A proposed health clinic for Alexandria teen-agers, which would prescribe birth control devices, would cost the city a minimum of $235,320 in its first year, a city task force was told last night.

The cost estimate was part of a city staff report to the task force detailing options on how the clinic could be run. The study was requested by the City Council in May after a majority of the 40-member task force recommended setting up the clinic.

Meeting under the chairmanship of Mayor James P. Moran last night, the group also discussed ways to educate the community about the controversial health clinic proposal before a public hearing on the matter is held in November.

The council will vote on whether to establish the clinic after the public hearing. If approved, Alexandria would be the first jurisdiction in the D.C. area to set up such a school-based clinic, which the staff recommended locating in or near T.C. Williams, the city's only high school.

A minority group in the task force is opposed to the clinic, arguing it would increase teen-age pregnancies and abortions. Under the task force recommendations, the clinic would offer information about contraception and family planning and provide students with vouchers and prescriptions for birth control devices. But the clinics would not be permitted to dispense contraceptive devices or perform abortions.

Aimed at improving the overall physical and mental health of students, the clinic also would offer general physical examinations, suicide prevention counseling, drug and alcohol abuse counseling, treatment for sexually transmitted diseases and testing for acquired immune deficiency syndrome.

The task force recommended requiring written consent from parents before students could use the clinic's services.

The task force had recommended setting up four clinics, but the staff report last night advised that initially only one clinic should be established and that it should serve T.C. Williams students.

If operated on a part-time basis and located within the school, first year costs were estimated at $235,320. If open full time, the cost could reach almost $400,000, the staff concluded. Operating costs could go higher if the clinic could not be housed in the school building, the report said.

The staff noted that parental consent is not required by law for some services such as mental health counseling, treatment for sexually transmitted diseases and reproductive health care.

The task force will meet next Tuesday to consider the staff report and discuss its public education effort.