As home sites with high-quality soils for onsite treatment systems grow scarcer, installers are looking to aerobic treatment units (ATUs). That’s true in the counties around St. Louis, Missouri, where Show Me Soils performs site evaluations.

The company’s soil analyses often point property owners and onsite system designers toward advanced treatment. In Franklin County, about 30 miles west of St. Louis, Show Me Soils owner Chris Chapman is the licensed distributor for Norweco. He often recommends the Singulair 960 treatment unit, featuring the BK 2000 Bio-Kinetic treatment system. He also offers the Singulair Green treatment system for difficult-to-reach locations.

The counties around St. Louis are known among onsite professionals for difficult soil conditions, from extremely shallow bedrock to highly impermeable clays. Such sites are typically ill-suited for conventional septic systems but may be workable if an ATU is part of the treatment package.

Chapman performs the maintenance on the roughly 50 Norweco units he has sold – state code requires the system owners to enter a contract with a maintenance professional for the first two years. He favors the Singulair 960 including the Bio-Kinetic system, which is easy to remove and replace during routine maintenance: “You go to the site, pull the dirty one out and put the clean one in. It’s like having a brand-new system every six months.”

Norweco says the Singulair systems are proven alternatives to conventional septic systems for domestic wastewater treatment. Employing the extended aeration process, the units are designed to provide flow equalization, pretreatment, aeration, clarification, tertiary filtration and optional chemical addition within a single precast concrete tank. By equalizing flows of up to 1,500 gpd, the manufacturer says the system helps prevent solids washout and hydraulic overloading of the drainfield. 

The systems’ only mechanical component is a fractional horsepower aerator, which runs at 1,725 rpm and is certified with a 30-minute-per-hour runtime. The Bio-Kinetic device ensures that all flow through the Singulair system is equalized and completely treated. The systems are designed for domestic flows from 500 to 1,500 gpd.

Read more about Show Me Soils in the October issue.