Oregon Public Broadcasting

Governor Kulongoski plans to sign the Oregon Legislature's bill  on dishwasher detergent.  The measure would ban the sale of dishwasher soap that contains more than .5 percent phosphorous starting next year.  Pete Springer reports.

Phosphorous is a nutrient -- too much of it in water promotes algae and weed growth.

That affects ph and oxygen levels, which in turn harms aquatic life, says Debra Sturdevant.

She’s a water quality expert with the Oregon Department of Environmental Quality.

Debra Sturdevant: “Sewage treatment plants don’t always remove nutrients from the discharge.  They take care of other things and they take care of bacteria and pathogens, but they don’t necessarily always remove nutrients like phosphorus and nitrogen.”

Phosphorus is not directly toxic to humans and opponents of the bill say phosphorus-free soaps don’t clean as well.

Similar legislation in Spokane has led to increased sales in nearby Idaho of detergents that do contain phosphates.

That may be due to Spokane’s water, though.  It’s considered moderately hard.

Softer water, such as that in the Portland area, tends to clean more efficiently with phosphorus free detergents than harder water does.