What is a "major repair" vs. a "minor repair"?

The line is usually drawn at the drainfield. Replacing or fixing the part of the system that treats and disperses wastewater into the soil is a major repair; replacing the tank or the pipes and parts around it is a minor one. Oregon, as a worked example, defines a major repair as “replacing the soil absorption facility, treatment unit, or any part of it,” and a minor repair as “replacing a septic tank, broken pipe, distribution unit, or any part of the onsite system external to the septic tank or treatment facility except the soil absorption system” (OAR 340-071-0100).¹ The difference matters because a major repair usually needs a site evaluation, a design and a larger permit, and on a lot with poor soil it can mean a more expensive system than the one it replaces. A minor repair is normally a simpler permit and a smaller bill. Not every state uses the major/minor labels, and some sort repairs by permit type instead, but the drainfield-versus-everything-else line is common. Check with the county before hiring the work, and ask for the repair permit and final inspection when buying a property with a recent repair.

Citations

1. Oregon Department of Environmental Quality, OAR 340-071-0100, Definitions, official text published by the Oregon Secretary of State; Oregon DEQ, Repair Permit Guide for Septic Systems. ↩