A Submerged Attached Growth Reactor (SAGR) Demonstration Site has been in operation following a primary aerated lagoon in Steinbach, MB since August 2007. This system provides nitrification, with influent winter water temperatures (post lagoon) below 0.5 degrees Celsius. The performance objective of the system was to achieve effluent cBOD5 and TSS levels of less than 10 mg/L, and ammonia of less than 5 mg/L in winter and 1 mg/L in summer from a dual-feed treatment train following the lagoon. A single-feed treatment train runs as a control. Both trains receive water from an uncovered aerated lagoon with approximately 28 days of retention time.
The SAGR performance has exceeded all expectations. Effluent ammonia, TSS and BOD levels were below detection for most of the winter. Maximum monthly average ammonia effluent was below 0.61 mg/l, and the maximum daily ammonia effluent level was 1.63 mg/l.
The paper further discusses the results of the demonstration site and the potential implications for small towns operating lagoon based wastewater treatment systems on the prairies.