities can result in acid mine drainage if the proper precautions are not taken. Brine waters flowing over the land not only cause erosion but prevent the soil from growing vegetation for many years. Today’s practice of using plastic pipe to collect brine contributes to current problems when these pipes become damaged by grassfires or vehicles. 16 Forestry Many people assume that timber harvesting contributes huge volumes of sediment to streams. How-ever, present-day forestry operations in Oklahoma implement environmentally friendly practices. Some small operations can still cause heavy erosion during logging, and these operations should be closely watched. Pollution problems observed should be reported. The major source of sediment from forestry operations is the unpaved logging roads that are used to get to and from the logging operations. Excellent “best management practices” to control erosion on these roads have been developed. These BMPs can be seen in national forests and large, privately-managed forests within Oklahoma. The remaining problems are primarily due to small logging operations working on private land under contract with individual landowners. Road Construction Road and highway construction goes on all over the state and is especially important in urban areas. As with forest roads, we now know how to control sediment during road construction, and contractors are starting to do this. Public street and highway construction has lagged behind forest road construction in the actual installation of BMPs, but more and more BMPs are in place. Most people know that hay bale dikes and black silt fences — often observed on disturbed sites — serve as sediment controls. Using environmentally friendly logging practices, many modern companies allow healthy streams and timber harvest to co-exist. Some timber harvesters fail to use best man-agement practices that could prevent or reduce erosion. This box culvert was filled with sediment from an unmanaged clearcut. The taxpayers will foot the bill to clean it out. Best management practices will help prevent sediment loss on this rural road, even though it is unpaved. 17 Recreation The major problems associated with recreation are trash, human waste, and soil erosion, all resulting from too many people and too many vehicles in too small an area. Although restroom facilities, trash receptacles, and barricades exist, vandalism and non-use of structures is a continuous problem. Education, coupled with the enforcement of vandalism laws, is one of the best solutions. Septic Tanks Almost everyone living in the country and not served by a municipal wastewater treatment system relies on a septic tank to partially treat their domestic waste. The remainder of the treatment is accomplished by the soil around the leaching field (the area where the waste water discharges). Problems associated with septic tanks can be fre-quent, and often are due to the: à disposal of waste that cannot be processed by the septic system (this can include dry-cleaning fluid, degreasers, pesticides, and other toxic chemicals that are poorly degraded by septic systems and will end up polluting ground and surface water.) à lack of tank maintenance and cleaning (this can cause the lateral lines to become plugged, routing wastewater to the surface, from where it can enter surface water). à siting the leaching field in incompatible soils (soil with too great or too low a permeability will often cause pollution of ground and surface water). All of these problems can be avoided by timely pumping of the tank, proper siting and construction, and proper disposal of toxic waste products. NOTES: _____________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ Motorized watercraft provide more than fun at the lake.... they can leave behind gasoline and other fluids. People want and expect locations where they can have a positive outdoor experience. Unfortunately, people sometimes lack the outdoor ethics necessary to conserve our resources. 18 Dams Dams are frequently viewed as a good thing, and they have helped many people and some wildlife through providing water storage and by reducing flooding in some areas. Dams also have contributed to stream habitat loss, stopped reproduction of certain migratory fish species, and lowered the reproduction of species that require high water or long stretches of open river for reproduction. While humans have benefited from the floodwater storage provided by dams, the floodplains, streams, and rivers that have been flooded have not. Floodplains are nature’s storehouse for extra water, silt, organic matter, and nutrients that would otherwise remain in the channel and damage stream health. Even the Corps of Engineers high-ranking officers are beginning to recognize the need to let floodplains do what floodplains are supposed to do. “I feel very strongly that the solutions we’ve been following are not the right solutions. We just need to keep people out of the floodplain.” .....Walter Yep, Chief of Planning, Corps of Engineers Sacrament o Office The paddlefish is one species whose range has been reduced due to the damming of our rivers. 19 Agriculture Farmers and ranchers make their living off the land. Consequently, a lot of land is put into production and this can have a significant impact on stream health; either positive or negative. One of the biggest challenges to agriculture in Oklahoma is profitable cattle production without environmental damage. When cattle are given unlimited access to streams, they may trample banks, add manure to the stream, and cause rangeland erosion. A highly trampled bank will add a great deal of sediment to a stream, while providing none of the benefits that a healthy riparian community provides. Incised cow trails that cut through an otherwise healthy riparian area will channel water right to the stream, thereby decreasing the riparian area’s ability to filter nutrients, sediment, and some pesticides. Manure in the stream supplies nutrients and organic matter which cause oxygen depletion and algal growth. Overgrazing of rangeland exposes sediment, which could reach a stream, and allows more manure to be washed from the land into the stream. There are several state and federal programs to help ranchers deal with these problems and we are beginning to notice change throughout the state as ranchers implement new practices. The production of any crop that requires regular working of the soil has environmental risks. The greatest risk is soil erosion, but the Natural Resources Conservation Service - through conservation plans tailored to each producer’s needs - has addressed this issue so well that the only people whose fields are eroding are the ones who haven’t taken the recommended steps to halt it. Education is likely the best answer for these hold-outs. Removal of riparian vegetation to increase the amount of land available for production remains a serious problem. Many people are aware that riparian area loss has a negative impact, but it remains a common practice. More land is lost through erosion, and the stream is deprived of the important benefits of the riparian area. People need to be educated to the fact that a stream flowing through their property moves on to their downstream neighbor, and the stream carries with it the upstream impacts. The application of farm chemicals is costly to the farmer, compared to his urban neighbors, so farmers tend to apply chemicals sparingly. Over-application is usually not a problem on agricultural lands. Buffalo, historically the primary large herbivore of this continent, roam widely, as opposed to cattle, which prefer to remain close to the water. Cattle can damage streams by adding manure when they loaf in the water, trampling banks, and by overgrazing the riparian areas. Conservation plans often contain grassed waterways and terraces as best management practices to decrease erosion and protect 20 Problems do occur because the farmer depends on his fields for his livelihood and sometimes can’t afford to wait for the wind or rain to stop before applying a pesticide. Healthy riparian areas without cow trails can make a big difference by forming a vegetated buffer zone. Beyond that, it is up to chemical companies to come up with more environmentally friendly pesticides. Animal waste from different types of feeding operations comes with its own set of problems. While it has value as a fertilizer, animal waste’s low density makes it cost-prohibitive to truck very far. It is a by-product of feeding operations and therefore doesn’t involve any capital outlay from the producer. Because animal waste is not expensive, and transportation is viewed as costly, waste is often over-applied to nearby land. Pollution of ground and surface water can result. The NRCS, the Oklahoma State Department of Agriculture, and the Oklahoma Conservation Commission are busy writing waste management plans for farmers who generate animal waste. Other state agencies, including OCC and several Conservation Districts, are investigating a system to transport animal waste out of watersheds where it is in oversupply , as well as alternate uses for the animal such as a fuel source for power plants. Atmospheric deposition Atmospheric deposition happens when pollutants are deposited in the air as gases or small particles and then deposited elsewhere as dust or in rain. The result is a serious form of pollution to which almost everyone contributes. The problem arises through two routes, the main route being volatilization and/or release into the air of polluting gases such as nitrogen oxides, ammonia, and sulphur compounds. Sulphur compounds are released when coal is burned and reacts in the atmosphere to cause sulfuric acid. This sulphuric acid then returns to Earth as acid rain. Much has been done to reduce this problem but there are still many waterbodies in the U.S. where no fish live because the pH is too low. Likewise, large forested areas in the eastern U.S. are dead or dying because of acid rain. A stable riparian area can help absorb the impacts of many problems - like chemical applications, erosion, and livestock. A large number of animals con-centrated in a small space con-centrates waste such that it be-comes a problem. Animal waste has been targeted as a prime pollutant of several of Oklahoma’s lakes and streams. 21 The second route through which pollutants become airborne is the action of wind picking up dust particles that have pollutants on them. This sounds minor, but DDT levels in fish in the American Great Lakes are rising due to atmospheric deposition of dust carried across our borders from foreign lands. Likewise, much rain in Iowa contains atrazine picked up from cornfields. At times, the rainwater in Iowa contains more atrazine than is allowed by safe drinking water standards. NOTES: _________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ Atmospheric deposition problems require technical solutions. Better pollution controls on exhaust stacks and vehicles and more environmentally friendly pesticides should help considerably. We are, indeed, a nation dependent upon our automobiles. Proper maintenance of these vehicles is very important. Another way to reduce atmospheric deposi-tion is to pay attention to “ozone alert” warnings. 22 Water: The Basic Facts At this point the reader is familiar with the major classes of pollutants and the sources that generate them. It is now time to see how these pollutant interact with the aquatic ecosystem. Water is often referred to as the universal solvent. This might sound like a trivial piece of information, but it isn’t. Every single chemical that constitutes the cells of our bodies and the cells of all living things - from bacteria to loblolly pines - either is dissolved in water or was at some point during its synthesis. Different organisms need different amounts of water, but without water, all life stops immediately. Water covers three-quarters of the planet. The oceans hold almost all of our water and are the repository for all the minerals that have dissolved from rocks over the last few billion years. This is why the oceans are salty. The Earth’s second largest collection of water is in the polar ice caps. Because these ice caps are made of frozen precipitation, they are composed of fresh water. Groundwater is found in the spaces between soil and rock particles of the Earth’s crust. It varies from very fresh to extremely salty and can often contain poisonous compounds. Fresh groundwater is a wonderful resource! Atmospheric water is found in the Earth’s atmosphere. While not a large portion of the total water on our planet, atmospheric water is the only reason we ever have any fresh water on the Earth’s surface. Without evaporation and rainfall, all water would be in the oceans and full of salt! NOTES:____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ Although most of us know people who count on groundwater, fresh, high-quality groundwater is not always available. Because of atmospheric water, we have rain, which produces rivers, streams, lakes, ice, and groundwater. Anything that changes the temperature of the air affects how much water will evaporate, how much water the atmosphere can hold, and, in the end, how much rain will fall. 23 Surface water lies on the surface of the Earth’s land masses. Surface water can be flowing or still, fresh or salty, deep or shallow. If deep and still, it is some type of lake. If flowing, it is a stream of some type. If it is flowing very slowly or is still, and is shallow or even dry for part of the year, then it is a wetland. Remember that humans invented these names. Nature has no interest in how humans classify things, or whether or not things fit neatly into one of our boxes. There will always be waterbodies on the border so that it’s impossible to say whether one thing is surface water, the other a wetland, or the other groundwater. Placing water in these general categories just makes it easier for us to think about and discuss the different waterbodies. Because of legislation and administrative rules, the Oklahoma Conservation Commission’s Water Quality Division is concerned primarily with flowing water. Other administrative units work with groundwater, lakes and reservoirs, wetlands, and atmospheric water. NOTES: ____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ Whether it is a wetland like this one or a stream, river, or lake, the liquid fresh water that exists on Earth is less than one percent of all of the water in the world. The Oklahoma Conservation Commission is concerned with the suitability of surface water for agriculture, fish and wildlife, human enjoyment, and as a source of raw water for drinking water systems under the authority of the federal Clean Water Act. The Oklahoma Department of Environmental Quality monitors the safety of finished drinking water under the authority of the federal Safe Drinking Water Act. 24 Stream Health = Water Quality + Biotic Quality + Physical Habitat Quality We will begin our discussion of aquatic health with streams. Of all living aquatic systems, streams are the most basic. The discussion of other types of waterbodies will build upon what is said about streams. The title of this section is a peculiar looking equation for a good reason. Most people want healthy, attractive streams that smell good and fit their image of a high-quality stream: scenic vegetation along the stream’s edges, clear water, some rocks, perhaps a submerged log or two, and plenty of fish. The water flowing in this ideal stream may be moving fast or slow and will have varying depths, but it is unlikely to smell bad, and it probably offers a great place to cool down after a hot day. Add the sounds of cicadas and the songs of birds, and the picture gets better still. The imagined stream contains far more than what has traditionally been termed “water quality.” Refer back to this imaginary stream and add this to the scene: the local transportation agency wants to build a large interchange across the stream. With heavy equipment they redesign the channel, so the stream is straight and the sides and bottom wear a permanent coat of concrete . Then the actual highway construction begins, and another 110 feet of concrete is installed on either side of the stream. At last it is time to stand back and cut the ribbon, because the new superhighway is finished. This stream is no longer a good place to fish and swim, observe wildlife, and relax. The water flowing through the channel, the one that was so recently a natural stream, is of the same quality that it was before. The changes that have taken place have been to the banks and bottom, not the water itself. However, it would be untrue to say that this is still a high- quality stream. The fish have been driven away, the birds are gone, the trees that shaded the water are just a memory. There is much more to a high-quality stream than good water quality. The physical habitat and biota of the stream are equally important. We will examine the three broad categories of water quality, biotic quality, and physical habitat quality in detail. The stream on the left is a well-functioning, high-quality stream. The stream on the right still boasts good water quality, but its habitat has been altered. No animals can make a home here, and people do not flock here to fish and swim. 25 Physical Habitat Everything needs a place to live, and has a preferred habitat where it thrives best. Usually, animals and plants can flourish in non-optimal habitats only when there is little or no competition. When an organism is found in large numbers outside of its normal habitat, its competitors probably have been removed. The more different kinds of habitat that are present, the more different kinds of animals and plants can be found. The most important parts of habitat are: Substrate - The material that composes the bottom of the waterbody is the substrate. It can consist of rocks, mud, sand, hardpan clay, organic material such as partially rotted leaves and twigs, and anything else that happens to be there. Structure - The three-dimensional materials in the water are known as “structure.” Submerged logs, underwater ledges, and large boulders are common examples of structure. Depth of Water - Not only must an organism be able to fit into the water, its preferred food must live there, and in many cases, its chief predators must be excluded, or at least hindered. Many animals occupy water of a certain depth that satisfies all of these requirements. Speed of Water - Some organisms like flowing water because they are stationary and get their meals delivered by flowing water. Others like still water. There are many reasons why water of a certain speed is preferred by different organisms. Riparian Vegetation - Found within the zone where land and water meet, riparian vegetation can cool water by 10 - 15 degrees Fahrenheit by providing shade. The plant’s along the water’s edge provide high qualit y food with leaves, twigs, and insects that fall into the water. Riparian vegetation also provides habitat and streambank stability. Water Temperature - How cool or warm the water is effects the metabolic rate of living things in the water and the water’s dissolved oxygen (DO) content. Factors that impact the water temperature are shade, water depth, and water source. Structure and substrate provide materials that are hidden under, burrowed around, and clung to. Varying speeds and depths of water are factors that make streams unique. 26 All of the factors discussed on the previous page are part of aquatic habitat. A healthy stream or lake has habitat that will support fish, aquatic insects, and other animals and plants. Habitat can be impacted when riparian areas are disturbed, which often contributes sediment loads to the water. Two other types of disturbances known to contribute sediment are channelization and landuse changes that cause increased stormwater flushes. Functional streams that support life and carry water efficiently can exist even in urban areas, and relatively easily in agricultural ones. “When we try to pick out anything by itself, we find it attached to everything else in the universe.” John Muir NOTES: ___________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ Riparian areas are important, productive zones where land and water meet. 27 Chemical Habitat Anything dissolved in water, and much of the fine particulate matter suspended in water is considered part of the chemical habitat of an aquatic organism. It is universally true that whenever there is too much of anything it can be considered a pollutant. Just as all organisms have a preferred physical habitat, they also have a preferred chemical habitat. The right concentration of a chemical or nutrient for one species might be too much or too little for another. There is no perfect amount of any chemical dissolved in the water. Even dissolved oxygen can be viewed as a pollutant under some circumstances. If too much oxygen is introduced into an area where it doesn’t occur naturally, the entire community’s metabolism will change. In the process, many species that did well with less oxygen will be replaced with new and different species. Several broad categories of dissolved or suspended chemicals make up the chemical habitat. These include: · macronutrients (nutrients needed in large quantities); · micronutrients (nutrients needed in small quantities); · salts (affect the ionic balance of the water); · dissolved inorganic carbon; · dissolved organic carbon; · pH; · oxygen; and · suspended solids. No living cell on earth can survive without most of these in one form or another. These chemicals are absolutely necessary for life, yet in too great a concentration, any one of these can become a pollutant! A category that is part of both the chemical and physical habitat is suspended solids, or fine clays and organic particles. Suspended solids can greatly influence the physical habitat, and they influence the chemical habitat by binding to phosphate and metal ions, many of which are essential micronutrients. The result can be micronutrients that are unavailable for plants and animals. In an otherwise unpolluted stream, micronutrients bound to suspended solids can cause growth limitations. Chemical monitoring on a regular basis provides important information about water quality. This information, along with habitat and biotic data, provides valuable feedback on the health of a particular waterbody. 