Confronting a Legacy of Contamination: Perchlorate
There’s danger lurking underground. The threat cannot be seen, heard or felt immediately, but there it resides – in shallow pockets of groundwater and deep, cold subterranean aquifers situated hundreds of feet below the surface. The danger manifests itself through the most vital human activity next to breathing, the consumption of water. Experts know there is no such thing as pure water. Microscopic bits of a host of elements that surround us are present in the water we drink. They exist at levels that are harmless, and in fact some of the constituents found in tap water are beneficial to human health.
But large pockets of groundwater today are tainted by an array of chemicals, some manmade, some naturally occurring, that threaten the integrity of supplies and the ability of agencies to provide safe, reliable service. In some cases, the chemicals are the remnants of long-dormant industrial and military operations conducted during a time of ignorance or indifference to the environmental impacts of careless handling and disposal. Other chemicals, such as the notorious methyl tertiary butyl ether (MTBE), are the unintended result of environmental policy enacted without enough cross-media analysis.
The wave of contaminants bear scientific-sounding names such as nitrate and chromium, or arranged into alphabet soup acronyms such as the aforementioned MTBE, TCE or PCE. Often, the sheer volume of contamination caused by decades of seepage presents regulators and responsible parties with a gargantuan task of cleanup and restoration. The amount of money spent nationwide for such an effort amounts to billions of dollars. Water sources have been cleaned to remarkable levels. Restoring eroded public confidence, however, has not always been so easy. Consumers hesitant about the quality of the water flowing from the kitchen faucet have turned to bottled water in growing numbers.
Taking its place as the contaminant du jour is perchlorate, a chemical most associated with solid rocket fuel that has been appearing with alarming frequency in sites nationwide. Like MTBE, perchlorate moves rapidly through water and soil and consequently is the fastest-growing contaminant in California’s groundwater. Thanks to improved detection technology, decades of groundwater pollution are slowly being uncovered as underground plumes have shut down or threatened to shut down dozens of wells up and down California. Meanwhile, across the border in Nevada, an underground swell of perchlorate slowly percolates into Lake Mead and the Colorado River, threatening the supply for millions of people dependent on the river for drinking water.
“It’s turned into much more than any of us expected,” said Kevin Mayer, Superfund project manager with the U.S. Environmental Protection Agency (EPA) Region IX in San Francisco. “It’s gone from a fairly localized release of a pretty unusual and specialized chemical to finding it in … many public water systems.”
Perchlorate’s presence in the environment has been known about for decades, but it was only fairly recently that technological develop- ments enabled its discovery in groundwater at the parts-per-billion (ppb) level. Such infinitesimal measurements are nearly incomprehensible given that one ppb is equivalent to a grain of sand in an Olympic-sized swimming pool.
Among the many chemicals that contaminate groundwater, perchlorate is particularly vexing because of its persistence and high solubility. Experts say that were it not for the threat posed to human health and the environment, perchlorate would be a good tool to track the movement of subsurface water.
“Perchlorate would be an ideal tracer if it didn’t have the toxicity,” Mayer said. “It stays in a solution without being attracted to soil or organic elements and moves as rapidly as water itself.”
The discovery of perchlorate in groundwater has moved beyond areas that were hubs of rocket engine production during the era of the Cold War and the early years of space exploration. Subsequent investigation has revealed contamination in and around facilities tied to the production of fireworks and even the charges used to deploy airbags in motor vehicles.
“What’s happened in the last two and a half years is that we now know that it’s not just a question of localized drinking water contamination,” said Bill Walker, West Coast vice president of Environmental Working Group (EWG). “We’re not at the end of the curve in discovering where the end of the problem is.”
Some say perchlorate’s presence has been overshadowed by MTBE, which became such a headache because of its propensity to contaminate groundwater. Authorized by the state as a way to ensure cleanerburning gasoline, the chemical was eventually ordered out of California gasoline through an executive order by Gov. Gray Davis. Larry Ladd, a medical geographer involved with perchlorate at the Aerojet facility in Rancho Cordova, said he’s been frustrated by the relative lack of attention given to the rocket fuel oxidizer.
“Perchlorate and MTBE started out at the same time, but perchlorate keeps getting put on the back burner,” he said. “MTBE isn’t very much of a health threat because people can taste it in the water at 5 ppb.”
