The D.C. Public Service Commission is "seriously considering" eliminating the requirements for security deposits that 75,000 or more customers in the District of Columbia have paid to the gas, electric and telephone companies.

Such a decision by the PSC, which regulates utilities, could involve refunds of millions of dollars in deposits. The subject has been a leading cause of consumer complaints against the companies.

Security deposits have been the traditional way for utilities across the country to insure that customers, who are considered credit risks, pay their bills. Unlike the District of Columbia, there has been no hint by the regulatory commissions in Maryland or Virginia that this tradition might change.

The commission's disclosure of its thinking on deposits was part of a notice announcing hearings on a proposed "Consumer Bill of Rights" for the District of Columbia that Carrell also would set new rules for utility billing, service cutoff and complaint procedures.

The notice, signed by former PSC chairperson Ruth Hankins-Nesbitt, said the three-member commission wanted to hear "additional substantive input" on deposits during the Oct. 4, 5 and 6 hearings beginning at 10 a.m. in room 314 of PSC headquarters at 1625 I St. NW.

"Also, if deposits are retained there is still a question as to whether the maximum deposit should be $100," said the notice. Hankins-Nesbit recently was replaced as chairperson by commissioner Elizabeth H. Patterson, but remains a member.

William R. Stratton, the third commissioner, said yesterday that the commission is "prepared to pass" a version of the consumer bill that would not drop security deposits unless the arguments in the hearing were strong enough for doing so.

He said that the current draft of the proposed bill, which has been under consideration since 1975, has "been massaged and reworked so many times now (that it) has no close association with any person's point of view."

Yesterday, lawyers for the D.C. people's counsel office, which represents consumers in utility cases, and for the utility companies were working on additional changes - their versions of what the bill ultimately should say. These versions must be filed with the commission by Monday, although members of the public may register to testify at the hearings any time before they are held.

The people's counsel office and spokesmen for Washington Gas Light Co., Potomac Electric Power Co., and C&P Telephone said they would not comment on security deposits or other issues in the case before Monday.

The gas company holds $1.5 million in security deposits from 20,000 of its 150,000 District of Columbia customers, a WGL spokesman said.

C&P holds 13,000 deposits from among its 260,000 District of Columbia customers, but a company spokesman said yesterday the total dollar amount of these could not be immediately found.

A Pepco spokesman said the company holds $692,000 in deposits from 19,500 of its 161,000 residential customers in D.C., and an additional unknown sum from 24,728 commercial customers. All residential customers are required to make a deposit, the spokesman said.

Deposit rules vary among companies but basically are required of customers not considered credit worthy. When a customer reestablishes credit-worthiness by paying bills on time or some other means, the deposit is returned with interest.

Utility billing procedures are another leading cause of customer complaints that the proposed consumer bill deals with, according to the Hankins-Nesbitt notice. Under the current draft of the bill before the commission, estimated bills could not be mailed more than two months in succession.

Under current law, Pepco is never supposed to send an estimated bill unless its representative is unable to read a meter. WGL may estimate bills every other month.

However, estimated bills from both companies can continue to arrive month after month if meters remain inaccessible and if customers fail to read their own meters and send in the information on cards provided by the companies.

Customers who receive a string of estimated bills often think, for one reason or another, that the company is at fault and is overcharging them, according to consumer advocates.