28 In a class all by itself, oxygen is a very important dissolved chemical. Oxygen is needed by all plants and animals. Oxygen is not very soluble in water, but aquatic plants and animals get their oxygen from the water, and at best, dissolved oxygen can be found at maximum concentrations of 15 parts per million (ppm). By contrast - the air we breathe is 200,000 ppm. While we would not notice our oxygen level being lowered by 10 ppm, decreasing the dissolved oxygen in the water by just a few ppm can have a drastic impact on the stream’s life. As water warms, it holds less and less oxygen. At 0 degrees Centigrade (32 degrees Fahrenheit), it can hold 15 ppm. At 35 degrees C (95 degrees F), it can hold only 7. Since most fish require 5 ppm to survive, high temperatures of summer pose greater risks. NOTES: __________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ A healthy stream has areas shaded by a good stand of trees and shrubs. The shade from the trees is important for keeping the water cool. Cooler water can hold more dissolved oxygen, thus making the stream home to a greater diversity of fish. This results in a more stable ecosystem that is better able to withstand certain types of pollution. 29 Macronutrients Macronutrients — nitrogen, phosphorous, and potassium — are familiar to any farmer and many homeowners. In streams, there is almost never too much or too little potassium, so we usually ignore it. Nitrogen and phosphorous, on the other hand, almost always limit growth in an unpolluted stream. All proteins contain nitrogen, and all DNA and RNA contain a lot of phosphorous. Nothing can live without these two elements, and, after water and carbon, they are the ingredients all life forms need the most. Because nitrogen and phosphorous stimulate plant and microorganism growth, these elements can be major pollutants. The pollution potential of these elements will be discussed in another section. Micronutrients Living organisms require other elements in very small quantities. Sulphur, silicon, manganese, cobalt, vanadium, iron, magnesium, and calcium are a few micronutrients needed by plants and animals to survive. While essential, many micronutrients are highly toxic if supplied in high doses or in the wrong form. Chromium and selenium, for example, are micronutrients that can be very poisonous. Common Salts Nothing can live in pure water. A fish placed in pure water will die quickly, as will bacteria, plants, and any other aquatic organism. A certain amount of dissolved salts in water is necessary to keep the right balance of salts and water in the living organisms. The common salts that do the bulk of this work are sodium chloride, calcium sulfate, and various carbonates. As with all other things, too much of any one of these salts can present a major problem, and even cause a fish kill, yet some of each is necessary for life to exist. Dissolved Inorganic Carbon Dissolved inorganic carbon consists of the various carbonate salts and dissolved carbon dioxide. Without these, plants cannot grow, and without plants, animals cease to exist. In a well balanced water-body, there is almost never a shortage of dissolved inorganic carbon, but again, too much can be very harmful. There is so little nitrogen and phosphorous in an unpolluted stream that life in the stream depends upon what falls in, such as insects, twigs, and leaves, for nutrients. 30 Dissolved Organic Carbon Most animals and many plants require vitamins. Most vitamins and other growth factors are produced by bacteria, and small but absolutely necessary amounts of them float around in all water. Other organic compounds, like sugars and organic acids, leak out of living cells and contribute to the mix of food on which bacteria in unpolluted waters feed. This leakage is a good thing, because bacteria are necessary for decay and vitamin production. Like everything else, though, too much is considered pollution. The high level of dissolved organic carbon in sewage effluent stimulates bacteria l growth to the point that all dissolved oxygen is used and the fish and macroinvertebrates die. pH An important chemical category is pH, a measure of the acidity of the water. Since even pure water produces a few hydrogen ions that contribute to acidity, pH is a characteristic shared by polluted and unpolluted water. A pH of 7 is neutral, values from 0-7 acidic, and values ranging from 7 - 14 caustic. Water with pH varying between 6.0 and 8.5 is generally suitable for most aquatic life. In the southeastern part of Oklahoma, pH can be as low as 6.0, while it tends to range from 6.8 to 8.5 over the rest of the state. A pH of less than 6.0 can affect reproduction of an aquatic species, but adults can often withstand a pH of 5.0 or less. An interesting and important characteristic of pH is that it affects the toxicity of many poisons that end up in streams. Lower pH values tend to increase the toxicity of metals, while higher pH values can render these same metals unavailable, causing deficiencies. High pH values drastically increase the toxicity of ammonia. Many pesticides have pH-dependent toxicity. “What’s the use of a house if you don’t have a decent planet to put it on?” Henry David Thoreau Testing for dissolved oxygen can be accomplished with meters or with simple field kits such as the one used here by a volunteer. 31 Biotic Quality Streams, lakes and wetlands depend equally on water quality, physical habitat quality, and biotic quality. If the water quality (chemical habitat) is high, and the physical habitat is high, and all the organisms that naturally live in the stream are present, then the biotic quality is probably high also. However, the same way that the removal of physical or chemical habitat components changed our ideal imaginary stream for the worse, changes to the biota can affect a waterbody also. These changes can occur with or without changes to the chemical and physical environment. Biotic interactions take place when a living entity is part of the physical habitat for something else. Aquatic plants always provide substrate and structure for invertebrates and fish. Young fish, in particular, have very poor survival rates without beds of aquatic plants in which they can hide from larger animals. If large beds of aquatic plants are removed from a stream, and there is no shallow water small fish can retreat to, the end result can be a few very large fish, which will go hungry after all the small fish are gone. The result can be a drastic decrease in total fish production. Other biotic interactions are more subtle and don’t result from any changes at all to the chemical or physical habitat. High fishing pressure that decreases the population of large predatory fish from a lake or stream can result in a community dominated by small, stunted insect-eating sunfish and an overabundance of insect-eating minnows. Because the main consumers of algae are insects, the population of algae often explodes when the population of insect-eating fish explodes. Excessive algae depletes oxygen in water, resulting in a fish kill. Remember - we would not have had too much algae had we not removed the large fish that kept the insect-eating fish population under control. Once the insect-eating fish became too numerous, the insects were eaten and the algal population exploded! Aquatic plants provide a fine place for aquatic insects and young fish to find refuge from larger, hungry animals. When urban development or farming practices result in streams that are devoid of aquatic vegetation over large areas, the diversity of fish and insects living in the stream will decrease. 32 There are countless ways that one animal or plant can influence another without eating it. Sometimes it is a simple matter of competition for food or habitat space. Another is when an animal uses the burrow of another animal for nesting space. Channel catfish will only nest in cavities and are often found nesting in abandoned beaver burrows. Fresh water mussel larvae get their start in life on the gills of certain fish species and cannot reproduce without these fish present. In summary, a healthy waterbody exists when the water quality is good, the waterbody’s physical components can provide homes for plants and animals, and the plants and animals that should be able to live there are present. The Oklahoma Conservation Commission’s Water Quality Division monitors the condition of waterbodies in Oklahoma through their own projects, support to conservation districts, and the administration of nonpoint source pollution grant projects. Commission staff members use data to prepare plans for stream protection and restoration throughout the state. “Our liquid planet glows like a soft blue sapphire in the hard-edged darkness of space. There is nothing else like it in the solar system. It is because of water.” John Todd The balance of life in a stream or lake is delicate. By removing too many fish at the top of the food chain, population levels of everything else will change. The result can be a change in the chemical quality of the water, altering the species composition even further. The intimate relationship between a stream’s water chemistry, habitat, and plants and animals holds many mysteries. Understanding these ecological concepts marks the beginning of finding a way to respect and conserve our many natural aquatic resources. 33 Stream Ecology: Foodwebs, Nutrients, and Oxygen A natural “follow-up” to the previous section that covers chemistry, habitat, and stream life is this highly simplified look at foodwebs, nutrients, and oxygen. Streams, ponds and wetlands have foodchains, or foodwebs. At the base of all foodwebs is some type of plant. Plants that form the base of a stream’s foodweb can grow in the stream or grow on dry land and fall into the stream. Nutrients, essential for plant growth, come from manure or fertilizers, with small amounts occurring naturally in all soils. Unpolluted streams are dominated by invertebrates that shred dead leaves and twigs and by small fish that eat insects. The water has no noticeable algae and underwater rocks and logs look clean. Dissolved oxygen levels remain close to saturation during both day and night, meaning that levels don’t vary much over a 24-hour period. Polluted streams are dominated by insects, and often small fish, that eat algae. At low levels of pollution, the invertebrates will scrape algae off of rocks and sticks. At higher levels, they will filter plankton (floating) algae out of the water. Where lots of algae exist, very wide swings in the levels of dissolved oxygen concentrations from day to night can be expected. DO levels are likely to be considerably more than 100 percent saturation level during the day, and much less than 100 percent at night. At night the algae and other aquatic plants are respiring, us ing oxygen but adding none. During the day, oxygen is added to the water as a by-product of photosynthesis. At even higher levels of pollution, algae don’t grow well (or at all). The stream becomes dominated by aquatic invertebrates (such as tubifex and bloodworms) that do not need much dissolved oxygen to survive. Bacteria and fungi grow so well in these waters that they also dominate. At these pollution levels, water will appear gray or black instead of green, and few or no fish will be present. An unpolluted stream gets most of its plant material from terrestrial vegetation. A polluted stream gets almost all of its plant material from algae. Very highly polluted waters usually host low levels of dissolved oxygen during the day (well below saturation) and approach 0 at night. These waters sometimes have an unhealthy gray or black coloration. 34 Lakes and Reservoirs - Health & Interactions with Pollutants With a few exceptions, concepts discussed throughout this primer are applicable to lakes and wetlands. Pollutants come from the same sources and have the same effects. Organisms in lakes require habitat and have the same type of interactions with habitat, other organisms, and water quality as do stream organisms. The food chain interactions that are vitally important in streams are just as important in lakes. Even the riffle zone of a stream has a lake counterpart. Many of the organisms that live in stream riffles live in the wave zone of a lake where water is always moving. A lake is an inland body of water that has no flow or flows so slowly that its speed is measured in feet per year. Lakes may or may not have an outlet. If there is no outlet, the lake will contain salt water. With few exceptions, most lakes with an outlet contain fresh water. Technically, lakes are naturally formed, and impoundments created by man are called reservoirs. This distinction is important to note when studying lakes, but in this publication, both lakes and reservoirs will be referred to as lakes. A lake is connected to its watershed in every sense of the word. The only water, dissolved chemicals, and silt that enter the lake from outside the watershed are contained in rain and dust that falls directly on the water’s surface. Everything else (by far the greatest percentage) is delivered to the lake by the running waters that feed it. These streams transport to the lake everything which can be dissolved in, suspended by, or floated on runoff. Any groundwater that surfaces in the watershed also makes its way to the lake via a stream. A lake’s problems are diagnosed within the lake, but to gain an idea of what pollutants are causing problems and to learn their sources, investigative work in the watershed will have to be done! One difference between lakes and streams is the form in which nutrients are found. In a stream, many pollutants, nitrate and phosphate for example, are transformed to new and different pollutants. Nitrate and phosphate that enter a stream in runoff from a fertilized lawn will be taken up by bacteria, fungi, and algae. Oklahoma’s natural lakes come in two varieties: “oxbow” lakes which are formed when rivers change channels and leave a bend behind; and “playa” lakes in western Oklahoma that hold water only during wet years. Most lakes in Oklahoma are actually reservoirs. The result of a desire to impound water, reservoirs have a variety of functions: water supply; hydro-electric power; flood prevention; and recreation are a few of the primary reasons people create “lakes.” 35 In general, the pollution sources and effects in streams also apply to lakes. If a stream flows into a lake and the travel time is short, nitrate and phosphate will enter the headwater areas of the lake. How-ever, although a pollutant was important in a stream, it may not be as important in a lake. Runoff water with a low pH mixes with and is diluted by other water, so that the pH is usually normal by the time it reaches the lake. Toxic metals and pesticides that become tightly bound to sediment particles in the stream are often no longer toxic by the time they get to the lake. A stream’s nutrient pollution load can be measured by nitrate, ammonia, and phosphate testing, but by the time this water arrives at the lake, many of these nutrients will have been incorporated into the bodies of single -celled organisms. Of course the phosphorus and nitrogen are still there, but in a different form. These nutrients now exist in the form of proteins, nucleic acids, and assorted other chemicals that compose the machinery of life. The concentration of nutrients can be measured in a lake, but not as effectively by using nitrate, ammonia, and orthophosphate tests. Tests that yield information about the amount of nitrogen and phosphorous found in proteins, nucleic acids, and other chemicals must be performed. It is easy to miss this concept. A lake that is pea-green and smelly will test low for nitrate, phosphate, and ammonia when it is obvious that it is enriched. In reality, the nutrients are simply already a part of an organism, and as more nutrients enter the lake, they are quickly transferred into organisms. In lakes, nitrate is important not only as a source of nitrogen, but also as a source of oxygen. When dissolved oxygen levels are low, bacteria living in oxygen-poor sediments and water take oxygen from the nitrate ion through a chain of reactions and release nitrogen gas or ammonia that eventually end up in the atmosphere. Therefore nitrogen does not accumulate over time. Phosphorous, on the other hand, doesn’t form any gaseous compounds naturally, and once in a lake, remains there for a very long time, possibly forever. If it combines with calcium to form calcium phosphate, it can no longer be used by living organisms, but in all other forms it is recyclable. A lake polluted with phosphorous may always have problems. There are ways that phosphorous may be “inactivated,” but these are expensive and almost always temporary. NOTE: _____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ An enriched lake is one which contains too many nutrients, like nitrogen and phosphorous. Symptoms of such enrichment may include excessive algae, odor problems, and low levels of dissolved oxygen. 36 Another big difference between lakes and streams is that lakes lack the strong mixing force that streams have. Gravity influences a stream through of its generation of current. Lakes act more like a big bowl of stagnant water. This leads to a very important phenomenon called thermal stratification. Water behaves very much like the gases that compose the atmosphere: cold water sinks and warm water rises. Once the sun starts heating surface waters in the spring, these waters tend to remain at the top of the lake. Throughout the summer, the surface waters continue to warm, and the cool water at the bottom of the lake experiences little change. This temperature difference becomes so pronounced by midsummer that the two different layers of water act like separate waterbodies. The upper layer, called the epilimnion, stays mixed within itself, but does not mix with the lower layer, called the hypolimnion. When the epilimnion cools in the fall and reaches the same temperature as the hypolimnion, mixing of the two layers begins to occur. This process is known as lake turnover or mixing. Stratification is important during the summer because the lower layer of cool water does not have any contact with the atmosphere. This means that no new dissolved oxygen is added to the hypolimnion while the lake is stratified, so the oxygen it contains in the spring must last until the fall turnover. The hypolimnion in an unpolluted lake retains enough oxygen to keep fish alive through the summer. Unfortunately, this is not the case in polluted lakes. Decomposition of leaves, twigs, and dead algae occurs slowly in an unpolluted lake. If decay occurs at a fast rate - which might be the case in polluted waters where nutrients are found - oxygen will be depleted in the hypolimnion. Fish will crowd into the epilimnion, moving away from their lake-bottom feeding opportunities and into warmer water. In addition, when the hypolimnion loses its oxygen, most of the phosphorous that is in an insoluble and unavailable form once again becomes available. Large algal blooms often occur in the fall after lake turnover. As living organisms die, their remains sink to the bottom of the lake where they will remain until the next turnover event. This type of phosphorous recycling can go on for decades with no new additions of phosphorous. Shallow lakes and ponds containing excess phosphorus are sometimes treated with alum (aluminum sul-fate) to inactivate the phosphorus by making it insoluble aluminum phosphate. This works if no new phosphorus enters the lake or if the phosphorus is not resolubilized by contact with anoxic water. Dis-cussions have taken place concerning the feasibility of inactivating the phosphorous in poultry litter with alum to reduce water quality problems. Combined, the two form aluminum phosphate, which is insoluble and therefore unavailable for algae. If, how-ever, the aluminum phosphate washes into an anoxic (oxygen depleted) lake, the phosphorous will be freed and it will once again nourish algae, perhaps for decades. Swimmers at a lake can even experience stratification, at least if they are tall enough. Ever notice how surface waters can be very warm, but the water around your ankles is quite cool? 37 Anoxic conditions lead to terrible taste and odor problems in water. While the smell remains in the hypolimnion, people don’t complain. When the lake turns over in the fall, the smell becomes obvious and water plant operators find it difficult to produce drinking water that is taste - and odor-free. In summary, these things are true about lakes: ¨ Lakes are basically stagnant, like big bowls of water sitting on the landscape; ¨ Almost everything that enters a lake comes from the watershed; ¨ Lakes are polluted by the same pollutants that affect streams; ¨ Nutrients and other chemicals that pollute streams are often found in a different chemical form in lakes; ¨ Phosphorous stays in lakes practically forever and continuously recycles, so stopping its input may not cure a lake’s problems; ¨ Lakes stratify into warm and cool water and because of this: a) the hypolimnion will become anoxic if the supply of nutrients is adequate; b) the hypolimnion will develop strong odors and tastes; and c) phosphorous is continually released and recycled by the hypolimnion. NOTES: ____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ Large or small, lakes and ponds dot Oklahoma’s landscape. At least 75% of Oklahoma’s drinking water comes from surface water, which is primarily lakes. 