Nutrients

Water Pollution Control Facility Nutrient Reduction Modifications

Project summary:

The City of Ames owns and operates the Ames Water Pollution Control Facility (WPCF). This facility provides wastewater services for the residents, businesses, and industries in Ames. The facility was originally brought on line in late 1989. While there have been multiple equipment upgrades, the treatment technology is essentially unchanged.

In December 2000, the US EPA published recommended regional water quality criteria with the goal of reducing the impact of excess nutrient discharges into the nation’s waterbodies. The Iowa Nutrient Reduction Strategy was adopted by the Iowa DNR in 2012 in an effort to develop water quality standards for nutrients for the state of Iowa. For wastewater plants treating typical domestic wastewater, the established effluent goals for Total Nitrogen (TN) and Total Phosphorus (TP) are 10 mg/L and 1.0 mg/L, respectively.

In 2019, a feasibility study was completed that evaluated the most appropriate means of achieving the goals of the Iowa Nutrient Reduction Strategy. That report was submitted to the Iowa DNR, who approved the recommendation to implement a phased program of converting the facility to a biological nutrient reduction process. The discharge permit for the Ames facility requires that the City make progress towards the projects identified in the 2019 feasibility study.

Iowa State Revolving Fund Finding of No Significant Impact (Report)(PDF, 890KB)

Facility Plan (Full Report - Draft)(PDF, 17MB)

Ames WPCF NPDES Permit, issued February 2022(PDF, 402KB)

Ames Water Pollution Control Facility Nutrient Reduction Feasibility Study (2019)(PDF, 3MB)