Washington Suburban Sanitary Commission customers will pay more for water consumption and sewer usage under newly adopted customer rates which went into effect last month.

The revised rates, which were adopted along with the WSSC's $289 million budget, include a boost in the water consumption charge of 70 cents per 1,000 gallons - a five-cent increase from the old rate of 65 cents per 1,000 gallons. The sewer usage charge also moves up three cents from the old level of 95 cents to 98 cents per 1,000 gallons of metered water use.

The basic changes in the water consumption and sewer usage rates would involve an increase of $8 a year for a WSSC customer who used 100,000 gallons of water a year, according to the WSSC. Service charges, which are based on customer meter size, will remain unchanged during fiscal year 1978.

The WSSC's budget and rate actions were in accord with joint approval given a sanitary commission budget and recommended rates by the county councils of Montgomery and Prince George's counties. Under the law, the two counties' governing bodies establish the level of operating and capital expenditures for the WSSC, and the counties' budget figures must be adopted by the Commission.

The recently adopted budget provides for a 4.2 per cent cost-of-living salary adjustment for WSSC employees. Budgeted operating expenditures during FY 1978 total $105 million, while approved capital outlays are expected to run $184 million, according to the WSSC.

The budget/rate resolution sets a flat sewer rate for "sewer only" customers, who are connected to the sewerage system but do not have metered water service at $24 per quarter and also provides for th continuation of the 20 per cent summer water consumption surcharge during July, August and September of this year.

In response to a request by the Montgomery and Prince George's County Councils, the WSSC promised to "develop and implement, by January, 1978, a new system for charging for water consumption in an effort to encourage water conservation and (provide for) an equitable distribution of the burden of costs." The WSSC reports that work is in progress on a pricing plan which it hopes to have ready for public review and discussion this fall.

The final adoption of the WSSC's fiscal year 1978 budget came after almost six months of hearings and reviews conducted after the commission presented its draft proposal last January.