The Carlisle Mosquito Online

Friday, May 7, 1999


Innovative alternative allowed for Berry Corner septic repair

A number of abutters appeared at the April 20 board of health public hearing for repairs to a septic system at 125 Berry Corner Lane. Engineer Bruce Ringwall of GPR described an Innovative Alternative septic system (IA system) to solve the problems on this property which has a partially completed septic system. The system has a huge mound surrounded by a clay barrier reef. The contour of the land causes water run-off to flood the garage and to travel onto the property of abutter Jack Schulz.The septic tank is placed at an angle and one corner of it is 7 feet from the house, violating the ten-foot town regulation.

Ringwall proposed a Bioclear system which uses an air pump installed below the effluent and sprays it over the active area. The suspended solids are 150 to 300 parts per million (ppm) going into the Bioclear unit and are 30 to 50 ppm heading to the leaching field. The system has only six inches of stone instead of 12 inches because there is no build-up of bio material underneath the system. Also, the system needs only two feet of fill for groundwater offset instead of the four feet required by Carlisle's regulations. Ringwall also requested that no garbage grinder be used, as Bioclear recommends against garbage grinders.

Schulz asked about the design's use of one-inch pipe with 3/16 inch holes in the bottom. Schulz was concerned that the pipe and holes seemed awfully small compared to the five-inch pipes required in a conventional system. Ringwall explained that the level of suspended solids was much less than that of a conventional system, the water was nearly clear, and smaller pipes and openings could be used to reduce the pump size. The pump runs for several minutes at a time.

Another abutter, Dick Wells, asked why some other part of the three-acre lot could not be used for a conventional system. Ringwall explained that this would require clearing a large area of trees, if suitable perc rates were found, and would cost upwards of $40,000 to $50,000, not including the cost to restore the present site. The IA design would use much of the existing material on the site and cost considerably less.

Member Skip Saunders asked how many Bioclear systems Ringwall's company had installed to date. Ringwall responded that one has been running in Harvard for over a year, and that four more have been approved by various towns.

Saunders explained that although there are a couple of IA systems (not Bioclear) in town, the board is reluctant to permit them because they require substantially more maintenance than conventional systems. Saunders explained that regulations require that the homeowner supply maintenance reports every two years similar to the pumper reports done when people pump conventional systems. Ringwall estimates maintenance costs at $400 per year.

The board of health approved the IA design with the following waivers: fill height of two feet instead of four, a garbage grinder, the septic tank at seven feet from the dwelling, and six inches of new stone instead of 12.

1999 The Carlisle Mosquito