Homes: Bigger polluters than thought

Scientists who have studied residential areas in California have found that the typical house is linked to about 50 percent more water pollution than previous thought.

The researchers, Lorence Oki and Darren Haver, both of  UC Davis, looked at runoff from rainfall and lawn-watering, which washes fertilizers and other contaminants into storm drains and then in to nearby waterways. They collected samples of runoff from eight residential areas in Sacramento and Orange Counties every one to two weeks and analyzed them for pesticides, pathogens, nutrients and "drinking water constituents of concern."

Previous estimates of runoff were based on data collected from the wet season.  "Use of pesticides, however, increases noticeably during the dry season due to gardening, and our data contains greater resolution than previous studies," Oki said. Factoring in more conditions, the researchers found that contamination from homes is likely much higher.

Oddly enough, one of the most prevalent pesticides they detected were compounds used to control ants, leading them to suggest that better ant control products would benefit local waterways.

The scientists presented their research last week at the 238th national meeting of the American Chemical Society.