South Dakota’s largest cities are embarking on wastewater projects to account for reliability, growth, and regulations. The City of Sioux Falls is putting $35 million into two major sanitary sewer projects officials say should last nearly a century. Rapid City leaders say their community needs $62 million for system upgrades.
Pumps churn at a construction site in northeastern Sioux Falls. Crews are working to lower the water table so they can bury large pipe for more than two miles. The diameter of the new pressure pipe is three-and-a-half feet.
Principal Engineer Ryan Johnson says this tube supplements a smaller line that now forces 90 percent of the city’s wastewater to the treatment plant.
"So we wanted to have an additional pipe to handle that capacity but also provide a redundant link from the pump station to water reclamation in the event of a failure," Johnson says.
Another phase of sanitary sewer upgrades includes replacing pipe from the 1980s with bigger, corrosion-resistant materials. Mark Cotter is director of Sioux Falls Public Works.
"If you look at, from the area near the spillway, there’ll be a large 72-inch diameter gravity sewer pipe that’s nearly two miles in length that will replace an aged 66-inch pipe," Cotter says.
Cotter says most people don’t think about wastewater management until the services stop working.
"We’ve experienced major collapse in 2010 that we certainly don’t want to experience again. And since 2010, we did a tier assessment of our system of Tier 1 projects which were the highest priority, Tier 2 were the next, and then Tier 3. We’ve made it through all of Tier 1. We’re progressing almost through Tier 2, and we’ve got some key projects in Tier 3," he says.
Cotter says Sioux Falls Public Works is borrowing from the State of South Dakota at a low interest rate to pay back over 10 years. Money for the system upgrades comes from payments people make as part of their monthly water bills.
Rapid City Water Superintendent Dave VanCleave says leaders want to study rates in their town to figure out how much upgrades there will cost citizens. He says the approved plan includes updates that look ahead 20 years and total $62 million. VanCleave says officials are working on a master plan for repairing, replacing, and expanding the sanitary sewer system in Rapid City.
