Starting Sept. 1 the cost of soft drinks sold in Fairfax County will have a 5-cent deposit added for each bottle and can.

Turning aside objections from soft-drink and container industries, the Fairfax Board of Supervisors this week decided to put in effective date on their 1 1/2-year-old ordinance requiring a deposit on soda containers. The ordinance also bans the use of snap-top cans.

Consumers will get their deposit back when they return containers to dealers. Refunds will be given on both returnable and throwaway containers.

The Fairfax ordinance does not cover beer containers because the Loudoun County circuit court - ruling on a similar law in Loudoun County - decided that only the Virginia Alcoholic Beverage Control Board can impose controls in that on beer cans.

Some supervisors asked that the ordinance, originally scheduled to into effect July 1, be delayed until next Jan. 1 either to await resolution of legal issues or state enabling legislation. But under the strong urging of Supervisor Alan H. Magazine (D-Mason), who said, "I don't think it's bad to be on the frontier (of law)," the board decided to go with the September date.

Faifax would be the only Northern Virginia jurisdiction with such and ordinance, although a similar one was enacted in Montgomery County and is scheduled to go into effect Jan. 1.

The aim of deposit ordinances is to reduce roadside litter caused by cans and bottles. Lobbyists for the soft-drink and container industries have maintained that beverage containers are only a small fraction of local litter. Supervisor Marie B. Travesky (R-Springfield) said, however, that workers in a cleanup drive in her district found they spent most of their efforts picking up bottles and cans. "They don't disintegrate like a lot of litter," she said.

In other action, the supervisors voted to impose a penalty fee of 10 per cent of the tax due or $5, whichever is greater, on personal property tax returns filed after the May 1 deadline.

The supervisors also decided to urge the Virginia State Corporation Commission to review the possibility that utility companies received excessive revenue during the energy cruch last winter. Supervisor review proposed last winter has not yet been made.

Supervisor Joseph Alexander (D-Lee) requested that the county staff come up with a program to repair roads. There has been a moratorium on road repair due to litigation with the citizens' group over responsibilities for repairing county roads.