Watershed Trend Analysis and Water-Quality Assessment Using Bottom-Sediment Cores From Cheney Reservoir, South-Central Kansas

An examination of Cheney Reservoir bottom sediment was conducted in August 1997 to describe long-term trends and document the occurrence of selected constituents at concentrations that may be detrimental to aquatic organisms. Average concentrations of total phosphorus in bottom-sediment cores ranged from 94 to 674 milligrams per kilogram and were statistically related to silt- and (or) clay-size particles. Results from selected sampling sites in Cheney Reservoir indicate an increasing trend in total phosphorus concentrations. This trend is probably of nonpoint-source origin and may be related to an increase in fertilizer sales in the area, which more than doubled between 1965 and 1996, and to livestock production.

Few organochlorine compounds were detected in bottom-sediment samples from Cheney Reservoir. DDT, its degradation products DDD and DDE, and dieldrin had detectable concentrations in the seven samples that were analyzed. DDT and DDD were each detected in one sample at concentrations of 1.0 and 0.65 microgram per kilogram, respectively. By far, the most frequently detected organochlorine insecticide was DDE, which was detected in all seven samples, ranging in concentration from 0.31 to 1.3 micrograms per kilogram. A decreasing trend in DDE concentrations was evident in sediment-core data from one sampling site. Dieldrin was detected in one sample from each of two sampling sites at concentrations of 0.21 and 0.22 micrograms per kilogram. Polychlorinated biphenyls were not detected in any bottom-sediment sample analyzed.

Selected organophosphate, chlorophenoxy-acid, triazine, and acetanilide pesticides were analyzed in 18 bottom-sediment samples. Of the 23 pesticides analyzed, only the acetanilide herbicide metolachlor was detected (in 22 percent of the samples).

Seven bottom-sediment samples were analyzed for major metals and trace elements. The median and maximum concentrations of arsenic and chromium, the maximum concentration of copper, and all concentrations of nickel in the seven samples were in the range where adverse effects to aquatic organisms occasionally occur. No time trends in trace elements were discernable in the August 1997 data.

Land use and human activities within a watershed can have considerable effects on the water quality in a downstream reservoir. Of particular concern in south-central Kansas are the effects of point-source discharges from municipal wastewater-treatment plants and nonpoint-source runoff from areas used for crop and livestock production. Suspended sediment, nutrients (species of nitrogen and phosphorus), pesticides, and major metals and trace elements may have detrimental effects on reservoir water quality through increased sedimentation, accelerated eutrophication, reduced light penetration, potentially harmful effects to human health and aquatic organisms, and a general decrease in recreational value. One such downstream reservoir in south-central Kansas is Cheney Reservoir, which serves as a public-water supply for more than 300,000 people in the city of Wichita and surrounding area.

Cheney Reservoir has a surface area of about 15 square miles, a mean depth of about 16 feet, a conservation pool storage of 151,800 acre-feet, and an additional flood-control pool capacity of 80,860 acre-feet. The contributing drainage area of about 933 square miles (597,000 acres) is predominately agricultural (fig. 2) and used mainly for crop and livestock production.

Human population in the watershed is less than 4,000, much of which is associated with the approximately 1,000 farms in the watershed (Cheney Reservoir Watershed Task Force Committee, written commun., 1996). Populations of the six largest towns in the watershed range from less than 200 to slightly more than 1,200 people (Helyar, 1994).

In south-central Kansas, precipitation and temperature vary considerably throughout the year. The average annual (1961-90) precipitation is about 27 inches, most of which occurs during the growing season (April through September). The average annual temperature is 56.6 °F, with an average monthly range of 30.7 °F in January to 81.3 °F in July (Kansas Department of Agriculture and U.S. Department of Agriculture, 1997, p. 8).

The North Fork Ninnescah River Valley and the surrounding plains are underlain by consolidated rocks of Permian age (230 to 280 million years old) covered by unconsolidated fluvial and windblown deposits of Pleistocene age (less than 1.5 million years old) (Zeller, 1968). Soils in the Cheney Reservoir watershed generally are classified as clayey loam on the uplands to sand or sandy loam on low-lying areas or where slopes are less than about 3 percent. Many of the soils in the watershed are subject to erosion by wind and rainfall runoff (Rockers and others, 1966).

Topography in the Cheney Reservoir watershed generally consists of flat to gently sloping hills. Total topographic relief is about 550 feet, with maximum local relief (within 1 mile) of about 50 feet.

