State pushes costly new water standard

Feb. 10, 2010

By JT LONG

California water agencies face a groundbreaking proposal to eradicate — at what could be a high cost to ratepayers — all but trace levels of hexavalent chromium, the industrial byproduct made famous by the movie Erin Brockovich a decade ago.

The California Office of Environmental Health Hazard Assessment draft health goal of 0.06 parts per billion of hexavalent chromium (also known as chromium VI or chromium 6) announced in 2009 would be the first step in the country to isolate, let alone shrink by three orders of magnitude, the presence of the anti-corrosive in drinking water. The federal government currently only regulates total chromium (chromium VI and beneficial chromium III) levels at 100 parts per billion. The state limit is 50 parts per billion. The cities of Burbank, Glendale and Los Angeles adopted voluntary chromium limits of 5 parts per billion.

Danielle Blacet, regulatory advocate for Sacramento-based Association of California Water Agencies, questioned the science behind the ambitious health goal. “While we recognize … the known toxicity of hexavalent chromium via inhalation… ACWA is concerned that the result of … referenced studies do not sufficiently demonstrate the human carcinogenicity of hexavalent chromium in drinking water,” Blacet said in a public letter during the comment period for the draft goal.

One study referenced by the Office of Environmental Health decision was a 2007 National Toxicology Program examination of gastrointestinal tumors in rats given varying doses of sodium dichromate dihydrate over a two-year period. It concluded that increased incidences of rare cancer in the mouth and lining of the small intestines that reduced body weight and water consumption qualified the chemical as a carcinogen when ingested.

“Another look needs to be made to quantify the reductive capacity in the human digestion system at realistic doses,” Blacet said.

Others disagreed. “The link between ingesting hexavalent chromium in water and serious health impacts, including cancer, cannot be taken too seriously,” read a letter from a consortium of environmental and health-related groups during the comment period. The letter estimated that some 33 million Californians are at risk.

The Public Health Goal is not a mandate. Even if it is adopted in the next two years as the level of a contaminant that does not pose a significant health risk (meaning that for every million people who drink two liters of water with that level of chromium VI daily for 70 years, no more than one person would be expected to develop cancer from the exposure) that does not make it a new standard. Instead, the finding would become the basis of the California Dept. of Public Health’s process for setting enforceable Maximum Contaminant Levels (MCL). The state sets MCLs “as close to the corresponding Public Health Goal as is economically and technically feasible.” This could occur as soon as 2013 and take effect immediately. However, the time allowed for each agency to comply would depend on the size of the problem and the impact to the community, according to Public Health Spokesman Ken August.

Test case

To determine what is economically and technically feasible, the U.S. Environmental Protection Agency, with help from the American Water Works Research Foundation, and local cities, are funding two demonstration plants totaling $1.9 million in Glendale, an area at the epicenter of the San Fernando Valley industrial aftermath and a federal Superfund site. Groundwater from this basin is a drinking water source for the cities of Los Angeles, Burbank and Glendale.

EPA first detected chromium contamination in the area in 1989. In 2006, chromium levels in one extraction well near the former Allied Signal facility in the North Hollywood rose sharply to over 200 parts per billion. The Los Angeles Department of Water and Power, which operates the North Hollywood system, shut down the well. To put that number into perspective, a chromium level of 580 parts per billion in Hinkley resulted in a $333 million settlement with Pacific Gas & Electric Co in 1996 and made Erin Brockovich an environmental superstar.

To avoid a big-budget sequel, water officials are staging real-world tests to find the most cost effective way to treat a dwindling water supply. At current acceptable levels, water containing trace levels of chromium VI can be blended with more expensive imported sources, but if the ultra-low health goal is adopted, that would no longer be an option and more expensive water would have to be imported.

After eight years of laboratory modeling, Glendale Water and Power built two treatment plants focused on best practices for chromium VI removal. Many of the San Fernando Valley water sources are already being treated for volatile organic chemicals, however process would have to be adjusted to manage this additional agent.

One treatment option being tested is called Weak Base Anion Exchange (WBA). This commonly-used technology uses carbon acid to create a low pH to facilitate a particle exchange with a resin to reduce chromium VI to chromium III and removing any residual brine.

Another proven technology being put to a new use is Reduction Coagulation Filtration. Ferrous sulfate is added to reduce the chromium VI to chromium III, which can then be precipitated and filtered out.

Test treatment plants large enough to process a total of 525 gallons per minute were completed in November 2009 and went online in February. Assumptions about the relative capital, operating and disposal coats could be available as soon as this summer. The test is scheduled to continue for a full year, according to Peter Kavounas, Glendale Water and Power assistant general manager.

Full-scale treatment implementation would require construction of a centralized larger-capacity facility capable of processing as much as 5,000 gallons per minute.

“Small volumes are easily treated, it is larger system that cost more to operate,” Kavounas said.

Footing the bill

Clean does not come cheaply. Jeanne Garcia, public information officer for the California Dept. of Toxic Substances Control, estimated that in the San Fernando Valley alone clean-up will likely be in the $100-200 million dollar range. A California Dept. of Health Services survey indicated that chromium VI could impact as much as a third of the ground water supply in hot spots around the state.

The Dept. of Toxic Substances Control is working with the Los Angeles Regional Water Quality Control Board and the U.S. EPA to determine and place the burden of cleanup on the responsible companies. The Water Quality Control Board investigated 4,000 businesses that may have allowed the chemical to leak it into the soil and groundwater. The board whittled the list down to 85 potential polluters and issued clean-up orders to seven companies so far.

Removing the contaminant from soil can take from one to five years depending on the extent of contamination. However, if the heavy metal has made its way into the groundwater, pump and treat operations can go on for 15 to 20 years.

Finding the responsible party can be a challenge. In addition to industrial sources such as stainless steel manufacturing, textile dyes and leather tanning, chromium VI can be a naturally-occurring element.

For sites where no viable responsible party exists, the state may use what is known as “State Orphan funds” to pay for investigation and source removal activities. U.S. EPA may also fund a portion in the event that settlement efforts fall short of the remedy costs, Garcia said.

Whatever isn’t picked up by the government could eventually come out of ratepayer pockets. “If there is not a responsible party, then the cost could fall to local agencies,” ACWA’s Blacet warned. That is where the balancing act comes in. “Water agencies want to make sure they are delivering the highest quality water at the best price,” Blacet said.

California is not alone in this struggle to balance treatment, technology, availability and price. Russell Ford, vice president and principle technologist for CH2M Hill in Colorado said other states – and countries – are watching what California does. “California often leads when it comes to regulation,” Ford said.