The regional body that is responsible for organizing the cleanup of the Potomac River in the Washington area asked Montgomery County citizens this week to learn about the area's water pollution problems and assist planners in finding solutions to them.

The appeal was made at the first of four public meetings the Water Resources Planning Board will hold throughout the region in coming weeks.

The board, an arm of the Metropolitan Washington Council of Governments, is supervising a $3.5 million staff effort to identify the sources of water pollution, predict future problems and establish plans to solve and prevent them.

"I urge you to think regionally," Rockwood Foster, a D.C. member of the citizens advisory committee to the board, told the group of about 25 people assembled in a Silver Spring auditorium. "Right now we have no mechanism" for regional decision-making in water quality planning, he said, although the Potomac's problems are regional in their making.

Water quality planning for areas such as the Potomac Basin was ordered by the Federal Water Pollution Control Act. That act provides federal money for most of the planning, but also requires that the plan be followed once it is adopted. If that proves to be the case, it will run counter to history.

Water pollution is defined by professionals as coming from two places: "point sources," such as rainstorm runoff from agricultural lands and city rooftops.

Most of the billion-dollar effort to date to clean the Potomac in the Washington area has been concentrated on building new, or improving old, sewage treatment plants. As the area continues to grow, more plant capacity will be needed.

Frank Lamm, staff director for the regional plan, said that Montgomery County had about 18 per cent of the region's population in 1970 and is expected to continue at that level through 1995. However, regional population is expected to increase from 2.8 million people to 4.2 million.

Montgomery County does not have enough sewage plant capacity at the moment to handle its needs, Lamm and Foster said. But the region as a whole does, and some of that capacity could be shared. At the moment most of suburban Maryland's sewage is treated at the giant regional Blue Plains plant in the District.

Montgomery County's long-term plans included until recently a major treatment plant at Dickerson, on the Potomac near the Frederick County line. That plant was scuttled by the U.S. Environmental Protection Agency on the grounds it would cost too much for the benefit provided.

While the EPA decision is being appealed in court, a major effort to find alternatives is under study by some Montgomery County Council members and by the EPA.

While the major effort to date has been on "point source" problems, fully 60 per cent of the pollutants swept into the Potomac come from "non-point sources," Foster said.

A major contribution to that load is the sediment (mud) that is carried into the Potomac after land is stripped of vegetation to make way for new subdivisions. If more people move here, there will be new subdivisions to house them.

Pesticides and herbicides used in agriculture and excrement from dairy herds and swine also contribute to the pollution problems of agricultural runoff.

Similar meetings are scheduled in the District of Columbia next Monday at the Martin Luther King Memorial Library, 901 G St. NW; in Prince George's County next Tuesday at the Maryland-National Capital Park and Planning Commission Auditorium, 6600 Kenilworth Avenue, Riverdale, and on Jan. 31 in Northern Virginia at the Falls Church City Hall Auditorium, 300 Park Avenue, Falls Church. All meetings begin at 7:30 p.m.

Citizens wishing to subscribe to a free newsletter detailing the progress of the plan are encouraged to write the Metropolitan Washington Council of Governments, Water Resources Planning Board, Water Resources Citizen Participation Coordinator, 1225 Connecticut Ave. NW, Washington, D.C. 20036.