Until recently," Jerome K. Eldridge wrote, "there were hopper cars filled with coal at GSA's heating plant on the K Street waterfront.

"Now there's a forest of oil storage tanks behind the plant. Is Big Brother saying, 'Don't do as I do, do as I say'? Is there a reasonable explanation?"

Kenneth F. Ward. manager of heating operations and transmission for GSA's National Capital Region, wasn't behind a desk when I called. He was taking a first-hand look at some problems at the Central Heating Plant at 13th and C streets SW. When I reached him there, he took my call on a phone that must have been in the busiest and noisiest part of the plant.

"You're talking about the West Heating Plant at 29th and K, in Georgetown," he said. "Up until 1972, we used nothing but coal there. But on Feb. 5, 1972, we were told there had been a change in national policy. We would have to switch to oil or gas, and thereby minimize air pollution.

"So on July 25 of '72 we signed a contract to begin converting our West Plant boilers. But then came the oil embargo in the fall of '73, and we had to change course again.

"Two of our five boilers in the West Plant had been converted to gas and are now in use. The other three boilers hadn't been converted yet, so we can still burn coal in them. But now we must abide by federal EPA requirements, and the District also passed rules on clean air, so we're going to have to buy and install new equipment to protect the environment before we can switch back to coal.

"We made an agreement with the District government that one of those boilers can burn coal until March, 1980, but that didn't leave us much time to figure out what new equipment we need, or for getting the money to buy it and install it.

"We've completed the first part of the task. We know what we need, and our budget request has been made. Now we have to wait for a green light on the money."

"Changing policies necessitated by changing conditions have kept you hopping for the past few years, haven't they?" I commented.

"Well, I suppose so, "Ward said, "but there's a silver linng. "In 1972, we were completely depenent on coal. We were alwayss concerned that a prolonged interruption to our coal supplies would shut us down completely.

"However, when we complete this conversion process, we'll be able to use three fuels -- coal, gas of oil -- and we'll be better able to conform to future national policy as it changes to meet changing conditions. So I would consider the end result of our conversion problems a distinct plus. One never knows what the future in store, but we have to be prepared."

Thanks for the inquiry, Jerome. It gave me a chance to talk to another of the many government workers who serve us so well. Ward has all his job-related facts in his head, even down to exact dates, and he's too busy adapting to ever-changing conditions to waste time bellyaching about how difficult his job is. POSTSCRIPT

Having paid our respects to government officials who do their jobs well, we must now turn to Tuesday's front page story about $73 million worth of recent Treasury Department checks that were cashed fraudulently.

When an intended recipient reports that he failed to receive an expected check, the Treasury ascertains whether the check has been cashed. If it has not been, the Treasury sends out another check, but does not stop payment on the first one.

The Treasury thinks that in about 25 percent of these cases, the first and second checks are both cashed. In these instances of duplicate payments, Treasury thinks that about a third of the money goes into the pockets of forgers -- usually people who have stolen the checks. And, presumably, in the other two-thirds of the cases, the person who reported nonreceipt of his check filed a false claim, then cashed both checks himself. Apparently word has gotten around that Uncle Sam doesn't keep very good records on such matters, and that it's easy to obtain double payments.

Several questions suggest themselves: Has the Treasury made any attempt to compile a file of those who allege nonreceipt of checks? Wouldn't Treasury's computers make it easy to compile such a list, so that we'd at least know whether the same names recur frequently on lost check reports? Why is no attempt made to stop payment on the first check before a second is issued" Banks are supposed to know a person before they cash a check for him. Why is it so easy for forgers to obtain cash for checks made out to others? Has any money been recovered from banks and stores that have negligently cashed forged checks?

The long-suffering taxpayer is entitled to some answers.