Without new sewer hookups, county sewer rates could continue to climb, Wade said.
The commissioners will meet with Hagerstown's mayor and City Council today at 3 p.m. in City Hall to discuss the city's proposed comprehensive plan and several other topics.
The plan calls for encouraging development in an urban services area served by city water and/or sewer rather than expanding services to developments outside the urban area.
The proposed urban services area runs from I-81 to north of Fountain Head, around Robinwood to south of the Interstate 70 interchange on Sharpsburg Pike and includes Halfway, but not Funkstown.
Those areas would be studied for possible annexation.
Since the city provides public water in that area, city officials could control growth, Wade said.
"We'll work something reasonable out," said Mayor Steven T. Sager. Water service will have to be provided to the I-81 corridor, which includes the county's Newgate Industrial Park, he said.
The city already is providing water services to part of the corridor, including to the new Staples distribution center off Hopewell Road, Sager said.
Commissioners President Gregory I. Snook said water service for new economic development along the I-81 corridor probably would be approved on a case-by-case basis and might depend on whether a company can pay for the cost of expanding the water line.
Commissioners Wade and Ronald L. Bowers said a water and sewer authority is needed to manage the city's and county's public utilities and direct growth.
The matter should be taken out of politicians' hands, they said.
Sager said the idea of an authority was "absurd."
"We have a well-managed triplet of utilities and the answer's simply no," he said. The city has its own water, sewer and electrical utilities.