This Technical Brief summarizes the information that is currently available from scientific research on Endocrine Disrupting Compounds (EDCs), sometimes known as hormonally active agents. It was prepared in response to concerns over the potential for EDCs to enter the environment in treated wastewater and reuse of biosolids. This document provides a primer on the endocrine system, the nature and sources of EDCs, and their potential effects on human health and the environment. The potential for man-made chemicals to cause endocrine disrupting effects came to light as early as the 1960s. The...

Enhanced biological phosphorus removal (EBPR) has been used for decades to remove phosphorus from municipal wastewater because it allows facilities to meet water quality goals while minimizing chemical consumption and sludge production. However, there is still substantial variability in both the practices applied to achieve EBPR and the level of soluble phosphorus removal achieved. The objective of this research project was to develop information that can be used to help municipal wastewater treatment plants more efficiently and cost effectively remove phosphorus through EBPR processes. This...

Integrated water resource management has been discussed since at least the Civil War; yet, there is still no integrated framework for sustainably managing water. Recognizing this need, the Water Environment Research Foundation (WERF) funded a research project to develop an integrated, conceptual framework for sustainable water resources management. Through WERF funding, this framework was developed over the past four years. Development of the framework was guided by the U.N. Agenda 21, Global Water Partnership, the Enlibra Principles, and Panarchy Theory. The conceptual framework for...

Anaerobic biological treatment systems can offer a number of advantages over their aerobic counterparts. The operational costs associated with anaerobic systems are typically lower than with aerobic systems, and anaerobic systems also generate less waste sludge. In addition, the energy associated with the biogas produced during anaerobic biological treatment can potentially be recovered. However, to date, the use of conventional anaerobic biological systems for the treatment of dilute wastewaters has been relatively limited. The present study was designed to address this current knowledge...

The drinking water and wastewater industries are interested in developing a better understanding of sources of fecal contamination. Microbial source tracking (MST) offers the potential to apportion the contribution of various animal groups to this contamination. However, while there are many methods available there is no clear indication as to the most appropriate approach. There has been little systematic comparison of methods and only a few blind trials, and issues of reproducibility, accuracy, sensitivity, specificity, resolution, and robustness need to be addressed. There is confusion...

Successful operation of the activated sludge process relies heavily on the ability to effectively separate mixed liquor into return activated sludge (RAS) and a high quality final effluent. Solids separation efficiency is dictated in large part by the relative population of floc-forming and filamentous microorganisms present in the activated sludge. During normal operation, mixed liquor will be composed primarily of floc-formers with relatively low levels of filamentous organisms. Some population of filamentous organisms is necessary to promote the formation of larger flocs and prevent...

With increasing water demands, the impetus to use treated wastewater to augment nonpotable and potable water supplies is growing. There is also increasing concern that recycled wastewater might contain contaminants harmful to human health or the aquatic environment. Contaminants of concern include endocrine disrupting compounds (EDCs), compounds that can interfere with the proper functioning of hormone systems.
The goal of this research was to develop approaches combining bioassays with chemical analysis to study removal of EDCs by different reclamation treatment process. Hydraulic...

A key step in the development of Total Maximum Daily Load (TMDL) allocations for water bodies impaired due to sediment toxicity is the identification of chemicals responsible for toxicity. Sediment toxicity identification evaluation procedures (TIEs) are one of the primary tools used in this process.
This project evaluated standardized and recently developed sediment TIE methods developed by the US EPA and others, to determine their utility for identifying chemicals responsible for toxicity. In this study, formulated sediments were spiked with five chemicals: copper, fluoranthene,...

This project evaluated the quality of data needed to determine relationships between chronic Whole Effluent Toxicity (WET) test results and in-stream biological condition. A data quality objectives approach was used, which included several proposed measurement quality objectives (MQOs) that specified desired precision, bias, and sensitivity of methods used. Six facilities (four eastern and two western U.S.) participated in this study, all having design effluent concentrations > 60% of the stream flow. In accordance with a Quality Assurance Project Plan most of the facilities completed four...

Municipal wastewater treatment facilities were not specifically designed to remove xenobiotics such as endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care products (PPCPs). European studies have described the need for a minimum critical SRT to achieve good removal of EDCs and pharmaceuticals. These studies have presented limited data on PPCPs from full-scale facilities.
The objective of this study was to expand published findings to the removal of twenty PPCPs commonly found in the influent of full-scale treatment facilities operating in the United States. The six...