Sustainable Return on Investment –Metro Wastewater Reclamation District's Application of Nutrient Criteria Cost Benefit Alternative Analyses

The Metro Wastewater Reclamation District (District), in Denver, Colorado, in preparation for Colorado Water Quality Commission (WQCC) Rulemaking Hearing regarding adoption of nutrient criteria, commissioned a report to assess the impacts upon the 220 mgd Robert W. Hite Treatment Facility (RWHTF). The District recognized that development of a triple bottom line cost benefit review would support the report's results and conclusions while also supporting the District's approach to improving water quality and aquatic life. The District retained HDR Engineering, Inc. (HDR) to apply its Sustainable Return on Investment (SROI) analytical tool on two complex alternatives to meet stringent effluent limits. The SROI analytical tool and its application on complex nutrient criteria alternative analysis relative to the proposed nutrient criteria limits are reviewed in this paper.