Chromium-6

On Oct. 25, 2016, the CVWD Board of Directors temporarily stopped construction of chromium-6 treatment facilities and approved launching a pilot study to evaluate the feasibility and effectiveness of an alternative process using test equipment installed at a CVWD well. This was followed by two months of laboratory testing on water from another well. In May 2017, test results showed that the alternative treatment technology successfully reduced chromium-6. This promising new option uses stannous chloride, an approved drinking water and food additive. 

The State approved CVWD’s plan for a full-scale demonstration project using stannous chloride treatment for the water system serving Indio Hills, Sky Valley and some areas in and around Desert Hot Springs. The demonstration project is scheduled to begin in August 2017 and results are expected before the end of the year.

If this alternative treatment proves to be a viable solution, CVWD expects to meet the State’s chromium-6 drinking water standard by the Jan. 1, 2020, deadline. The stannous chloride treatment option is substantially less expensive and has less impact to the community and the environment than other methods.

Chromium-6 Demonstration Project

Pilot Testing an Alternative Treatment Process PowerPoint 10/25/2016

Background information 

As far back as 2012, CVWD started evaluating possible treatment options to ensure that CVWD complied with the MCL in as timely, effective and affordable a manner as possible. When the MCL went into effect July 1, 2014 water agencies were given mere months to comply, prompting CVWD to begin designing treatment facilities based on known technologies. CVWD also pursued legislation signed by Governor Brown in September 2015 that now provides water agencies the ability to satisfy the new regulation while implementing compliance plans at the earliest feasible date no later than January 1, 2020.

In July 2016, the CVWD Board of Directors approved entering into an agreement for the construction of ion exchange and blending water treatment facilities at 29 drinking water wells throughout the service area. The Board also authorized construction of a Central Resin Regeneration Facility and pipelines to support these treatment facilities. Most customers are aware of this extensive plan, which was among the key reasons for recent rate

increases.

On Sept. 27, 2016, before construction of treatment facilities started, the results of a new water treatment study were released that showed significant removal of chromium-6 from drinking water using an alternative treatment process. A bench scale test performed at CVWD’s water quality laboratory in October 2016 indicates this new process is a Reduction-Coagulation-Filtration (RCF) process that is effective on water samples from CVWD wells and has the potential to be a simpler alternative that is more environmentally friendly, more cost-effective and would have less impact on the community. Some communities expressed concerns that the new treatment facilities would be too noticeable by neighbors and require too much traffic to maintain. The alternative treatment process would utilize tanks hidden behind well site walls and require less disruptive maintenance.

More details will be shared with the community as they become available.

Water samples
Coachella Valley Water District (CVWD) is committed to providing high quality drinking water that meets all state and federal water quality standards. This commitment includes delivering water that complies with the State Water Resources Control Board Division of Drinking Water (State) maximum contaminant level (MCL) of 10 parts per billion for chromium-6, a mineral that occurs naturally in Coachella Valley groundwater.

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Background information and important documents

News coverage about Chromium-6


Bottled water options


Some bottled water brands available at local grocery stores and other locations provide water quality reports indicating Cr6 or chromium (which includes Cr6) levels below 10 ppb. The following list is not intended to be a complete list of all bottled water with possible Cr6 levels below 10 ppb. Inclusion in the list does not represent an endorsement of any kind.

Links