Upgrades and Operations at Logan Regional Wastewater Treatment Plant

For decades, the City of Logan relied on an aging lagoon system to treat its wastewater, but new state and federal nutrient regulations made it clear the system could no longer keep pace. Without significant upgrades, Logan risked falling out of compliance, threatening both water quality in local waterways and the community’s ability to grow.

To meet this challenge, the City partnered with Carollo to plan, design, and deliver a modern 18-million-gallon-per-day wastewater treatment facility. The new plant replaced the outdated lagoons with advanced nutrient removal processes capable of meeting strict ammonia and phosphorus limits. This investment not only protected sensitive aquatic environments but also provided the community with reliable infrastructure to support long-term growth.

Carollo’s team approached the project with a focus on efficiency, cost savings, and future-ready design. By incorporating a ballasted activated sludge system, the City avoided constructing additional secondary clarifiers, ultimately reducing capital costs by roughly $40 million. The facility also included a new 28-mgd headworks and influent pump station, sized to manage both future expansion and the peak demands of wet-weather flows.

Innovation was another cornerstone of the project. In partnership with Utah State University, the project team piloted algae-based treatment and energy recovery technologies. These efforts not only provided real-time benefits to Logan but also advanced regional research in sustainable water management practices.

Now fully operational, the Logan Regional Wastewater Treatment Plant consistently delivers high-quality effluent, protects the environment, and provides the capacity needed to serve a growing population. More than just a compliance project, the facility positioned Logan as a leader in forward-thinking water stewardship, setting a new benchmark for communities across Utah and beyond.