Cheney Reservoir is considered eutrophic (nutrient enriched) because of large nutrient inputs from the watershed. Algal blooms during the summer months have created taste and odor problems in treated drinking water for the city of Wichita (Cheney Reservoir Watershed Task Force Committee, written commun., 1996).

Bottom-sediment cores were collected with a gravity corer using round transparent plastic liners of cellulose acetate butyrate construction with a 2.625-inch inside diameter. One to three cores were collected at each site to provide a sufficient quantity of material for the intended analyses.

All of the bottom-sediment cores collected penetrated into pre-reservoir material. This was ddetermined by a change in physical appearance of the sediment, change in particle-size composition, or the presence of pre-reservoir soil-surface organic matter such as small sticks, plant material, or roots or root hairs. The presence of pre-reservoir material ensured that a complete sedimentation record was represented by each core sample.

Processing of core samples was conducted at the USGS laboratory in Lawrence, Kansas. The plastic liners were cut longitudinally in two places 180 degrees apart. The cuts were partially completed with a 1/8-inch hand-held rotary saw and finished with a retractable razor knife set at a depth to minimize penetration of the sediment core. The cores were split in half by pulling a tightly held nylon string through the length of the two cuts and allowing the halves to separate. Each core then was segmented into equal intervals that ranged from 0.1 to about 0.3 foot depending on the length of core and the amount of bottom material required for the planned physical and chemical determinations.

All core segments were analyzed for percentage moisture, bulk density, and percentage of sand and silt and (or) clay at the USGS laboratory in Lawrence, Kansas, according to methods presented in Guy (1969). Core segments from selected sites were analyzed at the USGS National Water-Quality Laboratory in Arvada, Colorado, for total phosphorus, organophosphate, and chlorophenoxy-acid pesticides, and major metals and trace elements according to methods presented in Fishman (1993) and for organochlorine compounds according to procedures in Foreman and others (1994). Selected core segments also were analyzed for triazine and acetanilide pesticides at the USGS laboratory in Lawrence, Kansas, according to methods presented in Mills and Thurman (1992). Analytical results for all sediment-core samples collected during this study are on file at the USGS office in Lawrence, Kansas.

Analysis of reservoir bottom sediment can provide insight into water-quality characteristics of a reservoir watershed. These characteristics include historical perspectives on sediment and chemical transport and potential toxicological effects on aquatic organisms. Sediment distribution and physical and chemical composition were examined during this study to quantify chemical concentrations, identify trends in chemical deposition, and evaluate chemical composition in relation to sediment-quality guidelines for the protection of aquatic organisms. Identified trends in water-quality constituents were related to known watershed land-use and human-related characteristics.

Phosphorus is a macronutrient required by plants for growth and reproduction. It is present in soils in organic forms and as inorganic iron, manganese, aluminum, and calcium phosphates. Phosphorus is necessary in cellular reactions involving photosynthesis, respiration, energy storage and transfer, and cell division, growth, and genetic coding (Sine, 1993, p. B46). Ecologically, phosphorus is the single most-controlling factor in maintaining biogeochemical cycles because of its role in energy-transfer systems and its normally short supply (Reid and Wood, 1976, p. 236). Phosphorus availability is a critical factor in the eutrophication of water bodies because the nutrient in shortest supply controls biological production rates (Hem, 1985, p. 128).

Phosphorus often is added to agricultural soils to stimulate plant growth and increase crop yields. It is applied as an inorganic phosphate or as a component of manure from confined feeding operations or human sewage disposal. However, the use of phosphorus as a fertilizer has detrimental effects on water bodies receiving runoff from source areas when excessive concentrations of phosphorus promote algal growth (create algal blooms), which can produce taste and odor problems in treated drinking water.

Reservoir sediment may contain large quantities of phosphorus deposited as a result of inflow transport of particulate forms and of dissolved forms, which ultimately may be used during in-lake microbial cellular processes with subsequent bottom deposition upon death of the organisms. Examination of reservoir bottom sediment may reveal the extent and historical trend of phosphorus deposition.

