1,2,3-Trichloropropane (TCP), is an unregulated organic chemical that the State Water Resources Control Board (“SWRCB”) and its Division of Drinking Water have been studying for regulation for several years. In late 2017, the SWRCB approved a maximum containment level (MCL) for TCP of 5 parts per trillion, with compliance monitoring scheduled to commence in January 2018. This fast-track project was required for the City to meet TCP MCL compliance. The City identified 34 well sites that needed treatment with granulated activated carbon (GAC) and W. M. Lyles Co. (WML) was contracted under a progressive design-build agreement for engineering and construction services. WML provided the procurement, installation, carbon loading, and start-up and commissioning of 104 owner-furnished GAC vessels, which expeditiously brought all 34 well sites into full and complete TCP MCL compliance. Provost & Pritchard was engaged to perform engineering and construction management. Construction also included site grading and earthwork, mechanical piping, concrete foundations, backwash tanks and offsite piping.