U.S. and Canada took a step toward healthier waters in 2010--did you notice?

U.S. and Canada took a step toward healthier waters in 2010--did you notice?

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Last summer, something good happened for the waters of the United States. You can be excused for not having noticed, since this small step forward took place at the same time the Deepwater Horizon was spewing oil into the Gulf of Mexico. The major manufacturers of automatic dishwasher detergents started selling only products that are nearly phosphate-free.

The elimination of phosphates from dishwasher detergents brought them into line with other household products, such as laundry detergent, that have been required to work without phosphates for years.

The big manufacturers made the change in grudging response to strict limits on phosphates in dishwasher detergents enacted simultaneously by sixteen states, including Illinois. The choice faced by the manufacturers was whether to maintain different product lines for different states, or just meet the higher standard across the board.

While the switch to phosphate-free dishwasher detergents occurred without most people noticing (and plenty of people have been consciously choosing phosphate-free dishwashing products for years), others, especially people with hard water, have had trouble adjusting.

In fact, I learned of this story by way of an uncharacteristically bad report on National Public Radio, which focused on the complaints of two people whose dishes weren’t coming out at clean as they used to. This story neglected entirely the benefit to our waterways of reducing phosphorus pollution. It even included without comment the absurd statement from a woman in Texas who said, “I'm angry at the people who decided that phosphate was growing algae. I'm not sure that I believe that.” (If you're among people still looking for a no-phosphate solution, the September 2010 issue of Consumer Reports provides good options.)

For the record, Mark David, a professor in the UI Department of Natural Resources and Environmental Sciences who specializes in nutrient cycling, explained for me the effects of phosphorus pollution: “Phosphorus is usually the limiting nutrient for the growth of algae in streams and lakes. Even at low concentrations, it can lead to large amounts of algal growth, which can reduce the amount of dissolved oxygen in water and harm aquatic organisms, including fish.”

If you’ve ever looked down from a bridge and observed long strings of plants waving in the current of a stream, or seen a pond that’s bright green, you’ve seen the effects of excess phosphorus in fresh water.

David acknowledges a fact that the big manufacturers of dishwasher detergent like to point out, which is that removing phosphates from their products will not by itself solve the problem of phosphorus pollution. That’s because most phosphorus in streams and rivers comes from agricultural fields and what people eat, with the phosphorus entering the environment in sewage effluent. But, he says, removing phosphates from dishwasher detergents is a step in the right direction, especially when you consider that sewage treatment facilities are likely to face restrictions on how much phosphorus they discharge in the future.

In Spokane County, Washington, which enacted its own tight restrictions on phosphates in dishwasher detergent in 2009, a year’s worth of data showed that water entering the sewage treatment plant contained 10.7 percent less phosphorus than it had on average in the preceding three years.

Ultimately, much of the phosphorus pollution that enters streams in Illinois reaches the Gulf of Mexico, where it contributes to the creation of the dead zone. So while the Deepwater Horizon has been capped, this spill of nutrient pollution, which begins in the Midwest, continues. Ultimately, it will have to stop here.