The soils in the Palouse region in and near Idaho’s panhandle are well suited for conventional septic systems. Still, Tyson Koehn, owner of Palouse Valley Septic Service in Princeton, Idaho, uses plastic chambers for nearly all drainfields. That’s because the hilly terrain and wooded building sites make pipe-and-rock systems difficult to install.

“You dump your rock and park everything above the house or out beside the road, and then you have to cart everything down the hill, so you get a lot of labor and machine time involved with pipe-and-rock systems,” Koehn says. “With chambers, we carry them in or drag them down the hill. In our wooded areas, we can bend them around hillsides and obstacles.”

Koehn prefers Quick4 Plus Low Profile chambers from Infiltrator Water Technologies. They are designed to provide advanced contouring capability and include four center structural columns to maximize strength. They are available in sizes and styles to meet diverse regulatory and site requirements.

They are 8 inches high, 53 inches long and 34 inches wide to fit in 36-inch-wide trenches and allow for shallow installation.

Advanced contouring is enabled by a Contour Swivel Connection that permits turns up to 15 degrees right or left. End caps help maximize flexibility in system design and configurations.

The chambers reduce the amount of imported fill needed for cap-and-fill systems. A latching mechanism supports quick installation. Finished systems under 12 inches of cover support wheel loads of 16,000 pounds per axle.

While Tyson prefers precast concrete septic tanks, he turns to plastic tanks for sites where moving in a concrete tank would be difficult. In those cases, he selects 1,000-gallon IM-1060 plastic septic tanks from Infiltrator.

This lightweight, watertight tank is injection-molded for strength and durability. It is offered with the company’s custom-fit risers and heavy-duty lids. Built-in lifting lugs enable easy delivery and handling. Structurally reinforced access ports help prevent distortion during installation and pumpouts. Reinforced ribbing and fiberglass bulkheads add strength.

The tanks can be installed with 6 to 48 inches of cover and can be pumped dry. No special installation, backfill or water-filling procedures are required. The tanks can be backfilled with suitable native soil.