A plan aimed at fixing a large number of failing household septic systems on Kent Island is stirring debate, as Queen Anne's County looks to permit roughly 600 new homes on the low-lying gateway to the Eastern Shore while hooking existing homes up to its sewer system.

County officials say the $53 million state-financed sewer project, made possible by legislation passed this year, would resolve a long-standing public health and environmental problem while limiting how much new development can take place in an area virtually surrounded by the Chesapeake Bay.

But opponents say the project flies in the face of Maryland's Smart Growth policies and rewards real estate speculators who've been sitting on unbuildable housing lots there for years.

County Administrator Gregg A. Todd acknowledged that residents and even conservation groups are split on the sewer plan, which is scheduled for a public hearing Thursday evening at Kent Island High School in Stevensville.

"There are folks down there that are adamant about no … new homes," Todd said, "and there are folks down there who've been fighting for years for sewer."

Growth has been a hot-button political issue in Queen Anne's since the 1950s, when construction of the Bay Bridge opened Kent Island to a land rush for weekend and summer retreats before there was any zoning or rules on waste treatment. Many of those getaways have become permanent homes, and now, county health officials say most of the 1,500 dwellings on the southern end of the island have septic systems that are polluting the bay and potentially endangering their health.

Because of the high water table on the island, untreated sewage ponds in some yards during rainy times, officials say. Most are letting nitrogen pollution leak almost untreated into the bay, contributing to its algae blooms and dead zone. The health department imposed a moratorium years ago on building new homes there on septic systems.

A solution had been thwarted until now by the cost of extending the sewer line, and by many residents' fear it would trigger a new wave of building. There are roughly 1,600 lots recorded that might be built on once they have a reliable way to dispose of sewage.

To reduce costs, the county's sewer plan hinges on getting low-interest loans and a grant from the state, leaving homeowners to pay about $100 a month.

Until this year, the state had been legally barred from funding sewer projects outside designated growth areas, leaving southern Kent Island ineligible. But to help rural areas troubled by failing septic systems, the Department of the Environment received legislative approval to relax the prohibition, as long as new development is limited.

To curb new homes connecting to the island sewer line, the county wants to make lot owners combine their 1,600 unbuilt home sites into about 660. Officials predict that only about 560 would get built. Owners of the combined lots would have to pay $25,000 to $40,000 to connect, the county administrator said, though their lots would soar in value once they're buildable.

The Midshore Riverkeeper Conservancy, which has sued to block other large-scale development, supports the sewer project.

"There's been decades and decades of egregious overdevelopment on Kent Island," said Tim Junkin, the group's executive director. But he said even with 600 new homes, eliminating all the septic systems there would reduce the amount of nitrogen seeping into the bay by about 22,000 pounds a year, according to state estimates.

"That's a huge swipe," Junkin said. While he'd prefer not see new homes built there, he said, "we can't let the perfect get in the way of the good."

But Jay Falstad, executive director of the Queen Anne's Conservation Association, contends that county officials haven't fully explored alternatives to the sewer line. If it's built, he said, more woods and wetlands on the island would be lost, and more pavement built. The island is vulnerable to storm surges as sea level rises, he pointed out, with only a single two-lane road to get out.

"If we're really trying to protect the Chesapeake Bay, this is going about it in completely the wrong way," said Falstad. He said the county plan is saddling existing homeowners with unnecessary costs while enriching landowners and speculators.

Eugene M. McGuire Jr., a Northern Virginia investment executive who owns a vacation home as well as nine lots on the island, figures he'd have to merge the lots into three or maybe four under the plan.

"That's fine," he said. He said he's more concerned that residents there have safe sanitation they can afford, adding that he and his friends "don't want to see the place overrun, either."

tim.wheeler@baltsun.com