AFTER SO MANY dreadful years of bloated, inaccurate registration rolls in the District of Columbia, the city's elections officials have said goodbye to its dead and departed voters with a vengeance. Not only have the rolls been pared by nearly 200,000 names to bring the list down to 283,000; they also are being put to yet another test to verify and update the names that remain. This is a remarkably impressive job, led with expertise and good humor by Emmett H. Fremaux Jr., the energetic executive director of the elections board.

From now on, an annual mail canvass will check voters' addresses and remove the names of people who have moved without informing the board. The first of these mailings is in progress. If the information on the card is correct, no action is necessary by the voter or te board. If the Postal Service returns the card, a second notice will be mailed that is to be forwarded to the voter's new address; this notice will advise the voter that his or her registration is being canceled.

The cancellation policy is a good one. Voters who move are supposed to inform the board of their new local address within 30 days. As board chairman Edward W. Norton notes, the periodic removal of the names of people not registered where they live is essential -- to prevent abuses and preserve the integrity of elections in the city.

Just as the Election Day horrors of the past were singularly unacceptable to voters who fought so long for a measure of self-government, the new monitoring system is especially welcome. The District of Columbia has too much at stake to let the system break down again.