An innovative algae-based wastewater pilot program is expected to be implemented, on a small-scale, at Creston’s wastewater treatment facility by the end of the month.
After Libby Patton of Veestra & Kim and Max Gangestad, process engineer at Gross-Wen Technologies, explained and discussed the treatment solution with Creston City Council, the council voted unanimously to approve $20,000 necessary to begin the six month study.
The City of Creston officials began a two-phase wastewater project in 2014. During that time, a new Iowa Department of Natural Resources permit called for stricter limits and a nutrient reduction strategy.
During phase one of the project, a pilot study revealed the need to purchase a carbon source every year would be necessary, which is estimated at $500,000 annually. However, after the cities of Chicago, Columbus Junction and Slater have begun to implement the algae-based equipment and programs offered by Gross-Wen Technologies, city officials are interested in seeing how the technology could benefit Creston in terms of efficiency and sustainability, while potentially reducing long term costs of meeting the city’s nutrient reduction plan.
DNR enforced stricter limits due to issues associated with nutrient pollution caused by ineffective wastewater treatment. Because of this, state and federal agencies across the U.S. are requiring municipal wastewater treatment plants to meet new water quality standards.
How it works
On its website, Gross-Wen describes its revolving algal biofilm (RAB) treatment technology as “vertically oriented conveyor belts that grow algae on their surface.”
The algae essentially ‘eats’ nitrogen and phosphorus from the wastewater.
“It also uses carbon dioxide from the atmosphere and sunlight to rapidly grow algae biomass,” the website states.
In addition to cleaning wastewater, the byproduct of the process is then processed and sold as slow-release fertilizer pellets that can be used to fertilize in a variety of plants, such as vegetables, flowers and lawns. The profits made from its sales are then split between the company and city.
Gangestad said the goal of the pilot program is to identify an optimal treatment location for the RAB system that is specific to Creston’s plant, as well as establish a data set to have a more precise cost estimate, should city officials choose to implement the equipment on a full-sized scale.
While the cost estimate of a full-sized program is unknown at this time, Gross-Wen offers grant assistance and Gangstad told council members of a grant opportunity available through Iowa Energy Center.
A full-scale demonstration facility in the city of Slater is scheduled to be operational in June for engineers, public works directors or anyone else who would like to see it before making a decision to go large-scale.
“We wouldn’t be recommending you do another pilot if we didn’t think it was going to be a cost-effective alternative,” Patton said.