38 Wetlands - Health & Interactions with Pollutants Wetlands are basically “wet lands.” What these areas have in common is what makes them unique: shallow water, waterlogged soils, and vegetation. Wetlands support a great diversity of plant species and provide food, shelter, and nesting sites for a variety of resident and migratory birds, especially waterfowl. Many other creatures, like turtles, beaver, muskrats, frogs, water snakes, and many varieties of fish depend on wetland habitats as well. The particular types and arrangements of the wetland hydrology (water), hydric (water-saturated) soils, and hydrophytic (water-tolerant) vegetation are what makes one kind of wetland distinct from another. Wetlands may be any size or shape; they may be found inland or along coasts, and may contain fresh water, saltwater, or brackish water. Wetlands may be wet throughout the year, or only during certain seasons. Standing water may not be observed, but the hydrology must exist during the growing season at or near the soil surface for the area to be considered a wetland. Because water is present in wetlands much of the time, wetland soils have developed special characteristics. When the soil is saturated, most of the spaces between soil particles are filled with water, leaving little or no room for oxygen. These oxygen-depleted soils are “anaerobic”. Because hydric soil is saturated and anaerobic, a variety of chemical and biological reactions occur which affect the nature of the soil over time. Changes may take place in the color and texture of the soil, or a characteristic “rotten-egg” smell may be emitted by the soil as bacteria carry on anaerobic respiration. NOTES: ____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ Oklahoma’s wetlands are more common than its tallgrass prairie, more varied than its mountains, and just as important to wildlife as its forests. Almost two-thirds of the federally-listed threatened and endangered animals (such as the whooping crane and river otter) in Oklahoma spend all or part of their life cycle in wetland habitats. 39 Not all wetlands have plants, but those that do, have plants that are specially adapted to life in wet conditions. The plants which grow in the hydric soils of wetlands are called hydrophytes. Like other plants, they take carbon dioxide from the air and release oxygen. Like other plants, hydrophytes need oxygen in their roots. Since their roots are submerged, hydrophytes have developed various adaptations (including hollow tubes or sacs) to facilitate the exchange of carbon dioxide and oxygen and to transport oxygen to the roots. Oklahoma’s geographic location is the meeting ground between the arid west and the humid east. This interface harbors many wetland types, including: ¨ playa lakes ¨ riparian corridors ¨ shoreline wetland ¨ forested wetland ¨ oxbow lakes ¨ closed depressions and ¨ swamps and marshes. Each of these wetland types provide important habitat and forage to many different animal species, including many different species of migratory waterfowl, such as the Canada Goose and cinnamon teal, and amphibian spe-cies such as the Smallmouth Sala-mander. Much misunderstood, wetlands have been drained and filled without regard to their ecological value. People have only recently begun learning about the benefits derived from wetland resources. The increased awareness of wetland issues coupled with wetland regulation and financial incentives for wetland protection/enhancement is reducing wetland abuse. Because all plant needs (sunlight, water, nutrients) are met in abundance in wetlands, they are some of the most productive and varied ecosystems in the world. This diverse and productive plant community in turn supports a diverse and dense animal community. Wetlands such as the one pictured here used to be an uncommon sight in urban settings. 40 Wetland Functions and Values Wetlands have many functions and perceived values. Functions are generally objectively quantifiable whereas values are subjective and often the reason wetlands are controversial. Wetland functions and values include: ¨ Water Quality Improvement - Wetlands can be a great help in dealing with polluted water. Wetlands act as a natural filter, slowing water velocity and allowing silts and sediments to settle out before water moves on to lakes and streams. Pesticides and nutrient runoff are also trapped in the settling process as most contaminants adhere to sediment particles. The high rate of biological activity (growth, decomposition, nutrient recycling, energy recycling) in wetlands results in many contaminants being absorbed and incorporated into plant tissues and then given off as harmless gas. ¨ Flood Control - Wetlands help reduce flooding by slowing the force of floodwaters and providing temporary storage of storm or snowmelt waters. This function enables wetlands to protect adjacent and downstream properties and reduce damage to roads, bridges, and crops. Wetlands help to stabilize the stream environment for aquatic animals. They release water in dry periods and store water during storm events. ¨ Groundwater Recharge and Discharge - Some wetlands replenish or “recharge” groundwater supplies. Water migrates or “percolates” from wetlands into aquifers (groundwater), maintaining the level of the water table. Wetlands may also serve as a “discharge” area for groundwater, intercepting an aquifer formation where groundwater is returned to the earth’s surface. Because the water table seasonally fluctuates, some wetlands serve as recharge areas during dry periods and serve as discharge sites during wetter months. ¨ Wetlands Habitat - Estimates indicate that in Oklahoma alone, 150 different bird species are wetlands-dependent. Migrating birds utilize wetlands for feeding and resting points. Many of the fish and shellfish eaten by people and other animals lived in wetlands when they were immature. Many animal species require shallow water for egg-laying, feeding, and protection from predators, which are generally less common in shallow waters. ¨ Erosion Control - Wetland vegetation absorbs and dissipates the forces associated with wave action and current to reduce erosion along streams and shorelines. ¨ Education, Recreation, and Aesthetics - Wetlands are living, hands-on museums. They serve as outdoor laboratories where unique plants and animals can be observed. The principles of ecological systems (energy flow, recycling, and carrying capacity) can be studied first hand. Wetlands are often beautiful areas that are capable of evoking pleasure and awe when we witness ducks taking to the air from a playa lake or a heron intently stalking its prey, or an alligator coasting effortlessly in the moonlight. Wetlands provide endless opportunities for activities such as hiking, canoeing, boating, fishing, hunting, bird-watching, swimming, and photographing wildlife. ¨ Economic Values - A wealth of natural products are produced by wetlands. Those available for human use include timber, fish and shellfish, wildlife, blueberries, cranberries, and wild rice. The economic benefits of wetlands from fisheries and waterfowl are substantial, but they pale in comparison to the benefits derived from wetlands as areas that accomplish groundwater recharge, floodwater storage, water quality improvement, and erosion control. In Oklahoma, 87% of wetlands are privately owned, making Oklahoma’s private landowners the state’s most important wetland managers. Many state and federal programs are now offering incentives to private landowners to protect wetlands on their property. Through programs such as the USDA Wetland Resource Program and Wildlife Habitat Incentives Program, and the US Fish and Wildlife Service’s “Partners for Wildlife” Program, wetland restoration, enhancement, conservation, and protection is becoming more common. As more private landowners gain an understanding and appreciation for wetland resources, this positive trend should continue. 41 Groundwater - Health & Interactions with Pollutants A technical definition of groundwater is “water that occurs below the zone of saturation within soil or rock or clay.” The zone of saturation is the zone that contains no, or very little, free air. The upper layer of soil that contains free air is usually referred to as the vadose zone and water within this layer is usu-ally not considered groundwater. There are strong interactions between water in the vadose zone and groundwater however, and often both must be considered in a question that involves groundwater. The way groundwater is held within the earth may vary. At one extreme is water that is so tightly locked up in dense rock that the only way it can be extracted is through heating the rock. At the other extreme, free water can exist in underground streams and lake-like reservoirs. Most groundwater used by humans falls between these two extremes and is contained between the spaces between sand and gravel particles. Because we only use fresh groundwater, we often forget the fact that most groundwater is salty. Groundwater can also have high concentration of naturally occurring toxic compounds and it can be with or without dissolved oxygen. Some groundwater moves through the ground so slowly that geologists tell us it was last on the surface of the earth tens of thousands of years ago. We measure its speed in inches per year. Other groundwater moves through the earth quite rapidly. If it is flowing freely in an underground stream, speed can be measured in feet per second and the water may have been on the earth’s surface only hours earlier. Water of this type may return to the surface of the earth through a spring within hours or days after it entered the ground. “It is not until the well runs dry, that we know the worth of water.” Benjamin Franklin People cannot see groundwater until it surfaces, thus this water resource is rather mysterious. While science for the most part does not support the idea that spring water has medicinal qualities, many Oklahomans go to great lengths to collect spring water for drinking. 42 Aquifers When a layer of rock or loose sand or gravel in the earth contains water in great enough supply that it is useful to people, and it is feasible to pump that water to the earth’s surface, the water-bearing layer is called an aquifer. People that study groundwater (geohydrologists) separate the different types of aquifers into categories that have their own names, but the two main classes of aquifers are referred to as confined and unconfined. The two types are impacted differently by pollution. A confined aquifer has layers of impermeable material, usually dense rock or tight clay, both above and below the water bearing layer. Material from the surface or from deeper depths cannot migrate into a confined aquifer very easily. When a pollutant such as nitrate is dissolved in the shallow groundwater near the surface, the water in a confined aquifer is relatively protected. Over the course of a lifetime, it is unlikely that a pollutant will move into this confined aquifer. Most confined aquifers that have become polluted were contaminated when drilling activities punched holes in the confining layer. If the well were not cased correctly, or if it were abandoned unplugged, this damage can provide a route by which bacteria or nitrate can travel down the borehole and pollute the aquifer. The area on the earth’s surface through which a well may become contaminated is known as the wellhead protection area. In a confined aquifer, the wellhead protection area is small, encompassing only the area near the borehole. If the well was drilled through the lower confining layer, saltwater or other naturally occurring contaminants in deeper aquifers can rise up and pollute a fresh water aquifer. Confined aquifers that contain fresh water do have a connection to the surface, but it is usually many miles away from most of the aquifer. These connections are formed when the earth’s strata became tilted or folded through geologic processes. Over hundreds or thousands of years, the upper confining layer will erode, exposing the water-bearing layer at the earth’s surface. When surface water runs across this permeable, water-bearing layer, it soaks in and will slowly run downhill through the permeable layer that forms the aquifer. This keeps the aquifer full of fresh water. If humans pump water out of an aquifer faster that it can be replenished, the groundwater becomes depleted and wells run dry or must be pumped from greater depths. This area where the aquifer surfaces and is renewed is called the groundwater recharge area. Confined aquifers can be polluted by the careless handling of pollutants over the recharge area. Unconfined aquifers are those that have no upper confining layer of impermeable material. The most common type of unconfined aquifer forms in the loose sand and gravel that lie beside rivers and streams. This is an alluvial aquifer. Alluvial aquifers lie at or very near the surface of the ground, are very porous, and can be polluted by anything that is put on their surface in amounts that can filter down below the root zone. Wellhead protection areas for alluvial aquifers are much larger than those for confined aquifers, and can extend a mile or two from the well. The recharge area for alluvial aquifers is really just the river or stream valley. Much of the water in these aquifers is left there after floods covered the floodplain and infiltrated into the groundwater. The floodplain associated with this river is the recharge area for the alluvial aquifer that lies beneath it. 43 Alluvial terrace aquifers are older floodplain aquifers that remain after the river has changed course and cut down to a lower level over many thousands of years. They behave the same as alluvial aquifers except that they are recharged by rain and runoff. Terrace aquifers are well above the floodplain of present day rivers. Another type of unconfined aquifer is found in areas that are called karstic. Karstic geology occurs in areas of rock that are dissolved by water, usually carbonate rocks such as limestone or dolomite, or in western Oklahoma, gypsum. As water seeps along cracks in these rocks, it slowly dissolves rock and forms caves and fissures. Sinkholes are formed when a cave forms so close to the surface that it collapses, leaving a depression on the ground’s surface. Water in this type of aquifer moves so freely from the surface to underground and back again that the distinction between ground and surface water becomes blurry. Karstic aquifers, like alluvial aquifers, can be polluted by anything placed on the earth’s surface. Features like sinkholes allow even greater infiltration so that there is often no filtration at all as water passes down in into the aquifer. Karstic aquifers are the most vulnerable to pollution. Groundwater Ecology Until recently, the common belief was that nothing lived in deep confined aquifers, so there was no need to discuss ecology. Now that new, very technical, drilling methods that keep drilled material sterile have been developed, bacteria have been found even in the deepest fresh water aquifers. These bacteria respire very slowly, and unless they are provided with nutrients and a carbon source, they are not noticed. There is some hope that these bacteria may be able to clean up polluted groundwater by increasing their metabolic rate through the addition of nitrogen and phosphorous, and letting them use a pollutant such as a pesticide for a carbon source. This is a controversial idea because it requires the addition of new pollutants to remove a pollutant already in place. Unconfined aquifers have a much more complex ecology than confined ones due to their connectedness with the earth’s surface, where most life is found. Karstic aquifers and the air- and water-filled caves associated with them have entire ecosystems where bat guano forms the base of the food chain. Bats, spiders, centipedes, and many insects and other arthropods live in the air-filled portions of the caves. Fish, crayfish, aquatic sowbugs, and other arthropods, all blind, live in the water-filled parts of the caves. Bacteria and fungi also thrive in caves and Karstic aq-uifers. NOTES: ____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ The plant and animal life associated with karstic aquifers are especially sensitive, therefore visits to such areas must be made with a great deal of concern for these fragile ecosystems. 44 Alluvial aquifers also have thriving ecosystems that are contained within the water-filled spaced between sand and gravel particles. In unvegetated sandy river beds, enough light penetrates the top few inches of sand that algae grows in the water-filled voids. If the water contains enough nutrients, the algae get so dense that a green color is apparent. Organic detritus that sifts down through the spaces in the sand forms the base of the food chain for an ecosystem composed of small animals such as rotifers, nematodes, protozoans, other arthropods, and the ubiquitous fungi and bacteria. All of these life forms can be found in any alluvial aquifer, although the more polluted it is with nutrients and organic carbon, the denser the life will be. Much of the groundwater ecology that is important to surface dwellers occurs at the groundwater/ surface interface. Such areas, where the ground is saturated with water, and sunlight is available for photosynthetic organisms, are among the most productive on earth, and are called wetlands. Wetlands are discussed in more detail in their own section, but suffice it to say that pollutants in groundwater can have a major effect on wetland communities. In turn, wetlands can have a substantial effect on groundwater pollutants. A good example of this is seen where nitrate contaminated groundwater surfaces in a wetland. Because rates of bacterial production are so high (due to the high levels of nutrients and lots of organic carbon-containing materials), the groundwater is usually anaerobic (contains no oxygen). When this happens, certain bacteria, the denitrifying bacteria, utilize the oxygen in the nitrate ion and release nitrogen gas into the atmosphere. If enough other nutrients and carbon are present, this reaction can be quite intense and rid the water of much of its nitrate pollution. “Nothing in this universe exists alone. Every drop of water, every human being, all creatures in the web of life and all ideas in the web of knowledge, are part of an immense, evolving, dynamic whole as old - and as young-as the universe itself. To learn this is to discover the meaning of joy.” David Cavagnaro “The last word in ignorance is the person who says of an animal or plant: “What good is it?”