Mon June 20, 2011
Crunchy Water? How Floods Change the Taste of H2O
By Alex Smith
KANSAS CITY, Mo. – Sometimes when we hear about flooding in our area, it's easy to get a little leery about what's coming out of our facets. That's especially true when the tap water tastes a little different than usual. Could there be sewage or pesticides leaking into our water supply? Is it safe? This week, Alex Smith investigated.
A Matter of Taste
For most people, the taste of tap water is something we can usually take for granted. Fill up a glass, take a drink and it tastes like water. But for David Green, this taste is a matter of personal pride.
"I can definitely taste a difference from town to town and different water systems," Green says. "And I think our water tastes among the best that I've tasted."
David Green is the Acting Laboratory Manager for the Kansas City, Missouri water department. He works at the treatment plant just about mile north of downtown. Here, they pull in and treat water from the Missouri River for Kansas City, Missouri and about 30 nearby towns.
A Nose for Water
On average, around 100 million gallons of water are treated here every day. And in the labs of the water treatment center, highly-trained chemists like Green spend a lot of time smelling water.
"With all the sophisticated scientific instrumentation that we have among those tools are the human nose, which is incredibly sensitive, so we utilize that," he says.
Debunking the Change-is-Danger Myth
This treatment facility provides water for about 20 per cent of the state of Missouri, and David Green says whenever tap water starts to taste different, they hear about it.
"When people sense a change in the water, it makes you think that something might be different or that it might be tainted because you're sensing a change," he says. "So it might not even be a displeasurable flavor but you sense that change and that's what causes people to wonder if there is something wrong with their water."
But David Green is quick to point out that changes in the taste and smell of water are not dangerous. The potentially dangerous bacteria and pesticides are actually tasteless and odorless, and these elements are removed using chlorine and charcoal filtering.
Slight changes in water taste happen regularly, especially in the spring and early summer when lakes upstream drain more organic matter than usual into the Missouri River.
"Lakes turn over and it has to do with the density of the water and the temperature," Green explains. "In the springtime, the heavier, colder water that's been sitting on the bottom of the lake with all the decaying matter and sulfurous gases basically turns over and the lakes mix up. That water gets released from those dams and comes downstream so that's where we get this slug of this organic matter that causes taste.
"And when I talk about this organic matter, I'm talking about very, very small minute quantities of these chemicals down in the couple parts per trillion range. Even a few parts per trillion of certain compounds can cause taste and odor and people can sense that."
Despite the flooding, the water treatment center is operating more or less as usual right now, though the water department is doing extra testing for traces of leaked sewage or pesticides. But, in fact, the water is cleaner now that it typically is this time of year. That's because ice packs up the mountains are 40 per cent bigger than normal. So, as it gets warmer, the whole river system is being flushed out with lots of clean, freshly-melted rain water.
"Actually, with the amount the sheer volume of water that is coming down the river at this point, the water quality in the Missouri River is actually relatively good, which is surprising, so we are operating normally right now and we actually have more capacity to increase treatment chemicals," Green says.
So, until further notice, you can drink up. The water's fine.