Nutrients in Wastewater Discharges

Map and Data for This Study

• Objective:
  To quantify the contribution from wastewater treatment plants (WWTP) to nutrient loads downstream of WWTP's and to provide a snapshot of the movement of nutrients through the surface-water system.
• Approach:
  Water was collected and analyzed for nutrients at sites immediately upstream and downstream from 20 WWTP's, at the mouths of major tributaries, and along the main stem South Platte River. Samples were collected along the main stem from below Chatfield to North Platte, Nebraska.
• Timing:
  April 1994 and January 1995
• Targeted physical and chemical data:
  Flow, specific conductance (salinity), temperature and nutrients
• Selected Results:
  
  Treated wastewater effluent can account for as much as 100 percent of streamflow downstream from Denver and was the primary source of nitrate, ammonia, and phosphorus to Front Range streams.
  
  Phosphorus concentrations in the South Platte River from Denver to Balzac, Colorado, a 150 mile length of river were higher than generally accepted limits for control of eutrophication (USEPA, 1986).