Yet recent headlines suggest perchlorate is getting more attention. In southern California, home to the aerospace industry, regulators, local officials and residents are grappling with plumes near Simi Valley, in San Gabriel Valley and in the Inland Empire region. The problem has spurred a sometimes contentious process of identifying responsible parties and negotiating the terms by which cleanup will proceed.
“It’s a horrendously complicated issue in terms of the origin of contamination and who’s responsible,” said Mic Stewart, water quality section manager for the Metropolitan Water District of Southern California (MWD).
Meanwhile, in the northern California communities of Morgan Hill and San Martin, perchlorate contamination traced to a highway safety flare manufacturing plant has shut down several drinking water wells and frayed the nerves of outlying residents dependent on private wells. The Santa Clara Valley Water District has responded with free well testing and bottled water while efforts are made to confirm the extent of the plume.
As more reports of perchlorate in drinking water appear, scientists continue to study the chemical’s impact on the human body, including sensitive subpopulations – people for which ingestion poses unique health problems. Perchlorate is presently classified as an unregulated contaminant for which monitoring is required. Over time, estimates of an acceptable level in drinking water have steadily descended from 18 ppb in 2000 to the few parts per billion that could be settled upon by EPA and state health departments.
Perchlorate disrupts the proper function of the thyroid gland by blocking iodide uptake. The thyroid gland plays a sort of traffic cop role in the human body, regulating the release of hormones for growth, development and metabolism. Ironically, doctors once prescribed perchlorate to treat hyperthyroidism. While an iodidedeficient thyroid gland in adults can cause relatively moderate impacts such as fatigue, depression, weight gain and hair loss, it is perchlorate’s effect on developing fetuses and children that has prompted the most concern among public health officials and advocacy groups such as EWG. The organization suggests the drinking water standard be set at 1 ppb.
“There are understandable disagreements on how to define a safe dosage because a lot of this involves estimates and uncertainties,” Mayer said.
Part of the disagreement comes from the Department of Defense, which believes EPA has overestimated the risk posed by perchlorate while overlooking some human health data.
The final drinking water standard for perchlorate set by the state of California will be based on protective health criteria as well as technological and economical feasibility. Drinking water providers are keenly focused on the costs associated with the limits on perchlorate, given the expense of removing perchlorate from water. Agency officials already have encountered those ramifications in areas where wells taken out of service seriously hamper water delivery.
“The reliability of the local water supply is in jeopardy [and] without immediate action … we face the prospect of a clear and present public safety crisis this summer,” said Michael Whitehead, a member of the Chino Basin Watermaster Authority, at a Senate select committee hearing in January.
Whitehead received a sympathetic response by lawmakers anxious to deal with the problem, including State Sen. Nell Soto, D-Pomona, who called the wholesale contamination of aquifers the “single greatest threat to our economic stability.” State Sen. Mike Machado, D-Linden, described perchlorate as “a public health issue, an environmental issue and ultimately, a quality of life issue.”
This issue of Western Water examines the problem of perchlorate contamination and its ramifications on all facets of water delivery, from the extensive cleanup costs to the search for alternative water supplies. In addition to discussing the threat posed by high levels of perchlorate in drinking water, the article presents examples of areas hard hit by contamination and analyzes the potential impacts of forthcoming drinking water standards for perchlorate.
NOTE: A complete copy of the 16-page magazine is available from the Foundation for $3. Visit our Products Page and add the May/June 2003 issue of Western Water to your shopping cart.
“State of Denial” is the name of a special section recently published by the local Sacramento newspaper. The writer discusses how California’s environmental legacy of conserving resources at home is setting us on a collision course with its habit of consuming resources from abroad in record quantities. And often, he notes, the losers are impoverished citizens and communities - and their own spectacular ecosystems – in the remotest parts of the globe where the quest for money to survive is often more important than preserving the resources.
The author, Sacramento Bee reporter Tom Knudson, is a Pulitzer Prize winning reporter and he profiles several California lifestyles in terms of ecological footprints – the measure of our impact on the world and the area required to produce the resources consumed and absorb the wastes generated by each person. (You can determine your own ecological footprint at: http://www.myfootprint.org.) The national average is 24 acres but most Westerners (and Californians) rate a higher number. My footprint is about 30. According to this think tank, we would need about 7 planets if everyone on earth lived as me and my family. (We commute to work, mostly by car; we travel by air at least a couple of times a month and have a rich and diverse diet.)
