This article is part of our feature on the future of wastewater in the U.S.’s fastest growing metro areas. We’re using the Transcend Design Generator to automatically build, expand, or upgrade regional wastewater treatment systems in each of these regions.
We continue our mission of designing wastewater treatment plants for the U.S.’s Top 100 fastest growing metros, now in the beautiful state of Minnesota. The state has one county in list: Hennepin County, one of many surrounding the Minneapolis metropolitan region.
We will focus solely on this county, as the Minneapolis metropolitan region has multiple wastewater treatment plants in different counties, and Hennepin is by far the largest. The primary wastewater treatment plant in Hennepin County is the Blue Lake WWTP, which treats 27 MGD daily, with a peak capacity of 32 MGD, and serves around 300,000 people.
Given that the largest plant in the metropolitan area, the Metropolitan WWTP in St. Paul, can handle wastewater from many other counties with an average daily capacity of 172 MGD, we’ll concentrate on expanding the Blue Lake WTP to accommodate the anticipated population growth in Hennepin County from 2020 to 2030. With an expected increase of 127,000 people, this would require expanding the plant’s capacity by about 25% to serve a total of 427,000 residents.
Using the same per capita usage estimate as the current plant, the new target capacity would be 38.5 MGD, with a difference of 11.5 MGD. Since the region is fit for smaller plants, it makes sense to build a fully capable greenfield plant near the existing one, using the same Conventional Activated Sludge technology, and not try to fit around the existing buildings and the lake located near it.
If you enjoyed this piece you may also want to read about the future of wastewater in Nashville!