The Use of Stream Sediments to Infer Water Quality on a Stream in Northwestern Ohio

A primary sewage treatment plant discharges its effluents into Butler Ditch, Oak Openings, Lucas County, Ohio. A marsh habitat near the discharge outlet, high turbidity, sludge covering the stream bed and pungent odor gave reason to believe that the effluent from the sewage treatment plant contaminated the ditch. Water and stream sediment samples were collected from 24 sample locations over a 2 mile stretch downstream from the discharge outlet of the sewage treatment plant and analyzed for chemical composition. At the time of sample collection, the sewage treatment plant had discharged its effluents into the ditch for a period of 2 years. The water and the —80 mesh fraction of the sediment samples were analyzed for mineral content, the chemical components, alkalinity, hardness, total dissolved solids, specific conductance, pH, cation exhange capacity and mineralogy of the sediments. The tests showed that there was a cutoff point 450 ft downstream from the effluent outlet, where most of the element concentrations dropped abruptly, except sedimentary iron, which increased. Heavy vegetation retarded the flow of water, resulting in a more anaerobic environment upstream. Precipitation of many ions increased downstream probably as a result of increased oxygenation of the water. The use of sediment chemistry proved advantageous to infer the long term quality of the stream water. OHIOJ. SCI. 81(6): 247, 1981 In the summer of 1974, water and stream sediment samples from Butler Ditch in Oak Openings, northwestern Ohio, were collected and analyzed for a number of chemical elements and compounds. The purpose of this study was to determine the impact of the effluent from a sewage treatment plant on the ditch that receives its inflow mainly from effluent during the summer. Both water and stream sediment chemistry were analyzed because the water chemistry only assesses the effluent impact at time of sampling, while the stream sediment geochemistry gives a cumulative assessment of the pollution. If samples can be collected only once, and speed is important, this seems to be a good method to study stream pollution. Water was analyzed by the usual techniques, while stream sediments were subjected to cold hydrochloric acid extraction. Fortescue et al (1971) first used this technique in studies of landscape geochemistry. Manuscript received 13 June 1980 and in revised form 15 October 1980 (#80-33). Exploration geochemists use similar techniques because in their studies a fast and inexpensive approach is necessary and adequate. Alther (1975) used stream sediments successfully to determine the impact from the runoff of a pigyard on the stream environment. LOCATION AND DESCRIPTION OF OAK OPENINGS Oak Openings town, an unincorporated area, is located approximately 14 miles west of Toledo, Ohio, in Lucas County, Spencer Township. Oak Openings is a narrow sand belt extending from Detroit, Michigan to Maumee, Ohio and is 5 to 10 miles wide near the community with the crest of the belt roughly bisecting the area. Low hummocky dunes stabilized by vegetation characterize the land surface. All ditches in the area are man made and receive mostly ground water. Precipitation readily infiltrates into the sandy soil. Many of the ditches, including Butler Ditch, are ephemeral and experience high winter and spring floods.