..... If the land mechanism as a whole is good, then every part of it is good, whether we understand it or not.” Aldo Leopold “Like winds and sunsets, wild things were taken for granted until progress began to do away with them.” Aldo Leopold 45 Summary Through the course of each day, Oklahomans are likely to drive across a bridge under which flows a stream or river. Oklahomans will fill a glass with water and place ice cubes in the glass. Showers will be taken, washing machines will produce clean clothes. In many cases, hydro-electric power will make possible the conveniences that we take for granted. Somewhere, on any given day, an Oklahoman may bait a hook and reel in a fish from one of our many lakes or streams. Because of the Clean Water Act, the Oklahoma Conservation Commission’s Water Quality Division works each day to: Þ learn the condition of our water resources Þ use data to plan water resource protection measures Þ provide information to the people of Oklahoma so that our water resources can be protected The Water Quality Division accomplishes these tasks by working with local conservation districts on nonpoint source pollution projects. No matter where you live in Oklahoma, you live within a conservation district, which is the entity to help you care for your local natural resources. Conservation Districts work hand in hand with the USDA Natural Resources Conservation Service (formerly Soil Conservation Service) to provide technical assistance and information to landusers. This primer fits into the Oklahoma Conservation Commission’s goal of educating the people of Oklahoma. Everyone contributes to nonpoint source pollution, and informing the public of what pollutants are is step one to addressing our water pollution problems. Examples of nonpoint source pollutants of which all Oklahomans need to be aware are: Þ sediment from landclearing activities Þ toxins such as pesticides Þ nutrients (which may come from sources such as unmanaged animal waste; leaking sewer lines; fertilizers from lawns and crops) These are just a few of the pollutants that impact our rivers, streams, lakes, wetlands, and groundwater. If being aware of these pollutants is step one, then step two must be gaining the motivation and the knowledge to battle nonpoint source pollution. Oklahomans are reminded that laws such as the Clean Water Act have been passed because we are citizens in a nation that has chosen to place great value on our natural assets. Streams and rivers that are devoid of life are not acceptable to us. Primary water source lakes that produce foul tasting or unsafe water cause great expense to citizens, impact our quality of life, and are also unacceptable. Many challenges are faced by conservationists. The challe nge of motivating citizens to become stewards of soil, water, and wildlife, is perhaps the greatest challenge of all. Bringing people aboard as stewards - motivating them to personally invest in caring for our water resources - is essential to reducing pollution and protecting water resources. Through support to local conservation districts, the Oklahoma Conservation Commission’s efforts include: Þ natural resource days that introduce children to the world of nature Þ cost-share programs that help pick up the tab for implementing practices that protect water resources Þ education programs that turn data (collected on streams, rivers, and lakes) into usable information Þ workshops that bring people and resources together Þ volunteer programs that give citizens an opportunity to learn about and actively protect water resources 46 Work with children can be rewarding, because they seldom have to be encouraged to like the critters found beneath the surface of the water. Many of our aquatic insects have highly interesting lives. Children want to learn about their lifestyles underwater - and their lifestyles when they grow up and emerge. Take a group of children to the side of a stream, and you will only have to ask once for a helper to drag the seine. Children are fascinated with the variety of fish that make clean streams their home and they are saddened by the lack of fish in our more polluted waters. Often adults transform into children again when they are taken to the side of a stream. But getting adults to the side of a stream is a challenge. Leaving the field, the office, the automobile behind, .many adults feel they don’t have much time for this, and time is at a premium for most folks. Through programs that educate adults at the side of a stream, those who can change their schedule to be present often make an important connection with with the natural world. In most cases, this is a reconnection, a dusting off of a relic feeling born in childhood, when loving the earth came naturally. Funding is often made available to landowners in specific watersheds for the purpose of protecting a particular stream, river, or lake, that has been identified as a “priority watershed.” This funding - often referred to as “cost-share” money - may be used to: Þ establish riparian areas; Þ build ponds as an alternate source of water for livestock; Þ install rotational grazing cells; Þ and develop education programs specific to the watershed. Cost-share money helps landowners so that they can better afford to protect resources. An important goal of nonpoint source pollution programs that assist landowners with installing conservation practices is to show these practices to others and encourage additional participation. This is where the local conservation districts take the lead: practices that are installed with the aid of cost-share money need to be promoted. The promotion of such practices can help other landowners see the benefit of incorporating resource protection into their agricultural production activities. Volunteer opportunities - especially through the Oklahoma Conservation Commission’s Blue Thumb Pollution Education Program - bring aboard citizens who are already motivated to care for resources. Volunteers educate themselves and assist the Commission by collecting data and educating the public about water resource protection. Local conservation districts throughout the state pull together volunteers who take up much of the slack so a greater number of people can be reached. Volunteers are wonderful tools - they can speak of why they choose to be involved in protecting streams and lakes, yet they draw no government paycheck. Also, they are the local folks, which makes a difference as well. We Oklahomans live in a state with prairies, woodland, mountains, and plains. The streams and rivers which drain these different lands are filled with a variety of different fish and other life. As citizens, we have a responsibility to know what is impacting our streams, rivers, and lakes. As stewards, we have a responsibility to do our best to care for these important water resources,. As people who share this planet with all types of life, we have a responsibility (or a better word might be opportunity) to know, appreciate, and make room for the other “citizens” of planet Earth. 47 NOTES: ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ __________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ 48
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Okla State Agency |
Conservation Commission, Oklahoma |
Okla Agency Code | '645' |
Title | Water quality primer |
Authors | Oklahoma Conservation Commission. Water Quality Division. |
Publisher | Oklahoma Conservation Commission |
Publication Date | 2004 |
Publication type | Guide |
Subject |
Water quality--Oklahoma. Water--Pollution--Oklahoma. |
Purpose | This booklet is an introduction to water resources and pollution ecology. Many people feel that water pollution is an issue, but they do not necessarily know why various pollutants are a problem.; The 'Water Quality Primer' provides basic, up-to-date information to help citizens understand: * basic ecology of streams, rivers, lakes, wetlands, and groundwater * how healthy aquatic systems function * how pollutants are affecting our streams, rivers, lakes, wetlands, and groundwater * what are the sources of pollution * how to pollutants get in the water * why landuses are potential sources of pollution * how do pollutants affect life in the water * how do pollutants affect water needed by people |
Contents | Introduction; Nonpoint Source Pollutants; Watersheds; Natural Background or Pollution... What's the Difference?; Streambank Erosion; Landuse Classes - Sources of Nonpoint Source Pollutants; * Urbanization; Urban Landuses that can Impact Local Streams; * Industrial Facilities; * Mining; * Petroleum and Natural Gas Extraction; * Forestry; * Road Construction; * Recreation; * Septic Tanks; * Dams; * Agriculture; * Atmospheric deposition; Water: The Basic Facts; Stream Health; * Physical Habitat; * Chemical Habitat; * Biotic Quality; Stream Ecology: Foodwebs, Nutrients, and Oxygen; Lakes and Reservoirs - Health & Interactions with Pollutants; Wetlands - Health & Interactions with Pollutants; Wetland Functions and Values; Groundwater - Health & Interactions with Pollutants; Aquifers; Groundwater Ecology; Summary |
OkDocs Class# | C4700.5 W324q 2004 |
Digital Format | PDF, Adobe Reader required |
ODL electronic copy | Downloaded from agency website: www.okcc.state.ok.us/Publications/WQ_Primer.pdf |
Rights and Permissions | This Oklahoma state government publication is provided for educational purposes under U.S. copyright law. Other usage requires permission of copyright holders. |
Language | English |
Full text | O K L A H O M A C O N S E R V A T I O N C O M M I S S I O N , W A T E R Q U A L I T Y D I V I S I O N The Water Quality Primer 2 3 Introduction This booklet is an introduction to water resources and pollution ecology. Many people feel that water pollution is an issue, but they do not necessarily know why various pollutants are a problem. The “Water Quality Primer” provides basic, up-to-date information to help citizens understand: Þ basic ecology of streams, rivers, lakes, wetlands, and groundwater Þ how healthy aquatic systems function Þ how pollutants are affecting our streams, rivers, lakes, wetlands, and groundwater Þ what are the sources of pollution Þ how do pollutants get in the water Þ why landuses are potential sources of pollution Þ how do pollutants affect life in the water Þ how do pollutants affect water needed by people Certain aquatic ecology concepts will be introduced in this primer, but it is not a course in aquatic ecology. There are many important concepts that are not covered here. The “Water Quality Primer” was created by the Oklahoma Conservation Commission’s Water Quality Division with funding from the federal Clean Water Act. The Oklahoma Conservation Commission is concerned with the suitability of water for agriculture, fish and wildlife, human enjoyment, and as a source of raw water for drinking water systems. The term “nonpoint source pollution” will be seen in this publication time and time again. Nonpoint source pollution is the “pollution for which the specific point of origin is not well-defined.” The Oklahoma Conservation Commission’s Water Quality Division is the lead technical agency for nonpoint source proje cts and concerns. Nonpoint source pollution offers special challenges because it tends to be a problem to which many people and activities contribute. Education offers one of the best solutions to this problem. A few examples of nonpoint source pollution are: Þ sediment from landclearing activities Þ fertilizer & pesticide runoff Þ animal waste runoff Þ gasoline & oil which enters waterbodies Þ grass clippings placed in streams or lakes For more information, please contact: Oklahoma Conservation Commission Water Quality Division 5225 North Shartel, Suite 102 Oklahoma City, Oklahoma 73118 405-810-1002 The Oklahoma Conservation Commission as authorized by Executive Director Mike Thralls issues this publication, printed by Action Printing of Norman, Oklahoma, with funding through a grant from the United States Environmental Protection Agency. Five hundred copies were prepared at a cost of $8.99 each. Copies have been deposited with the Publications Clearinghouse of the Oklahoma State De-partment of Libraries. All programs and services of the Oklahoma Conservation Commission and the Oklahoma Conservation Districts are offered on a nondiscriminatory basis without regard to race, color, national origin, religion, gender, marital status or disability. 4 Nonpoint Source Pollutants Often the first information people learn about water concerns pollutants. For most of us, the source of our drinking water is a water treatment plant. Here the water is tested and chemically treated before being piped to our homes, schools, and businesses. The water that flows in our streams receives no treatment. Yet this water provides a home for fish and a drinking source for wildlife. On downstream, this water may be impounded and used for drinking water. The Clean Water Act states that our waters will be “fishable and swimmable.” This means our waters will be clean enough for aquatic creatures to survive in, and clean enough so that people can safely wade and swim. The following pollutants can have an impact on Oklahoma waterbodies. 1. SOIL Soil reaches streams chiefly as a result of water erosion. Larger particles fill in pools and voids under rocks and other debris, resulting in loss of habitat. Smaller particles cover and kill the spawn of many aquatic species and reduce water clarity, making it difficult for site-feeding species to capture prey, and for aquatic plants to grow. Both of these effects render water less attractive to humans. Many other pollutants, such as phosphorous, pesticides, and heavy metals, attach to soil particles, and therefore can be reduced by eliminating soil erosion. Soil is the most common and important of the conventional pollutants in Oklahoma. 2. NUTRIENTS Nutrients include different forms of nitrogen and phosphorous. Excessive amounts of either stimulate the growth of algae, other aquatic plants, bacteria, and fungi. Only algae and other plants can grow on nutrients alone. Rampant growth of such life forms lower dissolved oxygen levels, reduce water clarity, and affect a waterbody’s aesthetic value. With the exception of ammonia, none of these are toxic at levels found in streams. They are considered pollutants because of their growth-stimulating properties. Major sources of nutrients in water include fertilizer that is washed from land before it can be taken up by terrestrial plants, nutrients contained in the soil that reaches water, and nutrients contained within animal waste that reaches the water. One other increasingly important source is atmospheric deposition of nitrogen, mainly from vehicle and power plant exhaust. “We abuse land because we regard it as a commodity belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect.” Aldo Leopold When people are aware of an environmental problem, they usually want to do their part to reduce pollution. Providing information is an important tool in pollution reduction. 5 3. CHLORIDE Chloride is present naturally in all streams, rivers, and lakes. In Oklahoma, chloride concentrations are highly variable but generally increase along an east/west gradient. Many eastern streams have less than 5 parts-per-million (ppm) of naturally occurring chloride while some western streams approach 1000 ppm. Petroleum production generates large amounts of chloride, that is a potential pollutant, and street de-icing activities that use salt also can increase chloride levels in water. Wintertime levels of chloride may temporarily rise to one or two-hundred ppm. Some of the more sensitive aquatic species are displaced at these levels, but many species will not be affected until the total concentration exceeds 300 - 400 ppm. Chloride can be used as a water pollution indicator, since it often appears in combination with other types of pollution, and is very stable in water and will remain there once introduced. 4. CHLORINE Free chlorine doesn’t occur naturally and its presence is always due to pollution, usually a leaking potable water pipe, a recently drained swimming pool, or sewage effluent that hasn’t been properly dechlorinated. Chlorine is used as a disinfectant to kill bacteria in water. In surface water, it also kills all other aquatic species. Most fish and invertebrates will die at concentrations less than 1 ppm. Chlorine is a gas and will vaporize out of the water within a few hours. If chlorine gets into the water, the effects will either be immediate or not at all. 5. ANIMAL WASTE Manure is a good source of nutrients, and in addition, also contains considerable organic matter, which provides food for bacteria and fungi. When supplied with both food and nutrients, bacteria and fungi grow rapidly and use up all of the oxygen in the water. When only nutrients are added to the water, bacteria and fungi can’t grow, but algae can, sometimes resulting in an algal bloom. Algae grow over a matter of days, not hours, and also manufacture quite a bit of oxygen, so oxygen does not get used up nearly as quickly as when bacteria are growing. Given equal amounts of nutrients, the organic matter contained in animal waste will cause a greater oxygen depletion than would the same nutrients contained in a portion of inorganic fertilizer. A fish kill can occur a few hours after a large amount of manure has entered a stream or pond. Animal waste is the perfect food for bacteria - which grow quickly and consume lots of dissolved oxygen. NOTES: ____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ 6 6. PESTICIDES Pesticides kill things, and many do so indiscriminately. Many pesticides are so toxic to aquatic life that streams can be impacted by the pesticides clinging to wind-blown soil particles from fields that were sprayed. Pesticides are varied in their uses, and range from milk house disinfectant to germination inhibitors to biological agents. The full range of pesticides vary in toxicity to aquatic life from non-toxic to ex-tremely toxic. In general, insecticides are the most toxic and herbicides the least toxic to aquatic life, but there are many exceptions. Frequently, several different pesticides are found in the same batch of polluted water. When this occurs, there are often several sub-lethal stresses that by themselves would cause no harm, but together add up to a lethal combination. 7. OTHER TOXIC CHEMICALS A large number of poisonous chemicals are used around the home, farm, and in industry. Examples include cleaning agents, paints, solvents, motor fuels, various metals, and a variety of other chemicals. When any of these chemicals are found in streams, it is usually because someone dumped them down a storm drain or ditch, or spilled them on the ground. There are so many toxic compounds that it would be impossible to afford testing for them all, so the impacts of toxic chemicals are often seen without knowing exactly what chemical caused the problem. Only when the problem is ongoing do we have the time and resources to identify the cause and source of the problem. One of the best solutions is to educate people on how to properly dispose of waste. The main pesticides seen in urban areas are chlorpyrifos-based, and are probably used by homeowners in an effort to control fleas, ticks, and grubs. Several of the streams in Oklahoma City and Tulsa are seriously affected by two closely related pesticides, dursban and diazinon. As shown in this photograph, pesticides are often associated with sediment. Oklahoma City, Tulsa, and several other “environmentally aware” cities sponsor household pollutant collection events to encourage the proper disposal of many household chemicals and products that have a great potential to pollute waterbodies. 7 8. ACIDITY pH is a measure of how acidic water is. Unpolluted water in much of Oklahoma tends to vary between pH 7 and 8.5. The most common cause of low pH is acid rain, which is not a serious problem in Oklahoma. The most common cause of high pH is excessive algal growth. It is important to measure pH because it affects the toxicity of many metals, ammonia, and other poisons to aquatic animals. Lower pH generally increases the toxicity of metals, while higher pH increases the toxicity of ammonia. Toxic levels of ammonia, for example, can cause a fish kill. Many pesticides also have pH-dependent toxicity. At very high or low pH values, proteins are destroyed and aquatic life can be affected directly by the acids or bases in the water. 9. TEMPERATURE Most, but not all, of the aquatic animals that reside in Oklahoma are able to withstand a wide range of temperatures and aren’t directly affected by warming or cooling of the water. This doesn’t mean that temperature isn’t important. Oxygen isn’t very soluble in water; its maximum concentration is around 15 ppm at 0 degrees Celsius (32 degrees F). By contrast, the air we breathe is around 200,000 ppm oxygen. As water warms, it holds less oxygen. At 20 degrees C (68 degrees Fahrenheit), saturation is 9 ppm, and at 35 degrees C (95 degrees F), saturation is 7 ppm. The most sensitive species in our area begin to die if dissolved oxygen (DO) concentrations fall below 6 ppm. Many of the common species suffer at concentrations below 5 ppm. Frequently during the summer, warm water barely holds enough dissolved oxygen to maintain healthy aquatic populations. If any oxygen-demanding substances are added to the water at this time - like manure - DO concentrations fall low enough that fish kills occur. Because of thermal pollution’s severe consequences, industries are not allowed to discharge heated water, although the water is otherwise unpolluted. Similarly, sewage treatment plants are allowed to discharge more waste in the winter than in the summer because cold water holds more oxygen and is better able to withstand the effects of pollutants. 10. EXOTIC SPECIES The introduction of any non-native species is called biological pollution and often has severe consequences. Dandelions, starlings, and Norway rats are exotic species with which most people are familiar. A well-known introduced fish is the common carp. This fish reduces water quality by muddying the water, and it has displaced many native fish. Introduced lake trout are displacing the native cutthroat trout in Yellowstone Lake. Zebra mussels and Asiatic clams are spreading across the nation, displacing many of our native clam species. The most common cause of thermal pollution is the removal of trees along the streambank. This can cause water temperatures to increase from 6 to 9 degrees C (10 - 15 degrees F), and the impact that this has on the dissolved oxygen level is often enough to cause the disappearance of sensitive aquatic species. 