A new law that could improve Lake Champlain water quality makes it illegal for stores in New York to stock fresh supplies of household dishwasher detergents that contain phosphorus.
Stores have 60 days to sell old inventories. Sales for commercial use are to end July 1, 2013.
Starting in 2012, a similar ban will apply to lawn fertilizers.
Environmental officials say phosphorus drains into New York lakes and rivers, which turn green with algae, degrading drinking water and reducing oxygen that fish need. More than 100 bodies of water in the state are considered impaired, including Cayuga Lake and Lake Champlain.
With similar measures now effective in 16 other states, including neighboring Vermont and Pennsylvania, many detergent makers produce low-phosphate formulas. Consumer tests show some are cleaning better than even earlier detergents considered environmentally friendly.
"The impact of phosphorus is particularly significant in lakes and reservoirs. Over half of all the lake acres in the state have water quality impacts for which phosphorus is a contributing cause," according to a Department of Environmental Conservation analysis.
As a cleaning agent, dishwasher detergents may contain up to 9 percent phosphorus by weight, and as a plant nutrient, lawn fertilizer contains up to 3 percent. The New York law, signed last month by Gov. David Paterson, lowers permissible levels to 0.5 percent for household dishwasher detergent and 0.67 percent for lawn fertilizer.
The detergent restocking ban took effect Saturday.
"We're chipping away at sources of pollution. This is one. Nitrogen is another," said DEC Commissioner Pete Grannis. Pesticides are a third, and the agency backed legislation enacted earlier this year that will ban the use of pesticides on schoolyards and playing fields.
The agency says that while dishwasher detergent and lawn fertilizer are only two sources of phosphorus, they are relatively easy and inexpensive to control. Steps were taken in the early 1970s to eliminate phosphorus from hand soap and laundry detergents, but exempting dishwasher detergent, which was not common at the time.
Of the phosphorus found in municipal wastewater, dishwashing detergent accounts for 9 percent to 34 percent. Lawn fertilizer can account for about 50 percent of phosphorus found in storm runoff.
The provision on lawn fertilizers prohibits applying the compounds between Dec. 1 and April 1 or near surface water. It contains exceptions for new lawns or when a test shows an existing lawn has too little phosphorus. It does not affect fertilizer for agriculture or gardens.
The provision was modeled after Minnesota's law. Maine, Florida and Wisconsin also have fertilizer controls.
In a test of 24 low- or no-phosphate dish detergents, Consumer Reports recently rated Finish Quantum on top and recommended four products, though none equaled a now discontinued detergent that topped its ratings last year.
"Past tests found that some low-phosphate products performed the worst overall, but the newest formulations are worth a try," the consumer guide said.