Williamson County is mandated to enforce the new riser requirements that were adopted by the TCEQ effective September 1, 2023. Please see an excerpt from 30 TAC 285.38(c):
(c) For all OSSFs permitted on or after September 1, 2023, inspection and cleanout ports shall have risers over the port openings which extend to a minimum of two inches above grade. A secondary plug, cap, or other suitable restraint system shall be provided below the riser cap to prevent tank entry if the cap is unknowingly damaged or removed.
Williamson County will be reviewing for risers over all cleanout and inspection ports, including both ports on septic tanks, and the risers must extend two inches above grade. Please revise your septic tank, pump tank, and ATU design details accordingly.