Properties Without City Sewer Need a Permitted Septic System

Collin County regulates septic systems through its Development Services department. For lots created after 2008, you need at least 1 usable acre for an OSSF permit. If the property also has a water well, the minimum rises to 1.5 acres total with 1 usable acre. Lots created between 1983 and 2008 need at least 1 acre; with a well, 1.5 acres.

A licensed Registered Sanitarian or Professional Engineer must design the system. The permit expires if there is no activity for 365 days. If you are buying rural land in Collin County, confirm the lot size meets these requirements before assuming you can build. Information on permitted installers and the application process is at collincountytx.gov.