EPA releases guidance on implementing the 2018 recommended Aquatic Life Water Quality Criteria for Aluminum

Nearly one year after the publication of the 2018 Final Aquatic Life Ambient Water Quality Criteria for Aluminum, the EPA has released criteria implementation recommendations via the Draft Technical Support Document: Implementing the 2018 Recommended Aquatic Life Water Quality Criteria for Aluminum. The 2018 criteria are based on multiple linear regression models developed to characterize aluminum toxicity in aquatic systems using pH, total hardness, and dissolved organic carbon. As such, criteria are site-specific and based on local values for these parameters, which EPA considers to be the most influential variables for aluminum bioavailability and accounts for the range of differences in the observed aluminum toxicity values.

NCASI Corporate Correspondent Memorandum No. 19-008 provides an overview of the implementation guidance, its background and implications. This information will be of interest to all mills holding NPDES permits. Staff at mills located on streams where minimal dilution of treated effluents is available, where aluminum salts are used in mill or water treatment processes, and those whose permits include limits for aluminum or other metals will be particularly interested.