The Washington Post is reporting that the cancer-causing chemical made famous by the movie "Erin Brockovich" has turned up in 31 cities across the country. Unfortunately, we're one of them. The chemical, hexavalent chromium, has a concentration of .19 parts per billion. That's a number that sounds negligible but isn't, especially when you consider the consequences: the chemical causes cancer in humans when it is inhaled, and has recently been shown to cause cancer in lab animals when it is ingested (as in: on food or in water).

The concentration in our water is actually three times higher than a goal set by the California EPA (we'd use government number, but they don't have one). Lynn Goldman, the dean of GW's School of Public Health, says the widespread presence of the chemical signals "raises the issue of about a national drinking water standard...and why we don't have one."

What's worse: your Brita filter isn't removing this chemical, and bottled water often comes from the same source as tap water. Your best bet is investing in a reverse osmosis water filter (which run about $200).

The presence of cancer-causing chemicals in our water is bad, but don't go running for the hills just yet. Goldman also says: "it's premature to say we know really what the level (of contamination) is, whether it's there all the time or just intermittently and what the source is."

That being said, we don't actually know if we're off the hook. We won't know until Congress funds projects to research hexavalent chromium and other endocrine disrupting chemicals--then sets limits on or even bans the ones that are dangerous.