LA’S DRINKING WATER & CHROMIUM-6
November 16, 2016–A non-profit organization recently released a list of American cities with detected Chromium-6 levels in drinking water systems. The list included Los Angeles, thereby generating renewed interest and potential concern among Angelenos about the quality and safety of the tap water. Contrary to the organization’s findings, there is no Chromium-6 problem in the Los Angeles Department of Water and Power’s (LADWP) drinking water system. In 2015 alone, we collected more than 32,000 water samples throughout the city and performed more than 147,000 water quality tests for compliance as well as for research and operational improvements. We tested for more than 200 regulated contaminants, including Chromium-6, as well as unregulated contaminants and constituents of interest. Results from those tests conclusively show that the water served in the City of Los Angeles continues to meet all federal and California drinking water standards, including the nation’s only Chromium-6 standard.
In 2015, the Chromium-6 levels in LA’s water averaged less than one part per billion (ppb)— ten times less than the State’s Primary Drinking Water Standard, or Maximum Contaminant Level (MCL) of 10 ppb established in 2014. We reported this on our 2015 Annual Drinking Water Quality Report. To put things into perspective, one ppb is equivalent to one pint in 120 million gallons of water. That year, we supplied nearly 200 billion gallons of safe drinking water to four million residents and businesses.
The non-profit organization that released the report indicated that they found an average of 0.48 ppb of Chromium-6 from 76 LADWP water samples collected from 2013-2015. Their findings confirm LADWP’s Chromium-6 levels are well below the State’s MCL of 10 ppb. However, instead of measuring the Chromium-6 levels against the MCL which is California’s Primary Drinking Water Standard, they used California’s Public Heath Goals (PHG) of 0.02 ppb, which is considered the starting point in creating an MCL. The State Water Resources Control Board, Division of Drinking Water establishes the MCL as close as possible to the PHG, taking into consideration the confines of what is technologically available to test and treat drinking water, and is affordable to the public. The goal of any water provider is to serve water that is as far below the MCL as possible, with primary emphasis on the protection of public health. LADWP has and continues to meet this goal every day.
Chromium-6, or Hexavalent Chromium, is an ion of naturally occurring inorganic chromium that can be used in manufacturing processes such as electroplating, leather tanning and wood treatment. Chromium-6 can contaminate drinking water sources through discharges from industries, leaching from hazardous waste sites or the erosion of natural deposits into the groundwater. While LADWP’s water supply sources include groundwater, our blending operations ensure that the water delivered to you will never exceed the MCL of any regulated contaminant. Meanwhile, a collaborative cleanup project is underway for LA’s San Fernando groundwater “hotspots” under the auspices of the US EPA (Environmental Protection Agency) Superfund Division.
The external organization that released the report is giving utilities the opportunity to review the database and provide corrections to their Chromium-6 findings. LADWP has reviewed the findings and they appear to be accurate, if a bit misleading. Our goal is to provide additional treatment for chromium and Chromium-6 removal at the source. And, our commitment is to continue to provide water that surpasses all drinking water standards, including total chromium and Cr-6.
LADWP encourages you to remain informed about the facts about Chromium-6 levels. Read more on the State Water Resources Control Board, Division of Drinking Water website for Chromium-6 in Drinking Water.
For more information about the quality of LA’s tap water, read the LADWP Annual Drinking Water Quality Report at www.ladwp.com/waterqualityreport.
