Chromium-6 is a naturally occurring mineral found in rock formations in the City of Banning and throughout California.  In July 2014, the State of California adopted a new Maximum Contaminant Load (MCL) for Chromium-6 which has been set at 10 parts per billion (ppb). One part per billion is typically described as a drop in an Olympic-size swimming pool. The previous limit was 50 ppb. The Federal standard for total Chromium is currently set at 100 ppb. 

However, in May 2017, a California Superior Court judge ruled that the State Water Resources Control Board (SWRCB) must withdraw the 10 ppb Chromium-6 standard and that it must be reevaluated based on economic feasibility. On August 1, 2017, the SWRCB voted to remove the 10 ppb standard and revert back to the previous 50 ppb standard. A news release regarding this action can be viewed here: https://www.waterboards.ca.gov/press_room/press_releases/2017/pr080117_mcl_removal.pdf

Based on this development, the City of Banning currently meets the State’s standards for Chromium-6 in its drinking water.

The SWRCB was previously allowing public water systems until January 1, 2020 to come into compliance with the 10 ppb standard and the City had been working diligently to find a treatment solution that was both efficient and fiscally responsible. The City’s water currently meets all Federal and State drinking water standards, and can be used for drinking, cooking, and all other needs without any additional treatment during the compliance process. 

The City is carefully monitoring the developments regarding this issue and will provide updates if there are any future changes to the State’s MCL standard.

Historical Documents

Chromium-6 Running Annual Averages for Individual Wells 2016-2017

Chromium-6 Public Notice 2-1-2017 (English)

Chromium-6 Public Notice 2-1-2017 (Spanish)

Chromium-6 Running Annual Averages for Individual Wells 2015-2016

Chromium 6 Public Notice 8-22-2016

2016 Chromium 6 Study

2015 Chromium 6 Information and Regulations