D.C. General Hospital officials said yesterday they plan to open the city's first PCP detoxification unit on April 1, a 20-bed facility where treatment is expected to cost $520 a day per patient.

Of the $3.6 million budgeted for the unit, $2.2 million is to come from the D.C. Department of Human Services. The hospital hopes to get most of the remaining $1.4 million from collections from patients, officials said at a hearing of the D.C. City Council's Committee on Human Services.

Abuse of PCP, or phencyclidine, has reached epidemic proportions in the District, particularly among youths, according to city officials, police officers and mental health specialists. The hospital had planned a year ago to open a detoxification unit for heroin addicts but decided six months ago to shift its focus to PCP, according to hospital spokeswoman Penelope Anderson.

James L. Kunen, chairman of the D.C. General Hospital Commission, told the committee yesterday that the hospital gets about five to seven patients a day who are suffering from the acute effects of PCP.

The city has no inpatient PCP detoxification unit, Anderson said. Some of the patients will come to the hospital through the court system, but most are expected to present themselves to the hospital at its emergency room, she added.

Mayor Marion Barry's proposed fiscal 1987 budget also included $1.5 million to open two new drug treatment clinics in the city with a total of 700 more treatment slots. As a result, the budget anticipates a sharp jump in the number of admissions for drug treatment by the city, from about 5,000 expected in this fiscal year to more than 7,000 next year.

Council member John Ray (D-At Large) said it appears that D.C. General still does not have enough nurses, asking if the problem was lack of qualified candidates.

Sherman McCoy, D.C. General's acting executive director, said the city's public hospital continues to have a problem staying competitive because it pays lower salaries, offers less vacation and has poorer facilities than the city's private hospitals,.

Kunen told the committee that changes in the way the federal government makes Medicare payments will result in a $1.6 million decrease in Medicare payments to the hospital in fiscal 1987. Reimbursement in fiscal 1987 will be about what it was in fiscal 1981, with the same number of patients, he said.

E. Veronica Pace, executive director of the D.C. Office of Aging, said a proposed $2.7 million increase in her office's budget, to a total of $10.4 million, would be used to open two multipurpose senior centers in Wards 7 and 8 in Southeast, to operate seven buses for the elderly, to increase in-home health services and to open five new nutrition sites.