For most of the 20th century, organochlorine compounds have been manufactured and used extensively in both urban and agricultural environments as insecticides, and industrial chemicals such as polychlorinated biphenyls (PCBs). Most of the organochlorine insecticides, mainly because of their persistence and toxicity, have been exceptionally effective in controlling targeted organisms. However, these two qualities and the fact that these compounds may bioaccumulate in the food chain eventually generated concerns for human health and adverse effects on nontarget organisms. Because of these concerns, many of the organochlorine compounds, beginning in the late 1960's, were deregistered for certain uses or banned from use in the United States.

Organochlorine insecticides commonly are found in streambed and reservoir-bottom sediments in areas where the compounds have been used extensively (Elder and Mattraw, 1984; Smith and others, 1987; Gilliom and Clifton, 1990; Kalkhoff and Van Metre, 1997). These compounds have been used to control insect damage to crops as diverse as corn and pineapple, and tobacco and sugarcane, and to control nuisance insects such as ants, termites, beetles, fleas, flies, lice, mites, and mosquitoes.

PCBs have been used for almost 70 years as industrial chemicals in the manufacture of electrical transformers, cutting and lubricating oils, paints, printing inks, sealants, adhesives, plasticizers, and many other products. Worldwide, more than 1 million metric tons of PCBs have been produced (Schwarzenbach and others, 1993, p. 36). Generally, PCBs are nonreactive and very stable in the environment. They are resistant to chemical oxidation, photodegradation, hydrolysis, and are poorly metabolized by biological systems.

In addition to the organochlorine insecticides previously discussed, other classes of pesticides were analyzed in selected Cheney Reservoir bottom-sediment samples. The seven bottom-sediment samples analyzed for organochlorine compounds (sampling sites 4, 8, and 13) also were analyzed for organophosphate insecticides and chlorophenoxy-acid herbicides. Eighteen bottom-sediment core segments from sampling sites 1 (6 segments), 4 (9 segments), and 13 (3 segments) were analyzed for triazine and acetanilide herbicides.

The organophosphate insecticides have many of the same uses as the organochlorine insecticides and may be used on human food crops such as fruits and vegetables. The organophosphates insecticides are more water soluble and less persistent than the organochlorine insecticides. For instance, the organochlorine compounds DDT, DDD, and DDE are almost insoluble in water and have half-lives of between 2 and 15 years, whereas the organophosphate insecticide diazinon has a water solubility of 40 mg/L (milligrams per liter) and a half-life in soil of a few days (U.S. Environmental Protection Agency, 1989).

The chlorophenoxy-acid, triazine, and acetanilide herbicides have a wide range of uses in both urban and agricultural environments for the control of broadleaf weeds and annual grasses. The chlorophenoxy-acid herbicides are broadleaf weed and brush killers and are or have been used extensively on turf grasses in urbanized areas and on grain crops and rangeland in rural areas. The triazine and acetanilide herbicides represent some of the most extensively applied herbicides in the United States (U.S. Environmental Protection Agency, 1989) for control of annual weeds and grasses in crops such as corn, sorghum, and soybeans. Some of these herbicides are used alone, but many are used in combination with other compounds to increase weed-control effectiveness.

The acetanilide herbicide metolachlor was the only organophosphate, chlorophenoxy-acid, triazine, or acetanilide pesticide detected among the 23 analyzed in samples of Cheney Reservoir bottom sediment from selected sampling sites (table 4). Metolachlor was detected in one bottom-core segment each from sampling sites 1 and 4 and in two bottom-core segments from sampling site 13. This represents a detection rate of 22 percent of the samples analyzed. These detections ranged from 0.62 µg/kg in the bottom-core segment from sampling site 4 to 1.0 µg/kg in a segment from sampling site 13. The USEPA has not proposed TEL or PEL guideline concentrations in bottom sediment for metolachlor or any of the organophosphate, chlorophenoxy-acid, triazine, or acetanilide pesticides.

The low incidence of detections of the organophosphate, chlorophenoxy-acid, triazine, and acetanilide pesticides probably is related to their large solubility and rapid degradation relative to the organochlorine compounds even though some of these compounds may have been or currently (1998) are used extensively in the Cheney Reservoir watershed. The results presented in table 4 indicate that these four classes of pesticides, as groups, probably have little long-term, water-quality implications for aquatic organisms in Cheney Reservoir as a result of chemical storage in bottom sediment. However, the short-term implications, as a result of the occurrence of these pesticides in surface water, may be significant and is intended to be examined in subsequent phases of this cooperative assessment of water quality in the Cheney Reservoir watershed.

