Expansion and Major Upgrades to Teton Valley Regional Water Reclamation Facility: EPA Agreement Sets Path for Environmental Improvements and Sustainable Growth by City of Driggs January 15, 2025. Read the full Consent Decree online , the Amended Complaint , the Complaint Appendix A , and the Notice of Lodging . A public comment period will be announced in the coming days and information about how the public can participate will be updated here.

Rising Temperatures in the Spring Cause Normal and Temporary Odor from the WWTP by City of Driggs May 8, 2023.

Driggs' officials swamped with attention, concern over wastewater lawsuit by Conner Shea October 31, 2022

Press Release: WWTP Lawsuit Will Ultimately Help The City Of Driggs by City of Driggs October 24, 2022

Driggs' temper running thin with wastewater facility by Conner Shea October 19, 2022

Letter From the Mayor: October 10, 2022

Driggs approves utility fee increase By Julia Tellman Sep 28, 2022

Driggs Waste Water Treatment Plant Odor is Temporary By City of Driggs Jun 13, 2022

Driggs tests new sewage plant cleaning process By Julia Tellman Apr 28, 2021

Sewage plant upgrades are needed to achieve discharge compliance, study says By Julia Tellman Mar 10, 2021

Driggs faced with wastewater plant decision by Julia Tellman Feb 12, 2020

Industrial Waste Survey Requirement

In conjunction with the City of Victor, the City of Driggs requires that all new business and non-residential building permits include a submission of the Industrial Waste Survey. This study determines the nature of the wastewater discharged by our customers.  All existing sewer connections to the Teton Regional Wastewater Treatment Plant applying for permits to expand existing buildings must also submit a new survey.

This digital copy of The Industrial Waste Survey can be downloaded, filled out online, emailed to mrodman@driggsidaho.org , or downloaded, printed, and mailed in.

If you need assistance filling out the survey, please contact Mike Rodman, WWTP Lead Operator at 208-354-2362 or at mrodman@driggsidaho.org

Established in the late 1960s, the WWTP has been upgraded over the decades and converted from a lagoon system to a mechanical plant in 2013. The 2013 conversion to an MSABP Fixed Film Treatment Process, a Multi-stage Activated Biological Process Plant that uses bacteria to digest the contaminants in wastewater, was designed and constructed to handle 10 years of anticipated growth of up to 900,000 gallons/day. An additional 10 years of growth were included in the 2013 WWTP Plan, but not all infrastructure was installed to reduce construction and operational costs.

In 2018, staff identified groundwater infiltrating the pipes, and much work was done to reduce this unnecessary water treatment, a process called I & I Reduction: Inflow and Infiltration Reduction.

Facility expansion was delayed due to lower-than-anticipated population growth in the 2010s, so the current plant is still meeting demand for capacity. However, 2020 marked the 10-year period to reassess the capacity and growth of the community's treatment needs for the next 20 years. Forsgren Engineering conducted the study, and MurraySmith, based in Boise, Idaho, was hired for a third-party review of the Draft Facility Plan by Forsgren Engineering in 2022 to ensure that this is the most fiscally responsible plan. The review confirmed that the plan was correct.

City Council adopted the Teton Valley Regional WWTP Plan Study  on November 7, 2023, setting the stage for a plant expansion and upgrade that will come online in late 2028. Please read the What steps are being taken to fix the problem? section below for the projected timeline.

Yes. The WWTP is a Multi-Stage Activated Biological Process (MSABP) plant, which uses bacteria to digest the contaminants in wastewater. The MSABP has been unable to remove ammonia constantly, and the facility has long been out of compliance by exceeding the ammonia limits of its water discharge permit. In addition to the ammonia issue, the current facility is fast approaching its hydraulic and biological capacity and needs to be expanded.

There are different classifications of treatment plant capacity. The current plant has a daily hydraulic capacity of 0.9 million gallons of liquid and a peak hour capacity of 2.0 million gallons per day.  Based on current flows and growth, the current facility will exceed the daily capacity in 2033 and the peak hour capacity in 2029.

