Pennsylvania on January 14 published its final Maximum Contaminant Level (MCL) rule, setting limits of 14 parts per trillion (ppt) for PFOA and 18 ppt for PFOS in drinking water. The state is initially requiring quarterly monitoring for four consecutive calendar quarters at each entry point to the distribution system, beginning January 1, 2024 for public water systems serving more than 350 people and January 1, 2025 for community water systems and nontransient noncommunity water systems serving 350 or fewer people. Testing results will indicate whether the systems require repeat monitoring quarterly, annually, or triennially.
The MCL rule also establishes analytical requirements (including approved methods for analysis and minimum reporting limits) and approved treatment technologies (including granular activated carbon, ion exchange, and reverse osmosis), with the option of other treatment technologies as approved by the Pennsylvania Department of Environmental Protection if demonstrated to provide adequate and reliable quantities and qualities of water.
See more information on the MCL here.