Legislative And Regulatory History

After more than a decade of public concern about the polluted conditions of the Willamette River, the citizens of Oregon passed a referendum in 1938 setting water quality standards and establishing the Oregon State Sanitary Authority. With the establishment of the Sanitary Authority, it became Oregon's public policy to restore and maintain the natural purity of all public waters. As a result of regulatory actions by the Sanitary Authority, all municipalities discharging into the Willamette implemented primary treatment during the period from 1949 to 1957, with all costs borne by the municipalities. Beginning in 1952, industrial waste discharges from the pulp and paper mills were controlled by required lagoon diversions during summer months. In 1953, the new U.S. Army Corps of Engineers dams began to operate, resulting in augmentation of the natural summer low flow. Although not originally planned for water quality management, summer reservoir releases have become a significant factor in maintaining water quality and enabling salmon migration during the fall.

Although tremendous accomplishments had been made in controlling water pollution in the Willamette basin, large increases in industrial production and in the population served by municipal wastewater plants exceeded the assimilative capacity of the river. By 1960, the Sanitary Authority required that all municipalities discharging to the Willamette River achieve a minimum of secondary treatment (85 percent removal of BOD5). In 1964, the pulp and paper mills were directed to implement primary treatment, with secondary treatment during the summer months. In 1967, industrial secondary treatment was required on a year-round basis. The Sanitary Authority had thus established a minimum policy of secondary treatment for all municipal and industrial waste dischargers with the option of requiring tertiary treatment if needed to maintain water quality. The state initiated the issuance of discharge permits for wastewater plants in 1968, 4 years before the 1972 CWA established the National Pollutant Discharge Elimination System (NPDES). The policy adopted in 1967 remains the current water pollution control policy of the state of Oregon for the Willamette River (ODEQ, 1970).

In response to the 1965 Federal Water Quality Act, Oregon established intrastate and interstate water quality standards in 1967 that were among the first new state water quality standards to be approved by the federal government. The 1972 CWA provided even further authority for Oregon to issue discharge permits limiting the pollutant loading from municipal and industrial facilities.

From 1956 to 1972, Federal Construction Grants to Oregon totaled $33.4 million for municipal wastewater facilities (CEQ, 1973). Since 1974, the cities of Salem, Corvallis, and Portland have received Construction Grants under the 1972 CWA to build and upgrade secondary wastewater treatment facilities.

IMPACTS OF WASTEWATER TREATMENT Pollutant Loading and Water Quality Trends

As a result of the stringent regulatory requirements for municipal and industrial wastewater treatment, total pollutant loading has decreased substantially over the past 30-40 years (Figure 13-6), while total wastewater flow has increased over the same period. By 1972, when the CWA was passed, the total oxygen demand of wastewater discharges to the Willamette had been decreased to 25 percent of the demand of the pollutant load discharged in 1957 (CEQ, 1973). Following the implementation of basinwide secondary treatment for municipal and industrial wastewater sources, water quality model budgets have shown that about 46 percent of the oxygen demand in the Willamette River during the critical summer months results from upstream nonpoint source loads from rural tributary basins. The remaining half of the total oxygen demand is accounted for by municipal (22 percent) and industrial (32 percent) point source loads (Rickert and Hines, 1978).

Severe summer oxygen depletion has been the key historical water quality problem in the Willamette River. Since the 1970s, however, summer oxygen levels have increased significantly as a result of: (1) the implementation of basinwide secondary treatment for municipal and industrial point sources, and (2) low-flow augmentation from reservoir releases. Based on data obtained from the earliest water quality survey in 1929 to the most recently available monitoring programs, the dramatic improvements in summer oxygen levels in the river are clearly shown in the spatial distribution of oxygen from Salem to Portland Harbor (Figure 13-7) and the long-term historical trend for oxygen in the Lower Willamette River near Portland Harbor (Figure 13-8). These historical data sets document the grossly polluted water quality condi-

Figure 13-6 Long-term trends in municipal and industrial effluent BOD5 loading to the Willamette River. Sources: Gleeson, 1972; ODEQ, 1970; Bondelid et al., 2000.

