Louisville, there's something in your water. It's called hexavalent chromium, also known as chromium-6, a chemical compound that's both naturally occurring and an industrial waste from the production of stainless steel, leather tanning, wood preservation, and textile dyes, among others. It's also deadly.

In June of 2008, Louisville won top honors in a nationwide taste test for its drinking water. To celebrate, then-Mayor Jerry Abramson boasted, "Louisville's water is clearly superior," while handing out bottles of Louisville Pure Tap to kids and adults at Waterfront Park.

Thanks to the Environmental Working Group (EWG), we know it is clearly not superior. (Read EWG's report.)

With samples from 34 other American cities, Louisville's water was tested for hexavalent chromium, and results were released publicly, all for the first time, by EWG. Louisville is among 31 cities whose tap water contains a detectable level of the heavy metal, a known carcinogen. LEO Weekly reported dramatically in its offhanded Fat Lip news blog, with noteworthy chart, that Louisville's water already exceeds safe limits; however, it only exceeds the limit California has proposed should become the new standard of chromium-6 regulation.

Despite the State of California's initiative to legislate a "safe" level of chromium-6, presumably with a list and a dart--the magic number for no discernible reason being 0.06 parts per billion--the fact remains that there exists no scientifically known safe amount of hexavalent chromium.

Hexavalent chromium contamination comes from three ultimate sources. The first, from natural sources, including soil and rock containing metal ore; the second, industrial pollution; and, third, from a type of chlorination used to disinfect city water, converting the nutritionally necessary and naturally occurring mineral chromium-3 (trivalent chromium)--which aids the body's metabolization of glucose--into the deadly chromium-6. According to EWG, it seems some people with acidic stomachs can convert the deadly chromium-6 back into the nutritionally necessary chromium-3, but the process is thwarted by antacid use.

According to The Washington Post, the federal government has implemented a restriction of total chromium in drinking water, and has mandated testing for years; however, the total includes both the necessary chromium-3, and the deadly chromium-6, cumulatively, with no real benefit as the ratios vary from city to city.

Before you run to your local big box discount store for a cheap case of the spring waters, it's important to understand that if the water wasn't bottled in the state where it's purchased, it does not fall under the same regulations as your tap water. The U.S. Food and Drug Administration (FDA) oversees bottled water, whereas the U.S. Environmental Protection Agency (EPA) decides what qualities make tap water safe to drink.

It's a common mistake Americans make, believing that a classy label glued onto a processed food package ensures consumer safety and corporate integrity. The fact is, processed foods, bottled water among them, make big profits. If you think your $3.00 discount case of precipitation is superior, think again.

What flows from your tap is disinfected, as required by law, but the FDA does not require disinfection of bottled water. In fact, regulations are opposite across the board.

In bottled water, the absence of E. coli, fecal coliform, asbestos and phthalates are not regulated. Water bottlers are not required to filter for pathogens. And, consumers have no protected rights to knowledge of product contamination. Big city and small town tap water, and its consumers, are protected in every way that bottled water is not.

Additionally, bottled water facilities are only required to test for bacteria once per week; however, Louisville Water Company, like all big city water, is required to test hundreds of times per month, and must use a certified testing lab for results.

The only bonus of bottled water is that its lead levels are limited to 5 parts per million (ppm), versus 15 ppm in big city water. The higher allowable limit flowing from the faucet accounts for possible contamination from old pipes along its journey to your home.

But, forget lead; that's already regulated for safety, and any cheap home water filter will remove excess. Hexavalent chromium isn't regulated in its own right, and EWG's testing was the first of its kind. We just don't know in what concentrations it begins causing disease.

For now, we shouldn't fear Louisville's big city water, nor should we rush out to replace our drinking water with bottled; it's possible what's bottled is simply tap water from another big city with the potential to contain more hexavalent chromium than our own tap water. We already know bottles of Louisville Pure Tap are contaminated at 0.14 ppb--barely there compared to other cities' water. But, even at discount, bottled water is extremely expensive compared to what's available from your own kitchen faucet.

As knowledge and activism expand on the issue of chromium-6 in drinking water, there's only one sure way to greatly reduce or eliminate exposure, which is to invest in an in-home reverse osmosis water system filtering at the point where water enters your home; however, note that chromium-6 contamination can come from inside your home's old pipes, rendering a household system pointless. And, reverse osmosis eliminates fluoride from your water. Many home carbon filtration products, like Brita and PUR, do not sufficiently filter chromium, but ZeroWater filtration has been shown to reduce amounts of total chromium. Keep in mind, since all water comes from some natural source, there exist no precautions or interventions to eliminate all traces of dangerous contaminants from any drinking water.

According to Jim Bruggers' related story from the Courier-Journal, Louisville Water Company has begun pulling water from a source below the Ohio River, allowing layers of earth to act as a natural filter, but does that natural filtration reduce or eliminate either chromium-6 or total chromium? We don't have those answers, just yet.

For all its filth, the Ohio River runs pretty clean through our faucets. We should continue to drink the water we're already paying for, from the water company that employs Louisville families. We can't eliminate all danger from the water we drink, no matter its source, but we do need to hold EPA accountablefor allowing waste to be dumped into the river we drink, and further, to establish new enforceable drinking water standards. The current total chromium standards are 20 years old, yet our technology has increased with the ability to detect even smaller amounts of dangerous compounds like chromium-6. California aside, we need regulation that's based on science, and water that's truly clean, not just tasty. We each deserve to drink clean water, but we can't speak up with our throats dry.

Contact the writer at rachel@hurdanger.com

Photo: LouisvilleKY.gov