On Sept. 16, Martha S. Stewart dispatched a letter to the District's Water Department. Her letter said she had not received a water bill for a long time and it referred to a Washington Post article about tardy water bills. The letter said:

"This article pointed out that certain District residents who had not been sent bills, due to inefficient billing procedures at the Water Department, were finally sent their bills with large amounts of interest added.

"I am anxious to pay for the water I have used and not been billed for.However, since it is necessary for me to call this matter to your attention and to request my bill, I ask that you not charge me any interest."

In a manner of speaking, City Hall has compiled with Martha's request. She has not been billed for interest.

Unfortunately, she has also not been billed for the water she has used. In fact she has heard absolutely nothing from anybody in the District government.

Of course, only four weeks have elapsed since Martha expressed a desire to pay her account, and one must not become impatient while dealing with a government agency -- especially an agency that apparently uses a computer that runs on slow electricity. For all we know, Martha Stewart's water bill may at this very moment be emerging from electronic marination.

However, if her bill is not sent out in the next few days, I think Mayor Barry would be forgiven if he lost his patience, or even his temper, with the person or persons responsible for the Water Department's billing delays.

A city that is desperate for revenue simply cannot afford such Toonerville Trolley business practices.

A successful businessman's first priority is service to his customers. His second priority must be the prompt collection of what is owed to him. Everything else is in third place.

The District has turned off water service to those who didn't pay because they weren't billed, which is outrageous. But even turning off the leaking money faucet at the District Building will not balance the city's budget. Our troubles run deeper than that. Yet every dollar helps, and the psychological effect is important, too.

Firing people makes enemies, and conventional wisdom says that, to be successful, politicians must make friends. But sometimes conventional wisdom is wrong.

C'mon, Mr. Mayor, let's stop worrying about the best election and start thinking about the right way and the wrong way to run a city.

J.E. Carter Jr. plays politics adroitly, but conventional wisdom got his hintere whipped. He might have won more votes if he had dared to make more enemies. ONE VOTE REVISITED

Benjamin L. Schwartz of Vienna has replied to my "one vote" exhortation to cast a ballot. He writes, "There has never been a documented case of one vote deciding a popular election for a national office."

I can recall no case that would refute his statement. But that is of little importance.

It would be a statistical monstrosity if one vote were to settle an election in which 85 million ballots were cast. Nevertheless, it could happen And there are many documented cases in which a handful of votes -- perhaps 200, 100, 50, or 17 -- did determine the outcome of a national election.

And what about the dozens of local elections that end in ties?

Last Tuesday, one of those races (for a seat in the New Mexico legislature) made the national news tickers when the two tied candidatess agreed to decide the issue by "playing a hand of poker" (as our correspondent put it) for the job.

State law says ties shall be settled "by lot." Usually, tied candidates toss a coin. But these two preferred to settle their battle at the poker table.

When I had read that much of the story, I said to myself, "Hey, this is great. Sometimes you can tell more about a man by watching him play poker for 15 minutes than by living with him for 15 years."

Then I read on and discovered that these two turkeys were going to play one hand of showdown for the job. Showdown!

I hope they both lost. HERE WE GO AGAIN

Colleague Dan McCoubrey reports there is already a T-shirt on the market that bears the legend, "Impeach Reagan."