MARINE CORPS AIR GROUND COMBAT CENTER TWENTYNINE PALMS -- In July 2014, California became the only state in the nation to implement a maximum contaminant level in groundwater for Hexavalent Chromium, also known as Chromium-6. The Combat Center has always met and exceeded all water quality requirements and there have never before been separate regulations in place for Chromium-6. As a result of the change in regulations, the Combat Center, along with many water districts in California, is now out of compliance.
According to the Environmental Protection Agency website, cfpub.epa.gov, Chromium is a naturally occurring element in the earth's crust. The three main forms of chromium found in the environment are Chromium-0, Chromium-3 and Chromium-6. Chromium is widely used in manufacturing processes, and it can be found in many consumer products such as wood treated with copper dichromate, leather tanned with chromic sulfate, and stainless steel cookware. But in the case of the Combat Center, small traces of Chromium come from natural sources in the environment..
“The Combat Center has always complied with the most current environmental and natural resources practices,” said Chris Elliott, water resources manager, NREA. “but as regulations change, we are addressing them in the timeliest practical manner in order to meet today’s stricter standards.”
The new standard in California for Chromium-6 is a Maximum Contaminant Level of 10 parts per billion, and according to a sample taken in the second quarter of 2015, two of MCAGCC’s eight wells are reported to have 14 and 18 ppb. The Combat Center’s 2014 Consumer Confidence Report stated the installation’s average Chromium-6 levels to be sampled at 12 ppb.
In 2014 Consumer Confidence Reports from throughout the local area, Desert Water Agency detected 1.06 ppb of Chromium-6 in Palm Springs; Hi-Desert Water District reported Yucca Valley at 3.3 ppb; Twentynine Palms Water District reported 9.75 ppb; and Joshua Basin Water District sampled at 24 ppb in Joshua Tree’s ground water supply.
In August 2013, California Department of Public Health proposed the 10 ppb MCL for Chromium-6 and announced this proposal for public comment and final decision, according to the State Water Resources Control Board. As a result of this initial concern over Chromium-6, the Combat Center took action to address any possible issues before the potential implementation of a new standard by researching ways of treating the installation’s groundwater for Chromium-6. According to Elliott, this preemptive measure put MCAGCC ahead of the game when it comes to meeting the standard as quickly as possible.
“We recognized the issue prior to the regulatory change,” Elliott said. “Early on, MCAGCC started contract negotiations and scope of work for a drinking water feasibility study. The focus of the study is to look at options for construction of a drinking water treatment plant.”
The first phase of the study will look at all available treatment technologies for treatment of Chromium-6. MCAGCC will assess these options and determine what option best fits the needs and capabilities of the installation based on the installation’s location, manpower and budget. Additional factors taken into account will be energy consumption, water loss due to the treatment process, and potential hazardous material disposal costs, Elliott added.
“The third component of this study is the development of a Corrective Action Plan,” Elliott said. “This plan is essentially a roadmap we will be using in moving forward. It will be submitted to the state, identifying how the Marine Corps will be addressing this issue. That plan will be finalized and submitted by Oct. 15, 2015.”
As of Thursday, the top two treatment options had been selected and will continue to be further scrutinized for best compatibility with the installation’s capabilities and needs. The final selection will be identified in February 2016 once the study is completed.
For official information on California’s groundwater standards and Chromium-6, please visit www.waterboards.ca.gov.