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Hexavalent Chromium Compliance Plan and Updates - October 2017

2017 October Update

In July of 2014, the State Water Resources Control Board (State) adopted a new Maximum Contaminant Level (MCL) of 10 parts per billion (ppb) for hexavalent chromium (Cr6) in drinking water.  Hexavalent chromium occurs naturally in the ground water of the Santa Ynez Upland Basin as well as in many other ground water basins throughout California.  When the new MCL was set, the District found hexavalent chromium near or in some cases, above this new MCL in some of the District’s water supply wells.  Any wells that exceeded the new MCL were shut off and remained out of service.  District compliance with this new MCL was progressing on schedule with the Compliance Plan submitted in accordance with SB 385 that allowed water systems time to plan for and achieve compliance by January of 2020.

However, on May 5, 2017, a Superior Court judge ruled that, in establishing the new standard, the State failed to adequately assess the economic feasibility of complying with the new MCL.  The judge invalidated the 10 ppb MCL and ordered the State to establish a new Cr6 MCL.  The order also requires the State to establish a new MCL for Cr6 following an adequate economic feasibility analysis. In the meantime, the State’s MCL of 50 ppb for Total Chromium remains in place.

While postponing work on the mitigation of Cr6 in our water supply, the District continues to monitor the progress of the State in establishing a new MCL.  When the new MCL is established, the District will resume work to assure compliance with the new regulation.

For more information, please visit the following link to the State Water Resources Control Board website:

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