An advisory citizens' group, unhappy with the low level of public awareness that the region is in the midst of drawing a far-reaching blueprint for cleaning up the Potomac River, has gone to the public with an opinion survey. The questionnaire is being distributed throughout the metropolitan area.

The citizens' committee, which advises the Water Resources Planning Board of the Metropolitan Washingron Council of Governments, hopes that the results of the survey will not only stir public interest but will persuade policy makers to scrap the most controversial proposal in the draft blueprint - that a large regional sewage treatment plant be built in Montgomery County, up stream from the intakes that supply two-thirds of the area's drinking water.

Whether the public will respond in any greater numbers to the survey than it did to the informational and public hearings on the draft plan, remains to be seen.

The questions presume that those surveyed have a detailed knowledge of water quality in the metropolitan area and the various proposals to improve it - and are versed in the technology of identifying and cleaning up pollution.

For example, question one that one of five alternatives be chosen: 1) "I believe existing standards are adequate protection for drinking water quality;" 2) "I believe that Md., Va. and D.C. water quality standards should cover toxic substances and pollutants such as nitrogen and phosphorus;" 3) "I would, if necessary, be willing to pay for higher sewage treatment costs to meet more stringent water quality standards;" 4) "Undecided;" 5) " I have another suggestion."

The citizens' advisory committee which is controlled by staunch environmentalists, says COG officals and stagg were half-hearted or too late in trying to raise the public's consciousness about the draft plan, which (with periodic updating) will guide cleaning action in the river for the next 20 years.

There doesn't seem to be any argument about the low level of public awareness. The hearings held last week drew small crowds - none of them more than a hundred people, and most of those were aligned with the environmentalists who control the citizens' committee. Even skimpier crowds came for the informational meetings held the previous week.

But who was to blame, if anyone?

Louise Chestnut, of Arlington, vice chairwoman of the citizens' committee blames "the professionals in public relations" at COG. She was also critical of the Water Resources Planning Board for not allowing the citizens' commitee to use public funds for its opinion survey.

Another criticiam, made by Chestnut and other members of the committee, was that the information COG did get out to the public come too late to have any educational value. For example, the complete, two-inch-thick copies of the 20-year plan were sent to area libraries only shorly before the hearings.

COG officials acknowlege that the "frantic timetable" set by the Water Resources Planning Board didn't leave much time for leisurely review of all the implications of the 20-year plan. But one official who has been closely involved in the two-year effort to put a plan together said the citizens' committee itself "completely drummed out the legitimate involvementof concerned citizens with other views."

One member, Judy French, who represented Rockville, said, "I was so annoyed by the one-sidedness of the committee. There was no brooking another viewpoint. There was no way to listen to another side. . . I don't see how the staff could stand it.How they kept their cool, I don't know."

French considered resigning, but stayed on because, she said, there probably wouldn't have been enough time for a substitute to absorb all the technical data that had accumulated during the two years of analysis.

While the citizens' committee complained that "politics" frequently undercut the cleanup plan, the group itself was not alien to politics. Theoretically, the committee was supposed to include different factions of the metropolitan community, but it has been dominated by the environmentalists - and they scored their points in the various rebuttals that the citizens' group made to the draft plan as it took shape.

Nonetheless, even some of the targets of the criticism acknowledge that the committee, while it may not have helped to galvanize public participation, did perform a valuble service in reviewing the ongoing draft, and was responsible for many changes that make the plan tougher on pollution.