Thanks to lawmakers in Maryland who resisted a high-powered lobbying blitz by the soap and detergent industry, you may now add phosphates to the list of official dirty words in the effort to clean up the Chesapeake Bay and other waters of the state. Better still, there is support in the District of Columbia government, too, for a ban on phosphates in detergents. Obviously such a move would make water cleanup efforts in both jurisdictions all the more effective.

D.C. Council member William Spaulding says he is preparing legislation for introduction next week that would ban phosphates in much the same manner as Maryland's measure. Phosphorus, a fertilizer, contributes to excess growth of algae, which die and decrease the dissolved oxygen in fresh water. This in turn kills off submerged vegetation, fin fish, shellfish and other elements considered critical to the water's quality. Supporters of a phosphate ban say that a regionwide prohibition also could save money -- reducing by perhaps 15 percent the amount of sludge now being produced by the city's Blue Plains sewage treatment plant. In all, the savings could amount to millions, Mr. Spaulding estimates.

Mere mention of the news that city officials are considering a ban will probably bring on the same wave of lobbyists to sing the praises of detergents with phosphates and to minimize any damage that they create. But if Maryland's legislators could recognize the cleaner way to vote, so should their counterparts in the District. And then maybe Virginians will wish to help preserve the waters of their state as well.