Carpe Datum

Lead Pipe Cinch

Under the Boy King, the EPA Has Become
More Like the Enable Polluters Agency.
(Image credit: Steve Jackson Games)

I mentioned my problems with public water utilities and lead a few days ago in reaction to the news that they discovered city officials in Washington, D. C. have been suppressing the news about dangerous levels of lead in the drinking water there. Well, wouldn't you know it, this month's Scientific American has some interesting news about some unexpected consequences:

The public reporting last year of high lead levels in the drinking water in Washington, D.C., has led to a congressional investigation, the firing of a D.C. health official, and calls for a review of the 1991 law that is supposed to keep the neurotoxic metal out of drinking water. That law, however, may not contribute to the problem as much as the changes made to disinfection procedures resulting from another water safety rule. The conflicting regulations mean that other municipalities may also soon find too much lead coming out of their faucets.

To date, at least 157 houses in D.C. have lead levels at the tap higher than 300 parts per billion (ppb), and thousands more have exceeded the Environmental Protection Agency's limit of 15 ppb. Residents have received contradictory advice about whether tap water is safe to drink and whether replacement of lead service lines will solve the problem.

Lead should not normally enter the flow, because layers of different lead-snaring minerals naturally build up inside the pipes. But these mineral scales act as a trap for lead only as long as they remain insoluble; a sudden shift in water chemistry can change that.

Such a change may have triggered the D.C. problems. In 2000 Washington Aqueduct, the area's water treatment plant, modified its procedures to comply with the 1998 Disinfection Byproducts Rule (DBR), which restricts the presence of so-called halogenated organic compounds in water. These compounds form when disinfectants, particularly chlorine, react with natural organic and inorganic matter in source water and in distribution systems. The DBR directs water companies to make sure that the by-products, which might cause cancer, stay below a certain level.

This is what they do these days, I guess, to get rid of the complex organic molecules that form with chlorine (they're called THM's, and I can't recall what that stands for off the top of my head). Those are potentially some of the nastiest pollutants. Most places refer to this class of chemical as VOC's, for Volatile Organic Compounds.

One of the most common ways to comply with the DBR is to use a mixture of chlorine and ammonia--called chloramines--instead of chlorine. Some 30 percent of major U.S. water companies currently take this route, and the proportion will probably grow as limits on disinfection by-products are tightened during the next few years. Because no one has investigated the effects of chloramines on corrosion in drinking-water systems, meeting DBR requirements may mean violating the 1991 lead-copper rule, which sets maximum limits on these metals (for lead, 15 ppb).

Evidence for chloramines' effect on Washington's pipes comes from EPA chemist Michael Schock. He discovered that different mineral scales--especially lead dioxide scales--are particularly vulnerable to changes in water chemistry. With chlorine, Washington's water was highly oxidizing. As a result, the mineral scales that formed consisted of lead dioxide, which Schock has found in every sample of Washington's lead service lines that he has examined. The switch to chloramines lowered the oxidizing potential of D.C.'s water, which probably dissolved the lead dioxide scale and thereby liberated the lead.

Corrosion scientists warned about potential conflicts between the two rules. "We were concerned that drastic changes in water treatment could disturb scales and mobilize metals," says one scientist involved in the investigation of the D.C. lead problem, who asked not to be named. Another researcher echoed the point: "There was essentially no research concerning interactions between the lead-copper rule and the DBR. There was zero consultation with corrosion scientists even though we screamed for it."

The EPA noted potential conflicts in a 1999 publication entitled Microbial and Disinfection Byproducts Rules Simultaneous Compliance Guidance Manual. But the document offers little in the form of specific procedural advice, scientists say. Virginia Tech engineer Marc Edwards, a former EPA consultant who first called attention to the D.C. problem, has warned the agency and the water industry for years that changes in drinking-water treatment were liable to cause trouble for home plumbing systems.

He believes that lead problems may lurk in other cities, too. Chemist Mark Benjamin of the University of Washington concurs, noting that the factors affecting corrosion--the pipe material, the mineral scales and the water quality--are universal in water systems. "It would be remarkable and unlikely to think that these factors just happened to combine in a unique way in Washington," he states.

Note well that this problem began back during the Clinton administration (though under the Republican Congress, which never met an EPA funding bill it liked). No administration is immune to scientific foolishness, of course, but the current crop of idiots is completely unprecedented. That link points to a page where Henry Waxman (a House Democrat) has been keeping track of all the different ways the Bushies ignore or abuse science. You should follow the links there regarding drinking water and lead poisoning (just two relevant examples) to find out the difference between scientific ignorance (which is sad but typical most of the time) and malicious hostility toward science (which is sad but typical for this administration).

Science policy in this administration is basically being written by the equivalent of tobacco industry science whores. When it comes to your own health and safety vs corporate profits, you can't trust these people. I'm thinking of getting our own drinking water tested (and the bottled water we buy, for that matter), just to satisfy my curiosity, but crap, places like Aqua MD, ETR Labs or e-watertest charge 100-200 bucks to test for lead, MTBE and other crap. If I could get it done for 10-20 bucks, maybe I'd do both. 100 bucks is a bit steep just to play Erin Brockovich, you know?

Posted by Observer at July 22, 2004 06:57 AM