{"id":3522,"featured":0,"modified":"2026-04-17 19:58:10","latitude":46.0282599131794114555304986424744129180908203125,"longitude":-112.535033941285291803069412708282470703125,"title":"Stormwater and Sanitary Sewer Water Contamination","subtitle":"","fullsize":"https://storyofbutte.org/files/fullsize/52949802fb7cd7e2db44eb076996aa24.jpg","address":"","all_locations":[],"zoom":19,"creator":["Jon Sesso"],"description":"Because the heavy metals were so widespread at the surface on the Butte Hill, every time it rains the stormwater can sweep these metals down the 11-degree slope and deposit harmful concentrations in Silver Bow Creek and throughout its floodplain. At the same time, Butte’s municipal stormwater collection system is designed to discharge to Silver Bow Creek. This is the reason the Butte-Silver Bow government was named by EPA as a responsible party, along with ARCO and the railroads, to clean up that pollution. <br />\r\n<br />\r\nIn this case, the remedial cleanup response has been to 1) cap the contaminated soils on the Hill to eliminate, as much as possible, stormwater contact with the heavy metals; and 2) build a system of ditches, sediment basins and hydraulic control devices to collect the stormwater coming off the Hill. These facilities allow the heavy metals to drop out of the stormwater before reaching Silver Bow Creek. Generally, the solution has been largely successful, with more than 90% reduction in metals in stormwater discharged to Silver Bow Creek.<br />\r\n<br />\r\nBut more work remains. To capture the last 10%, the protective caps on the Butte Hill already in place are under review and those that don’t meet standards are being rebuilt. Other areas on the Hill that were never reclaimed (more than 100 acres) will be addressed, and maintenance protocols will continue to be assessed regularly for performance and effectiveness. Maximum action is required on the caps to eliminate contact between stormwater and heavy metals on the surface.<br />\r\n<br />\r\nOn the stormwater collection side another series of sediment catch basins are necessary. Over the next few years, these facilities will be installed at the bottom of the Hill, along the Silver Bow Creek corridor and in-line with the major drainages coming down the Hill – Warren Avenue Gulch, Buffalo Gulch and Missoula Gulch. <br />\r\n<br />\r\nMost if not all sanitary sewer collection pipes on the Butte Hill have been embedded in mine waste and tailings since they were installed. The pipes have been deteriorated substantially by the mine waste, and when it rains, stormwater infiltrates through mine wastes into the sanitary pipelines. That water is carried to the sewage treatment plant, producing a marked increase in heavy metals reaching the plant. The solution is to dig up and replace the most deteriorated pipelines, or re-line the largest pipelines to eliminate the infiltration. A multi-million-dollar program has been established to systematically perform the work over the next 20 years.<br />\r\n<br />","sponsor":"Superfund Advisory and Redevelopment Trust Authority and The Foundation for Montana History","accessinfo":"","lede":"Stormwater and sanitary sewer water were also contaminated by the heavy metals that Butte&#039;s mining industry left behind. Stormwater pollution is an omnipresent challenge and has proved to be a very difficult problem to address.","website":"","related_resources":[],"factoids":[],"files":{"https://storyofbutte.org/files/fullsize/52949802fb7cd7e2db44eb076996aa24.jpg":{"id":5764,"mime-type":"image/png","title":"Missoula Gulch, Before","description":"Courtesy of the Butte-Silver Bow Department of Reclamation and Environmental Services.","thumbnail":"https://storyofbutte.org/files/square_thumbnails/52949802fb7cd7e2db44eb076996aa24.jpg"},"https://storyofbutte.org/files/fullsize/65b7b5e4e4268a65f0514f371ebf306a.jpg":{"id":5765,"mime-type":"image/png","title":"Missoula Gulch, After","description":"Courtesy of the Butte-Silver Bow Department of Reclamation and Environmental Services","thumbnail":"https://storyofbutte.org/files/square_thumbnails/65b7b5e4e4268a65f0514f371ebf306a.jpg"},"https://storyofbutte.org/files/fullsize/e0109a452c3b56e03b330e3d9688d786.jpg":{"id":5766,"mime-type":"image/png","title":"Aerial View, Gulches","description":"All of Butte’s gulches where stormwater must be monitored.  | Courtesy of the Butte-Silver Bow Department of Reclamation and Environmental Services","thumbnail":"https://storyofbutte.org/files/square_thumbnails/e0109a452c3b56e03b330e3d9688d786.jpg"},"https://storyofbutte.org/files/fullsize/30eda9aa9d3e305c395a03bcdff12cfe.jpg":{"id":5767,"mime-type":"image/png","title":"Aerial, Butte’s Sanitary Sewer System","description":"Courtesy of the Butte-Silver Bow Department of Reclamation and Environmental Services","thumbnail":"https://storyofbutte.org/files/square_thumbnails/30eda9aa9d3e305c395a03bcdff12cfe.jpg"}}}