Publications

EPA uses the Unregulated Contaminant Monitoring Rule (UCMR) program to collect nationally representative data for contaminants suspected to be present in drinking water, but that do not have regulatory standards. UCMR 4 requires monitoring for 30 chemicals between 2018 and 2020.

A study just published in the journal ‘Lake and Reservoir Management’ is the first to report “airborne anatoxin-a (ATX) collected outside an aquatic ecosystem.” In addition to potential recreational exposure and in association with irrigation systems, this could theoretically have implications for drinking water treatment.

This guideline technical document outlines the evaluation of the available information on 4-chloro-2-methylphenoxyacetic acid (MCPA) with the intent of updating the guidelines for MCPA in drinking water. The purpose of this consultation is to solicit comments on the proposed guidelines, on the approach used for its development, and on the potential impacts of implementing it.

Briefly, it presents the current state of knowledge on cyanobacteria and cyanotoxins, and from a drinking water treatment perspective it provides guidance for monitoring and controlling risks in source water and at intakes.

There are changes from the 1998 guideline, which it replaces, and from the August 30 2019 proposed values when it was posted for comment. The new “maximum acceptable concentration (MAC) for total aluminum in drinking water is 2.9 mg/L (2,900 µg/L) based on a locational running annual average of a minimum of quarterly samples taken in the distribution system.