Marion officials again discussing wastewater treatment wetland

MARION - A wetland that filters wastewater.

This environmentally friendly idea has been on table for years in Marion, according to city officials. It surfaced again after the Linn County Board of Supervisors in November purchased 485 acres of land along Squaw Creek Park that it intends to use for conservation projects.

The idea would entail installing a pipe, leading from Marion's trunk sewers, into an underground basin above the sewer line. The wetland would be developed on top of the basin, and reedy plants and rocks would filter the wastewater.

Filtered water would flow back into the trunk sewer.

Marion City Manager Lon Pluckhahn said the prospective project would take seven to eight years to come to fruition. He said despite talk for years about such a project, city officials never identified a good location.

Pluckhahn and Linn County supervisor Brent Oleson discussed constructing the wetland over Marion's sewer that runs near Squaw Creek. The city has another trunk sewer that runs along Indian Creek.

'They have a willing partner in the county,” Oleson said. 'It's so close to Marion city limits. We wanted to make Squaw Creek available to them.”

The Board of Supervisors last week approved the $7.2 million land purchase - 306 acres north of the Gardner Golf Courseand another 179 acres to the south of the golf course - from the Sutherland Dows Family Trust.

Oleson said the plan is to pay for the acquisition with local-option sales tax funds, general obligation bonds based on the establishment of an urban renewal area, budget reserves and future sale of some of the parcels.

It remains to be seen which parcels are to be sold, but Oleson said they are likely to be sections of property adjacent to nearby residential zones in Marion.

To establish an urban renewal district, the county first must create a legal description of the property proposed for development and draft a general description of what the urban renewal area aims to establish and what projects that may entail. The process involves a few public hearings, including a hearing to vote on the issuance of general obligation bonds to finance acquisition of property.

Oleson said his hope would be to use any revenue from sold parcels to pay off the general obligation bonds.

Oleson and Pluckhahn said it's too early to know if Marion would buy or lease a portion of the 485 acres, and Pluckhahn said the city hasn't identified the specific section on which the wetland and new wastewater infrastructure would be constructed.

The benefits of developing a wetland for filtering wastewater extend beyond environmental.

All of Marion's wastewater is treated in Cedar Rapids. Marion pays a flat fee for the service regardless of how much wastewater it sends into the Cedar Rapids system.

Marion officials would like to reach an agreement to pay based on the specific amount of wastewater being treated, rather than the flat fee. A wetland would help reduce the amount of solids in the wastewater, resulting in added savings for Marion.

Pluckhahn said Marion officials hope to change the agreement with Cedar Rapids by January or February.

'It's a more accurate way of making sure we're paying for what we contribute,” Pluckhahn said. 'We have months where we're over and months under. There's an incentive for us to send less down there.”

Sara Baughman, communications coordinator for utilities in Cedar Rapids, said a meeting with Marion officials to discuss a renegotiation is set for next week.

A 1-acre wetland can filter up to 1 million gallons of wastewater a day, Pluckhahn said. The trunk sewer along Squaw Creek allows for 1 million gallons of water to flow from Marion each day.

'We don't want to take it down to the point where it (the sewer line) would do nothing because you need some flow to keep it warm and make sure the solids don't stop and cause clogs,” he said. 'We would probably target a half million gallons a day for our first phase, and as the line got more customers, we would make sure we have the ability to expand.”

Developing a wetland filtration project could cost up to $4 million, Pluckhahn said, adding it is too early to know how Marion would fund the project. Saving money on the city's deal with Cedar Rapids is a first step. Grants may be another option.

'We have to save enough on our billing to justify making the adjustment and to make sure we've got the ability to expand in the future,” he said. 'The idea would be it would be transparent to the ratepayers on the sanitary sewer.”

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