Major metals and trace elements form the matrix core of or can be sorbed to sediment particles and ultimately deposited in reservoirs. Resuspension or desorption of these elements may create water-quality problems for humans or aquatic organisms using reservoirs as water-supply sources. Major metals are among the most abundant elements in the Earth's crust and include aluminum, calcium, iron, magnesium, potassium, sodium, and titanium. Trace elements are much rarer and generally occur at concentrations of a few hundred micrograms per gram or less. Many of these trace elements are essential nutrients for plants and animals in small concentrations but in larger concentrations may be toxic. Most of the major metals and trace elements occur naturally in bottom sediment and are a reflection of the chemistry of soil types within a watershed. However, human activities in a watershed may cause sediment enrichment of major metals and trace elements, particularly those activities associated with industrial or commercial areas (Wilber and Hunter, 1979; Hopke and others, 1980; Pope and Bevans, 1987; Pope and Putnam, 1997). Reservoir bottom sediment, therefore, can serve as a watershed integrator or sink for major metals and trace elements, and trend analysis can be used to examine possible effects of changes in land use in a watershed.

The seven bottom-sediment samples collected at sampling sites 4, 8, and 13 and analyzed for organochlorine compounds also were analyzed for major metals and trace elements. A statistical summary of those analytical results is presented in table 5 along with TEL and PEL sediment-quality guidelines for several elements (U.S. Environmental Protection Agency, 1998).

Land use and human activities can have considerable effects on the water quality in a downstream reservoir. Constituents such as suspended sediment, nutrients (species of nitrogen and phosphorus), pesticides, and major metals and trace elements may have detrimental effects on reservoir water quality through increased sedimentation, accelerated eutrophication, reduced light penetration, potentially harmful effects to human health and aquatic organisms, and a general decrease in recreational value. Of particular concern in south-central Kansas is the long-term quality of water in Cheney Reservoir, which serves as a water-supply source for more than 300,000 people.

In 1996, the U.S. Geological Survey entered into a cooperative study with the city of Wichita, Kansas, with technical assistance provided by the Bureau of Reclamation, U.S. Department of the Interior, to define the water quality in the mostly agricultural, 933-square-mile Cheney Reservoir watershed. An examination of Cheney Reservoir bottom sediment was conducted as part of this study to describe long-term trends and document the occurrence of selected constituent concentrations that may be detrimental to aquatic organisms.

Bottom-sediment cores were collected at 13 sampling sites in Cheney Reservoir in August 1997. These cores were segmented into equal-length intervals, with most segments analyzed for percentage moisture, bulk density, percentage of sand and silt and (or) clay, and total phosphorus. At selected sites, core segments also were analyzed for pesticides, polychlorinated biphenyls, and major metals and trace elements.

Sedimentation and sediment-particle sizes were not uniformly distributed in the reservoir. Most sedimentation occurred in or near the original river channel. Most sand-size sediment particles were deposited in the upstream part of the reservoir, whereas the silt- and (or) clay-size particles were more widely distributed.

Average concentrations of total phosphorus in bottom-sediment cores ranged from 94 to 674 milligrams per kilogram and were statistically related to silt- and (or) clay-size particles. The implication of this relation for watershed management is that to mitigate the transport of phosphorus into Cheney Reservoir it would be necessary to either reduce the annual distribution of phosphorus in the watershed or to control the movement of silt- and (or) clay-size particles from the watershed.

Results from selected sampling sites in Cheney Reservoir indicate an increasing trend in total phosphorus concentrations. This trend is probably of nonpoint-source origin and may be related to an increase in fertilizer sales in the area, which more than doubled between 1965 and 1996, and to livestock production.

Few organochlorine compounds were detected in bottom-sediment samples from Cheney Reservoir. Only DDT, its degradation products DDD and DDE, and dieldrin had detectable concentrations among seven samples analyzed. DDT and DDD were each detected in one sample at concentrations of 1.0 and 0.65 microgram per kilogram, respectively. By far, the most frequently detected organochlorine insecticide was DDE, which was detected in all seven samples ranging in concentrations from 0.31 to 1.3 micrograms per kilogram. A decreasing trend in DDE concentrations was evident in data from one sampling site. Dieldrin was detected in one sample from each of two sampling sites at concentrations of 0.21 and 0.22 microgram per kilogram. Polychlorinated biphenyls were not detected in any bottom-sediment sample analyzed.

