FOR ALL WHO may have a participating interest in this September's city elections--or who presume they do, even if elections officials can't seem to verify it--we offer another in our series of reports on the Great Voter Roll Cleanup at city hall:

The mess, in case you missed it at the polls last November or when they lifted up a few rocks after election day, consisted of impossibly fouled-up voter registration data--unindexed, inaccurate and conflicting computer tapes that were passing for voter rolls. It was then that a vols pursuit of a chimerical "sunteer team of private computer experts moved in to let the chips fall where they should; and they produced a master list that showed more than 51,000 names that had been dropped from the rolls after the November 1980 elections.

While that list is getting a twice-over, operations have been put in the hands of a highly acclaimed new executive director of the elections board, Teddy Filosofos--and both efficiency and morale seem to be up, along with the number of registered voters. No one is pledging a perfect primary day on Sept. 14, but officials now say they are at least reasonably confident that the rolls will be accurate.

One way to check them out quickly--and reserve ahead for ballots--is to take advantage of a new service established by Mr. Filosofos: a 24-hour telephone hot line that will tell you where you do or don't stand. Within 24 hours of your inquiry to 347- 3383, the board will mail you either an official verification of your registration or--if your name doesn't show up in the files--a mail-in registration form.

There are other steps that should follow in the weeks ahead. A vigorous, thoroughly publicized registration effort is essential. Also, there should be a comprehensive, crystal-clear training program for all precinct workers, including a dress rehearsal and procedures for handling any challenged voters and their ballots.

We will continue to check in from time to time on these election preparations because this city's hard- won democratic franchise is at stake. Continued disgraceful election day foul-ups could ruin the integrity of the whole electoral system here-- and cost the District every home rule gain it has struggled so long to achieve and improve. That is a terrible prospect that should haunt local officials thoroghout this renewed quest for accuracy on election day.