MPCA rules govern how sub-surface sewage treatment systems (SSTS) — also called septic systems — are designed, installed, and managed in the state, and are drafted to protect state waters and public health from the pathogens in sewage. Counties, cities, and township governments implement and enforce the SSTS rules through local ordinances. Inadequate or failing septic systems have been identified as sources of bacterial pollution in lakes, rivers, and streams in many areas around the state. But reporting from 2018 shows that local government septic programs continue to make progress toward improved compliance and environmental protection.
The recently released SSTS Annual Report for 2018 compiles data submitted by 207 local governments and offers a snapshot of Minnesota’s approximately 575,726 septic systems. An estimated 463,500 septic systems — about 80% of the state's total — now fully comply with standards, up from 334,500 in 2007. Septic systems in Minnesota treated approximately 39.4 billion gallons of wastewater in 2018, about 25% of all the state's wastewater.
Since 2002, local SSTS program administrators have issued 197,685 SSTS construction permits, more than 100,000 of them for replacement systems. Of the 10,311 septic systems installed in 2018, 5,436 were replacement systems that represent about 372 million gallons per year of wastewater brought into compliance. Sixty-one Minnesota counties (80% of the local programs) require inspections when a property is sold or transferred, which can catch inadequate systems that might otherwise be missed. Thirty-four percent of all the septic systems in the state are less than 17 years old. A septic system can last 25 to 30 years — sometimes much longer — depending on how it's constructed, used, and maintained.
"Another significant statistic is the number of compliance inspections performed during 2018," says report author and MPCA staffer Lisa McCormick. "There were nearly 15,000 inspections performed last year, or about 2.6% of all the systems in the state. That represents a lot of effort by the counties, townships, and other local governments that administer the program in Minnesota. We really appreciate the work they do and reporting those accomplishments to our agency."
Learn more about the 2018 SSTS annual report or find a licensed SSTS business or certified professional to maintain your septic system. Or see the MPCA's recommendations for homeowners on how to maintain a healthy septic system.