More than 26 percent of septic systems in Minnesota have been installed in the last 12 years, according to the Minnesota Pollution Control Authority. Of the 146,400 construction permits issued during that time, more than 72,000 were for replacement systems, accounting for about 4.96 billion gallons of sewage per year being treated by modern systems.The MPCA reports the estimated number of compliant systems in the state increased from 334,500 in 2007 to 427,000 in 2013. That’s according to an MPCA article in the August/September issue of the Minnesota Onsite Wastewater Association Little Digger newsletter. Local officials reported approximately 534,000 septic
