Millions of Americans have been ingesting them for years—perchlorate, hexavalent chromium, volatile organic compounds—not because they’re safe, but because they are among 6,000 toxins the EPA has not gotten around to regulating in municipal drinking water systems.
But after a change in administrations and a scathing review by the General Accounting Office, the EPA has begun to develop regulations to remove these chemicals from tap and bottled water—and industry has begun efforts to delay or prevent their implementation.
While government and industry wrestle over regulations, here are the prime suspects and the best ways to remove them from your water without government help:
Earlier this year the EPA reversed a Bush Administration decision to leave perchlorate unregulated and to pursue perchlorate first in a new push for stricter drinking water regulations.
An important ingredient in rocket fuel, fireworks, and explosives, Perchlorate can disrupt the thyroid gland’s production of hormones essential to prenatal and postnatal development and body metabolism, according to EPA and National Sanitation Foundation.
“Monitoring data show more than 4 percent of public water systems have detected perchlorate and between 5 million and 17 million people may be served drinking water containing perchlorate,” according to EPA.
Perchlorate can be removed from drinking water through reverse osmosis.
“The protocol requires a reverse osmosis unit to be able to reduce 130 ppb perchlorates to 4 ppb or less in the treated water supply,” according to NSF.
The EPA has a drinking water standard for total chromium, but not all forms of chromium pack the same punch, and the total chromium standard may be allowing unhealthy levels of toxic chromium into the water supply.
Hexavalent chromium, or chromium-6, in drinking water has been traced to stomach cancer in humans and animals, according to the Agency for Toxic Substances and Disease Registry. Workers exposed to chromium have developed lung cancer from inhaling it. It has also been linked to liver, kidney, circulatory and reproductive disorders.
An example of a chromium-6 compound: chromium trioxide.
Hexavalent chromium is produced by metal plating, the production of dyes, and the production of steel. Steel mills in Indiana dump chromium into Lake Michigan, which supplies drinking water for 7 million people in the Chicago area.
Earlier this year the EPA recommended municipal water agencies increase monitoring of hexavalent chromium.
Last week the city of Chicago released test results showing levels of hexavalent chromium more than ten times higher than California’s recently-adopted health standard. The California standard, 2 parts per billion, is designed for a risk level of one additional case of cancer per million people:
“For every million people who drink tap water with that level of chromium 6 each day for 70 years, there is likely to be one additional case of cancer from exposure to the chemical,” according to the California Office of Health Hazard Assessment.
Like perchlorate, hexavalent chromium can be removed from water through reverse osmosis. According to NSF, it can also be removed through distillation and certain types of water filters.
EPA proposes to streamline the regulation of additional toxins by regulating chemical groups rather than individual compounds. The first group in its crosshairs is a set of 16 volatile organic compounds known to cause cancer.
The EPA already regulates eight VOCs, including common industrial solvents and petroleum products, as carcinogens. In revising its standard for some of those, it intends to add eight that are currently unregulated:
The Agency is considering eight currently regulated compounds (benzene; carbon tetrachloride; 1,2- dichloroethane; 1,2-dichloropropane; dichloromethane; tetrachloroethylene; trichloroethylene; vinyl chloride) and eight unregulated compounds (aniline; benzyl chloride; 1,3-butadiene; 1,1-dichloroethane; nitrobenzene; oxirane methyl; 1,2,3-trichloropropane and urethane). All of these VOCs are known or suspected to cause cancer.”
via EPA (pdf)
EPA expects the regulation effort, which began this year, to take two or more years to produce a new rule. The effort is bound to be controversial because many VOCs are used in hydraulic fracturing, the process behind the current boom in domestic natural gas production.
In the meantime, reverse osmosis won’t help you get volatile organic compounds out of your water, according to the National Santitation Foundation, but carbon filtration will.