Figure 13-6 Long-term trends in municipal and industrial effluent BOD5 loading to the Willamette River. Sources: Gleeson, 1972; ODEQ, 1970; Bondelid et al., 2000.

Figure 13-7 Long-term trends in the spatial distribution of DO in the Willamette River. Source: Reprinted with permission from D. A. Rickert and W. G. Hines, River quality assessment: Implications of a prototype project, Science 200 (June 9, 1978): 1113-1118, Copyright © 1978 American Association for the Advancement of Science.

Figure 13-7 Long-term trends in the spatial distribution of DO in the Willamette River. Source: Reprinted with permission from D. A. Rickert and W. G. Hines, River quality assessment: Implications of a prototype project, Science 200 (June 9, 1978): 1113-1118, Copyright © 1978 American Association for the Advancement of Science.

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1940 1950 1960 1970 1980 1990

Portland - Milwaukie OR (Mile 0-15.7)

Figure 13-8 Long-term trends in summer DO in the Lower Willamette River at Portland, OR, for RF1 reach 17090012017 (River Mile 0-15.7). Source: USEPA STORET.

tions that existed prior to implementation of a minimum level of secondary treatment for municipal and industrial discharges to the river.

Although the current status of the river is visibly much improved and water contact sports and salmon migration are once again possible in most of the river, there are still concerns about the levels of toxic contamination. Oregon's 1990 water quality status assessment report (ODEQ, 1990a) classified the river as "water quality limited" as a result of seven contaminants exceeding USEPA draft sediment guidelines (arsenic, chromium, lead, zinc, and DDT), state water quality standards (arsenic), or both (2,3,7,8-TCDD). Surveys have found levels of toxic chemicals in water, sediments, and fish tissue at various locations in the river basin (ODEQ, 1994). Surveys conducted by ODEQ in 1994 indicated that levels of metals (arsenic, barium, cadmium, chromium, copper, lead, mercury, nickel, silver, and zinc), pesticides (chlordane and DDT), other organic chemicals (carbon tetrachloride, creosote, dichloro-ethylene, dioxin, PAHs, PCBs, phenol, pentachlorophenol, phenanthrene, phthalates, trichloroethane, trichloroethylene, and trichlorophenol), and bacteria exceed regulatory or guidance criteria for the protection of aquatic life and human health in at least one location of the river.

As a result of these findings, in 1990, the Oregon legislature directed ODEQ to develop a comprehensive study that would generate a technical and regulatory understanding and an information base on the river system that could be used to protect and enhance its water quality. To meet this directive, ODEQ developed and implemented a comprehensive, multiphase investigation known as the Willamette River Basin Water Quality Study (WRBWQS) (ODEQ, 1990b; Tetra Tech, 1995).

Recreational and Living Resources Trends

The first comprehensive study of the Willamette River biota was conducted by Dim-ick and Merryfield (1945) in the summer of 1944. Their study was specifically intended to assess the impact of water pollution on fish and benthic invertebrates in the river. Benthos are particularly good indicators of long-term trends in water quality because most benthic species are sedentary and have long life spans. Their state of health is therefore a gauge of both past and present water quality. Reactions to even occasional toxic discharges are measurable as variances in the species assemblages of benthic invertebrates. For pollution studies, benthos are divided into three categories: (1) intolerant species (e.g., stoneflies, mayflies, caddisflies) are indicative of good water quality because of their inability to survive in or tolerate low DO concentrations; (2) facultative species are indicative of a transition between good and poor water quality because they can survive under a wide range of DO conditions; and (3) tolerant species (e.g., sludgeworms), which are adapted to low DO levels, become dominant where poor water quality is prevalent.

Dimick and Merryfield (1945) found very different biological conditions in different stretches of the river. Upstream of Salem, where pollutant sources to the river were few, they found an abundance of healthy fish and populations of intolerant cad-disfly, mayfly, and stonefly nymphs (Figure 13-9). Downstream of Salem to Portland, where pollutant loadings to the river were greatest, they found few to no fish, dead

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