Legislative And Regulatory History

Large-scale action was delayed by the need for cooperation throughout the basin to achieve significant improvements in water quality. In 1908, the Ohio state legislature adopted the Bense Act, which exempted every Ohio village and municipality from installing sewage treatment works until similar facilities were provided by all municipalities upstream from it. This attitude endured until 1924, when the Ohio River Valley Negotiating Committee reported an agreement between industries and state health commissioners to cooperate in carrying out a policy for the conservation of interstate streams. Congress authorized the states to negotiate the compact in 1936 and approved the resulting document in 1940. In June of 1948, the Federal Water Pollution Control Act (Public Law 80-845) was passed and the ORSANCO Compact was signed by Illinois, Indiana, Kentucky, New York, Ohio, Pennsylvania, Virginia, and

West Virginia, setting a precedent for cooperation among federal agencies, state governments, municipalities, and industries. Soon after, wastewater treatment standards were enacted for the Cincinnati pool. Bacterial quality objectives for the Ohio River were established in 1951, and an assessment of potential health hazards from trace constituents in wastewater was initiated. By 1954, municipal wastewater treatment standards for the Ohio River had been established. In relation to the industrial dischargers, a resolution adopted in 1959 placed responsibility on industries for reporting spills and accidental discharges to state agencies.

Following the 1965 Federal Water Quality Act, ORSANCO adopted stream water quality recommendations. In 1970, ORSANCO Pollution Control Standard 1-70 revised the pollution control standards established in 1954, making secondary treatment the minimum requirement for wastewater treatment plants and establishing equivalent treatment requirements for industry. From 1957 to 1965, $82,786,500 in federal aid was allocated to 638 projects in the Ohio Valley. The communities matched every federal dollar with $2.50 of local funds for a total of $282,966,000 spent on improving conditions. The majority of treatment works, both in place and under construction during this time, were equipped for secondary treatment. For 3 years before federal aid was offered, Pennsylvania provided incentives for smaller communities to upgrade their treatment by offering funds to communities upon compliance with standards. Although the population served by municipal facilities has increased greatly under these programs (Figure 11-6), increasingly high water quality criteria and limited funds have caused a sharp increase in population served by facilities classified as inadequate between 1965 and 1990.

Figure 11-6 Long-term trends in population served by municipal wastewater treatment plants in the ORSANCO District. Sources: ORSANCO, 1978, 1988.

IMPACTS OF WASTEWATER TREATMENT Pollutant Loading and Water Quality Trends

Following the 1948 advances in cooperative management, water quality conditions in the Ohio River began to improve. A dramatic decrease occurred in the discharge of raw sewage from 1950 to 1963 (Figure 11-6). As a result of the stringent permit requirements on dischargers and improvements in wastewater treatment facilities implemented in the late 1960s and 1970s, even more advances have been made to upgrade wastewater treatment plants. Levels of BOD5 effluent loading have decreased significantly, even as the influent loading continues to increase as population increases (Figure 11-7). Corresponding to the decreasing levels of pollutant loading is the increased amount of DO available to support aquatic organisms. Figure 11-8 shows the typical oxygen sag curve observed during the mid-1960s downstream from Cincinnati, Ohio, while Figures 11-9, 11-10, and 11-11 indicate long-term trends of DO at various sampling locations. These data clearly illustrate an overall increase in oxygen following the 1972 CWA requirement for secondary treatment. A remarkable improvement in oxygen concentration occurs in the critical minimum occurring near North Bend/Fort Miami (River Mile 490) and at the pool formed by Markland Lock/Dam (River Mile 449-453). During the 1988 drought, for example, levels of DO continued to meet standards near Cincinnati and Louisville, in contrast to the mid-1960s when consistent low-flow conditions resulted in DO concentrations below water quality standards (see Figures 11-9 and 11-13). Using the data compiled for

-A- Flow Q^l Effluent BOD5

Figure 11-7 Long-term trends of wastewater flow, influent and effluent BOD5 for the ORSANCO District. Data based on population served with 165 gallons per person per day, influent BOD5 of 215 mg/L, and removal efficiencies of 36 percent (primary), 85 percent (secondary), and 95 percent (tertiary). Sources: ORSANCO, 1978, 1987.

-A- Flow Q^l Effluent BOD5

Figure 11-7 Long-term trends of wastewater flow, influent and effluent BOD5 for the ORSANCO District. Data based on population served with 165 gallons per person per day, influent BOD5 of 215 mg/L, and removal efficiencies of 36 percent (primary), 85 percent (secondary), and 95 percent (tertiary). Sources: ORSANCO, 1978, 1987.

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