The City of St. Cloud in Minnesota has selected Ostara Nutrient Recovery Technologies Inc. to install a nutrient recovery system at their St. Cloud Wastewater Treatment Facility. This is part of the $22 million Nutrient Recovery and Reuse (NR2) Project, which includes installation of biofuel storage to help optimize the fuel produced for the biofuel generator and reduce energy costs. Biosolids will be reused, which will require expanding the treatment process to produce Class A biosolids.
The St. Cloud Wastewater Treatment Plant, a biological nutrient removal facility with a 17.9 MGD design flow, will serve a population of over 120,000 people in St. Cloud, St. Joseph, Sartell, Sauk Rapids, Waite Park, and St. Augusta. Ostara’s technology will help the facility increase operational efficiencies through struvite avoidance (a cement like scale in pipes caused by an excess of nutrients) and the recovery of phosphorus.
Phosphorus is considered a major contributor to nutrient pollution, entering bodies of water from numerous sources including sewage treatment plants. Phosphorus in waterways cause algae to grow and bloom, creating a toxic condition called eutrophication, which destroys aquatic life and limits recreational enjoyment of waterways.
The Mississippi River Delta is called the Gulf of Mexico dead zone, and has one of the highest levels of eutrophication in the world. Programs such as the Minnesota Clean Water Legacy Act (CWLA) have plans to restore water resources to meet state water quality standards and protect them from degradation. The NR2 Project was partially funded through a $6.6 million Point Source Implementation Grant made possible by the CWLA.
The fertilizer - sold as Crystal Green - will be produced upon commercial operation of the new system. Crystal Green will further protect the Mississippi River Basin through its application on local agricultural land. The fertilizer releases nutrients according to root demand, improves crop uptake, and significantly reduces leaching and runoff into surrounding waterways.
“Ostara’s technology is a key part of the entire NR2 project, and illustrates how St. Cloud is leading the way in sustainability in Minnesota with the implementation of innovative and cost effective technology,” says Patrick Shea, Public Services Director for the City of St. Cloud.
Ostara completed a demonstration project at the facility in 2014, and through a series of evaluations, was selected for the project. Criteria included qualifications, site visits & installation references, life cycle cost, operations, customer support, safety, and sustainability. The system is expected to be fully operational by Spring 2019.