The ESA's Impact on Wastewater Treatment

Alexandra Dapolito Dunn
Association of Metropolitan Sewerage Agencies

In addition to meeting challenges such as total maximum daily loads, reducing combined and sanitary sewer overflows, and stemming discharges of nutrients and mercury, many publicly owned wastewater treatment works (POTWs) are adapting their operations to conserve plants and wildlife protected by the Endangered Species Act (ESA) of 1973. Continued suburban development and population growth are causing an increase in the number of potential conflicts between activities like wastewater treatment and various endangered species. This trend is not surprising, given that nearly half of the 515 animal species listed in the United States depend on aquatic systems (there are 19 amphibian species, 115 fish species, 70 clam species, and 21 crustacean species).

The following examples provide a snapshot of recent impacts that the ESA has, and will continue to have, on POTWs' past, present and future operations.

Effluent Temperature. For many years, several California POTWs have been chilling their effluent to ensure that it is discharged at the proper temperature for endangered steelhead salmon in the receiving waters. Environmental groups have raised similar issues with Portland, Oregon, POTWs and other dischargers, as they seek to effect cooling of the lower reaches of the Willamette and Columbia rivers to protect threatened trout.

Wastewater Discharge Diversion. POTWs in the Las Vegas, Nevada, Valley are evaluating whether a pipeline is needed to divert wastewater to other portions of Lake Mead to reduce impacts on endangered razorback sucker fish.

Advanced Wastewater Treatment. In early 2002, the City of Reno, Nevada and the Tahoe-Truckee Sanitation Agency agreed to construct a Biological Nutrient Removal (BNR) process for all existing plant capacity, and future increases of up to 9.6 million gallons a day. BNR will eliminate up to 7,000 pounds of total dissolved solids and 3,000 pounds of chlorides per day from their discharge, protecting the endangered cui-ui fish and the threatened lahontan cutthroat trout.

Innovative Wastewater Treatment Plant Design. When Kearney, Arizona, relocated its wastewater treatment plant following a 100-year flood, the town adapted its new facility to maintain endangered species habitat. The plant's design used closed holding tanks as opposed to open evaporation ponds. However, the town agreed to maintain some flow of clean water discharge from the new plant into a neighboring wetland, habitat of the southwestern willow flycatcher.

Storm Water Sediment Reduction. Some POTWs with storm water management responsibility are seeing early indications that they may need to reduce storm water sediment to avoid impacts on endangered fish. In addition, a POTW in Sonoma County, California, was required to control soil runoff from a wastewater treatment reservoir construction site, because the runoff washed into a wetland occupied by several endangered species.

Biosolids Management. Biosolids (sewage sludges) are treated, nutrient-rich organic solids removed during wastewater treatment and generally land applied as fertilizer. Where threatened or endangered species are present, the land application of biosolids is reviewed to ensure that there will be no adverse impact on protected populations. For example, in May 2000, the NMFS found that King County, Washington's, biosolids program complied with the ESA in relation to Puget Sound chinook salmon. Similarly, in authorizing the State of South Dakota to administer and enforce a biosolids management program, EPA determined, after Section 7 consultation, that the state's program was not likely to jeopardize the continued existence of any listed species or to adversely modify critical habitat. See 66 Fed. Reg. 64,978 (Dec. 17, 2001).

Habitat Conservation Planning. Several POTWs are intensively developing Habitat Conservation Plans (HCPs) under ESA Section 10. For example, as King County, Washington plans to upgrade its wastewater treatment system to meet increasing needs, the county is developing a HCP that focuses on reducing impacts to the habitat of listed and unlisted species, including the chinook salmon and bull trout. Typically, POTWs have addressed endangered species issues through the Section 7 consultation process. POTW development of HCPs marks a new development.

In addition, POTWs (and, in some cases, the cities in which the POTW is located) have been, and likely will continue to become, involved on the front end in litigation surrounding endangered species issues. For example, three Alaska municipalities intervened in a lawsuit concerning the NMFS' decision not to list the Cook Inlet Beluga Whale as endangered or threatened under the ESA. The municipalities were concerned that placing the whales on the list of endangered species would increase regulatory burdens on wastewater treatment with little beneficial effect on the whale population. See Cook Inlet Beluga Whale et al. v. Daley, 156 F. Supp.2d 16 (D.D.C. 2001); see also Southwestern Center for Biological Diversity v. Babbitt, 150 F.3d 1152 (9th Cir. 1998) (involving the southwestern willow flycatcher and the City of Phoenix, among other parties).

These are just a few examples of the challenges that are confronted when a threatened or endangered species, or critical habitat, are proximate to critical urban activities, such as wastewater treatment. POTWs, as local government stakeholders, are demonstrating that they have a stake in the outcome of these matters, and that they often are in a solid position to address endangered species issues in innovative ways.