Metro Waste Reclamation District is one of the largest wastewater treatment plants between the Mississippi River and the west coast. Treated water is discharged into the South Platte River, and contributes 90% of the river’s annual flow at the point of discharge.
This important river serves as the major source of drinking water for the Denver area, as well as eastern Colorado. Because of their efficiency and quality of treatment, this large plant has received much recognition from the EPA as they are constantly updating their standards and monitoring capabilities.
Analysis of the discharge for nitrogenous compounds is critical, as excessive ammonia and nitrate levels can pose a threat to marine and human life. High nitrate levels (>10 mg/l) represent a human health concern since they can cause methemoglobinemia, or “blue-baby” syndrome.
Ammonia is not only toxic to fish, but exerts an oxygen demand in aquatic environments; as 4.7 grams of oxygen are required to oxidize one gram of ammonia, threatening marine life.
These factors call for effective removal and analysis of these forms of nitrogen from wastewater before they are discharged to natural water systems. Monitoring nutrients in wastewater effectively will become even more important with new requirements from the EPA to control nutrient discharges in the near future.