A Fast Track Approach to Achieving Low Effluent Nutrient Limits on a High Strength Wastewater

Recently, more stringent nutrient effluent limits have been imposed by the Province of Manitoba to protect Lake Winnipeg. These limits include restricting the amount of total nitrogen to less than 15 mg/L and total phosphorus to less than 1 mg/L. Achieving concentration based effluent limits on high strength wastewaters present unique challenges not encountered with municipal wastewaters. For example, municipal wastewaters typically contain about 40 mg/L of nitrogen in the influent and therefore have to remove approximately 65% of nitrogen to meet the new 15 mg/L effluent limit. However, influent nitrogen concentrations in meat processing wastewaters are about 250 mg/L, requiring over 95% removal to meet the same limit. This also applies to the phosphorus content where municipal influents typically contain about 5 mg/L while meat processing wastes contain around 25 mg/L.The purpose of this paper is to describe a fast track approach taken to complete the preliminary design, detailed design and construction a large expansion within a one year period to become Manitoba's first treatment facility to meet the Province's new nutrient effluent limits. In addition, the first 16 months of operating data is provided highlighting some of the challenges of commissioning a new treatment facility and meeting concentration based limits with a high strength wastewater.