Septic Tank Limits Delayed for More Study by Supervisors : Pollution: The goal of the requirement for sewer lines and treatment plants is to prevent nitrates in septic tanks from seeping into the water supply in fast-growing rural areas.

At the urging of the Ventura County Board of Supervisors, state water-quality officials agreed Monday to delay action on a sweeping proposal to restrict use of septic tanks in fast-growing, rural areas of Ventura and Los Angeles counties.

Environmental specialists of the California Regional Water Quality Control Board, fearing that nitrates seeping from septic tanks will pollute water supplies, have recommended that developers be required to install sewer systems and build water treatment plants in rural areas that rely heavily on ground water.

The proposal, which would not apply to existing homes, would affect fast-growing rural communities that obtain most of their water from local wells.

Robert Gallagher, a spokesman for the Ventura County Environmental Health Department, said the Ventura supervisors learned of the plan only last month and wanted more time to study the proposal.

“Potentially, it could have an impact throughout our county,” Gallagher said after a hearing by the state agency’s control board for the Los Angeles Region, which includes Los Angeles and Ventura counties.

The control board agreed to hold another public hearing on the proposal May 21 in Ventura, and perhaps vote on the issue in June.

Community groups from Agua Dulce and Acton in northern Los Angeles County attacked the proposal, saying sewers would spur unwanted growth in rural enclaves fighting to retain a country flavor.

“The sewer system is not the solution,” said Charles E. Brink Jr., a member of the Acton Town Council.

“It would be a bigger problem than what we have now.”

The groups also insisted that, contrary to the control board’s findings, there is little if any nitrate pollution in the wells of Agua Dulce and Acton.

Control board officials said high concentrations of nitrates in drinking water can cause the sometimes fatal “blue baby” syndrome, which impairs the ability of infants’ blood to carry oxygen to the lungs.

The proposal would require sewers to be installed for all dwellings built on lots smaller than two acres.

Builders on lots from two to five acres could continue to use septic tanks but would be required to install standby sewer piping in case sewers are required later.

Lots larger than five acres would remain exempt.

The proposal has been in the works for almost a year, and developers complained Monday that the lengthy delay has left many of their projects in limbo.

The proposal is overly rigid, the developers said, and does not consider the plight of builders who designed their projects with septic tanks, and not costly sewers, in mind.

“This policy is not flexible at all,” said Gary L. Kaiser, a consultant to more than 50 developers in the Acton area.

“It’s not practical.”