Perchlorate in California Drinking Water


Perchlorate (ammonium perchlorate), is used as an oxidant (energetics booster) in solid propellant for rockets, missiles and fireworks. Perchlorate can be found in matches, flares, pyrotechnics, and explosives.

Perchlorate has been known to be a widespread inorganic contaminant found in California drinking water since 1985, however perchlorate contamination of water sources nationwide was not recognized until 1997. The U.S. Environmental Protection Agency (EPA) estimated that approximately 11 million people nationwide are exposed to perchlorate in their public drinking water supplies. This estimate was based on a data sampling collected as of May 2004, showing the Minimum Reporting Level for that date of collection at four parts per billion (ppb).

Unfortunately there is not a drinking water standard for perchlorate, known as a maximum contaminant level (MCL). The California Department of Health Services has proposed that an MCL be established for perchlorate by the end of this year.

The National Academy of Sciences’ report, “Health Implications of Perchlorate Ingestion”, which was released January 2005, includes a review of the U.S. Environmental Protection Agency’s assessment, originally released in 2002. The EPA’s report will be used in developing the federal MCL. In the meantime, the California Department of Health Services will notify statewide water systems of any perchlorate findings in the water above six parts per billion.

The EPA’s 2002 findings show birth defects in children and tumors in adults as possible affects of inhibition of thyroid iodide uptake. The committee reviewing the findings can only conclude that humans exposed to perchlorate have suffered an inhibition of thyroid iodide.

Perchlorate can interfere with iodide uptake by the thyroid gland. This can cause a decrease in the production of thyroid hormones, which are needed for normal metabolism and mental function. Extended exposure to perchlorate can lead to thyroid dysfunction, either hypothyroidism (deficiency of thyroid hormone production) or hyperthyroidism
(excess of thyroid hormone production).

Perchlorate has been detected in more than 350 drinking water sources within California, primarily the wells and groundwater in Los Angeles, San Bernardino and Riverside Counties.

Ammonium perchlorate manufacturing facilities in Nevada have contaminated the Colorado River, a major source of drinking water and irrigation for California.

Southern Santa Clara County has detected unacceptable levels of perchlorate in 235 of their private wells. Government regulators say it could take decades and millions of dollars to clean up the 7 mile long plume of perchlorate at the site.

“It could take 30 or 40 years,” said Kevin Meyer, regional perchlorate coordinator for the U.S. EPA in San Francisco. ” It took 40 years to get contaminated, so chemically, it will probably take longer to get it out.” An article in the San Jose Mercury-News from March 2003, went on to explain that the pollution came from a factory that produced highway flares from 1955 to 1996 in southern Morgan Hill.

Visit the following link to see a statewide summary of information on perchlorate contaminated sites, at the California Department of Health Services:

Ecologic studies (those that include exposure data and outcome data for large geographic areas, rather than individuals), have examined the association of perchlorate exposure with the thyroid function and thyroid disease in newborns, children, and adults.

The National Academy of Sciences’ report noted that while “acknowledging that ecologic data alone are not sufficient to demonstrate whether or not an association is a causal one, the committees found that they can provide evidence bearing on possible associations and reached the following conclusions regarding the proposed association of perchlorate exposure with various health end points.”

These so-called “health end points” include: congenital hypothyroidism; changes in thyroid function in newborns; neurodevelopmental outcomes (ADHD); hypothyroidism and other thyroid disorders in adults; and thyroid cancer in adults.


The two technologies currently being used in perchlorate cleanup are: using a modular ion exchange system (running the polluted water over resin beads, which attract the perchlorate ions, removing them from the water) and biological technology (breaking down the pollution in the water with bacteria).

The ion exchange system has been chosen to clean the California rocket testing facilities of AeroJet Corporation, the company responsible for the 8 mi. plume located in Baldwin Park, in the San Gabriel Valley. According to Charles Drewry, Regional Sales Manager for Calgon Carbon, the cleanup will cost $90 million and could take as long as 25 years. The Calgon Carbon company built the ion exchange system that will be used in the cleanup.

At another AeroJet facility in Rancho Cordova, near Sacramento, the biological reactor treatment will be used instead. The contaminated water is pumped into tanks which utilize good bacteria, and that bacteria basically “eats away” the perchlorate. The water is then chlorinated and filtered, and then it’s safe to drink.

Many of the Superfund cleanup sites (the nation’s most serious hazardous waste sites) involve government land housing military installations and other facilities making rocket fuel. One such facility is the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory located Pasadena, California. Although currently JPL is involved in the automated exploration of the solar system and deep space, due to former activities utilizing volatile organic compounds (VOC) and perchlorate, JPL is now responsible for cleaning up soil and groundwater contamination at the Pasadena site.

The Agency for Toxic Substances and Disease Registry visited JPL in 1997 to assess possible public health hazards and identified the two primary concerns as: future groundwater and drinking water quality, and possible increased incidence of Hodgkin’s disease in local residents.

