Septic systems are not a subject that most people like to dwell on, but the giant multiuser system proposed for a new retirement community in Marriottsville is getting attention anyway.
Its dimensions make it hard to ignore.
Brantly Development Corp. and Landsource Ltd. are proposing a 147-unit complex for "active seniors" on 73 acres at the northeast corner of Route 144 (Frederick Road) and Marriottsville Road. Under their plans, wastewater from all 147 homes would flow into a single septic system tucked in one 11-acre corner of the parcel - a flow that developers say could reach 45,000 gallons a day.
The developers are confident the system, which would be the largest of its kind in the county, would run like clockwork. State and county officials who will be reviewing the system are not so sure.
"Generally, on-site sewage disposal systems work best if they're kept small," said Frank A. Skinner, the county's environmental health director. "You start getting into the thousands and thousands of [gallons of] sewage flow, and it gets more difficult to deal with."
The outcome of the proposal, which returns to the Board of Appeals on Tuesday evening, carries a significance beyond tiny Marriottsville, officials and residents say. For the most part, the county has discouraged high-density development in its rural west by, among other things, limiting public sewer and water service to the eastern county.
If large septic systems become more prevalent, that could change. Developers could build higher-density housing without regard for public sewerage - though they still would be hampered by the cost of large septic systems and the availability of well water.
"It's a very bad precedent to set," said Donna Mennito, former director of Howard's farmland preservation program. "I'm not sure there are many citizens who understand the ramifications."
In their initial plans, developers had hoped to serve the retirement community with public sewer lines, which run very close to the site. They noted that the area around the site is served by public water because of concerns 10 years ago about potential groundwater contamination from the nearby Alpha Ridge landfill.
But county officials made clear that they were unwilling to expand sewer lines anytime soon, and the developers switched to the multiuser septic system solution.
The developers have not provided detailed plans for the system, but it has been penciled in for 11 acres in the northwest corner of the parcel, where the elevation is highest. Sewage from the homes would flow first into a pretreatment unit, where it would undergo denitrification before being pumped into the septic field.
In theory, state and county officials have been inclined to support large septic systems that serve multiple homes because they reduce the amount of land that must be set aside for septic fields. In addition, said Tom Miller, a University of Maryland Cooperative Extension water-quality specialist, large systems are typically under very close oversight.
In this instance, though, regulators have doubts. Properties bordering the site, which is a few hundred yards from Doughoregan Manor, the home of founding father Charles Carroll, have had serious septic troubles. A 1968 survey of the county's soils shows that about half the area set aside for the septic system would have "moderate" difficulty absorbing sewage.
This doesn't necessarily mean that a septic field would be impossible there; it does mean that the system would have to be spread over a broader area. Officials estimate the system would require 45,000 square feet of trenches - not counting the two required backup systems.
"The system could be competing for house locations," Skinner said. "That may cut down and interfere with their plans."
Environmental engineer Robert W. Sheesley, who is working for the developers, dismisses such concerns. The preliminary tests he has done at the site show that the soils are "deep and well-drained." And if the septic field needs to be expanded at the expense of a few homes, it can be, he said.
"I have the facts; I dug the holes. The key is how you the lay the system out," he said. "People in this county who have public water and sewer wouldn't know septic if they tripped over it. When something like this comes up, it's different. So they think it's bad."
The Board of Appeals has been reluctant to consider the site's septic prospects in deciding whether to approve the project. That will be the job of county and state health officials, members say.
Some criticize this approach, saying it is the board's job to weigh all aspects of proposals.
"The downside is it puts pressure on the Health Department to approve something it may not be comfortable with," said Planning and Zoning Director Joseph W. Rutter Jr.
Others wonder if the developers' ambitious septic plans are a bluff, to bide time until the county extends sewer lines to the site.
A new County Council will be elected next year, and the developers could delay septic construction in hopes that new members would back sewer expansion. Brantly President John Liparini said last week that he still thinks the council should include the site in the public sewerage area.
Or, officials speculate, developers could build the septic system, figuring that if it fails, the county would have no option but to offer public sewer service.
"I hope that's not the strategy," said Councilman Allan H. Kittleman, a western county Republican who is against extending sewerage to the site. "My gut feeling on [the septic proposal] is, 'Wow, that's awfully large.'"