A consultant recommended a smaller, but more frequent, discharge of treated wastewater into Cedarville Bay to further reduce phosphorous levels in the water, as members of the township board waded through proposed changes to their sewer system at a special meeting Wednesday, March 24. The options presented by C2AE to the Clark Township board and the Sewer Advisory Board at the meeting included findings on alternative treatments, how many grinders should be replaced, and how to handle major pump stations.

Under the current treatment system, adopted in 1993, wastewater is collected, treated, and released into the bay twice a year. Alternative proposals included optimizing the current operation, setting up an effluent filtration system where the discharge would be continuous, or land application, a process by which treated wastewater is sprayed onto a nearby crop. Prior to 1993, Clark Township had a similar irrigation system, but switched to accommodate and expansion project that increased usage from approximately 200 customers to 900.

The treatment issue is spurred by concerns over the amount of phosphorous discharged into the bay. This nutrient contributes to rapid weed growth that can choke off waterways. Efforts already have been made by the township to reduce phosphorous levels.

“They've already made great strides in reducing the phosphorous content of the discharge,” said project manager and construction engineer Chuck Lawson, who said, for this reason, C2AE is not recommending further optimization. That plan would maximize effectiveness by further adjusting chemical feed rates and other variables.

“The goal is to reduce your phosphorous levels by half, to the same background levels as the Great Lakes. It is our opinion that you've probably gone as far as you're going to go with optimization at your treatment facility,” he told the board. “We don't believe optimization will get you where you want to be with seasonal discharge.”

What C2AE recommends is effluent filtration, which would be a continuous, daily discharge into the bay at much lower flow rates.

The land application option would carry a $1.37 million price tag, while effluent filtration is deemed the most cost-effective, at $970,000. Next to doing nothing, making minor adjustments to the existing operation would be the cheapest alternative, at $320,000.

Part of the price of land application is obtaining and preparing a site for spray irrigation and adding the appropriate equipment. There are also additional regulatory hurdles to consider, including testing to ensure the process is not detrimental to drinking water.

Recommendation: Replace

Half of Grinders To have contractors replace 80% of the grinders would cost $4.82 million, while a 50% replacement plan would run $3.42 million. Since some grinders already have been replaced, the consultants recommend the latter option. Both grinder scenarios involve providing the full allotment of replacements, but the township would have to install the remainder of them. C2AE estimates that all of the grinders should be replaced within three to five years, the impetus for including this in the sewer system recommendations.

Also recommended is to replace three pump stations with submersible-type stations and including a trailer-mounted force main cleaner/vacuum to aid force main maintenance and eliminate sewer spills. Chemical additives for odor control are also included. Altogether, these additions and replacements would total $1.27 million.

If the township accepts C2AE's recommendations, the estimated total cost for the project is $6.3 million, which could raise the utility rates of residents nearly $15 a month in coming years.

Substituting land application as the treatment alternative would only raise the monthly bill 63¢, assuming the project is partly funded by a United States Department of Agriculture/Rural Development Utilities Grant, which could provide up to half of the funds. If this grant is not awarded, going with the land application option would incur an additional $1.53 on the monthly bill.

Trustee Mike Lofdahl saw benefits from both treatment methods, saying he was encouraged by the land application reducing the wastewater going into the bay, while he envisions the daily discharge of effluent filtration solving other problems.

To receive a grant, Clark Township may have to choose the most cost-effective option, Mr. Lawson said. If the township strays from what has been deemed most economical, they may be required to shoulder more of the costs.

The chances of receiving the grant would also be increased by obtaining a letter from the Department of Natural Resources and Environment stating that this project would improve the reliability of the current system.

“In order to qualify for a higher grant amount and a discounted loan rate, they would have to establish that the project helps them meet either state or federal standards,” Mr. Lawson said.

There is an incentive to decide quickly, however, as the Department of Agriculture may permanently close the application process for this grant in May.

Replacing Worn Out Pumps

Randy Scott, C2AE's director of Upper Peninsula operations, offered advice on how to prepare for replacing and maintaining the system. According to C2AE, the township is not currently funding replacement of pumps that have been worn out.

This could be accomplished by putting a designated amount, recommended at $166,000, into a restricted fund each year. The township would prepare a list of expenses this could cover and only things on that list would be approved for those funds.

Treasurer Katie Carpenter agreed with Mr. Scott's assertion that, even if the township doesn't do a project, the board should consider setting up this restricted fund. Without it, it would be hard to find the money for replacements, and redirecting the money from other avenues shortchanges the township in other pursuits.

“I plan on being here 25 years from now,” Mrs. Carpenter said. “I don't want to keep paying for the same things three times over.”

The Department of Natural Resources and Environment has been advised of all alternative treatments under consideration. The current wastewater system serves 873 customers, 740 of which are residential. Another special meeting to discuss the scope of the project and when to schedule a public meeting on the matter is planned for 9 a.m. this Thursday, April 1.