As of December 14, 2017, the California Maximum Contaminant Level (MCL) for 1,2,3-Trichloropropane (1,2,3-TCP) in drinking water is 0.000005 mg/L (five parts per trillion). Pursuant to California Code of Regulations, Title 22, Section 64445, water systems must initiate quarterly monitoring for 1,2,3-TCP in the calendar quarter beginning January 2018. In addition to being certified by ELAP to perform these methods, Babcock Laboratories also has 15 years of experience with these methods under UCMR.