How pure must our water be to be safe to drink? This is no simple question
for the chemists who are asked to answer it. We think of chemists as the ones
who can answer this because we rely on the chemical, chlorine, to clean water
and the introduction of chlorine into water creates new chemical byproducts.
Do those byproducts present a threat to water quality? Or more precisely, what
are the levels of chlorine byproducts that are acceptable?
Such technical, arcane matters may seem best left to scientists. Yet, ultimately, government regulators must be involved. Government must play a role because we would not want to permit private parties to decide on their own what microbial pathogens are allowed in drinking water. Serious diseases can be borne by water and, thus, water must be chemically treated before it comes out of the tap in our homes and offices. As one EPA (Environmental Protection Agency) official put it: "We use chlorine-in the twentieth century there's no single other health measure that's been more effective than chlorine disinfectant at reducing typhoid [and] cholera. Basically, what it does is kills most of the bacteria and virus pathogens that may be in the source water."
The EPA's authority to regulate drinking water derives from the Clean Water Act. Congress, however, has left decisions on the hard science questions to EPA. There is a good deal of scientific literature on chlorine byproducts. Some research shows a relationship between chlorine byproducts and cancer or reproductive abnormalities in laboratory animals. Other studies fail to find such a connection. The familiar question also arises of whether we extrapolate incidence rates from mice or rats receiving high doses of the chemicals to the low doses that humans are exposed to in their drinking water.
There are many lobbying groups that have a strong interest in this matter. Chlorine manufacturers want their product protected. Municipal water authorities don't want to have to make any unnecessary expenditures to add new equipment or purchase more chemicals. Environmental groups want to ensure that our drinking water is as safe as possible. A major effort to move the controversy over drinking water forward was a negotiated regulation in 1992. A negotiated regulation (or "reg-neg" in the jargon of Washington) is a procedure that allows interested parties to try to formulate a regulation on a policy matter that government is contemplating action on. Instead of the more common process of a government agency determining through its own research what should be done, the agency asks the most important interested parties in that policy area if they would like to see if they can find common ground. If the negotiations are successful, the government puts the regulation into effect. The 1992 reg-neg, which was considered the first stage in a longer-term process, produced a regulation that set water standard thresholds at 80 parts per billion (ppb) for total trihalomethanes, 60 ppb for haloacetic acid, and 10 ppb for bromate.
Further specification of standards began with stage two in 1999. Again, a reg-neg was initiated and the same lobbies came back to the bargaining table. The goal was for EPA to issue a proposed rule on standards sometime in 2001. It took a little longer to accomplish but the reg-neg did propose enhanced regulatory standards in the summer of 2003.