8 11. HYDROMODIFICATION Hydromodification is the human-caused modification of a stream’s natural flow regime. The Arkansas River in Tulsa is a good example of hydromodification. The Arkansas’ flow varies tremendously depending on activities at the Keystone Dam. Fluctuating water levels strand small fish on dry ground and cause the disappearance of fish that require extended periods of high water or long stretches of free flowing river in which to live and spawn. In urban areas, hydromodification is seen in watersheds where impervious surfaces such as roads, roofs, and parking lots increase the runoff and velocity of small streams. 12. PATHOGENS Pathogens are micro-organisms capable of causing diseases. Normally we’re concerned with human pathogens, which almost always enter the water through the introduction of human or animal waste. Pathogens are worrisome because of the diseases that can be caused when they are introduced into the body. Pathogen contamination most commonly takes place when animal waste reaches water and sewage pipes leak. Poorly functioning sewage treatment plants are a less common source. 13. TOXIC ALGAE The most common type of toxic algae are a special type of primitive algae, the Blue-Green algae, which are actually photosynthetic bacteria. Like other algae, toxic algae produce oxygen in light and use it at night, all the while using the nutrients nitrogen and phosphorous. Sometimes, however, for reasons we do not understand, they produce very deadly toxins. These episodes are rare but very serious. Usually toxic blooms of Blue-Green algae occur in small ponds and are discovered when cattle die. Other types of toxic algae are Dinoflagellates and Cryptomonads. Like the Blue-Greens, these algae only produce toxins some of the time, but their toxins are very poisonous. Dinoflagellates are responsible for red tides in the ocean and for massive fish kills and disorders of the central nervous system in humans. A very large outbreak of one type of toxic Dinoflagellate in North Carolina is thought to be tied to swine and human waste increases in the Neuse River. In the urban area, impervious surfaces cause increased volumes of water to enter streams in a great flush, stressing streambanks and making it difficult for plants and animals to become established. NOTES: ____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ 9 Watersheds What is a watershed? A watershed is an area of land that drains to a given point. This point can be a bridge over a stream, a property boundary, a dam, or just a mark on a map. All the pollutants discussed - and the land-uses and activ ities that created them - happen within watersheds. For example, the area of land that drains into the Grand Lake O’ the Cherokees is the entire area of land from which runoff will eventually reach Grand Lake. The watershed contains about 6,000,000 acres. Included in this watershed are the watersheds of every small pond and large lake that lie on the tributaries of the Neosho and Spring Rivers. Likewise, the watershed of Grand Lake lies within the Arkansas River watershed, which in turn lies within the Mississippi River watershed. When talking about a watershed, normally a specific point is designated, and the land area that impacts the stream, lake, pond, or wetland to that point is the watershed. However, varying statutory definitions for the term “watershed” exist which often leads to confusion. Although numerous defin i-tions exist, they do not change the scientific definition of a “watershed”. The definition provided in the Oklahoma Department of Environmental Quality statutes states that “a lake’s watershed is all the land within 600 feet of the high water mark.” The USDA Natural Resources Conservation Service, Oklahoma State Office, defines a watershed as “the topographically defined area drained by a river/ stream or system of connecting rivers/streams such that all outflow is discharged through a single outlet.” The Oklahoma Conservation Commission’s definition is “an area of land that drains to a given point.” As rain falls and moves over the land’s surface as runoff, it dissolves any water soluble substance it contacts, floats anything buoyant enough to float, and dislodges any particles small enough and loose enough to be kept in suspension. These dissolved, suspended, and floating particles all impact water quality if they reach a stream or pond. Everyone lives in a watershed. This is an important concept. Our lawns, driveways, and rooftops contribute runoff to nearby waterbodies. We as individuals impact water quality. Once we understand the concept of watersheds, that we impact our streams, rivers, lakes, and wetlands, we place ourselves in a position to care for our resources on a more personal level. Regardless of what any law states, a watershed is an area of land that drains to a particular point. Activities that take place within a watershed have an impact on water resources. Every square foot of land on this planet is part of a watershed. 10 Natural Background or Pollution....What’s the Difference? Unpolluted waterbodies have stable concentrations of dissolved, suspended, and floatable particles (and have had stable concentrations for thousands of years). Organisms that are adapted to these conditions thrive in the water. When human activities cause concentrations of any substance to increase beyond what the native organisms are adapted to, then their health suffers, and this water is considered polluted. Pollution-causing activities occur in watersheds everywhere and have an impact on water quality and habitat quality of streams. The closer these activities are to streams or ponds - or to a direct channel to these waterbodies - the greater the impact. Pictured on this page are some of the activities that can take place in a watershed that may have an impact on streams. Agriculture Industry Mining Urbanization Recreation 11 Streambank Erosion Extreme examples of streambank erosion can be seen throughout Oklahoma, in urban areas, out in the country, and in all of the small towns between. Streambank erosion problems affect many aspects of a stream, but because of the activities that tend to contribute to unstable banks, this section is being placed with the watershed portion of this primer. Eroding banks contribute to sediment in streams, threaten structures, and reduce habitat and crop production area. Bank erosion problems are accelerated when riparian vegetation is disturbed by: ¨ crops planted too close to a stream; ¨ cattle allowed unlimited access to streams; ¨ encroaching development; and ¨ landuse changes which cause greater flushes of water. Many of the problems faced by streams and rivers could be battled by leaving natural buffer zones along the stream. The area directly adjacent to the stream should remain undisturbed. No development should ever take place within 50 feet or so of a perennial stream. A larger buffer should be left in areas where the floodplain is greater. Agricultural activities also should leave stream and river riparian areas undisturbed, and, if possible, cattle should be allowed only limited access. The urban storm sewer system should be designed to release water into streams at a low rate of flow so that banks are not chewed up by massive flushes of water. Consider the urban area; streets, sidewalks, parking lots, driveways, and roofs. These impervious surfaces do not allow water to soak in, and are in fact usually designed to move water into our streams quickly. Multiply this modified hydrology by riparian area removal and you are almost assured of an unstable stream channel. Streambank erosion is a major problem throughout the state. Bridges and structures become endangered, productive grazing and cropland is lost, and habitat is destroyed. 12 Landuse Classes - Sources of Nonpoint Source Pollutants The pollutants discussed on the preceding pages began the journey to an understanding of aquatic pollution. The following section describes general classes of landuse that can generate pollutants. Urbanization Urban areas are concentrated collections of humans. Since human activities are usually the cause of pollution, many different types of pollutants come from cities and towns. Sewage treatment plants come to mind when considering urban pollution. Under the best of circumstances, sewage treatment plants do not release ideal water. However, billions of dollars have been spent in the United States to ensure that fish and other organisms can live in the waters below a sewage treatment plant. Because equipment wears out, populations grow, and accidents happen, sometimes water released from treatment plants is poorly treated. In extreme situations, untreated waste water flows into streams, usually after a rain. Stormwater runoff is another urban threat to stream health. Most urban areas have storm sewers that directly route water to a stream quickly and efficiently. Neighborhood activities — such as fertilizer and pesticide application, new home construction, etc. — can result in chemical- and soil-laden runoff entering urban streams via the storm sewer system, on a daily basis, particularly in the late spring, early summer, and fall, when rainfall is greatest. Keep in mind that all human activities in the urban area have the potential of impacting streams. In an effort to speedily route water away from neighborhoods, businesses, and streets, storm sewer systems are designed to send water to the nearest stream and away from town. This is quite different from many years ago - before urbanization - when water was allowed to make its way to the stream by gentle movement through the soil. The Clean Water Act has resulted in great success in bringing the effluent from community treatment plants up to grade. Concrete channels strip streams of their ability to provide habitat for plants and animals. This stream has no chance of meeting the Clean Water Act’s “fishable” goal. 13 Urban Landuses that can Impact Local Streams Earth moving activities - like this new residential development - will contribute sediment to local streams if the appropriate “best management practices” are not employed to reduce erosion and maintain sediment on site. Although proper lawn maintenance and pet care will drastically reduce flea and tick populations, many homeowners be-lieve they must dose their lawns regularly with pesticides. Automobile activities within cities contribute to nonpoint source pollution. Motor oil, gasoline, coolants, and by -products of tire and brake wear are a few of the transportation-related pollutants that have a negative impact on our water. All the impervious surfaces over which our stormwater flows allow little time and no place for the filtering of pollutants. High-maintenance lawns abound in urban areas. Many homeowners subscribe to lawn care services that systematically apply fertilizers and pesticides. Often these lawns have high moisture requirements, and the idea of “conservation” never comes into play. Down the drain and into a stream! The US EPA says that urban area runoff is the third largest source of impairment to surveyed lakes. 14 Industrial Facilities Industries generally are thought of as urban facilities, but many are locating more frequently in rural areas too. Many industries discharge treated wastewater, and like effluent from a sewage plant, if everything works accordin g to plan, major pollution problems are not caused. However, people make mistakes, equipment gets old and worn, and new processes are added that create new and different pollutants. The Oklahoma Department of Environmental Quality (the agency that regula tes industrial discharges) must stay vigilant to keep streams safe from industrial discharges. Industries can be large contributors to air pollution (as can cities), primarily through the burning of fossil fuels. Industrial atmospheric pollution is not nearly the problem it was a few years ago. It does, however, remain the major source of acid rain, and through rainfall, is an increasingly significant source of nitrate in water. Mining Mining and the associated extraction and processing of minerals or metals can have tremendous impacts on water quality. Fortunately for Oklahoma waters, there are no more large deposits of metals such as lead or zinc left in the state. Metals can generate very toxic by-products, as did the lead and zinc deposits of Ottawa County. Most present-day mining in Oklahoma focuses on rock, clay, and sand, with smaller but important amounts of coal and gypsum being extracted. The major pollutant generated by modern Oklahoma mining activities is sediment. Most sediment comes from small, loosely-regulated (or not regulated) borrow pits. The mining of gypsum generates silt but the gypsum itself is not a major pollutant. Waters in the gypsum-rich part of the state have a natural abundance of gypsum, and the life in these streams has adapted to it. Like cities and towns, industries, in addition to their wastewater treatment plant, must comply with a stormwater pollution prevention plan. The plan should prevent solvents, petroleum products, sediment, and an array of chemicals from entering streams. Industrial activities remain the leading cause of acid rain and contribute many other pollutants to waterways. As with all surface mines, sediment is potentially the major pollutant. 15 With a couple of notable exceptions, mining in present-day Oklahoma doesn’t create much of a problem (other than sediment) because it is a declining industry and modern mining operations go to much greater lengths to control pollution. Most of the stream health problems that stem from mining are the result of acid mine drainage from mines that were active in the first half of this century. State and federal agencies are slowly getting these problems under control, although the very worst ones may have to wait for Nature to clean up our mess. In Oklahoma, acid mine drainage occurs mainly in Pittsburgh, Ottawa, and Latimer counties, with some also in LeFlore, Craig, and McIntosh counties. Petroleum and Natural Gas Extraction As with mining, most of the environmental problems associated with the petroleum industry are due to past practices. Laws (and the pollution controlling efforts of the industry) were once much more lax. Although still a large industry in our state, oil production, like mining, is declining. Natural gas production remains high. Large volumes of sediment are still contributed by areas of land where vegetation and soil microor-ganisms were killed and soil was destabilized by brine waters produced during petroleum activities. In the past, many streams and ponds were also killed by crude oil that was allowed to flow into them from uncontrolled wells and overflowing tanks. Most of these problems have been slowly remedied by Mother Nature. The industry itself also funds cleanup and plugging of abandoned wells and sites. Today’s problems are mostly due to pipeline breaks that occur where streams wash out poorly-designed pipeline crossings or where very old collection lines corrode and begin discharging. In the oil and natural gas extraction industry, constant observation and prompt reporting of problems is a good way to control pollution. In some areas coal mining activities can result in acid mine drainage if the proper precautions are not taken. Brine waters flowing over the land not only cause erosion but prevent the soil from growing vegetation for many years. Today’s practice of using plastic pipe to collect brine contributes to current problems when these pipes become damaged by grassfires or vehicles. 16 Forestry Many people assume that timber harvesting contributes huge volumes of sediment to streams. How-ever, present-day forestry operations in Oklahoma implement environmentally friendly practices. Some small operations can still cause heavy erosion during logging, and these operations should be closely watched. Pollution problems observed should be reported. The major source of sediment from forestry operations is the unpaved logging roads that are used to get to and from the logging operations. Excellent “best management practices” to control erosion on these roads have been developed. These BMPs can be seen in national forests and large, privately-managed forests within Oklahoma. The remaining problems are primarily due to small logging operations working on private land under contract with individual landowners. Road Construction Road and highway construction goes on all over the state and is especially important in urban areas. As with forest roads, we now know how to control sediment during road construction, and contractors are starting to do this. Public street and highway construction has lagged behind forest road construction in the actual installation of BMPs, but more and more BMPs are in place. Most people know that hay bale dikes and black silt fences — often observed on disturbed sites — serve as sediment controls. Using environmentally friendly logging practices, many modern companies allow healthy streams and timber harvest to co-exist. Some timber harvesters fail to use best man-agement practices that could prevent or reduce erosion. This box culvert was filled with sediment from an unmanaged clearcut. The taxpayers will foot the bill to clean it out. Best management practices will help prevent sediment loss on this rural road, even though it is unpaved. 17 Recreation The major problems associated with recreation are trash, human waste, and soil erosion, all resulting from too many people and too many vehicles in too small an area. Although restroom facilities, trash receptacles, and barricades exist, vandalism and non-use of structures is a continuous problem. Education, coupled with the enforcement of vandalism laws, is one of the best solutions. Septic Tanks Almost everyone living in the country and not served by a municipal wastewater treatment system relies on a septic tank to partially treat their domestic waste. The remainder of the treatment is accomplished by the soil around the leaching field (the area where the waste water discharges). Problems associated with septic tanks can be fre-quent, and often are due to the: à disposal of waste that cannot be processed by the septic system (this can include dry-cleaning fluid, degreasers, pesticides, and other toxic chemicals that are poorly degraded by septic systems and will end up polluting ground and surface water.) à lack of tank maintenance and cleaning (this can cause the lateral lines to become plugged, routing wastewater to the surface, from where it can enter surface water). à siting the leaching field in incompatible soils (soil with too great or too low a permeability will often cause pollution of ground and surface water). All of these problems can be avoided by timely pumping of the tank, proper siting and construction, and proper disposal of toxic waste products. NOTES: _____________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ Motorized watercraft provide more than fun at the lake.... they can leave behind gasoline and other fluids. People want and expect locations where they can have a positive outdoor experience. Unfortunately, people sometimes lack the outdoor ethics necessary to conserve our resources. 18 Dams Dams are frequently viewed as a good thing, and they have helped many people and some wildlife through providing water storage and by reducing flooding in some areas. Dams also have contributed to stream habitat loss, stopped reproduction of certain migratory fish species, and lowered the reproduction of species that require high water or long stretches of open river for reproduction. While humans have benefited from the floodwater storage provided by dams, the floodplains, streams, and rivers that have been flooded have not. Floodplains are nature’s storehouse for extra water, silt, organic matter, and nutrients that would otherwise remain in the channel and damage stream health. Even the Corps of Engineers high-ranking officers are beginning to recognize the need to let floodplains do what floodplains are supposed to do. “I feel very strongly that the solutions we’ve been following are not the right solutions. We just need to keep people out of the floodplain.” .....Walter Yep, Chief of Planning, Corps of Engineers Sacrament o Office The paddlefish is one species whose range has been reduced due to the damming of our rivers. 