OLYMPIA – The Legislature on Friday approved a ban on lawn fertilizers that contain phosphorus.
On a 56-37 vote, the House of Representatives sent the governor a bill that restricts the sale of that type of fertilizer with that chemical, starting in 2013.
The bill, HB 1489, went through several changes in the past two months. The final version allows the use of phosphorus-laced fertilizers to start a new lawn or to repair a damaged one but bans it on healthy lawns.
It doesn’t restrict phosphorus in fertilizers for farming, flower or vegetable gardens or houseplants.
The theory behind the restriction – disputed during hearings and floor debates – is that phosphorus is less likely to bind with the soil when applied to healthy lawns, and with rain or over-watering more likely to run off the lawn, down the storm drain and into the nearby streams, rivers and lakes. Once there, it tends to help algae grow.
The bill was supported by the city of Spokane as a way to cut down on phosphorus loading in the Spokane River and Lake Spokane. It now goes to Gov. Chris Gregoire who has the choice to sign it or veto it.
In 2006, Gregoire signed a bill to ban phosphorus in dishwashing detergents, making Washington the first state in the nation to do so. The ban went into effect in Spokane, Whatcom and Clark counties in 2008 and in the rest of the state last summer.
Phosphorus in runoff causes accelerated plant and algae growth in lakes and rivers. As the plants die, bacteria consume the oxygen needed for the survival of fish and other aquatic life, according to the Washington State Department of Ecology.