A comparison of several organochlorine compounds to U.S. Environmental Protection Agency sediment-quality screening guidelines indicates that all detectable concentrations in Cheney Reservoir bottom sediment were considerably less than guideline values. This probably indicates that concentrations of DDT, its degradation products DDD and DDE, and dieldrin in Cheney Reservoir bottom sediment are less than those concentrations calculated to produce direct adverse effects on organisms associated with the sediment. However, this does not negate the possibility of bioaccumulation of these insecticides in the food chain to a concentration that may produce adverse effects on some higher order predatory organism.

Beside the organochlorine insecticides, selected organophosphate, chlorophenoxy-acid, triazine, and acetanilide pesticides were analyzed in 18 bottom-sediment samples. Of the 23 pesticides analyzed, only the acetanilide herbicide metolachlor was detected (in 22 percent of the samples). These results indicate that these last four classes of pesticides probably have little long-term, water-quality implications for aquatic organisms in Cheney Reservoir.

Seven bottom-sediment samples were analyzed for major metals and trace elements, and the results were compared to sediment-quality guidelines. The median and maximum concentrations of arsenic and chromium, the maximum concentration of copper, and all concentrations of nickel in the seven samples were in the range where adverse effects to aquatic organisms occasionally occur. However, because of the uncertainty associated with these guidelines, the actual environmental significance of these concentrations is not known. No time trends in trace elements were discernible with the August 1997 data.

Bachman, R.W., 1980, The role of agricultural sediments and chemicals in eutrophication: Journal of the Water Pollution Control Federation, v. 52, no. 10, p. 2425-2431.

Baker, D.B., 1985, Regional water quality impacts of intensive row-crop agricultural--a Lake Erie basin case study: Journal of Soil and Water Conservation, v. 40, no. 1, p. 125-132.

Balsters, R.G., and Anderson, C., 1979, Water quality effects associated with irrigation: Kansas Water News, v. 22, no. 1 and 2, p. 14-22.

Beaulac, M.N., and Reckhow, K.H., 1982, An examination of land use--nutrient export relationships: Water Resources Bulletin, v. 18, no. 6, p. 1013-1024.

Berg, R.D., and Carter, D.L., 1980, Furrow erosion and sediment losses on irrigated cropland: Journal of Soil and Water Conservation, v. 35, no. 6, p. 267-270.

Blalock, H.M., Jr., 1979, Social statistics (2d ed.): New York, McGraw-Hill, 625 p.

Blomqvist, Sven, 1985, Reliability of core sampling of soft bottom sediment--an in situ study: Sedimentology, v. 32, p. 605-612.

Blomqvist, Sven, and Bostrom, Kurt, 1987, Improved sampling of soft bottom sediments by combined box and piston coring: Sedimentology, v. 34, p. 715-719.

Callender, Edward, 1993, Transport and accumulation of radionuclides and stable elements in a Missouri River reservoir: Water Resources Research, v. 29, no. 6, p. 1787-1804.

Christensen, V.G., and Pope L.M., 1997, Occurrence of dissolved solids, nutrients, atrazine, and fecal coliform bacteria during low flow in the Cheney Reservoir watershed, south-central Kansas, 1996: U.S. Geological Survey Water-Resources Investigations Report 97-4153, 13 p.

Dixon, J.E., Stephenson, G.R., Lingg, A.J., Naylor, D.V., and Hinman, D.D., 1983, Comparison of runoff quality from cattle feeding on winter pastures: Transactions of the American Society of Agricultural Engineers, v. 26, no. 4, p. 1146-1149.

Elder, J.F., and Mattraw, H.C., Jr., 1984, Accumulation of trace elements, pesticides, and polychlorinated biphenyls in sediment and the clam Corbicula manilensis of the Apalachicola River, Florida: Archives of Environmental Contamination and Toxicology, v. 13, no. 4, p. 453-469.

Emery, K.O., and Hulsemann, J., 1964, Shortening of sediment cores collected in open barrel gravity corers: Sedimentology, v. 3, p. 144-154.

Engberg, R.A., and Sylvester, M.A., 1993, Concentrations, distribution, and sources of selenium from irrigated lands in western United States: Journal of Irrigation and Drainage Engineering, v. 119, no. 3, p. 522-536.

Fishman, M.J., 1993, Methods of analysis by the U.S. Geological Survey National Water-Quality Laboratory-methods for the determination of inorganic and organic constituents in water and fluvial sediments: U.S. Geological Survey Open-File Report 93-125, 217 p.