19 Agriculture Farmers and ranchers make their living off the land. Consequently, a lot of land is put into production and this can have a significant impact on stream health; either positive or negative. One of the biggest challenges to agriculture in Oklahoma is profitable cattle production without environmental damage. When cattle are given unlimited access to streams, they may trample banks, add manure to the stream, and cause rangeland erosion. A highly trampled bank will add a great deal of sediment to a stream, while providing none of the benefits that a healthy riparian community provides. Incised cow trails that cut through an otherwise healthy riparian area will channel water right to the stream, thereby decreasing the riparian area’s ability to filter nutrients, sediment, and some pesticides. Manure in the stream supplies nutrients and organic matter which cause oxygen depletion and algal growth. Overgrazing of rangeland exposes sediment, which could reach a stream, and allows more manure to be washed from the land into the stream. There are several state and federal programs to help ranchers deal with these problems and we are beginning to notice change throughout the state as ranchers implement new practices. The production of any crop that requires regular working of the soil has environmental risks. The greatest risk is soil erosion, but the Natural Resources Conservation Service - through conservation plans tailored to each producer’s needs - has addressed this issue so well that the only people whose fields are eroding are the ones who haven’t taken the recommended steps to halt it. Education is likely the best answer for these hold-outs. Removal of riparian vegetation to increase the amount of land available for production remains a serious problem. Many people are aware that riparian area loss has a negative impact, but it remains a common practice. More land is lost through erosion, and the stream is deprived of the important benefits of the riparian area. People need to be educated to the fact that a stream flowing through their property moves on to their downstream neighbor, and the stream carries with it the upstream impacts. The application of farm chemicals is costly to the farmer, compared to his urban neighbors, so farmers tend to apply chemicals sparingly. Over-application is usually not a problem on agricultural lands. Buffalo, historically the primary large herbivore of this continent, roam widely, as opposed to cattle, which prefer to remain close to the water. Cattle can damage streams by adding manure when they loaf in the water, trampling banks, and by overgrazing the riparian areas. Conservation plans often contain grassed waterways and terraces as best management practices to decrease erosion and protect 20 Problems do occur because the farmer depends on his fields for his livelihood and sometimes can’t afford to wait for the wind or rain to stop before applying a pesticide. Healthy riparian areas without cow trails can make a big difference by forming a vegetated buffer zone. Beyond that, it is up to chemical companies to come up with more environmentally friendly pesticides. Animal waste from different types of feeding operations comes with its own set of problems. While it has value as a fertilizer, animal waste’s low density makes it cost-prohibitive to truck very far. It is a by-product of feeding operations and therefore doesn’t involve any capital outlay from the producer. Because animal waste is not expensive, and transportation is viewed as costly, waste is often over-applied to nearby land. Pollution of ground and surface water can result. The NRCS, the Oklahoma State Department of Agriculture, and the Oklahoma Conservation Commission are busy writing waste management plans for farmers who generate animal waste. Other state agencies, including OCC and several Conservation Districts, are investigating a system to transport animal waste out of watersheds where it is in oversupply , as well as alternate uses for the animal such as a fuel source for power plants. Atmospheric deposition Atmospheric deposition happens when pollutants are deposited in the air as gases or small particles and then deposited elsewhere as dust or in rain. The result is a serious form of pollution to which almost everyone contributes. The problem arises through two routes, the main route being volatilization and/or release into the air of polluting gases such as nitrogen oxides, ammonia, and sulphur compounds. Sulphur compounds are released when coal is burned and reacts in the atmosphere to cause sulfuric acid. This sulphuric acid then returns to Earth as acid rain. Much has been done to reduce this problem but there are still many waterbodies in the U.S. where no fish live because the pH is too low. Likewise, large forested areas in the eastern U.S. are dead or dying because of acid rain. A stable riparian area can help absorb the impacts of many problems - like chemical applications, erosion, and livestock. A large number of animals con-centrated in a small space con-centrates waste such that it be-comes a problem. Animal waste has been targeted as a prime pollutant of several of Oklahoma’s lakes and streams. 21 The second route through which pollutants become airborne is the action of wind picking up dust particles that have pollutants on them. This sounds minor, but DDT levels in fish in the American Great Lakes are rising due to atmospheric deposition of dust carried across our borders from foreign lands. Likewise, much rain in Iowa contains atrazine picked up from cornfields. At times, the rainwater in Iowa contains more atrazine than is allowed by safe drinking water standards. NOTES: _________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ Atmospheric deposition problems require technical solutions. Better pollution controls on exhaust stacks and vehicles and more environmentally friendly pesticides should help considerably. We are, indeed, a nation dependent upon our automobiles. Proper maintenance of these vehicles is very important. Another way to reduce atmospheric deposi-tion is to pay attention to “ozone alert” warnings. 22 Water: The Basic Facts At this point the reader is familiar with the major classes of pollutants and the sources that generate them. It is now time to see how these pollutant interact with the aquatic ecosystem. Water is often referred to as the universal solvent. This might sound like a trivial piece of information, but it isn’t. Every single chemical that constitutes the cells of our bodies and the cells of all living things - from bacteria to loblolly pines - either is dissolved in water or was at some point during its synthesis. Different organisms need different amounts of water, but without water, all life stops immediately. Water covers three-quarters of the planet. The oceans hold almost all of our water and are the repository for all the minerals that have dissolved from rocks over the last few billion years. This is why the oceans are salty. The Earth’s second largest collection of water is in the polar ice caps. Because these ice caps are made of frozen precipitation, they are composed of fresh water. Groundwater is found in the spaces between soil and rock particles of the Earth’s crust. It varies from very fresh to extremely salty and can often contain poisonous compounds. Fresh groundwater is a wonderful resource! Atmospheric water is found in the Earth’s atmosphere. While not a large portion of the total water on our planet, atmospheric water is the only reason we ever have any fresh water on the Earth’s surface. Without evaporation and rainfall, all water would be in the oceans and full of salt! NOTES:____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ Although most of us know people who count on groundwater, fresh, high-quality groundwater is not always available. Because of atmospheric water, we have rain, which produces rivers, streams, lakes, ice, and groundwater. Anything that changes the temperature of the air affects how much water will evaporate, how much water the atmosphere can hold, and, in the end, how much rain will fall. 23 Surface water lies on the surface of the Earth’s land masses. Surface water can be flowing or still, fresh or salty, deep or shallow. If deep and still, it is some type of lake. If flowing, it is a stream of some type. If it is flowing very slowly or is still, and is shallow or even dry for part of the year, then it is a wetland. Remember that humans invented these names. Nature has no interest in how humans classify things, or whether or not things fit neatly into one of our boxes. There will always be waterbodies on the border so that it’s impossible to say whether one thing is surface water, the other a wetland, or the other groundwater. Placing water in these general categories just makes it easier for us to think about and discuss the different waterbodies. Because of legislation and administrative rules, the Oklahoma Conservation Commission’s Water Quality Division is concerned primarily with flowing water. Other administrative units work with groundwater, lakes and reservoirs, wetlands, and atmospheric water. NOTES: ____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ Whether it is a wetland like this one or a stream, river, or lake, the liquid fresh water that exists on Earth is less than one percent of all of the water in the world. The Oklahoma Conservation Commission is concerned with the suitability of surface water for agriculture, fish and wildlife, human enjoyment, and as a source of raw water for drinking water systems under the authority of the federal Clean Water Act. The Oklahoma Department of Environmental Quality monitors the safety of finished drinking water under the authority of the federal Safe Drinking Water Act. 24 Stream Health = Water Quality + Biotic Quality + Physical Habitat Quality We will begin our discussion of aquatic health with streams. Of all living aquatic systems, streams are the most basic. The discussion of other types of waterbodies will build upon what is said about streams. The title of this section is a peculiar looking equation for a good reason. Most people want healthy, attractive streams that smell good and fit their image of a high-quality stream: scenic vegetation along the stream’s edges, clear water, some rocks, perhaps a submerged log or two, and plenty of fish. The water flowing in this ideal stream may be moving fast or slow and will have varying depths, but it is unlikely to smell bad, and it probably offers a great place to cool down after a hot day. Add the sounds of cicadas and the songs of birds, and the picture gets better still. The imagined stream contains far more than what has traditionally been termed “water quality.” Refer back to this imaginary stream and add this to the scene: the local transportation agency wants to build a large interchange across the stream. With heavy equipment they redesign the channel, so the stream is straight and the sides and bottom wear a permanent coat of concrete . Then the actual highway construction begins, and another 110 feet of concrete is installed on either side of the stream. At last it is time to stand back and cut the ribbon, because the new superhighway is finished. This stream is no longer a good place to fish and swim, observe wildlife, and relax. The water flowing through the channel, the one that was so recently a natural stream, is of the same quality that it was before. The changes that have taken place have been to the banks and bottom, not the water itself. However, it would be untrue to say that this is still a high- quality stream. The fish have been driven away, the birds are gone, the trees that shaded the water are just a memory. There is much more to a high-quality stream than good water quality. The physical habitat and biota of the stream are equally important. We will examine the three broad categories of water quality, biotic quality, and physical habitat quality in detail. The stream on the left is a well-functioning, high-quality stream. The stream on the right still boasts good water quality, but its habitat has been altered. No animals can make a home here, and people do not flock here to fish and swim. 25 Physical Habitat Everything needs a place to live, and has a preferred habitat where it thrives best. Usually, animals and plants can flourish in non-optimal habitats only when there is little or no competition. When an organism is found in large numbers outside of its normal habitat, its competitors probably have been removed. The more different kinds of habitat that are present, the more different kinds of animals and plants can be found. The most important parts of habitat are: Substrate - The material that composes the bottom of the waterbody is the substrate. It can consist of rocks, mud, sand, hardpan clay, organic material such as partially rotted leaves and twigs, and anything else that happens to be there. Structure - The three-dimensional materials in the water are known as “structure.” Submerged logs, underwater ledges, and large boulders are common examples of structure. Depth of Water - Not only must an organism be able to fit into the water, its preferred food must live there, and in many cases, its chief predators must be excluded, or at least hindered. Many animals occupy water of a certain depth that satisfies all of these requirements. Speed of Water - Some organisms like flowing water because they are stationary and get their meals delivered by flowing water. Others like still water. There are many reasons why water of a certain speed is preferred by different organisms. Riparian Vegetation - Found within the zone where land and water meet, riparian vegetation can cool water by 10 - 15 degrees Fahrenheit by providing shade. The plant’s along the water’s edge provide high qualit y food with leaves, twigs, and insects that fall into the water. Riparian vegetation also provides habitat and streambank stability. Water Temperature - How cool or warm the water is effects the metabolic rate of living things in the water and the water’s dissolved oxygen (DO) content. Factors that impact the water temperature are shade, water depth, and water source. Structure and substrate provide materials that are hidden under, burrowed around, and clung to. Varying speeds and depths of water are factors that make streams unique. 26 All of the factors discussed on the previous page are part of aquatic habitat. A healthy stream or lake has habitat that will support fish, aquatic insects, and other animals and plants. Habitat can be impacted when riparian areas are disturbed, which often contributes sediment loads to the water. Two other types of disturbances known to contribute sediment are channelization and landuse changes that cause increased stormwater flushes. Functional streams that support life and carry water efficiently can exist even in urban areas, and relatively easily in agricultural ones. “When we try to pick out anything by itself, we find it attached to everything else in the universe.” John Muir NOTES: ___________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ Riparian areas are important, productive zones where land and water meet. 27 Chemical Habitat Anything dissolved in water, and much of the fine particulate matter suspended in water is considered part of the chemical habitat of an aquatic organism. It is universally true that whenever there is too much of anything it can be considered a pollutant. Just as all organisms have a preferred physical habitat, they also have a preferred chemical habitat. The right concentration of a chemical or nutrient for one species might be too much or too little for another. There is no perfect amount of any chemical dissolved in the water. Even dissolved oxygen can be viewed as a pollutant under some circumstances. If too much oxygen is introduced into an area where it doesn’t occur naturally, the entire community’s metabolism will change. In the process, many species that did well with less oxygen will be replaced with new and different species. Several broad categories of dissolved or suspended chemicals make up the chemical habitat. These include: · macronutrients (nutrients needed in large quantities); · micronutrients (nutrients needed in small quantities); · salts (affect the ionic balance of the water); · dissolved inorganic carbon; · dissolved organic carbon; · pH; · oxygen; and · suspended solids. No living cell on earth can survive without most of these in one form or another. These chemicals are absolutely necessary for life, yet in too great a concentration, any one of these can become a pollutant! A category that is part of both the chemical and physical habitat is suspended solids, or fine clays and organic particles. Suspended solids can greatly influence the physical habitat, and they influence the chemical habitat by binding to phosphate and metal ions, many of which are essential micronutrients. The result can be micronutrients that are unavailable for plants and animals. In an otherwise unpolluted stream, micronutrients bound to suspended solids can cause growth limitations. Chemical monitoring on a regular basis provides important information about water quality. This information, along with habitat and biotic data, provides valuable feedback on the health of a particular waterbody. 28 In a class all by itself, oxygen is a very important dissolved chemical. Oxygen is needed by all plants and animals. Oxygen is not very soluble in water, but aquatic plants and animals get their oxygen from the water, and at best, dissolved oxygen can be found at maximum concentrations of 15 parts per million (ppm). By contrast - the air we breathe is 200,000 ppm. While we would not notice our oxygen level being lowered by 10 ppm, decreasing the dissolved oxygen in the water by just a few ppm can have a drastic impact on the stream’s life. As water warms, it holds less and less oxygen. At 0 degrees Centigrade (32 degrees Fahrenheit), it can hold 15 ppm. At 35 degrees C (95 degrees F), it can hold only 7. Since most fish require 5 ppm to survive, high temperatures of summer pose greater risks. NOTES: __________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ A healthy stream has areas shaded by a good stand of trees and shrubs. The shade from the trees is important for keeping the water cool. Cooler water can hold more dissolved oxygen, thus making the stream home to a greater diversity of fish. This results in a more stable ecosystem that is better able to withstand certain types of pollution. 29 Macronutrients Macronutrients — nitrogen, phosphorous, and potassium — are familiar to any farmer and many homeowners. In streams, there is almost never too much or too little potassium, so we usually ignore it. Nitrogen and phosphorous, on the other hand, almost always limit growth in an unpolluted stream. All proteins contain nitrogen, and all DNA and RNA contain a lot of phosphorous. Nothing can live without these two elements, and, after water and carbon, they are the ingredients all life forms need the most. Because nitrogen and phosphorous stimulate plant and microorganism growth, these elements can be major pollutants. The pollution potential of these elements will be discussed in another section. Micronutrients Living organisms require other elements in very small quantities. Sulphur, silicon, manganese, cobalt, vanadium, iron, magnesium, and calcium are a few micronutrients needed by plants and animals to survive. While essential, many micronutrients are highly toxic if supplied in high doses or in the wrong form. Chromium and selenium, for example, are micronutrients that can be very poisonous. Common Salts Nothing can live in pure water. A fish placed in pure water will die quickly, as will bacteria, plants, and any other aquatic organism. A certain amount of dissolved salts in water is necessary to keep the right balance of salts and water in the living organisms. The common salts that do the bulk of this work are sodium chloride, calcium sulfate, and various carbonates. As with all other things, too much of any one of these salts can present a major problem, and even cause a fish kill, yet some of each is necessary for life to exist. Dissolved Inorganic Carbon Dissolved inorganic carbon consists of the various carbonate salts and dissolved carbon dioxide. Without these, plants cannot grow, and without plants, animals cease to exist. In a well balanced water-body, there is almost never a shortage of dissolved inorganic carbon, but again, too much can be very harmful. There is so little nitrogen and phosphorous in an unpolluted stream that life in the stream depends upon what falls in, such as insects, twigs, and leaves, for nutrients. 30 Dissolved Organic Carbon Most animals and many plants require vitamins. Most vitamins and other growth factors are produced by bacteria, and small but absolutely necessary amounts of them float around in all water. Other organic compounds, like sugars and organic acids, leak out of living cells and contribute to the mix of food on which bacteria in unpolluted waters feed. This leakage is a good thing, because bacteria are necessary for decay and vitamin production. Like everything else, though, too much is considered pollution. The high level of dissolved organic carbon in sewage effluent stimulates bacteria l growth to the point that all dissolved oxygen is used and the fish and macroinvertebrates die. pH An important chemical category is pH, a measure of the acidity of the water. Since even pure water produces a few hydrogen ions that contribute to acidity, pH is a characteristic shared by polluted and unpolluted water. A pH of 7 is neutral, values from 0-7 acidic, and values ranging from 7 - 14 caustic. Water with pH varying between 6.0 and 8.5 is generally suitable for most aquatic life. In the southeastern part of Oklahoma, pH can be as low as 6.0, while it tends to range from 6.8 to 8.5 over the rest of the state. A pH of less than 6.0 can affect reproduction of an aquatic species, but adults can often withstand a pH of 5.0 or less. An interesting and important characteristic of pH is that it affects the toxicity of many poisons that end up in streams. Lower pH values tend to increase the toxicity of metals, while higher pH values can render these same metals unavailable, causing deficiencies. High pH values drastically increase the toxicity of ammonia. Many pesticides have pH-dependent toxicity. “What’s the use of a house if you don’t have a decent planet to put it on?” Henry David Thoreau Testing for dissolved oxygen can be accomplished with meters or with simple field kits such as the one used here by a volunteer. 