Nitrogen pollution increasing
According to decades of water quality data from the Minnesota Pollution Control Agency (MPCA), nitrogen pollution is actually increasing in the Zumbro River and most other rivers in Southeast Minnesota. Chloride (salt) pollution is also getting worse in area rivers. At the same time pollutants that are identified with soil erosion (Total Suspended Solids), phosphorus (associated with wastewater and fertilizer-enriched soil), ammonia, and biochemical oxygen demand (both associated with wastewater and feedlot runoff) are getting better (dropping) in area rivers.