Calgon Carbon and California Water Service (Cal Water) have signed a system supply contract worth $13.2m to treat contaminated drinking water wells.

Under the contract, Calgon Carbon will provide granular activated carbon and related equipment systems to treat more than 30 drinking water wells contaminated with 1,2,3-Trichloropropane (1,2,3-TCP).

The contract, which starts in 2017, is the largest drinking water-related carbon adsorption equipment project in Company history.

Under the terms of the contract, Calgon Carbon will supply 104 GAC adsorption vessels and over 2 million pounds of Filtrasorb 400 GAC to treat more than 40 million gallons of water per day at 38 of Cal Water’s well sites. The GAC adsorption equipment will be installed in stages, with all of the equipment expected to be in service by June 2018. Both the activated carbon and vessels will be manufactured in the United States.

GAC removes 1,2,3-TCP from water through a process called adsorption. The California Division of Drinking Water expects that GAC will be named as the best available technology (BAT) in the new TCP regulation.

1,2,3–TCP is a manmade, colorless, chlorinated hydrocarbon that was found in soil fumigants commonly used in California prior to the 1990s. 1,2,3-TCP causes cancer in laboratory animals (U.S. EPA, 2009). In 1992, the state of California added 1,2,3-TCP to the list of chemicals known to the state to cause cancer, pursuant to California’s Safe Drinking Water and Toxic Enforcement Act.

The compound is currently not regulated by the U.S. EPA, although it is on the Contaminant Candidate List 4 for future regulation. On March 3, 2017, the California State Water Resources Control Board proposed a draft maximum contaminant level (MCL) for 1,2,3-TCP of 5 parts per trillion.

“Calgon Carbon has provided hundreds of GAC adsorption systems over the last thirty years to numerous water providers, and we are honored to have been selected by Cal Water to be its granular activated carbon and equipment supplier for this important project,” said Nora Stockhausen, VP of the Municipal and Reactivation Business Unit.

“With 1,2,3-TCP detected in many drinking water sources in California, Calgon Carbon is excited to be part of a solution that will provide so many public water systems with TCP-free drinking water,” said James Coccagno, Executive Vice President of the Core Carbon and Services Division.

“While the standard for TCP has not been finalized in California, we intend to be fully prepared to meet any MCL ultimately set, because protecting our customers’ health and safety is our highest priority,” said Martin A. Kropelnicki, Cal Water President and CEO. “We are pleased to be partnering with Calgon Carbon, a leader in carbon treatment technologies, which will be instrumental in helping us comply with the new standard as quickly as possible.”

Cal Water is the largest subsidiary of the California Water Service Group, which also includes Washington Water Service Company, New Mexico Water Service Company, Hawaii Water Service Company, HWS Utility Services, and CWS Utility Services.

California Water Service Group is the largest investor-owned American water utility west of the Mississippi River and the third largest publicly traded in the country. Its San Jose-based subsidiary, Cal Water, was formed in 1926 and serves more than 480,300 customers through 28 Customer and Operations Centers throughout California. As a whole, the Group provides high-quality regulated and non-regulated utility services to approximately 2 million people in 100 communities.