Foreman, W.T., Connor, B.F., Furlong, E.T., Vaught, D.G., and Merten, L.M., 1994, Methods of analysis by the U.S. Geological Survey National Water-Quality Laboratory--determination of organochlorine insecticides and polychlorinated biphenyls in bottom sediments: U.S. Geological Survey Open-File Report 94-140, 78 p.

Gilliom, R.J., and Clifton, D.G., 1990, Organochlorine pesticide residues in bed sediments of the San Joaquin River, California: Water Resources Bulletin, v. 26, no. 1, p. 11-24.

Guy, H.P., 1969, Laboratory theory and methods for sediment analysis: U.S. Geological Survey Techniques of Water-Resources Investigations, book 5, chap. C1, 58 p.

Helgesen, J.O., Stullken, L.E., and Rutledge, A.T., 1993, Assessment of nonpoint-source contamination of the High Plains aquifer in south-central Kansas, 1987: U.S. Geological Survey Water-Supply Paper 2381-C, 51 p.

Helyar, Thelma, ed., 1994, Kansas statistical abstract 1992-93: Lawrence, University of Kansas Institute for Public Policy and Business Research, 420 p.

Hem, J.D., 1985, Study and interpretation of the chemical characteristics of natural water (3d ed.): U.S. Geological Survey Water-Supply Paper 2254, 263 p.

Hoffman, R.J., Hallock, R.J., Rowe, T.J., Lico, M.S., and Burge, H.L., 1990, Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in and near Stillwater Wildlife Management Area, Churchill County, Nevada, 1986-87: U.S. Geological Survey Water-Resources Investigations Report 89-4105, 150 p.

Hollon, B.F., Owen, J.R., and Sewell, J.I., 1982, Water quality in a stream receiving dairy feedlot effluent: Journal of Environmental Quality, v. 11, no. 1, p. 5-9.

Hongve, Dag, and Erlandsen, A.H., 1979, Shortening of surface sediment cores during sampling: Hydrobiologia, v. 65, no. 3, p. 283-287.

Hopke, P.K., Lamb, R.E., and Natusch, D.F.S., 1980, Multi-elemental characterization of urban roadway dust: Environmental Science & Technology, v. 14, no. 2, p. 164-172.

Johnson, H.P., Baker, J.L., Shrader, W.D., and Laflen, J.M., 1979, Tillage system effects on sediment and nutrients in runoff from small watersheds: Transactions of the American Society of Agricultural Engineers, v. 22, no. 5, p. 1110-1114.

Juracek, K.E., 1997, Analysis of bottom sediment to estimate nonpoint-source phosphorus loads for 1981-96 in Hillsdale Lake, northeast Kansas: U.S. Geological Survey Water-Resources Investigations Report 97-4235, 55 p.

Kalkhoff, S.J., and Van Metre, P.C., 1997, Organochlorine compounds in a sediment core from Coralville Reservoir, Iowa: U.S. Geological Survey Fact Sheet FS-129-97, 4 p.

Kansas Department of Agriculture and U.S. Department of Agriculture, 1995-97, Kansas farm facts: Topeka, Kansas, published annually.

Kansas State Board of Agriculture and U.S. Department of Agriculture, 1964-94, Kansas farm facts: Topeka, Kansas, published annually.

Kashner, J., and Hunter, J.V., 1983, Influence of land utilization on hydrocarbon runoff pollution: Journal of Environmental Science and Health, part A, v. 18, no. 1, p. 135-144.

Laenen, Antonius, and LeTourneau, A.P., 1995, Upper Kalamath Basin nutrient loading study--estimate of wind-induced resuspension of bed sediment during periods of low lake elevations: U.S. Geological Survey Open-File Report 95-414, 11 p.

McHenry, J.R., and Ritchie, J.C., 1981, Dating recent sediments in impoundments, in Stefan, H.G., ed., Surface water impoundments, volume II: New York, American Society of Civil Engineers, p. 1279-1289.

Mills, M.S., and Thurman, E.M., 1992, Mixed-mode isolation of triazine metabolites from soil and aquifer sediments using automated solid-phase extraction: Analytical Chemistry, v. 64, no. 17, p. 1985-1990.

