The State Water Resources Control Board unanimously voted to adopt a maximum contaminant level (MCL) for a chemical known as 1,2,3-TCP in drinking water. The contaminant is a by product in pesticides and industrial degreasers. Almost 100 communities will be affected by the adoption of the new 5 parts per trillion MCL. Community Water Systems and Non-Transient/Non-Community Water are required to start monitoring for the contaminant in January 2018.