Research Helps Ensure High-Quality Louisville Pure Tap®

image of woman in water labLouisville Water’s core mission is based on public health and safety. Every day, nearly one million people depend on us for high-quality and reliable drinking water.

The Environmental Protection Agency (EPA) regulates public water providers using regulations developed under the Safe Drinking Water Act. Research on the occurrence and potential public health effects of various chemicals helps EPA decide which chemicals to regulate and at what levels to ensure high-quality, safe drinking water. Louisville Water conducts required monitoring and independent research and works with other utilities and national organizations to advance the science of drinking water treatment, improve our processes, and prepare for new, more stringent regulations.

On August 17, the EPA released initial monitoring results for research into a group of 30 chemicals that are not currently regulated. Louisville Water is one of more than 10,000 public water systems participating in this effort. Called the “Fifth Unregulated Contaminant Monitoring Rule,” or UCMR 5, this EPA mandate requires utilities to sample for the presence of 29 PFAS chemicals and one metal, lithium, in drinking water. UCMR 5 provides data that helps EPA and utilities understand the occurrence of the chemicals in drinking water, including the concentration and frequency. This data is part of science-based decisions for possible future regulation.

Under UCMR 5, utilities are required to monitor for the target chemicals and report their findings to the EPA during a 12-month period between January 2023 and December 2025. EPA then publishes the monitoring results quarterly. The EPA has released a limited set of monitoring results from seven percent of the public water systems participating in UCMR 5.

Lab tech checking water samplesLouisville Water has completed 3 of the 4 rounds of quarterly UCMR 5 monitoring. Samples are analyzed by our contract laboratory and reported to EPA before they are reviewed and published. We have received results from two rounds of monitoring and all results are below the method reporting limits established by EPA.

The UCMR 5 target chemicals include a group of six PFAS chemicals that EPA has proposed to regulate. EPA plans to finalize the PFAS rule by early 2024. Louisville Water’s own research shows levels of PFAS that are below the proposed regulation but we continue to research how to further reduce the presence of these chemicals in our drinking water through advanced treatment options. PFAS are manufactured chemicals that do not naturally occur. Louisville Water also supports efforts to minimize the risk of these chemicals getting into the environment. Learn more about PFAS and water quality here.

Beyond UCMR 5, Louisville Water conducts hundreds of tests daily to ensure safe drinking water and each year we share the Annual Water Quality Report with our community. Louisville Water meets all state and federal regulations for water quality; the report also details the testing we do and explains the water treatment process.