The performance of a septic system and drain field is directly linked to natural bacteria that can percolate in the soil, and to the presence of oxygen. However our cold climate, with frozen or saturated soil, inhibits their positive action, prompting plugging, accumulation of solids and backing up. Adding selectively adapted strains of bacteria will ensure a purifying bacterial flora that is effective all year long and will improve the quality of treatment while reducing accumulation of solids and maintaining the system’s healthiness.