County sets out plans for regional septage treatment facility

Flathead County on Thursday is holding two meetings regarding a proposed regional septage treatment and biosolids composting facility.

Meetings will be held at 10 a.m. and 6 p.m. at the Flathead County Commissioners’ Chambers on the third floor of the historic County Courthouse, 800 S. Main St., Kalispell. At both meetings, the project engineer is expected to give an informal presentation about the proposed project followed by an opportunity for the public to ask questions.

The county has an estimated 30,000 wastewater treatment systems and as rapid growth has occurred over the last decade the suitable land for the disposal of septic waste has become limited.

“The increasing number of septic systems, in addition to the dwindling amount of available land for current septage disposal methods, has created a potential problem that could negatively impact the environment and our groundwater resource in the valley,” the county notes in a document explaining the potential facility.

HDR Engineering is in the process of creating — at the county’s behest — a plan and design for a regional septage treatment and biosolids composting facility.

Septic tanks provide the primary treatment of wastewater before it discharges into a drain field, but some of the leftover matter, known as septage, needs to be removed from the septic tank about every three to five years.

Septage can’t be disposed of at wastewater treatment facilities in the county’s municipalities because it could disrupt treatment processes in turn causing those plants to exceed state regulations. Thus septage from the county is currently disposed of through land application, which includes injecting the untreated septage into the soil.

The new facility, which would be the first of its kind in the state, according to the county, will take untreated septage and treat it in a way that the liquid can be used for irrigation and the solids converted into compost.

COUNTY COMMISSIONERS in October approved a buy-sell agreement with the intent of purchasing 36.9 acres on Wiley Dike Road for the facility. The agreement allows for analysis of the property, located just north of the existing Lakeside Water and Sewer District wastewater treatment lagoons, to determine whether it will be suitable for the project and to obtain an appraisal of the property with a purchase price of $1.5 million.

The agreement has drawn the ire of neighbors who say the potential facility would affect their rural lifestyle and have questioned whether the location makes sense with a portion of the property within the floodplain.

The study by HDR Engineering is expected to be completed by the end of the year and include an estimated cost to construct the facilities.

The county has said the study, along with analysis of the Wiley Dike property, is expected to aid in making a definitive decision on whether to purchase the property for the facility.

The engineer has been analyzing the county’s needs taking into account 20- and 40-year growth projections. The septage plant is expected to be capable of processing 5 million gallons of waste and effluent annually for the county.

While designs for a plant are not final, the county says that the facility is planned to be located indoors and incorporate odor control. The compost material from the plant would be available for use by the county and cities, and additional compost could be made available for sale to the public.

The funding for the construction of the facility comes from a 2021 ARPA grant that includes a $15 million construction budget, but exact costs remain undetermined.

In terms of operation, the plant could be run by a private contractor, managed through the county or leased to the Lakeside sewer district. The county expects that operation of the plant would be funded through tipping fees or a charge based on the volume of septage or biosolids being delivered to the site.

The county has set up an information page on its website regarding the septage treatment facility at https://tinyurl.com/4dtxa5mp.

Features Editor Heidi Desch may be reached at 758-4421 or hdesch@dailyinterlake.com.