The California State Water Resources Control Board (SWRCB) considers the chromium-6 chemical compound to be a dangerous carcinogen. In April 2024, the board restricted the delivery of water that contains chromium-6 levels above 10 particles per billion (PPB).
As a result, five of the Coachella Valley’s six water providers will need to invest more than $525 million to comply—all within the next one to two years.
This is the SWRCB’s latest attempt to enact such a standard. In 2017, a similar restriction was successfully challenged in court by water providers who argued that the state failed to consider the costs of them meeting the stringent regulation. California is only state to establish a specific drinking water standard for chromium-6, the chemical at the center of the film Erin Brockovich.
The largest potable water provider in the valley is the Coachella Valley Water District (CVWD), with 115,748 active accounts, delivering 80.3 million gallons daily to its domestic water customers. In a recent interview, Lorraine Garcia, the communication manager and public information officer, explained the district’s chromium-6 response; 34 of the CVWD’s 96 drinking water wells are impacted by the new standard.
“This has been in the works for about 25 years,” Garcia said, “and there’s been a lot of conflict.”
In 2016, the CVWD initiated studies and design processes for buildout including new treatment plants, new wells and new pipelines, all focused on the reduction of chromium-6 levels.
“The MCL (maximum contaminant level) was thrown out years ago (in 2017),” Garcia said. “So it was back to the drawing board for the state, which was tasked to do an economic feasibility study.”
In the meantime, Garcia said, the CVWD began working on a compliance plan—which has already been submitted to the state for approval.
“We still do not have that (state approval),” she said. “We’ve been waiting since last year.”
Back in 2015, the CVWD board of directors conducted a study to establish a five-year rate increase plan, which went into effect briefly in 2016, calculated to meet the then-estimated $250 million cost of chromium-6 reduction efforts. While some of those increases were paid, those funds have since been used to cover other expenses.
“The estimate is about $350 million at this point in time,” Garcia said. “So what we will have to do is a ‘cost-of-service study.’ We will have to look at all of the costs again … and see what the actual costs will be to customers.”
The Mission Springs Water District (MSWD) serves more than 40,000 domestic water customers of Desert Hot Springs and the surrounding areas. The Independent exchanged emails with Marion Champion, the assistant general manager.
“At Mission Springs Water District, four of our 13 groundwater wells are currently impacted by the new chromium-6 standard,” Champion wrote. “These wells have been removed from service while MSWD evaluates cost-effective treatment options to support future water supply needs and works through the state approval process for its chromium-6 compliance plan. … We have been open and transparent throughout this process by holding community workshops, creating a dedicated chromium-6 information section on our website, and regularly providing updates.”
Champion said the MSWD estimates it will cost about $25 million “for both well-clustering and treatment options.”
“We expect this work to be completed within approximately two years,” Champion said. “Working with our chromium-6 consultant, MSWD has already begun work on treatment design and will move into implementation once our compliance plan is approved by the state.”
At the east end of the valley, the Indio Water Authority (IWA) supplied “6.3 billion gallons (19,566 acre-feet) of water to approximately 85,000 businesses and residents in 2018,” according to the website.
Roman Gonzalez, the water project construction manager for the IWA, told the Independent that 13 of the 20 IWA wells have chromium-6 levels that exceed the 10 PPB. The authority’s compliance plan, which was delivered to the SWRCB in January, estimated a total cost of $130 million, or roughly $10 million per affected well, Gonzalez said.
In March 2026, the IWA was the only Coachella Valley water provider to join a court filing seeking the overturn of the new chromium-6 regulation. After being denied in Fresno Superior Court, the petitioners filed an appeal, which is pending as of this writing.
The east valley city of Coachella provides roughly 43,500 domestic water customers with drinking water through the Coachella Water Authority and Sanitary District (CWA). According to the CWA website, five of the authority’s six wells exceed the chromium-6 MCL of 10 PPBs.
“Before the old limit (on chromium-6 levels) was abandoned, the Water Authority was working to find the most effective and economical way to reduce chromium-6 in affected wells,” the CWA website reads. “Ion exchange technology was chosen, and construction of treatment facilities is under way in anticipation of a new state standard. Treatment technology is a costly investment. To lower the burden on our ratepayers, the water authority is pursuing all possible grant funding. The cost of ion exchange systems on the impacted well sites will range from $10 million to $16 million, and will require $2 million to $3 million per year for operations and maintenance, which will affect water rates.”
Many water providers statewide, including most if not all of our local systems, submitted compliance plans in 2025 or early 2026, as directed—but have yet to receive approval. As a result, they’re somewhat stuck.
The Myoma Dunes Mutual Water Company (MDMWC) was founded in 1953 and is a small mutual water company serving approximately 2,450 residents in parts of Bermuda Dunes and La Quinta. According to the MDMWC website’s chromium-6 information page, the company owns five water wells, and they all exceed the 10-PPB level. The projected total cost to bring the drinking water supply into compliance is $10 million to $15 million.
“These costs will significantly impact water rates once treatment systems are installed,” the website warns.
The western end of Coachella Valley, in and around Palm Springs and Cathedral City, has been served by the Desert Water Agency since 1968. “DWA currently has about 24,000 domestic water connections that serve approximately 75,000 people (including seasonal population),” according to the DWA website—and it is the only local water agency in compliance with the new state chromium-6 standard.
“DWA’s most recent testing confirms that all of our drinking water sources remain below California’s maximum contaminant level (MCL) of 10 parts per billion for chromium-6,” wrote Victoria Llort, the DWA’s public affairs and conservation director, and public information officer. “Those results are reflected in DWA’s annual Water Quality Report (www.dwa.org/wqr). … The agency has not needed to make operational changes as a result of the chromium-6 regulation.”
The SWRCB’s deadlines for compliance depend on the number of customers a system serves. For systems with 10,000-plus customers, the deadline is Oct. 1, 2026; for systems with 1,000-9,999 customers, the deadline is Oct. 1, 2027; and for systems with fewer than 1,000 customers, the deadline is Oct. 1, 2028.
However, many water providers statewide, including most if not all of our local systems, submitted compliance plans in 2025 or early 2026, as directed—but have yet to receive approval. As a result, they’re somewhat stuck.
“We’re still in preparation time to get these projects going,” said Garcia, of CVWD. “We want to be prepared, so if we get an approval, we can move forward. But that is challenging for water agencies, because construction design takes time. Getting contractors takes time, and we need to budget for these things. So we’ve been budgeting, and also thinking how, if we get approved, we can do these projects. … Other agencies are in the same situation—ready to move forward, but still needing to be approved.
“I do want to point out that … our engineering team is being very strategic when we are doing other projects, and keeping in mind that this MCL is 10 parts per billion. So, if we are constructing a new reservoir, or a well, or anything that has to do with the domestic system, we are strategically putting it in areas that make more sense in regards to the regulation.”
If the SWRCB could be convinced to establish a more lenient chromium-6 MCL—of, say, 15 PPBs—it would drastically reduce the financial costs to water systems and their customers across the state, with what many argue would be minimal health risks. But so far, the state is adamant about sticking to the 10 PPB MCL.
“This is all naturally occurring chromium,” Garcia said. “It’s been here since we’ve all been here, and even before that. The challenge is the 10 parts per billion MCL. That’s not just a challenge for Coachella Valley Water District; it’s a challenge across the entire state.”