The California Institute of Technology is currently under contract with NASA to manage the facilities at JPL. It was found that the research and development laboratories have used chlorinated solvents, solid rocket fuel propellants (perchlorate), cooling tower chemicals, sulfuric acid, Freon, mercury and other laboratory chemicals.

In a Public Health Assessment report issued by JPL, they reported that “from 1945 to 1960 JPL disposed of liquid and solid wastes, including chemical wastes in over 40 seepage pits and waste pits on the facility grounds. In 1980 the City Pasadena detected VOC’s in municipal wells located east of the Arroyo Seco, spreading southeast. Other contaminated wells affected the communities of Altadena.”

Two Pasadena municipal wells were closed in 1985 due to the high levels of contaminants, another two closures in 1987 and finally the remaining two in 1989. By 1992 the problem had become serious enough to warrant their addition to the US EPA’s National Priorities List, basically putting them at the top of the Superfund site list of environmental clean-ups.

In an investigation held jointly by the EPA, the state of California, and JPL in December 1992, they found remedial activities have included installation of five groundwater monitoring wells in nearby Altadena and Pasadena. The continued monitoring of these wells will indicate whether contaminants have moved off site and determine the direction and extent of possible contamination.

The EPA’s National Center for Environmental Assessment released a report in September of 1998 examining the risks involved with perchlorate, entitled “Perchlorate Environmental Contamination: Toxicological Review and Risk Characterization based on Emerging Information.”

Although the Agency for Toxic Substances and Disease Registry (ATSDR) is unable to fully evaluate the potential public health hazards and/or any causal relationship related to perchlorate contamination until further information becomes available, they have assigned exposure to perchlorate in off site ground water as an indeterminate public health hazard.

ATSDR did not find a relationship between exposure to perchlorate and Hodgkin’s disease, however, perchlorate has been potentially associated with cancer of the follicular thyroid cells in a study by the EPA in 1999.

Their conclusions, based on the available data:

* on-site and off site groundwater at JPL does not present a past, present or future public health hazard because of the limited exposure to this water.

* perchlorate contamination in off site ground water presents no health hazard because the new treatment facilities include ion exchange systems which will remove contaminants from the water.

* contaminants in the soils at JPL pose no public health hazard and are inaccessible to workers.

* after public hearings to consider community members’ concerns about contamination levels, researchers agreed Hodgkin’s disease is not associated with perchlorate exposure.

Where are we now? The Twelve Month Miracle

The Pasadena Star News began writing articles on the perchlorate contamination in Pasadena ground water in January of 2004. According to an article dated January 26th, the City of Pasadena had filed a $2 million claim against NASA and the U.S. Army to recoup the costs of closing nine wells for perchlorate contamination in and around JPL. The federal government listed JPL. as a Superfund site in 1992, however the first public meetings concerning the contamination did not begin until 2004.

At that time, a few Washington lawmakers introduced a bill requesting that the military be exempt from liability for perchlorate contamination, however it didn’t pass the U.S. Senate.

A major obstacle in the cleanup is the general lack of a national safety standard for drinking water contaminated with perchlorate. According to the Pasadena Weekly, in an article dated May 20th, 2004 the National Academy of Sciences (NAS) was under review for allegedly violating a conflict of interest by appointing two scientists who had working relationships with Lockheed Martin (one of the companies allegedly responsible for perchlorate contamination), to a panel assessing the health impacts of perchlorate on human health.

U.S. Democratic Senators Barbara Boxer and Dianne Feinstein, wrote a letter to NAS president Bruce Alberts requesting that he “fully investigate and disclose any conflicts of interest” citing that “the appearance of conflict of interest or bias undermines NAS’ credibility.”

The EPA currently recommends water contaminated with more than 18 ppb perchlorate not be served. Two of the nine contaminated water wells in Pasadena were reactivated after the state lowered water purity requirements, according to the Pasadena Weekly’s article.

By December 22, 2004 The Pasadena Star News reported that the situation had become more serious, as the city closed the 10th well which was beginning to show levels of perchlorate contamination. In order to replace the necessary water, ground water is being pumped from wells on the east side of the basin. Unfortunately, this may draw the plume farther eastward.

“We believe that at this point we need to do something now to contain the perchlorate plume and then work out the responsibility any potential reimbursement,” said Phyllis Currie general manager of Pasadena Water and Power.

This year Pasadena Water and Power will be installing treatment plants for the Sunset, Bangham and Copelin wells. The city council approved an $800,000 budget to plan the treatment plant. Curry said that the actual costs to buy and install the plant will be much more than that. The city may take up to 18 months to get the proper permits to begin construction, and the longer it takes the farther the contamination plume will spread unimpeded.

The cost to the people who live in the city of Pasadena will be felt in two immediate areas; increasing water bills due to the city having to import clean water to make up for lost ground water; and increasing health costs citywide from residents who are ill with a variety of thyroid dysfunction related diseases which may have been caused by drinking contaminated city water for several decades.

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