Ames advances $60 million nutrient reduction upgrade amid 35-year compliance streak

Ames advances $60 million nutrient reduction upgrade amid 35-year compliance streakThe Iowa utility is transitioning from trickling filters to simultaneous nitrification-denitrification to aggressively target nitrogen and phosphorus levels in the South Skunk River watershed.

Ames is investing just under $60 million in a 20-year facility upgrade to reduce nitrogen by two-thirds and phosphorus by three-quarters.

The utility is shifting treatment technology from trickling filter solids contact to simultaneous nitrification-denitrification.

The Water Pollution Control facility has achieved 35 consecutive years without a numeric permit violation.

Updates to the fats, oils, and grease (FOG) receiving station will allow for on-site methane capture and electricity generation.

Supply chain disruptions have delayed the completion of the city’s AMI metering rollout by approximately two years.

The City of Ames, Iowa, outlined a significant capital intensive period for its wastewater infrastructure during a February 3 budget hearing, headlined by a nearly $60 million investment in nutrient reduction modifications. Utility leadership presented the Fiscal Year 2026-27 operating budget, emphasizing a strategic shift in treatment technologies to meet evolving environmental regulations. The Water Pollution Control (WPC) facility, which treats approximately 6 million gallons daily from Ames, Iowa State University, and Kelly, is undergoing a major upgrade designed to support the Iowa Nutrient Reduction Strategy. According to Parul, a department representative who presented the budget alongside John Dunn, the project aims to reduce nitrogen levels by two-thirds and phosphorus by three-quarters over the next decade. The technical scope of the project involves moving away from the facility's legacy trickling filter solids contact technology. Instead, the plant will implement a simultaneous nitrification-denitrification process. The upgrade includes the construction of two aeration basins, a new electrical building, and a sludge pumping building. Parul noted that these changes are intended to make operations "more efficient, sustainable, and reliable," using less energy while achieving higher water quality standards for discharge into the South Skunk River. The utility is undertaking this complex construction while maintaining a historic compliance record. Officials reported that the facility has achieved the "Platinum 35 Peak Performance Award" from the National Association of Clean Water Agencies, marking 35 consecutive years without a single violation of a numeric permit limit. This streak covers compliance with more than 58,000 individual limits. In addition to nutrient management, the WPC facility is upgrading its fats, oils, and grease (FOG) receiving station. The modifications will enable the capture of methane from FOG to be converted into electricity on-site, a move designed to lower the facility's carbon footprint and operating costs. On the drinking water side, the utility is navigating supply chain challenges related to its metering infrastructure. The division selected Aclara, a recognized market leader in smart infrastructure solutions, for its Advanced Metering Infrastructure (AMI) rollout, but disruptions have pushed the project schedule back by roughly two years. Currently, fewer than 3,000 meters remain to be upgraded, with full completion expected within the next two and a half years. Water quality monitoring remains a priority, particularly regarding PFAS. The utility confirmed that one well was taken offline immediately after higher levels of PFAS were identified, well ahead of EPA mandates. While the well remains available for emergency use, it is currently not part of daily production. To bolster resilience, the city is also installing emergency standby generators at the SAM Booster Pump Station and the Youth Sports Complex Well Field, supported by a FEMA grant covering 85% of the cost.