Pollutant sources and flows in a municipal sewage system

Area of Science:

• Environmental Science
• Wastewater Engineering
• Pollution Control

Background:

• The Kokomo, Indiana wastewater system faces challenges with heavy metal and cyanide contamination.
• Understanding pollutant sources is crucial for effective wastewater treatment and sludge disposal.

Purpose of the Study:

• To quantify the contributions of domestic and non-domestic sources to heavy metal and cyanide loads.
• To assess required discharge controls for municipal sludge disposal via landfill or landspreading.
• To develop a cost-effective sampling strategy for pollutant source tracking.

Main Methods:

• Analysis of heavy metals (Cu, Ni, Cr, Cd, Zn, Pb) and cyanide flow within the collection system and wastewater treatment plant.
• Sampling at point sources, major sewer lines, and the treatment plant.
• Utilizing production and waste treatment data to characterize pollutant discharges.
• Performing a heavy metal mass balance for the treatment plant.
• Presenting metal removal factors for various treatment operations.
• Applying a statistical approach for sampling program design.

Main Results:

• Characterization of heavy metal and cyanide discharges from various sources.
• Estimation of pollutant contributions from domestic versus non-domestic origins.
• Evaluation of metal removal efficiencies in wastewater treatment processes.
• Development of a statistically sound sampling design for source identification.

Conclusions:

• The study provides critical data for managing heavy metal and cyanide pollution in the Kokomo wastewater system.
• Findings inform decisions on sludge disposal and the necessary level of discharge control.
• The proposed sampling methodology offers a cost-effective approach to pollutant source apportionment.