The U.S. Environmental Protection Agency’s Office of Pollution Prevention and Toxics (EPA/OPPT) assesses approximately 1,000 new chemicals per year under the Toxic Substances Control Act (TSCA; amended by the Lautenberg Chemical Safety Act), but does not routinely receive measured data on endpoints including fate and transport, environmental partitioning, or general population and worker exposure. One of the most important endpoints for fate assessment is wastewater removal rate estimate. It directly affects the level of exposure and hence, the risk estimate of the chemical in receiving water, soil, sediments and biosolids. The fate assessors in the New Chemicals program assign wastewater removal rate for each chemical submitted based on one or more methods: models, published articles, or fate test results submitted by companies. EPA models, including the Sewage Treatment Plant Model (STP Model) in EPA’s Estimation Programs Interface (EPI) Suite™ are commonly used to derive WWTP removal estimates. The model uses physical-chemical properties measured for the chemical or derived from chemical structure and activated sludge half-lives, if known. For metals, published data of measured removal rates are generally used. When data gaps critical to the estimation of removal in wastewater treatment plants are identified, EPA may recommend or require tests, using OECD or EPA guideline methods, of physical--chemical properties and fate properties to achieve better estimates for the removal of a chemical in WWTP. This presentation will discuss current approaches, data gaps and challenges to estimating the removal of untested chemicals during wastewater treatment. Disclaimer: The views expressed in this abstract are those of the authors and do not represent Agency policy or endorsement.

Models, guidelines and references for wastewater removal rate assessments in the U.S. EPA TSCA New Chemicals Program

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.