31 Biotic Quality Streams, lakes and wetlands depend equally on water quality, physical habitat quality, and biotic quality. If the water quality (chemical habitat) is high, and the physical habitat is high, and all the organisms that naturally live in the stream are present, then the biotic quality is probably high also. However, the same way that the removal of physical or chemical habitat components changed our ideal imaginary stream for the worse, changes to the biota can affect a waterbody also. These changes can occur with or without changes to the chemical and physical environment. Biotic interactions take place when a living entity is part of the physical habitat for something else. Aquatic plants always provide substrate and structure for invertebrates and fish. Young fish, in particular, have very poor survival rates without beds of aquatic plants in which they can hide from larger animals. If large beds of aquatic plants are removed from a stream, and there is no shallow water small fish can retreat to, the end result can be a few very large fish, which will go hungry after all the small fish are gone. The result can be a drastic decrease in total fish production. Other biotic interactions are more subtle and don’t result from any changes at all to the chemical or physical habitat. High fishing pressure that decreases the population of large predatory fish from a lake or stream can result in a community dominated by small, stunted insect-eating sunfish and an overabundance of insect-eating minnows. Because the main consumers of algae are insects, the population of algae often explodes when the population of insect-eating fish explodes. Excessive algae depletes oxygen in water, resulting in a fish kill. Remember - we would not have had too much algae had we not removed the large fish that kept the insect-eating fish population under control. Once the insect-eating fish became too numerous, the insects were eaten and the algal population exploded! Aquatic plants provide a fine place for aquatic insects and young fish to find refuge from larger, hungry animals. When urban development or farming practices result in streams that are devoid of aquatic vegetation over large areas, the diversity of fish and insects living in the stream will decrease. 32 There are countless ways that one animal or plant can influence another without eating it. Sometimes it is a simple matter of competition for food or habitat space. Another is when an animal uses the burrow of another animal for nesting space. Channel catfish will only nest in cavities and are often found nesting in abandoned beaver burrows. Fresh water mussel larvae get their start in life on the gills of certain fish species and cannot reproduce without these fish present. In summary, a healthy waterbody exists when the water quality is good, the waterbody’s physical components can provide homes for plants and animals, and the plants and animals that should be able to live there are present. The Oklahoma Conservation Commission’s Water Quality Division monitors the condition of waterbodies in Oklahoma through their own projects, support to conservation districts, and the administration of nonpoint source pollution grant projects. Commission staff members use data to prepare plans for stream protection and restoration throughout the state. “Our liquid planet glows like a soft blue sapphire in the hard-edged darkness of space. There is nothing else like it in the solar system. It is because of water.” John Todd The balance of life in a stream or lake is delicate. By removing too many fish at the top of the food chain, population levels of everything else will change. The result can be a change in the chemical quality of the water, altering the species composition even further. The intimate relationship between a stream’s water chemistry, habitat, and plants and animals holds many mysteries. Understanding these ecological concepts marks the beginning of finding a way to respect and conserve our many natural aquatic resources. 33 Stream Ecology: Foodwebs, Nutrients, and Oxygen A natural “follow-up” to the previous section that covers chemistry, habitat, and stream life is this highly simplified look at foodwebs, nutrients, and oxygen. Streams, ponds and wetlands have foodchains, or foodwebs. At the base of all foodwebs is some type of plant. Plants that form the base of a stream’s foodweb can grow in the stream or grow on dry land and fall into the stream. Nutrients, essential for plant growth, come from manure or fertilizers, with small amounts occurring naturally in all soils. Unpolluted streams are dominated by invertebrates that shred dead leaves and twigs and by small fish that eat insects. The water has no noticeable algae and underwater rocks and logs look clean. Dissolved oxygen levels remain close to saturation during both day and night, meaning that levels don’t vary much over a 24-hour period. Polluted streams are dominated by insects, and often small fish, that eat algae. At low levels of pollution, the invertebrates will scrape algae off of rocks and sticks. At higher levels, they will filter plankton (floating) algae out of the water. Where lots of algae exist, very wide swings in the levels of dissolved oxygen concentrations from day to night can be expected. DO levels are likely to be considerably more than 100 percent saturation level during the day, and much less than 100 percent at night. At night the algae and other aquatic plants are respiring, us ing oxygen but adding none. During the day, oxygen is added to the water as a by-product of photosynthesis. At even higher levels of pollution, algae don’t grow well (or at all). The stream becomes dominated by aquatic invertebrates (such as tubifex and bloodworms) that do not need much dissolved oxygen to survive. Bacteria and fungi grow so well in these waters that they also dominate. At these pollution levels, water will appear gray or black instead of green, and few or no fish will be present. An unpolluted stream gets most of its plant material from terrestrial vegetation. A polluted stream gets almost all of its plant material from algae. Very highly polluted waters usually host low levels of dissolved oxygen during the day (well below saturation) and approach 0 at night. These waters sometimes have an unhealthy gray or black coloration. 34 Lakes and Reservoirs - Health & Interactions with Pollutants With a few exceptions, concepts discussed throughout this primer are applicable to lakes and wetlands. Pollutants come from the same sources and have the same effects. Organisms in lakes require habitat and have the same type of interactions with habitat, other organisms, and water quality as do stream organisms. The food chain interactions that are vitally important in streams are just as important in lakes. Even the riffle zone of a stream has a lake counterpart. Many of the organisms that live in stream riffles live in the wave zone of a lake where water is always moving. A lake is an inland body of water that has no flow or flows so slowly that its speed is measured in feet per year. Lakes may or may not have an outlet. If there is no outlet, the lake will contain salt water. With few exceptions, most lakes with an outlet contain fresh water. Technically, lakes are naturally formed, and impoundments created by man are called reservoirs. This distinction is important to note when studying lakes, but in this publication, both lakes and reservoirs will be referred to as lakes. A lake is connected to its watershed in every sense of the word. The only water, dissolved chemicals, and silt that enter the lake from outside the watershed are contained in rain and dust that falls directly on the water’s surface. Everything else (by far the greatest percentage) is delivered to the lake by the running waters that feed it. These streams transport to the lake everything which can be dissolved in, suspended by, or floated on runoff. Any groundwater that surfaces in the watershed also makes its way to the lake via a stream. A lake’s problems are diagnosed within the lake, but to gain an idea of what pollutants are causing problems and to learn their sources, investigative work in the watershed will have to be done! One difference between lakes and streams is the form in which nutrients are found. In a stream, many pollutants, nitrate and phosphate for example, are transformed to new and different pollutants. Nitrate and phosphate that enter a stream in runoff from a fertilized lawn will be taken up by bacteria, fungi, and algae. Oklahoma’s natural lakes come in two varieties: “oxbow” lakes which are formed when rivers change channels and leave a bend behind; and “playa” lakes in western Oklahoma that hold water only during wet years. Most lakes in Oklahoma are actually reservoirs. The result of a desire to impound water, reservoirs have a variety of functions: water supply; hydro-electric power; flood prevention; and recreation are a few of the primary reasons people create “lakes.” 35 In general, the pollution sources and effects in streams also apply to lakes. If a stream flows into a lake and the travel time is short, nitrate and phosphate will enter the headwater areas of the lake. How-ever, although a pollutant was important in a stream, it may not be as important in a lake. Runoff water with a low pH mixes with and is diluted by other water, so that the pH is usually normal by the time it reaches the lake. Toxic metals and pesticides that become tightly bound to sediment particles in the stream are often no longer toxic by the time they get to the lake. A stream’s nutrient pollution load can be measured by nitrate, ammonia, and phosphate testing, but by the time this water arrives at the lake, many of these nutrients will have been incorporated into the bodies of single -celled organisms. Of course the phosphorus and nitrogen are still there, but in a different form. These nutrients now exist in the form of proteins, nucleic acids, and assorted other chemicals that compose the machinery of life. The concentration of nutrients can be measured in a lake, but not as effectively by using nitrate, ammonia, and orthophosphate tests. Tests that yield information about the amount of nitrogen and phosphorous found in proteins, nucleic acids, and other chemicals must be performed. It is easy to miss this concept. A lake that is pea-green and smelly will test low for nitrate, phosphate, and ammonia when it is obvious that it is enriched. In reality, the nutrients are simply already a part of an organism, and as more nutrients enter the lake, they are quickly transferred into organisms. In lakes, nitrate is important not only as a source of nitrogen, but also as a source of oxygen. When dissolved oxygen levels are low, bacteria living in oxygen-poor sediments and water take oxygen from the nitrate ion through a chain of reactions and release nitrogen gas or ammonia that eventually end up in the atmosphere. Therefore nitrogen does not accumulate over time. Phosphorous, on the other hand, doesn’t form any gaseous compounds naturally, and once in a lake, remains there for a very long time, possibly forever. If it combines with calcium to form calcium phosphate, it can no longer be used by living organisms, but in all other forms it is recyclable. A lake polluted with phosphorous may always have problems. There are ways that phosphorous may be “inactivated,” but these are expensive and almost always temporary. NOTE: _____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ An enriched lake is one which contains too many nutrients, like nitrogen and phosphorous. Symptoms of such enrichment may include excessive algae, odor problems, and low levels of dissolved oxygen. 36 Another big difference between lakes and streams is that lakes lack the strong mixing force that streams have. Gravity influences a stream through of its generation of current. Lakes act more like a big bowl of stagnant water. This leads to a very important phenomenon called thermal stratification. Water behaves very much like the gases that compose the atmosphere: cold water sinks and warm water rises. Once the sun starts heating surface waters in the spring, these waters tend to remain at the top of the lake. Throughout the summer, the surface waters continue to warm, and the cool water at the bottom of the lake experiences little change. This temperature difference becomes so pronounced by midsummer that the two different layers of water act like separate waterbodies. The upper layer, called the epilimnion, stays mixed within itself, but does not mix with the lower layer, called the hypolimnion. When the epilimnion cools in the fall and reaches the same temperature as the hypolimnion, mixing of the two layers begins to occur. This process is known as lake turnover or mixing. Stratification is important during the summer because the lower layer of cool water does not have any contact with the atmosphere. This means that no new dissolved oxygen is added to the hypolimnion while the lake is stratified, so the oxygen it contains in the spring must last until the fall turnover. The hypolimnion in an unpolluted lake retains enough oxygen to keep fish alive through the summer. Unfortunately, this is not the case in polluted lakes. Decomposition of leaves, twigs, and dead algae occurs slowly in an unpolluted lake. If decay occurs at a fast rate - which might be the case in polluted waters where nutrients are found - oxygen will be depleted in the hypolimnion. Fish will crowd into the epilimnion, moving away from their lake-bottom feeding opportunities and into warmer water. In addition, when the hypolimnion loses its oxygen, most of the phosphorous that is in an insoluble and unavailable form once again becomes available. Large algal blooms often occur in the fall after lake turnover. As living organisms die, their remains sink to the bottom of the lake where they will remain until the next turnover event. This type of phosphorous recycling can go on for decades with no new additions of phosphorous. Shallow lakes and ponds containing excess phosphorus are sometimes treated with alum (aluminum sul-fate) to inactivate the phosphorus by making it insoluble aluminum phosphate. This works if no new phosphorus enters the lake or if the phosphorus is not resolubilized by contact with anoxic water. Dis-cussions have taken place concerning the feasibility of inactivating the phosphorous in poultry litter with alum to reduce water quality problems. Combined, the two form aluminum phosphate, which is insoluble and therefore unavailable for algae. If, how-ever, the aluminum phosphate washes into an anoxic (oxygen depleted) lake, the phosphorous will be freed and it will once again nourish algae, perhaps for decades. Swimmers at a lake can even experience stratification, at least if they are tall enough. Ever notice how surface waters can be very warm, but the water around your ankles is quite cool? 37 Anoxic conditions lead to terrible taste and odor problems in water. While the smell remains in the hypolimnion, people don’t complain. When the lake turns over in the fall, the smell becomes obvious and water plant operators find it difficult to produce drinking water that is taste - and odor-free. In summary, these things are true about lakes: ¨ Lakes are basically stagnant, like big bowls of water sitting on the landscape; ¨ Almost everything that enters a lake comes from the watershed; ¨ Lakes are polluted by the same pollutants that affect streams; ¨ Nutrients and other chemicals that pollute streams are often found in a different chemical form in lakes; ¨ Phosphorous stays in lakes practically forever and continuously recycles, so stopping its input may not cure a lake’s problems; ¨ Lakes stratify into warm and cool water and because of this: a) the hypolimnion will become anoxic if the supply of nutrients is adequate; b) the hypolimnion will develop strong odors and tastes; and c) phosphorous is continually released and recycled by the hypolimnion. NOTES: ____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ Large or small, lakes and ponds dot Oklahoma’s landscape. At least 75% of Oklahoma’s drinking water comes from surface water, which is primarily lakes. 38 Wetlands - Health & Interactions with Pollutants Wetlands are basically “wet lands.” What these areas have in common is what makes them unique: shallow water, waterlogged soils, and vegetation. Wetlands support a great diversity of plant species and provide food, shelter, and nesting sites for a variety of resident and migratory birds, especially waterfowl. Many other creatures, like turtles, beaver, muskrats, frogs, water snakes, and many varieties of fish depend on wetland habitats as well. The particular types and arrangements of the wetland hydrology (water), hydric (water-saturated) soils, and hydrophytic (water-tolerant) vegetation are what makes one kind of wetland distinct from another. Wetlands may be any size or shape; they may be found inland or along coasts, and may contain fresh water, saltwater, or brackish water. Wetlands may be wet throughout the year, or only during certain seasons. Standing water may not be observed, but the hydrology must exist during the growing season at or near the soil surface for the area to be considered a wetland. Because water is present in wetlands much of the time, wetland soils have developed special characteristics. When the soil is saturated, most of the spaces between soil particles are filled with water, leaving little or no room for oxygen. These oxygen-depleted soils are “anaerobic”. Because hydric soil is saturated and anaerobic, a variety of chemical and biological reactions occur which affect the nature of the soil over time. Changes may take place in the color and texture of the soil, or a characteristic “rotten-egg” smell may be emitted by the soil as bacteria carry on anaerobic respiration. NOTES: ____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ Oklahoma’s wetlands are more common than its tallgrass prairie, more varied than its mountains, and just as important to wildlife as its forests. Almost two-thirds of the federally-listed threatened and endangered animals (such as the whooping crane and river otter) in Oklahoma spend all or part of their life cycle in wetland habitats. 39 Not all wetlands have plants, but those that do, have plants that are specially adapted to life in wet conditions. The plants which grow in the hydric soils of wetlands are called hydrophytes. Like other plants, they take carbon dioxide from the air and release oxygen. Like other plants, hydrophytes need oxygen in their roots. Since their roots are submerged, hydrophytes have developed various adaptations (including hollow tubes or sacs) to facilitate the exchange of carbon dioxide and oxygen and to transport oxygen to the roots. Oklahoma’s geographic location is the meeting ground between the arid west and the humid east. This interface harbors many wetland types, including: ¨ playa lakes ¨ riparian corridors ¨ shoreline wetland ¨ forested wetland ¨ oxbow lakes ¨ closed depressions and ¨ swamps and marshes. Each of these wetland types provide important habitat and forage to many different animal species, including many different species of migratory waterfowl, such as the Canada Goose and cinnamon teal, and amphibian spe-cies such as the Smallmouth Sala-mander. Much misunderstood, wetlands have been drained and filled without regard to their ecological value. People have only recently begun learning about the benefits derived from wetland resources. The increased awareness of wetland issues coupled with wetland regulation and financial incentives for wetland protection/enhancement is reducing wetland abuse. Because all plant needs (sunlight, water, nutrients) are met in abundance in wetlands, they are some of the most productive and varied ecosystems in the world. This diverse and productive plant community in turn supports a diverse and dense animal community. Wetlands such as the one pictured here used to be an uncommon sight in urban settings. 