Regional Septage Treatment Facility

HDR Engineering will finalize the facility Basis of Design report, which will include an updated business plan. Flathead County will hire an engineering firm to complete the final facility design and prepare construction documents. A contractor will then be hired to build the septage treatment and biosolids composting faciliity. 

The Flathead County Commissioners voted on September 14, 2023, to purchase the property.

Construction is scheduled to begin in the summer of 2024 following the final design process.

We anticipate the facility will be ready to accept materials by the end of 2025.

Yes, the facility is expected to create employment opportunities during both the construction and operational phases, thereby contributing to the local economy. 

Yes. Flathead County has invested over $600,000 in exchange for LCWSD reserving 20,000 gallons per day of capacity for the facility. However, the facility is estimated to require up to 60,000 gallons per day of capacity in the future. LCWSD has submitted a permit to DEQ that, if approved, would allow LCWSD to increase its capacity and reserve the full 60,000 gallons per day required. 

Flathead County is closely monitoring LCWSD's permit application process. Both parties are optimistic about the permit's approval. In the unlikely event that the permit is not approved, the invested funding is refundable.

The Flathead County Septage Treatment Facility is a solution to preserve environmental quality and address population growth within our community. Flathead County has an estimated 40,000 wastewater treatment systems currently in place, and with the predicted increase in the number of homes/businesses that will need septic systems, this could negatively impact the environment and our groundwater resources in the valley. Therefore, Flathead County needs a regional solution to mitigate issues to septage and biosolids disposal. 

A wastewater treatment system is a system that is used to treat, or reduce contaminants, from wastewater that has been discharged from a home or business.  The treated water, or effluent, is then discharged back into the receiving environment. A WWTS is commonly referred to as a drainfield.  Septic tanks are an important part of on-site wastewater treatment systems, and they provide primary treatment of the wastewater before it is discharged into the groundwater. Over the years organic and inorganic solids and some liquid, also known as septage , accumulates in the septic tank and must be removed every 3-5 years to prevent from overfilling and passing this undesirable material into the drainfield which may cause catastrophic failure of the system. The septage that is pumped from septic tanks will be taken to the Flathead County Regional Septage Treatment Facility to be treated.

The local wastewater treatment plants located in Whitefish, Kalispell, and Columbia Falls are required to meet strict effluent limits and and as a result utilize sensitive biological treatment processes.  Septage, which is a very high strength waste, can easily upset these treatment processes resulting in an exceedance of effluent limits which is a violation of State law. Therefore, the treatment plants are unable to accept septage from surrounding septic tanks. As a result, septage in Flathead County is currently disposed of through land application which includes injecting the untreated septage into the soil.

The proposed septage treatment facility will be the first of its kind in Montana.  The biosolids composting process is far more common and there are similar facilities in Hamilton and Missoula as well as Coeur d’ Alene, ID

Discussions of a solution for septage treatment has been ongoing for several years due to the projected population growth of our county and the limited availability of land for land application purposes. This project came together as a collaborative effort between the Flathead County Health Department, the cities of Kalispell, Columbia Falls, and Whitefish, and the Lakeside Water and Sewer District. The current project also includes information from past planning efforts including the 2018 City of Kalispell Biosolids Management Plan, the 2018 City of Columbia Falls Wastewater Facility Plan, and the 2016 City of Whitefish Preliminary Engineering Report.

Flathead County will continue to update this webpage with the latest project information. Additionally, you are encouraged to check the Latest Commissioner Agenda located on the homepage of Flathead.mt.gov.

Flathead County purchased land located at 305 Wiley Dike Road for the purpose of constructing the septage treatment plant and biosolids composting facility.

This site was selected for several reasons. The property is of adequate size to house the proposed facility while meeting the required setbacks. It is in close proximity to the Lakeside County Water and Sewer District (LCWSD), allowing a direct connection between the facilities so LCWSD can further treat the effluent from the facility. It was for sale and within budget.

The design of the facility including the aesthetics of the buildings will be completed by the project engineer during the final design. More information about the design will be provided as information becomes available.

The facility is planned to be located indoors and will be equipped with odor control.

Funding for the construction of the Regional Septage Treatment Plant and Biosolids Composting Facility comes from a 2021 ARPA grant application. The grant included a construction budget of $15M, however, exact costs will depend on the facility location, the extent of off-site costs, and the final design. The cost of the project will be updated once the final design of the project is completed.

Careful consideration was put into the design of this project to ensure that the facility will meet all Montana DEQ and EPA requirements with minimal impact to our watershed. The new facility will take untreated septage that is currently disposed of on land in the valley with no treatment, and instead, with the help of Lakeside’s treatment facility, treat this such that the liquid can be used as irrigation for crops and the solids can be converted into compost.  An engineering report was developed that was used as the basis of the ARPA grant application previously mentioned.  This report, combined with previous studies completed by Kalispell, Whitefish, and Columbia Falls served as the basis of the sizing and development of cost estimates for this project. 

The project will meet the requirements of the funding agency and Montana DEQ which includes following the Montana Environmental Project Act (MEPA) Process.

Final decisions for plant operations are still being determined, and there are multiple options being considered. One option would be to have a private contractor run the facility. Other options include management through the County, or to lease the facility to Lakeside. More information about operations will be provided as information becomes available.

The biosolids compost material will meet Class A requirements for suitable public distribution. Compost will be available for use by the County and municipalities and will be available for sale to the public.

The operation of the facility will be funded by tipping fees. A tipping fee is a fee paid to the septage treatment facility to help cover the operational costs of treating and disposing of septage. The tipping fee is charged based on the volume of septage or biosolids being delivered to the site. Additional information about tipping fees will be provided as it becomes available. In addition, the compost material will meet Class A requirements for suitable public distribution, and the compost will be available for sale to the public.

Septic trucks are not exempt from spring road weight limits.  Septic pumpers, however, can apply for an overweight permit ($500) and the Flathead County Road Department has the authority to grant an exemption depending on the condition of the road and outside temperatures.  Enforcement of road weight limits is enforced by the Montana Department of Transportation Motor Carrier Services.

No. There are no zoning restrictions for the Wiley Dike Road site. Should we move forward with the purchase, we will abide by all regulatory agency requirements.