FAQ
The Terrebonne Sanitary District is an officially formed entity responsible for developing, managing and maintaining the sanitary sewer system in Terrebonne. Our goal is to provide efficient and reliable wastewater services to the community.
The Terrebonne Sanitary District (TSD) was established to provide a long-term, sustainable sanitary sewer system for the community. Our goal is to replace failing septic systems with a reliable sewer system to protect public health, the environment, and existing properties in Terrebonne.
The official website for the Terrebonne Sanitary District is https://www.terrebonnesd.org. Any other websites impersonating the District or claiming to represent the "true details" of the District are not legitimate. Be cautious of other sources that may provide misleading or incorrect information. For accurate and official information, always refer to our official website or contact our office directly.
This study was initiated by a Terrebonne resident who petitioned and gathered signatures from individuals in the community who were interested in seeing an updated wastewater feasibility study for Terrebonne. In response, Deschutes County agreed to fund the feasibility study, but has no intent to operate and maintain a sewer system in Terrebonne.
- Researched the extent of existing septic system issues and problems in Terrebonne (unincorporated community boundary).
- Explored options for a municipal wastewater (sewer) system in Terrebonne.
- Estimated construction costs and operational costs to determine potential sewer utility rates for residences and businesses in Terrebonne.
- Explored potential grant funding opportunities to fund construction.
- Identified governance options for operation of a sewer utility.
- Outlined next steps for the community to take in establishing a sewer system in Terrebonne.
Many of the septic systems in Terrebonne were installed over shallow bedrock more than 30 years ago and are reaching the end of their life cycles. Failing septic systems can result in health risks, expensive repairs, and the closure of residences and businesses when septic systems cannot be repaired. With the shallow bedrock and small lot sizes in Terrebonne, onsite wastewater systems are not a safe and sustainable solution for our community.
Deschutes County has observed a noticeable increase in septic repair permits in the last few years, resulting in expensive repair costs. The Deschutes County Sanitarian has reported that Terrebonne has a septic system failure rate that is roughly two times higher than the rest of the County, largely due to the age of onsite systems, shallow impermeable bedrock, and inadequate lot sizes for proper drainfields.
When septic systems fail, people and pets can be exposed to raw sewage that includes infectious bacteria, viruses, and parasites. Toxic fumes including Methane gas, Hydrogen Sulfide gas, and airborne bacteria can lead to sinus infections and other respiratory problems.
There are several commercial and residential lots in Terrebonne that cannot be developed because of inadequate lot size or soil conditions for septic systems. More businesses will open and stay open in Terrebonne if reliable sewer service is available. Installation of public sewer would help support the local economy with new homes, businesses, and jobs.
Through the process of the feasibility study, the project team explored a variety of possible sewer system designs for Terrebonne, including a facultative lagoon, packaged treatment plant, and a STEP (Stepic Tank Effluent Pumping) collection system connected to the City of Redmond wastewater treatment system. Input gathered from community meetings helped to inform the preliminary sewer design process. Based monetary factors, non-monetary factors, and stakeholder input, it was determined that the preferred system alternative is a STEP collection system connected to the City of Redmond wastewater treatment system.
The exact upfront and ongoing costs are not yet established at this point and would depend on system construction costs, the extent of grant funding, and what potential ratepayers can afford. The TSD Board of Directors is working to keep rates and fees affordable for customers and comparable to nearby communities by minimizing construction costs and pursuing infrastructure grants.
Assuming a $6 Million Project Cost, a $3 Million CWSRF loan at 1.57%, $3 Million in grant funding, and annual operating expenses around $100,000 per year, SDC fees are estimated to be roughly $7,500/EDU and monthly rates are projected to be as follows, based on the number of Equivalent Dwelling Units (EDUs) connected to the system:
If a septic tank effluent pumping (STEP) collection system is installed, septic tanks in good condition could remain and be retrofitted with small low-pressure pumps connected to the public sewer. If septic tanks are in poor condition, they should be pumped dry and then removed, filled in place, or crushed and buried in place. In both cases, the septic drainfield can be removed after a year without use, according to the County’s Tank Abandonment Procedures. After proper abandonment, drainfield areas may become available for other more valuable uses.
It could take approximately 2-3 years for design, funding, contractor bidding, and construction of a municipal sewer system. The latest project schedule estimates that funding applications would occur in 2024 and design and construction would occur 2025-2027.
The public sewer system in Terrebonne would be owned and operated by the Terrebonne Sanitary District.
This feasibility study process gathered and incorporated feedback from Terrebonne property owners through a series of open house events. A group of Terrebonne stakeholders known as the Terrebonne Sewer Advisory Group (TSAG) met on a monthly basis to provide input on the planning process and represent community interests.
A grassroots movement of community members formed an official sanitary district, which has been actively pursuing construction funding for the project based on the completed Preliminary Engineering Report. The Terrebonne Sanitary District board members are residents and owners of property within the District service area and were elected by voters registered within the district to represent their interests. After confirming the design, project funding sources, construction costs, and customer charges, the Sanitary District Board will make the official decision on when to proceed with development with a public wastewater system.
Terrebonne owners and residents can share their input with the District Board by phone, email, online contact form, and the public comment portion of monthly board meetings.
The proposed sanitary sewer system in Terrebonne aims to reduce groundwater pollution by replacing failing septic systems with a reliable sewer system. A short segment of the sewer main on B Avenue was planned to be approximately 80 feet from TDWD Well #4. Initially, it appeared that a waiver was needed because OAR 333-061-0050 prohibits pressure sewer lines within 100 feet of a public well unless a waiver is granted by the Oregon Health Authority (OHA). However, during the review process, it was clarified that these construction standards apply only to drinking water systems, not sewer lines. The applicable standards for sewer systems, set forth in OAR 340-052, require sewer mains to be at least 50 feet from existing wells, which the proposed location met. Therefore, the waiver was not necessary for compliance but was issued to proactively safeguard the water district’s continued use of Well #4. The waiver was withdrawn by OHA on July 16, 2024, not due to any procedural or hydrogeologic issues, but because the TDWD did not need it at this time and requested its withdrawal.
The OHA conducted a hydrogeologic review and determined that the well’s water quality would not be affected by the sewer line installation due to its proper construction and the favorable conditions of the confined aquifer. However, to alleviate TDWD concerns, the Terrebonne Sanitary District (TSD) offered to implement additional protective measures, such as alternate sewer routing, dual containment piping, steel encasement, and waterproofing methods, to further minimize any risk of sewer lines impacting a well. These measures, though not required by law, demonstrate TSD’s commitment to ensuring the highest level of environmental protection.
The Terrebonne Sanitary District (TSD) takes the safety of the community’s water supply very seriously. The TSD’s proposed sanitary sewer system will facilitate the removal of these groundwater pollution sources, thereby reducing the risks of groundwater contamination by sewage. Properly designed and constructed pressure-rated sewer lines do not pose greater risks to the wells than the hundreds of existing drainfields and drill holes that are constantly injecting wastewater effluent into the ground above the wells. The sewer line design and placement were and will continue to be thoroughly evaluated to minimize risks of potential contamination, in coordination with the Department of Environmental Quality (DEQ) and the Oregon Health Authority (OHA). The OHA geologist review suggests that water from the well is not susceptible to contamination from the sewer line, because the well is properly constructed in a confined aquifer.
For any questions or concerns, please contact our office at (425) 224-2458 or email us at terrebonnesanitary@gmail.com. Our team is here to assist you and provide accurate information.