40 Wetland Functions and Values Wetlands have many functions and perceived values. Functions are generally objectively quantifiable whereas values are subjective and often the reason wetlands are controversial. Wetland functions and values include: ¨ Water Quality Improvement - Wetlands can be a great help in dealing with polluted water. Wetlands act as a natural filter, slowing water velocity and allowing silts and sediments to settle out before water moves on to lakes and streams. Pesticides and nutrient runoff are also trapped in the settling process as most contaminants adhere to sediment particles. The high rate of biological activity (growth, decomposition, nutrient recycling, energy recycling) in wetlands results in many contaminants being absorbed and incorporated into plant tissues and then given off as harmless gas. ¨ Flood Control - Wetlands help reduce flooding by slowing the force of floodwaters and providing temporary storage of storm or snowmelt waters. This function enables wetlands to protect adjacent and downstream properties and reduce damage to roads, bridges, and crops. Wetlands help to stabilize the stream environment for aquatic animals. They release water in dry periods and store water during storm events. ¨ Groundwater Recharge and Discharge - Some wetlands replenish or “recharge” groundwater supplies. Water migrates or “percolates” from wetlands into aquifers (groundwater), maintaining the level of the water table. Wetlands may also serve as a “discharge” area for groundwater, intercepting an aquifer formation where groundwater is returned to the earth’s surface. Because the water table seasonally fluctuates, some wetlands serve as recharge areas during dry periods and serve as discharge sites during wetter months. ¨ Wetlands Habitat - Estimates indicate that in Oklahoma alone, 150 different bird species are wetlands-dependent. Migrating birds utilize wetlands for feeding and resting points. Many of the fish and shellfish eaten by people and other animals lived in wetlands when they were immature. Many animal species require shallow water for egg-laying, feeding, and protection from predators, which are generally less common in shallow waters. ¨ Erosion Control - Wetland vegetation absorbs and dissipates the forces associated with wave action and current to reduce erosion along streams and shorelines. ¨ Education, Recreation, and Aesthetics - Wetlands are living, hands-on museums. They serve as outdoor laboratories where unique plants and animals can be observed. The principles of ecological systems (energy flow, recycling, and carrying capacity) can be studied first hand. Wetlands are often beautiful areas that are capable of evoking pleasure and awe when we witness ducks taking to the air from a playa lake or a heron intently stalking its prey, or an alligator coasting effortlessly in the moonlight. Wetlands provide endless opportunities for activities such as hiking, canoeing, boating, fishing, hunting, bird-watching, swimming, and photographing wildlife. ¨ Economic Values - A wealth of natural products are produced by wetlands. Those available for human use include timber, fish and shellfish, wildlife, blueberries, cranberries, and wild rice. The economic benefits of wetlands from fisheries and waterfowl are substantial, but they pale in comparison to the benefits derived from wetlands as areas that accomplish groundwater recharge, floodwater storage, water quality improvement, and erosion control. In Oklahoma, 87% of wetlands are privately owned, making Oklahoma’s private landowners the state’s most important wetland managers. Many state and federal programs are now offering incentives to private landowners to protect wetlands on their property. Through programs such as the USDA Wetland Resource Program and Wildlife Habitat Incentives Program, and the US Fish and Wildlife Service’s “Partners for Wildlife” Program, wetland restoration, enhancement, conservation, and protection is becoming more common. As more private landowners gain an understanding and appreciation for wetland resources, this positive trend should continue. 41 Groundwater - Health & Interactions with Pollutants A technical definition of groundwater is “water that occurs below the zone of saturation within soil or rock or clay.” The zone of saturation is the zone that contains no, or very little, free air. The upper layer of soil that contains free air is usually referred to as the vadose zone and water within this layer is usu-ally not considered groundwater. There are strong interactions between water in the vadose zone and groundwater however, and often both must be considered in a question that involves groundwater. The way groundwater is held within the earth may vary. At one extreme is water that is so tightly locked up in dense rock that the only way it can be extracted is through heating the rock. At the other extreme, free water can exist in underground streams and lake-like reservoirs. Most groundwater used by humans falls between these two extremes and is contained between the spaces between sand and gravel particles. Because we only use fresh groundwater, we often forget the fact that most groundwater is salty. Groundwater can also have high concentration of naturally occurring toxic compounds and it can be with or without dissolved oxygen. Some groundwater moves through the ground so slowly that geologists tell us it was last on the surface of the earth tens of thousands of years ago. We measure its speed in inches per year. Other groundwater moves through the earth quite rapidly. If it is flowing freely in an underground stream, speed can be measured in feet per second and the water may have been on the earth’s surface only hours earlier. Water of this type may return to the surface of the earth through a spring within hours or days after it entered the ground. “It is not until the well runs dry, that we know the worth of water.” Benjamin Franklin People cannot see groundwater until it surfaces, thus this water resource is rather mysterious. While science for the most part does not support the idea that spring water has medicinal qualities, many Oklahomans go to great lengths to collect spring water for drinking. 42 Aquifers When a layer of rock or loose sand or gravel in the earth contains water in great enough supply that it is useful to people, and it is feasible to pump that water to the earth’s surface, the water-bearing layer is called an aquifer. People that study groundwater (geohydrologists) separate the different types of aquifers into categories that have their own names, but the two main classes of aquifers are referred to as confined and unconfined. The two types are impacted differently by pollution. A confined aquifer has layers of impermeable material, usually dense rock or tight clay, both above and below the water bearing layer. Material from the surface or from deeper depths cannot migrate into a confined aquifer very easily. When a pollutant such as nitrate is dissolved in the shallow groundwater near the surface, the water in a confined aquifer is relatively protected. Over the course of a lifetime, it is unlikely that a pollutant will move into this confined aquifer. Most confined aquifers that have become polluted were contaminated when drilling activities punched holes in the confining layer. If the well were not cased correctly, or if it were abandoned unplugged, this damage can provide a route by which bacteria or nitrate can travel down the borehole and pollute the aquifer. The area on the earth’s surface through which a well may become contaminated is known as the wellhead protection area. In a confined aquifer, the wellhead protection area is small, encompassing only the area near the borehole. If the well was drilled through the lower confining layer, saltwater or other naturally occurring contaminants in deeper aquifers can rise up and pollute a fresh water aquifer. Confined aquifers that contain fresh water do have a connection to the surface, but it is usually many miles away from most of the aquifer. These connections are formed when the earth’s strata became tilted or folded through geologic processes. Over hundreds or thousands of years, the upper confining layer will erode, exposing the water-bearing layer at the earth’s surface. When surface water runs across this permeable, water-bearing layer, it soaks in and will slowly run downhill through the permeable layer that forms the aquifer. This keeps the aquifer full of fresh water. If humans pump water out of an aquifer faster that it can be replenished, the groundwater becomes depleted and wells run dry or must be pumped from greater depths. This area where the aquifer surfaces and is renewed is called the groundwater recharge area. Confined aquifers can be polluted by the careless handling of pollutants over the recharge area. Unconfined aquifers are those that have no upper confining layer of impermeable material. The most common type of unconfined aquifer forms in the loose sand and gravel that lie beside rivers and streams. This is an alluvial aquifer. Alluvial aquifers lie at or very near the surface of the ground, are very porous, and can be polluted by anything that is put on their surface in amounts that can filter down below the root zone. Wellhead protection areas for alluvial aquifers are much larger than those for confined aquifers, and can extend a mile or two from the well. The recharge area for alluvial aquifers is really just the river or stream valley. Much of the water in these aquifers is left there after floods covered the floodplain and infiltrated into the groundwater. The floodplain associated with this river is the recharge area for the alluvial aquifer that lies beneath it. 43 Alluvial terrace aquifers are older floodplain aquifers that remain after the river has changed course and cut down to a lower level over many thousands of years. They behave the same as alluvial aquifers except that they are recharged by rain and runoff. Terrace aquifers are well above the floodplain of present day rivers. Another type of unconfined aquifer is found in areas that are called karstic. Karstic geology occurs in areas of rock that are dissolved by water, usually carbonate rocks such as limestone or dolomite, or in western Oklahoma, gypsum. As water seeps along cracks in these rocks, it slowly dissolves rock and forms caves and fissures. Sinkholes are formed when a cave forms so close to the surface that it collapses, leaving a depression on the ground’s surface. Water in this type of aquifer moves so freely from the surface to underground and back again that the distinction between ground and surface water becomes blurry. Karstic aquifers, like alluvial aquifers, can be polluted by anything placed on the earth’s surface. Features like sinkholes allow even greater infiltration so that there is often no filtration at all as water passes down in into the aquifer. Karstic aquifers are the most vulnerable to pollution. Groundwater Ecology Until recently, the common belief was that nothing lived in deep confined aquifers, so there was no need to discuss ecology. Now that new, very technical, drilling methods that keep drilled material sterile have been developed, bacteria have been found even in the deepest fresh water aquifers. These bacteria respire very slowly, and unless they are provided with nutrients and a carbon source, they are not noticed. There is some hope that these bacteria may be able to clean up polluted groundwater by increasing their metabolic rate through the addition of nitrogen and phosphorous, and letting them use a pollutant such as a pesticide for a carbon source. This is a controversial idea because it requires the addition of new pollutants to remove a pollutant already in place. Unconfined aquifers have a much more complex ecology than confined ones due to their connectedness with the earth’s surface, where most life is found. Karstic aquifers and the air- and water-filled caves associated with them have entire ecosystems where bat guano forms the base of the food chain. Bats, spiders, centipedes, and many insects and other arthropods live in the air-filled portions of the caves. Fish, crayfish, aquatic sowbugs, and other arthropods, all blind, live in the water-filled parts of the caves. Bacteria and fungi also thrive in caves and Karstic aq-uifers. NOTES: ____________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ The plant and animal life associated with karstic aquifers are especially sensitive, therefore visits to such areas must be made with a great deal of concern for these fragile ecosystems. 44 Alluvial aquifers also have thriving ecosystems that are contained within the water-filled spaced between sand and gravel particles. In unvegetated sandy river beds, enough light penetrates the top few inches of sand that algae grows in the water-filled voids. If the water contains enough nutrients, the algae get so dense that a green color is apparent. Organic detritus that sifts down through the spaces in the sand forms the base of the food chain for an ecosystem composed of small animals such as rotifers, nematodes, protozoans, other arthropods, and the ubiquitous fungi and bacteria. All of these life forms can be found in any alluvial aquifer, although the more polluted it is with nutrients and organic carbon, the denser the life will be. Much of the groundwater ecology that is important to surface dwellers occurs at the groundwater/ surface interface. Such areas, where the ground is saturated with water, and sunlight is available for photosynthetic organisms, are among the most productive on earth, and are called wetlands. Wetlands are discussed in more detail in their own section, but suffice it to say that pollutants in groundwater can have a major effect on wetland communities. In turn, wetlands can have a substantial effect on groundwater pollutants. A good example of this is seen where nitrate contaminated groundwater surfaces in a wetland. Because rates of bacterial production are so high (due to the high levels of nutrients and lots of organic carbon-containing materials), the groundwater is usually anaerobic (contains no oxygen). When this happens, certain bacteria, the denitrifying bacteria, utilize the oxygen in the nitrate ion and release nitrogen gas into the atmosphere. If enough other nutrients and carbon are present, this reaction can be quite intense and rid the water of much of its nitrate pollution. “Nothing in this universe exists alone. Every drop of water, every human being, all creatures in the web of life and all ideas in the web of knowledge, are part of an immense, evolving, dynamic whole as old - and as young-as the universe itself. To learn this is to discover the meaning of joy.” David Cavagnaro “The last word in ignorance is the person who says of an animal or plant: “What good is it?”..... If the land mechanism as a whole is good, then every part of it is good, whether we understand it or not.” Aldo Leopold “Like winds and sunsets, wild things were taken for granted until progress began to do away with them.” Aldo Leopold 45 Summary Through the course of each day, Oklahomans are likely to drive across a bridge under which flows a stream or river. Oklahomans will fill a glass with water and place ice cubes in the glass. Showers will be taken, washing machines will produce clean clothes. In many cases, hydro-electric power will make possible the conveniences that we take for granted. Somewhere, on any given day, an Oklahoman may bait a hook and reel in a fish from one of our many lakes or streams. Because of the Clean Water Act, the Oklahoma Conservation Commission’s Water Quality Division works each day to: Þ learn the condition of our water resources Þ use data to plan water resource protection measures Þ provide information to the people of Oklahoma so that our water resources can be protected The Water Quality Division accomplishes these tasks by working with local conservation districts on nonpoint source pollution projects. No matter where you live in Oklahoma, you live within a conservation district, which is the entity to help you care for your local natural resources. Conservation Districts work hand in hand with the USDA Natural Resources Conservation Service (formerly Soil Conservation Service) to provide technical assistance and information to landusers. This primer fits into the Oklahoma Conservation Commission’s goal of educating the people of Oklahoma. Everyone contributes to nonpoint source pollution, and informing the public of what pollutants are is step one to addressing our water pollution problems. Examples of nonpoint source pollutants of which all Oklahomans need to be aware are: Þ sediment from landclearing activities Þ toxins such as pesticides Þ nutrients (which may come from sources such as unmanaged animal waste; leaking sewer lines; fertilizers from lawns and crops) These are just a few of the pollutants that impact our rivers, streams, lakes, wetlands, and groundwater. If being aware of these pollutants is step one, then step two must be gaining the motivation and the knowledge to battle nonpoint source pollution. Oklahomans are reminded that laws such as the Clean Water Act have been passed because we are citizens in a nation that has chosen to place great value on our natural assets. Streams and rivers that are devoid of life are not acceptable to us. Primary water source lakes that produce foul tasting or unsafe water cause great expense to citizens, impact our quality of life, and are also unacceptable. Many challenges are faced by conservationists. The challe nge of motivating citizens to become stewards of soil, water, and wildlife, is perhaps the greatest challenge of all. Bringing people aboard as stewards - motivating them to personally invest in caring for our water resources - is essential to reducing pollution and protecting water resources. Through support to local conservation districts, the Oklahoma Conservation Commission’s efforts include: Þ natural resource days that introduce children to the world of nature Þ cost-share programs that help pick up the tab for implementing practices that protect water resources Þ education programs that turn data (collected on streams, rivers, and lakes) into usable information Þ workshops that bring people and resources together Þ volunteer programs that give citizens an opportunity to learn about and actively protect water resources 46 Work with children can be rewarding, because they seldom have to be encouraged to like the critters found beneath the surface of the water. Many of our aquatic insects have highly interesting lives. Children want to learn about their lifestyles underwater - and their lifestyles when they grow up and emerge. Take a group of children to the side of a stream, and you will only have to ask once for a helper to drag the seine. Children are fascinated with the variety of fish that make clean streams their home and they are saddened by the lack of fish in our more polluted waters. Often adults transform into children again when they are taken to the side of a stream. But getting adults to the side of a stream is a challenge. Leaving the field, the office, the automobile behind, .many adults feel they don’t have much time for this, and time is at a premium for most folks. Through programs that educate adults at the side of a stream, those who can change their schedule to be present often make an important connection with with the natural world. In most cases, this is a reconnection, a dusting off of a relic feeling born in childhood, when loving the earth came naturally. Funding is often made available to landowners in specific watersheds for the purpose of protecting a particular stream, river, or lake, that has been identified as a “priority watershed.” This funding - often referred to as “cost-share” money - may be used to: Þ establish riparian areas; Þ build ponds as an alternate source of water for livestock; Þ install rotational grazing cells; Þ and develop education programs specific to the watershed. Cost-share money helps landowners so that they can better afford to protect resources. An important goal of nonpoint source pollution programs that assist landowners with installing conservation practices is to show these practices to others and encourage additional participation. This is where the local conservation districts take the lead: practices that are installed with the aid of cost-share money need to be promoted. The promotion of such practices can help other landowners see the benefit of incorporating resource protection into their agricultural production activities. Volunteer opportunities - especially through the Oklahoma Conservation Commission’s Blue Thumb Pollution Education Program - bring aboard citizens who are already motivated to care for resources. Volunteers educate themselves and assist the Commission by collecting data and educating the public about water resource protection. Local conservation districts throughout the state pull together volunteers who take up much of the slack so a greater number of people can be reached. Volunteers are wonderful tools - they can speak of why they choose to be involved in protecting streams and lakes, yet they draw no government paycheck. Also, they are the local folks, which makes a difference as well. We Oklahomans live in a state with prairies, woodland, mountains, and plains. The streams and rivers which drain these different lands are filled with a variety of different fish and other life. As citizens, we have a responsibility to know what is impacting our streams, rivers, and lakes. As stewards, we have a responsibility to do our best to care for these important water resources,. As people who share this planet with all types of life, we have a responsibility (or a better word might be opportunity) to know, appreciate, and make room for the other “citizens” of planet Earth. 47 NOTES: ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ __________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ 48 |
Date created | 2011-07-12 |
Date modified | 2012-11-29 |
OCLC number | 746494201 |
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