Ben B. Ruby, an executive for Montgomery Ward, stayed up all night trying to find out whether his company stores should be open or closed yesterday. William Austin, an executive for the Washington Suburban Sanitary Commission, spent most of a 24-hour period trying to disseminate such information.

Despite their efforts, Montgomery Ward and the WSSC came to confrontation yesterday at the Iverson Mall Shopping Center.

Prince George's County police ordered the Ward store there closed. The store manager refused. The WSSC readied a crew to descend on the store and turn off all its water. Attorneys for Ward told the WSSC to go ahead, but that the store would remain open. Austin prepared to ask the county health department to close the store because very shortly it was about to be without water.

Before a valve could be turned county officials and the WSSC issued a new emergency order: after 5 p.m it would be permissible for businesses to be open.

Austin, noting it was already nearly 2 p.m. decided to take no action. The police went away. The store remained open - but reported business was way off because potential customers didn't know it would be open.

This story, perhaps an extreme example, nevertheless illustrates the confusion expressed by many businessmen yesterday over the emergency water rationing, and the difficulty WSSC officials had in enforcing it.

Ruby had heard Thursday afternoon that some of the five Ward stores in Montgomery and Prince George's counties might have to be closed. But which ones? The press conference, conducted by local officials Thursday evening, "told us nothing," Ruby said. WSSC and the counties had ordered customers who consumed more than 15,000 gallons of water a day to close down. But, Ruby wondered, how much did the Ward stores use? And how about Ward competitors Sears, Woodward and Lothrop, The Hecht Co.)?

"We wanted to comply with the community interest," an exhausted Ruby said yesterday evening, "but we're also businessmen and we wanted to be sure that if we were going to be closed, so would our competitors."

Ruby and other officials scrambled through the evening, pulling water bills, trying to determine daily capacity. At about 10 someone rushed in with the list of businesses to be closed. The only Ward store on it was the Iverson Mall outlet at 3750 Branch Ave., Hillcrest Heights.

That didn't jibe with the figures complied by company officials. And the Woodies store at the other end of the Iverson Mall was not on the list.

Ruby was perplexed at the eriteria used and called the WSSC. "I got put on hold for an hour," he said.

Meanwhile, Austin, the head of the WSSC customer services department, had been working through the evening so swamped with calls that he and his staff had no time to notify businesses.

When Ruby reached Austin shortly before midnight, he questioned the WSSC's figures and asked for an explanation. Austin told him the computers were shut down. "There was no discussion." Ruby said. "He said if you're on the list, you're on the list."

Austin said he offered to double check the figures for Ruby in the morning and the figures eventually proved correct, but that Ruby never called backs.

Ruby huddled with Ward officials all night weighing options. When morning arrived employees began arriving for work. Ruby and Ward officials decided to follow the order, he said yesterday. He ordered the Iverson store closed. Only it opened anyway.

Ruby, informed by a reporter yesterday that the store had opened and there had been a confrontation, said he would have to check with store manager Foster. "Let just say there was a lack of communication, he explained later.