Presentation Abstract

Wastewater Treatment Plant Perspectives: Preliminary Data Suggesting Endocrine Disruptor Effects of Wastewater Discharge into the Pacific Ocean
Jeffrey L. Armstrong
Orange County Sanitation District, Fountain Valley, CA

The presence and effect of endocrine disrupting chemicals (EDCs) in the environment has become a major focus of scientific research and public concern. Research conducted in the United Kingdom and elsewhere has shown that the release of wastewater (municipal and industrial) is a source of EDCs that can adversely affect fish populations. The Orange County Sanitation District (sanitation district) is a publicly owned treatment works (POTW) that serves 2.3 million residents and almost 1,000 permitted industries in a service area of 470 square miles. The sanitation district treats an average of 243 million gallons per day, most of which is discharged through a submarine outfall pipe extending 8 km offshore of Huntington Beach, California. In 1999, the sanitation district began collaborating with local university researchers and others to determine if the release of the treated wastewater was eliciting an endocrine response in flatfish in the monitoring area. This was assessed using a suite of biomarkers and tests, including vitellogenin (vtg) induction, cortisol stress response, CYP1A induction, and DNA damage. Population- and community-level effects were assessed using diversity indices, such as species richness, total abundance, Shannon-Wiener Diversity, and species evenness. The initial approach was to facilitate the work of university researchers, who had the expertise that sanitation district staff lacked, to begin to address the EDC issue. The sanitation district provided scientific staff time and in-kind services, such as vessel use and field crew time for sample collection; provided some supplies; and paid page costs for journal publication of results. Demersal flatfish species were used as target organisms because of their life history characteristics (mode of feeding and site fidelity). The findings of the studies to date have found elevated levels of vtg in both male and female fish at the outfall compared to farfield reference stations, the inhibition of cortisol induction in fish collected at the outfall compared to reference stations, and greater concentrations of EDCs in sediment collected near the outfall compared to stations away from the outfall. The results of the pilot projects indicate that endocrine function is compromised in fish collected near the outfall as measured by estrogenic activity and stress responses. There is no indication, however, of population-level effects at this time. In fact, the population of hornyhead turbot (Pleuronichthys verticalis) near the outfall is slightly masculinized, even though males have high vtg levels. In addition to researching potential environmental degradation, the sanitation district also is focused on studying the potential for human health effects that could result from water reuse projects. Based on the results of these pilot projects, subsequent studies are narrowing the focus of endpoints and attention is moving into the treatment plant and to attempt cause-effect relationships with specific responses and chemicals. To better address these issues, the sanitation district is increasing the level of effort both internally and in its collaborations with university researchers and other POTWs. Presently, the sanitation district is entering multi-year, multi-agency projects to better characterize the effect from the release of treated wastewater effluent into coastal southern California waters.

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