The idea of “footprints” relates to this issue of Western Water. Our use of chemicals created in World War II and used into the Space Age has left a heavy footprint on our nation. In the West, large pockets of groundwater are tainted by a wide array of chemicals, many manmade, that threaten the integrity of local water supplies and the ability of agencies to provide communities with safe, reliable water service. In this issue, Writer Gary Pitzer takes a look at the footprint one particular chemical - perchlorate – has made in California and Nevada. As Gary explains in this article, much of the perchlorate contamination deals from past disposal practices in which wastewater containing perchlorate was simply allowed to drain directly into the ground.
“Prevention, prevention, prevention” is the common mantra chanted by most groundwater experts today – especially in light of the expensive and extensive efforts underway to treat the contamination caused, at many places, by past practices. The importance of this fact is that we need to learn from past mistakes. That’s where the Water Education Foundation can help. Our low-cost, easily understood materials help everyone, from K-12 students to the newspaper reporter to water district customers, understand what groundwater is, how it is connected to the surface of the land (and to surface water) and how to protect it from future contamination. See page 15 for a partial list of our groundwater and water quality materials, which include videos, guides, maps, school programs, and much, much more - including an Oct. 15-17 Southern California Groundwater Tour.
Groundwater is a hidden resource, and it is important to help the public understand that underneath the ecological footprint is a source of water that supplies, statewide, some 30 percent of our annual water with some communities 100 percent reliant upon this underground water. It is vital that we use this resource wisely, and strive to protect it from pollution.
In the News
Judge OKs Extra Trinity Flows to Ease Burden on Lower Klamath River
Seeking to avoid the conditions that may have contributed to the deaths of thousands of salmon in the Lower Klamath River last summer, a federal judge has ordered that extra water be released into the Trinity River to help boost Lower Klamath flows. The rivers meet about 40 miles upstream from the Pacific Ocean in prime spawning habitat.
The decision was made after U.S. Fish & Wildlife Service biologists cautioned that a similar disaster could be in the making because of continued drought in the Klamath Basin.
U.S. District Court Judge Oliver Wanger April 7 ruled that 453,000 acre-feet of water be released from the Trinity and Lewiston dams to protect salmon migrating upstream. In addition, 50,000 acre-feet of water could be available, if necessary. An estimated 33,000 salmon died on the Lower Klamath last summer. Opinions are mixed as to why the die-off occurred, with the California Department of Fish and Game citing insufficient flows.
Meanwhile, farmers served by the Klamath Project will receive near-normal water supplies this year, the U.S. Bureau of Reclamation (Bureau) announced. The region is again feeling the impact of a drier-than-normal winter, meaning that 299,000 acre-feet of water will be available, about 7 percent less than the 323,000 acre-feet delivered in past dry years.
In issuing its annual Klamath Project Operations Plan, the Bureau classified the water year as “dry.” Buttressing the plan is a temporary water bank in which willing farmers are paid to fallow fields in order to limit diversions. “The combination of the water bank, efficient water management and some help from Mother Nature will all be needed to get us through this hole,” said Dan Keppen, executive director of the Klamath Water Users Association.
Critics of the region’s water management say the problem of overallocation has yet to be properly addressed. “What is most disappointing is that in spite of years now of ongoing federal water crises throughout the basin, so little has changed,” said Glen Spain with the Pacific Coast Federation of Fishermen’s Associations (PCFFA). “Federal mismanagement put both farmers and fishermen in this mess by promising too many irrigators water that was never really there.”
PCFFA is the lead plaintiff in a federal case that alleges the Bureau is violating the Endangered Species Act by not releasing enough water from Iron Gate Dam on the Upper Klamath. A hearing before Wanger was scheduled for April 29.
Citing the water woes of the Klamath, a conservation group named the river as the second most endangered in the country. “The Klamath River and its fisheries are the real victims when too much irrigation demand chases little water,” said Rebecca Wodder, president of American Rivers, which recently issued its annual list of the top 10 endangered rivers. “These chronic water shortages in the river are compounded by the hydropower dams that block many miles of salmon spawning habitat.”
U.S. Reps. Mike Thompson, D-Calif., and Earl Blumenauer, D-Ore., have introduced the Klamath River Basin Restoration & Emergency Assistance Act, which would provide $200 million for water conservation and economic assistance for communities affected by last year’s fish kill.