Mueller, D.K., DeWeese, L.R., Garner, A.J., and Spruill, T.B., 1991, Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Middle Arkansas River Basin, Colorado and Kansas, 1988-89: U.S. Geological Survey Water-Resources Investigations Report 91-4060, 84 p.

Omernik, J.M., 1976, The influence of land use on stream nutrient levels: U.S. Environmental Protection Agency Report 600/3-76-014, 114 p.

Polls, I., and Lanyon, R., 1980, Pollutant concentrations from homogenous land uses: Journal of the Environmental Engineering Division, American Society of Civil Engineers, v. 106, no. EE1, p. 69-80.

Pope, L.M., and Bevans, H.E., 1987, Relation of urban land-use and dry-weather, storm, and snowmelt flow characteristics to stream-water quality, Shunganunga Creek basin, Topeka, Kansas: U.S. Geological Survey Water-Supply Paper 2283, 39 p.

Pope, L.M., Brewer, L.D., Foley, G.A., and Morgan, S.C., 1997, Concentrations and transport of atrazine in surface water of the Delaware River-Perry Lake system, northeast Kansas, July 1992 through September 1995: U.S. Geological Survey Water-Supply Paper 2489, 43 p.

Pope, L.M., and Putnam, J.E., 1997, Effects of urbanization on water quality in the Kansas River, Shunganunga Creek basin, and Soldier Creek, Topeka, Kansas, October 1993 through September 1995: U.S. Geological Survey Water-Resources Investigations Report 97-4045, 84 p.

Reid, G.K., and Wood, R.D., 1976, Ecology of inland water and estuaries: New York, D. Van Nostrand Co., 485 p.

Ritchie, J.C., and McHenry, J.R., 1990, Application of radio-active cesium-137 for measuring soil erosion and sediment accumulation rates and patterns--a review: Journal of Environmental Quality, v. 19, no. 2, p. 215-233.

Rockers, J.J., Ratcliff, Ivan, Doed, L.W., and Bouse, E.F., 1996, Soil survey of Reno County, Kansas: U.S. Department of Agriculture, Soil Conservation Service, 72 p.

Schwab, G.O., Fausey, N.R., and Kopcak, D.E., 1980, Sediment and chemical content of agricultural drainage water: Transaction of the American Society of Agricultural Engineers, v. 23, no. 6, p. 1446-1559.

Schwarzenbach, R.P., Gschwend, P.M., and Imboden, D.M., 1993, Environmental organic chemistry: New York, John Wiley, 681 p.

Sine, Charlotte, ed., 1993, Farm chemical handbook 1993: Willoughby, Ohio, Meister Publishing Co., various pagination.

Smith, J.A., Harte, P.T., and Hardy, M.A., 1987, Trace-metal and organochlorine residues in sediments of the Upper Rockaway River, New Jersey: Bulletin of Environmental Contamination and Toxicology, v. 39, no. 3, p. 465-473.

Terry, R.V., Powers, W.L., Olson, R.V., Murphy, L.S., and Rubison, R.M., 1981, The effect of beef feedlot runoff on the nitrate-nitrogen content of a shallow aquifer: Journal of Environmental Quality, v. 10, no. 1, p. 22-26.

U.S. Environmental Protection Agency, 1989, Drinking water health advisory-pesticides: Chelsea, Michigan, Lewis Publishers, 819 p.

--- 1998, The incidence and severity of sediment contamination in surface waters of the United States, volume 1--national sediment survey: U.S. Environmental Protection Agency Report 823-R-97-006, various pagination.

Van Metre, P.C., Land, L.F., and Braun, C.L., 1996, Water-quality trends using sediment cores from White Rock Lake, Dallas, Texas: U.S. Geological Survey Fact Sheet FS-217-96, 4 p.

Wauchope, R.D., 1978, The pesticide content of surface water draining from agricultural fields--a review: Journal of Environmental Quality, v. 7, no. 4, p. 459-472.

Wendt, R.C., and Corey, R.B., 1980, Phosphorus variations in surface runoff from agricultural lands as a function of land use: Journal of Environmental Quality, v. 9, no. 1, p. 130-136.

Wilber, W.G., and Hunter, J.V., 1979, Distribution of metals in streat sweepings, stormwater solids, and urban aquatic sediments: Journal of the Water Pollution Control Federation, v. 51, no. 12, p. 2810-2822.

Zeller, D.E., ed., 1968, The stratigraphic succession in Kansas: Kansas Geological Survey Bulletin 189, 81 p.

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