Published March 2007

Built to Last

By Roger E. Machmeier

Research on septic tank performance has shown one of the most important features is the volume of liquid in the tank. Usually there is very little difference in the cost of a larger tank. I want to thank my installer friend, Jon Olson, of Olson Sewer Service in Minnesota, for some cost estimates on septic tanks and drainfield trench. These are average costs and the actual costs will vary from site to site. The cost of installing a single 1,500-gallon septic tank under average conditions is estimated to be $1,685. This is about $1,300 less than the cost of two 1,000-gallon tanks. So I would suggest that the largest size tank available be installed as a single tank.