ENVIRONMENT: Snow from wastewater marks first successes
HARBOR SPRINGS – The preliminary tests are complete and the results are encouraging.
A pilot project conducted at a northern Michigan wastewater treatment facility holds financial promise and an environmentally-friendly alternative to wastewater storage during the winter.
The Harbor Springs Area Sewage District Authority provides sewer collection and treatment for the City of Harbor Springs, Little Traverse Township, Littlefield Township, and the Village of Alanson.
Like most treatment facilities in the state, Harbor Springs has a wastewater lagoon for the storage of treated water. In the summer, the water is sprayed onto farm fields and the nitrogen and phosphorous fertilizes the crops.
“It’s a great system,” said Coates, “but you can only do it in the growing season.”
The lagoon at the Harbor Springs facility covers 27-acres, but a report done by Gosling Czubak Engineering Services of Traverse City last year revealed it is operating at capacity. Expansion of the lagoon would cost between two and three million dollars, said Doug Coates, a project engineer with Gosling Czubak who was involved in the report.
Officials had heard about a winter irrigation system, pioneered in Canada, that makes snow from wastewater and would take the pressure off the storage lagoon.
Bob Morris, superintendent of the Harbor Springs Area Sewage Disposal Authority, knew of a place in Maine called Carabassett Valley which had a treatment facility similar to the Harbor Springs plant. It, too, was facing a multi-million expansion. So three years ago, it started making snow from its wastewater and has had great success.
After drawing up a pilot test plan for the Harbor Springs site, they sought approval from the Department of Environmental Quality to run a winter irrigation study.
“The study is solely to see if it would work, to analyze snow samples and the treatment effectivenesss,” Morris said.
The project was approved and last fall the Authority installed a new pipe and two towers for snow guns. Nubs Nobb Ski Resort, just a short distance from the wastewater treatment plant, designed the project and loaned the City the snow guns.
The facility began making snow the first of the year. Treated water in the lagoon went through a “flash freezing” process, which further treated the water, and then the snow was sprayed onto a field next to the lagoon on facility property.
“It was quite successful,” Morris said. “The sole problem was the weather.”
While the winter was uncooperative this year, as it needs to be 25 degrees or less to make snow, the facility still “flash froze” approximately one million gallons of water. “We didn’t get to make as much snow as we wanted, though it was about nine feet deep in some spots,” Coates said, adding the system was shut down in mid-March.
“It was sufficient enough to get weekly analyses,” Morris said, adding that by late spring or early summer final data on the project will be complete. Because of the unusually warm winter, Morris said they would like to run the project again next year, granting DEQ approval.
“We’re encouraged because if we can make it work this year with the poor winter, we can do much better with a more typical snow year,” Coates added.
Project coordinators are currently monitoring the snow pack. As it melts, they will test the runoff, the soil and the groundwater, Coates said.
“The preliminary samples of snow look very promising,” he added. “As the snow pack ages, more treatment takes place.”
The goal is to process 20 percent of the flow, but with only two snow towers that isn’t feasible. Coates said they may add one or two more towers if the study is approved for a second year.
“If a second year of data supports the effectiveness of treatment, it is very viable for communities in terms of saving money on expanding lagoons and occupying land,” Coates added.
Morris was also optimistic about the results of the first year.
“We see this as a means of keeping cost to municipalities down as well as capital costs down,” he said.
As for someday skiing on it?
“That has a ways to go, in terms of the public’s perception of it,”
Coates said. BIZNEWS