Loading Capacity, which is how dirty the water is with things like human waste, ammonia, grease, etc., is broken down into subcategories. Levels measured in this category are the BOD or biological oxygen demand, the TSS or total suspended solids, Ammonia, and E. Coli. The current facility is designed to process 1,877 lbs of BOD/day; last year averaged 1,625 lbs of BOD/day (87% of capacity). The plant is removing 90-95% of BOD and TSS; thus, it does not exceed discharge limits in these categories.

However, it is approaching the designed loading capacity and has historically failed to meet standards to mitigate the ammonia levels. Therefore, the city is in the process of a Facility Expansion and Process Upgrade to comply with state, federal, and Clean Water Act regulations.

The current plant is located 1 mile west of Main Street on Bates Road. Please note that the site is not open to the public for safety and security reasons.

Treated effluent is discharged into the unnamed tributary of Woods Creek which then flows approximately 3 river miles to reach the Teton River.

The City of Driggs, the City of Victor, and a few subdivisions in Teton County are connected to the plant.

Yes. The EPA determines the max Ammonia discharge limit for each WWTP. The City of Driggs WWTP ammonia discharge limit is 0.84mg/L average monthly limit and 1.6mg/L instantaneous maximum daily limit. The city is required to test all variables on a set schedule. Please see the chart below for more data requirements.

The city initiated the design of an expanded and upgraded facility to process wastewater through 2048, assuming an annual growth rate of 4%.

1. 2018-2023: A new 20-year Facility Plan was created by Forsgren Associates, approved by the State of Idaho, and adopted by the City Council.  
2.  April 2024: Forsgren Associates began the design of the facility expansion and upgrade to an extended, aeration-activated sludge facility.  A Membrane Bioreactor System was selected as the preferred technology due to its performance, timing, and ability to fit into existing infrastructure.
3. November 2024: Kubota Membrane USA was selected to provide membrane bioreactor equipment.
4. December 2024:  A 30% Design and Cost Estimate was presented to the City Council, with an estimated cost of $31.6 Million.
5. February 2025:  Forsgren Associates will present a 60% Design and Cost Estimate to the City Council.
6. April 2025: Submit Preliminary Engineering Report to the State of Idaho for review and approval.
7. July 2025: Forsgren Associates will present a 90% Design and Cost Estimate to the City.
8. October 2025: Submit 100% to the State of Idaho for review and approval.
9. February 2026: The City of Driggs will advertise for construction bids.
10. May 2026: Begin construction of facility expansion and upgrade.
11. September 2028: Initial start-up of the expanded and upgraded WWTP Facility.
12. January 2029: The expanded and upgraded plant will be fully online.
13. February-September 2029: Removal of accumulated sludge from lagoons.

Yes, a significant amount of the existing equipment, along with the existing buildings and piping, is being re-used.  The membrane bioreactor technology was selected as it will fit into our existing concrete basins and not require additional construction of new concrete basins.

However, some new construction is required, including a building over the existing concrete basins that will house new air blower units and bio-solids handling equipment.

The City of Driggs is contracted with Altura Community Consulting and Business Fiance to pursue grants and low-interest loans to help finance the project. Altura will assist the City by applying for multiple funding options each year leading up to the new facilities going online.

Alas, the answer is: It Depends. It depends on how much grant money is received and the loan interest rate required to meet the final costs.

Yes, all users connected or connecting to the facility will be required to pay their fair share of the upgrade costs.  Connection fees will be adjusted to ensure new development is paying for their associated capacity expansion.

Yes!

Disconnect roof/storm drains from your sewer, and don’t connect sump pumps to the sewer.

DO NOT FLUSH wipes, feminine products, or grease! Using water conservation best practices and minimizing difficult-to-process waste will help our current situation. See our Water Conservation and FOG prevention information on the Utilities: Water and Sewer Page

Please contact city staff with any additional questions that we can help answer. As more information becomes available with the new facility plan and phases toward a solution, we will update this page. Thank you for taking the time to learn about our city's wastewater treatment plant.