The Peak Health & Wellness Center is located southwest of Missoula. The Peak facility is located on approximately 5.0 acres and expanded through the use of a boundary line relocation to develop a tennis facility. The remainder of the lot modified by the boundary line relocation has been developed with the Watson Children’s Shelter, a temporary housing facility for children in crisis throughout western Montana.
The Peak and Watson sites faced some unusual challenges that had up to this point hindered development of the lot. The aquifer under the Peak Health & Wellness Center has historically had high nitrate levels and therefore, the Missoula City-County Health Department had placed severe restrictions on any additional drainfield development in this area. In addition, this area of Missoula is not served by municipal water, therefore the existing public water system was in need of upgrade to meet current regulations. In addition to water and sewer designs, Territorial-Landworks completed grading and drainage designs. These designs presented their own challenges as the existing site was previously used as a gravel pit and had some areas of very steep slopes.
The high existing nitrate levels in the aquifer required that the wastewater treatment system used for this additional development provide superior treatment than a conventional system. After reviewing several options and consulting with the clients, Montana Department of Environmental Quality (MDEQ) and Missoula City-County Health Department, a Sequencing Batch Reactor (SBR) system was selected to treat the wastewater from the new proposed facilities as well as the existing Peak Health & Wellness Center. Even with almost double the original flow, the SBR will provide a reduction of phosphorus and nitrate discharge into the aquifer to levels up to 62% less for nitrates and 25% less for phosphorus than was previously being discharged into the aquifer. In addition, the nitrate concentration of the effluent after treatment will be reduced to less than half of the nitrate concentrations that currently exists in the aquifer.
Also, due to cost and space restrictions, the existing drainfield serving Peak Health & Wellness Center was analyzed and was rehabilitated to dispose of the treated effluent from the sequencing batch reactor, saving cost and land consumption.
Due to the high nitrates in the aquifer in this area, new wells for the proposed uses were not feasible without additional treatment. Peak Health & Wellness Center has two existing wells that were installed at the time of the facilities development in the mid-1980s. These existing wells draw from a different aquifer and produce sufficient water to serve the existing and proposed developments but because of the increased use, were required to be upgraded to current MDEQ standards. The current standards are significantly more stringent than those when the wells were installed and therefore presented additional challenges.
The existing Big Flat Ditch is less than the required 100 feet from the public water supply wells. Current regulations require additional testing of wells to determine if there is a link to surface water in the wells if there is surface water within 100 feet of the wells. Territorial-Landworks, Inc. worked closely with MDEQ to determine what would be required to allow continued use of these wells and at the request of MDEQ, performed two Microscopic Particulate Analysis (MPA) tests. This test showed that the wells were not under direct influence of surface water but, an additional regulation required disinfection to be installed on this water system since the wells have static water levels shallower than 25 feet below the ground surface.