The laboratory tests, conducted by the Environmental Working Group of Washington, D.C., found the highest levels in the drinking water of Norman, Okla.; Honolulu; and Riverside, Calif. Bend, the only Oregon city sampled, had the 10th-highest level of the 35 large and small cities studied.
State, federal and local drinking water officials say they'll review the findings, one of the broadest surveys for hexavalent chromium ever conducted. Hexavalent chromium is the toxic form of chromium, which can enter water through erosion from natural deposits or from industrial discharges from the manufacture of stainless steel, metal plating, wood products or textiles. The point sources in the study were not identified.
The findings are expected to further press the Environmental Protection Agency to toughen drinking water standards. Currently, the EPA does not have a legal limit for hexavalent chromium and does not require water utilities to test for it. Since 1992, the agency has required tests for total chromium compounds, which include both a nutritional form, chromium 3, as well as the cancer-causing form, chromium 6.
Scientific and legal debate has raged over hexavalent chromium since a file clerk named Erin Brockovich uncovered nearly two decades ago that the toxic chemical had leaked from a Pacific Gas & Electric plant into the groundwater in Hinkley, Calif. In 1996, PG&E paid $333 million to about 600 residents who had high rates of cancer and other diseases. It was then the largest tort injury settlement in U.S. history.
California became the only state to test for hexavalent chromium and recently reported detecting it in one-third of its 7,000 water sources.The Hinkley levels were at concentrations 10 times the current California legal limit. But concerns over even low levels of hexavalent chromium have grown.
Bend was one of 35 cities included to illustrate the national scope, said scientist Rebecca Sutton, an environmental chemist and lead author of the study. The nonprofit selected cities in 23 states that had elevated levels of total chromium in past water quality reports. Bend had registered two spikes in total chromium in 2004, although both were nearly 100 times less than the EPA's legal limit, state water quality officials said.
The test detected .78 parts per billion of hexavalent chromium in Bend's tap water.
Bend officials who had not yet seen the study responded: "The city of Bend follows all rules to test for total chromium on a strict schedule for all of our groundwater wells and Bridge Creek source water. Looking back at total chromium data to 1987, the city has always been below EPA's maximum contamination level of 100 parts per billion. The majority of samples tested for total chromium have been non-detects. In other words, no contamination was found."
Sutton said the Environmental Working Group recruited water collectors via its staff and other contacts. Tap water samples were collected from unfiltered taps in homes or in public buildings such as hospitals, libraries and malls. Utility bills were reviewed to verify the water source. Volunteers used a standardized sample collection protocol, including running the cold water tap for two minutes to clear pipes of standing water and then placing the sample in chilled freezer packs and shipping for analysis.
Sutton said people concerned about their water should invest in a reverse osmosis filter system, not bottled water, which may come from a suspect source.
David Leland, manager of the drinking water program for the Oregon Department of Human Services, said the few detections for total chromium in Oregon water have been so low "this has not been on our radar."
But he said the state would review the study.
Currently, 36 Oregon Army National Guard veterans are suing war contractor Kellogg, Brown and Root for exposing them to hexavalent chromium at the Qarmat Ali water treatment plant where they guarded operations early in the Iraq war. The material, used as a rust fighter, had been piled up and blowing around the plant. The case is in U.S. District Court in Portland.
Scientists have known for almost 20 years that inhaling hexavalent chromium can cause people to develop lung cancer. But it wasn't until two years ago that California officials asked the National Toxicology Program scientists to conduct animal studies on ingesting hexavalent chromium. They found rats and mice developed mouth and small-intestine malignant tumors. California has proposed the strictest limits yet, a public health goal of 0.06 parts per billion for hexavalent chromium. California also allows half the level of total chromium the federal government does.
Professor Max Costa, chairman of the New York University School of Medicine's department of environmental medicine, says current EPA and California levels are "are very high and not safe."
"It is disturbing that other states do not test for this common contaminant that is carcinogenic by ingestion. It is also disturbing that 25 cities have levels of hexavalent chromium greater than the (proposed) California public health goal."
A spokesman for the EPA said that in 2011, the agency will consider the results as it reviews the drinking water standards for total chromium.
Bend officials said they will comply with whatever changes may come.
"If the EPA and state of Oregon require the city to monitor specifically for hexavalent chromium, then that's exactly what we will do. Our duty is to protect the public health for the citizens of Bend," a city spokesman said in a statement.