As the County Council considers requiring more homeowners to have pollution-reducing septic systems, environment officials are encouraging people to install them voluntarily.

A state grant program is available to dramatically reduce the costs, but participation has been slow. Just 63 county homeowners have participated, getting an average of $17,700 toward the new systems, according to the county Health Department, which administers the program.

"We got the most money initially and we're still using that money," said Ed Peters, an environmental sanitarian for the Health Department.

The money comes from the state's Bay...