Project Background & Challenges

The Town of Shellbrook is a rural community in Northern Saskatchewan with nearly 1,300 residents. Like many other small communities faced with the challenge of an aging lagoon-based wastewater treatment facility and increasingly stringent regulations, the Town of Shellbrook was evaluating options to upgrade its wastewater treatment facility. Shellbrook’s objective was to treat its wastewater to the standards set by the CCME (Canadian Council of Ministers of the Environment), which Saskatchewan Environment was in the process of adopting. The desired solution would bring cBOD₅ and TSS levels under 15 mg/L as well as provide effective ammonia and phosphorous removal on a year-round basis.

The Nexom Answer

Nexom, which at the time of this project was still Nelson Environmental Inc., designed a continuous discharge, 3-cell aerated lagoon system followed by a SAGR® attached growth reactor and two parallel sand filters. Designed for cold water treatment, the horizontal flow SAGR removes ammonia through nitrification (conversion of ammonia to nitrates) and provides BOD₅ and TSS polishing. The subsequent filtration and effluent treatment with alum addition ensures effective phosphorous removal.

Upgraded System Performance

Starting up in the spring of 2012, the SAGR system was able to reduce effluent TAN from 24 mg/L to 0.01 mg/L within two weeks of commissioning.

Implementation of Nexom’s optAER/SAGR system in Shellbrook demonstrates the cost-effective approach of a lagoon-based treatment facility combined with the reliable effluent quality produced by the SAGR process.

Now, almost 12 years after the initial start-up, their SAGR is still showing very low effluent limits! The charts below show the last 10 years of data in keeping below the limits for almost each year.