Recently the U.S. Environmental Protection Agency completed its biennial review of the 503C regulations that provide oversight to the regulation and use of biosolids in the United States. The review is mandated by statutory requirements under the Clean Water Act (Section 405(d)(2)(C)). As required, the EPA reviews federal biosolids standards to identify additional toxic pollutants that occur in biosolids and set regulations for those pollutants if sufficient scientific evidence shows they may harm human health or the environment. EPA recently published the 2013 and 2015 Biosolids Biennial reviews.
EPA uses models that require the following information:
- Human health and ecological toxicity values (e.g., studies that are adequate for evaluating hazards following acute or chronic exposure);
- Adequate data on pollutant concentrations in U.S. biosolids based on a suitable analytical methodology for detecting and quantifying pollutant concentrations (data are considered adequate when sufficient details are provided regarding sampling, handling, and analysis); and
- Fate and transport data for these pollutants. The Agency assesses whether data for pollutants are sufficient to conduct human health and ecological risk assessments, and revisits previously identified pollutants when literature searches of bibliographic databases reveal newer data.
For the 2013 review, the EPA concluded that the available data for many of the chemicals and microbial pollutants identified are not sufficient to evaluate risk using current biosolids modeling tools. However, EPA is closely collaborating on scientific and regulatory issues related to triclosan and ensure regulatory consistency. EPA did not identify any pollutants for additional regulation in either the 2013 or 2015 biennial review, however review and assessment of pollutants is continuing pursuant to the Clean Water Act.
Details of the Biennial Reviews can be found by accessing the EPA website here.