He said a lower rate also would be contingent on the county continuing to pump money into sewer operations from the general fund.
The County Commissioners are using $3.5 million from the general fund to subsidize water, sewer and industrial pretreatment operations this year.
A 9 percent rate increase would raise the cost for the average residential customer using 12,000 gallons a quarter by $7.85 every three months. That customer pays $87.20 a quarter at the current rate.
A 5 percent increase would cost that same average customer $4.36 more a quarter.
Murray said closing down the Nicodemus Wastewater Treatment Plant and diverting its flow to the Conococheague Wastewater Treatment Plant will save the county $4 million in upgrade costs at the Nicodemus plant.
The upgrade at the Conococheague plant would cost about $5 million, instead of an estimated $12 million to $14 million cost of upgrading both facilities.
The state will pay 40 percent to 50 percent of the costs.
County Commissioner James R. Wade asked Murray and County Finance Director Debra Bastian to explore options for reducing the draw on the general fund and cutting rate increases.
Last year, the county had projected yearly increases as high as 9 percent over the next 10 years, and a rate study by Black & Veatch two years ago had projected annual rate increases of up to 14 percent.
Murray said that the sewer operating budget will drop by more than 15 percent next year, amounting to a $300,000 savings. Murray attributed the savings to increased operating efficiencies and reductions in capital costs.
Public Works Director Gary Rohrer said an emphasis on preventive maintenance was starting to show dividends.
"We're not fighting as many fires," Rohrer said.
When the county took over water and sewer operations from the Sanitary Commission, maintenance had been neglected, resulting in costly repairs, he said.
"This is just another example of the improvement to the operating efficiencies of the department since we took over," Rohrer said.
Bastian said the county's combined water, sewer and pretreatment debt had dropped to about $53 million, down from its peak of near $55 million.
Bastian projected that the $40.2 million sewer debt would drop to $23.9 million by June 30, 2007, provided the county continues to pump money into sewer operations from the general fund.