New "conservation oriented" water and sewer rates, to take effect in early 1978, are being considered at informal hearings in Prince George's and Montgomery Counties.

Under the Washington Suburban Sanitary Commission proposed rate changes, the majority of homeowners - those using less than 350 gallons a day - would have their water and sewer bills reduced by an estimated $6 to $35 a year. In the non-residential category, rates for users would increase an average of 3.4 per cent. Increases as high as 11 per cent could be felt at garden apartments and high-rise developments.

The new rate proposals were developed in response to a request from the county governments that WSSC replace its current 20 per cent summer surcharge on all water bills with a "more fair and equitable system." A citizens advisory committee and WSSC's staff have recommended that the commission adopt a new, increasing-rate schedule, based on the customer's consumption of water.

Currently, WSSC's water and sewer rates are based on matered water comsumption, with the charge per 1,000 gallons remaining the same regardless of the amount of water used.Under the proposals, the charge per 1,000 gallons would rise or fall, dependent on the customer's average daily consumption of water (ADC). ADC is computed by dividing the total amount of water consumed during the billing period by the number of days in that period.

WSSC officials have said that the proposals are "designed to reward customers who conserve water and to penalize those customers who waste water." Officials stress that the new rates are not designed to raise additional money for the commission.

The proposals have come under attack by apartment dwellers, who say their attempts to conserve water would not be "rewarded." The renters point out that their average daily consumption is based on the total consumption of the entire apartment building, meaning that they could pay a much higher rate, through their rent, than the individually metered homeowner.

"It's the same old argument," said WSSC spokesman Arthur P. Brigham. Apartment dwellers say thay are exploited by politically active homeowners and that "homeowners don't feel that apartment dwellers are paying for their share of governmental services."

Apparently in sympathy with the renters and other "non-residential" users, the Prince Georges County Council and some WSSC officials are questioning the value of having an increasing rate schedule for customers who do not have direct control over their water consumption.

In answer to those objections, WSSC is offering an alternative proposal which keeps the increasing-rate schedule for resident-class for all non-residential customers.

Most of the 18 people present at the first hearing objected to the proposals because, they said, the new rates would not encourage water conservation.

Del. Charles S. Blumenthal (D-District 27) said he came to the hearing to voice his "disappointment with the new rates. I was hoping that this would be a straight-out conservation proposal, however, I find that it rewards the water wasters."

Blumenthal said that although there were the same numbers of apartment dwellers as homeowners in the two counties, homeowners use 48 per cent of all water consumed while apartments use only 28 per cent (the remaining percentage is consumed by business and government).

"A rate that was truly conservation-oriented would not raise the bills of those who are relatively conservative in their water use (tenants), while lowering the bills of those who are relatively wasteful (homeowners)," Blumenthal said.

Homeowner Sandra Montain of Oxon Hill, said, "The rates are unfair to large families. I follow all of the water saving suggestions WSSC puts out; I've bought water saving appliances. I don't wash my car, and I don't water my lawn and yet my rates will go up, because I have seven people living in my house. Per capita, we use less water than our neighbors, and yet under these so-called conservation oriented rates we will pay more per gallon than they do."

Those present at the hearing blamed the low turnout on poor publicity, saying that WSSC should have notified its customers of the proposals and hearing dates by mail.

It is not yet clear how much water will be consered under the new rate proposals. WSSC's Genereal Manager Robert S. McGarry has said that any sustained reduction in demand for water and sewer service could result in savings on customers bulls because WSSC's capital outlays for treatment and conveyance facilities would be reduced.

The remaining hearings on the proposed rate changes will be held at the following times and places:

Thursday, Oct. 6, 8 p.m., Montgomery County Office Building, (first floor auditorium) Rockville.

Thursday, Oct. 13, 8 p.m. WSSC Main Office Building Auditorium, Hyattsville.

Monday, Oct. 17, 8 p.m. Gaithersburg Junior High School, Gaithersburg.

Tuesday, Oct. 18, 8 p.m. Laurel Junior High School, Laurel.

A general public hearing on the final proposed rates will be held Thursday, Nov. 3 at 8 p.m. in the commission's auditorium, 4017 Hamilton St., Hyattsville.