Engineering Cost Analysis of Current and Recently Adopted, Proposed, and Anticipated Changes to Water Quality Standards and Rules for Municipal Stormwater and Wastewater Systems in Minnesota

The Minnesota State Legislature requested an engineering analysis to determine the cost of complying with current and future water quality regulations to communities in Minnesota. The legislature request required: - The study to include a diverse, representative sample of at least 15 communities; - The study to estimate the infrastructure costs required to upgrade wastewater and stormwater systems to meet current and future water quality standards; and - The study to estimate the incremental change in water quality as a result of those upgrades; Five pollutants were identified for inclusion in this study t the legislature: -Total suspended solids. Solids are the most visible indicators of water quality. Excessive solids cause cloudy water, and can inhibit use by humans and aquatic life. - Chloride. Chloride gets into wastewater and stormwater in a myriad of ways, and can be toxic to aquatic life. -Nutrients (Phosphorus and Nitrogen). Excess nutrients in freshwater ecosystems can cause algal blooms, which can decrease the aesthetic value of a water way and adversely affect aquatic life. - Nitrate. Nitrate is form of nitrogen and high levels of nitrates in drinking water are harmful to human and animal health. In some areas, nitrate contributes to freshwater algal blooms. Nitrate is also the primary cause of dead zones in the Gulf of Mexico. - Sulfate. Sulfates have the potential to impact production of wild rice. The Legislature request specifically identified "nutrients", which includes phosphorus and nitrogen. The legislature also specified that the study include nitrates, the dominant form of nitrogen in surface waters. Barr also evaluated current and future ammonia water quality standards because ammonia is another form of nitrogen. Ammonia has the potential to be toxic in freshwater ecosystems, and can be turned into nitrate by biological processes in natural waters. The legislature also specified that the study address total maximum daily load analyses, the recently adopted antidegradation rule, and the potential future tiered aquatic life use rule. In completing the study, Barr also evaluated the recently adopted variance rules. A 20-year planning timeframe was used as a boundary for the study.