In 1995 ABL was retained by a private developer requiring a treatment plant upgrade in order to obtain a permit for the expansion of his facilities. His existing plant was an old packaged extended aeration plant, which had already reached its limits. Through flow monitoring, ABL determined the hydraulic load was largely due to infiltration. Replacement of the site sewer reduced flows by 50%, leaving capacity for expansion. However, under a revised environmental permit, treatment to better than 15/15 mg/l BOD and SS was a requirement and, given the plant age, filters were considered necessary. Effluent filters were estimated to cost about $20,000 and would require increased maintenance.

ABL proposed the use of the ABL Biopyramid Greenhouse Treatment System as a demonstration project and test facility. With approval from the environmental regulatory authorities, a facility was constructed at about 50% of the cost of the conventional filter option. The effluent has typically been less than 10/10 mg/l BOD and SS and is usually about 5/5 mg/l BOD and SS. The Biopyramid Greenhouse has the capability to improve effluent quality from an aging packaged plant with low operating manpower requirements, and without any costly heating requirements to sustain native plants through the winter months.