To permanently close a UST system, the owner shall:

1. (a) Remove all liquid and sludge from the system;
2. (b) Clean the system;
3. (c) Dispose of all liquid, sludge, and used cleaning materials in accordance with applicable state and federal rules;

4. (d) After all regulated substances have been removed from the system:

   1. (1) Disconnect and remove all piping system components, including secondary piping; or
   2. (2) If all piping system components cannot be completely removed, remove the piping system components to the greatest extent possible, test the remaining portions for tightness, and permanently cap or plug the piping;
5. (e) Test the tank for hazardous or explosive vapor, and remove or render such vapors inert;

6. (f) Remove the UST system unless:

   1. (1) Removing the system would undermine the integrity of any overlying structure or compromise the structural integrity of an adjacent UST system;
   2. (2) Plans have been approved pursuant to Env-Or 407.01 through Env-Or 407.04 to install a field-erected tank within the permanently-closed tank; or
   3. (3) For piping secondary containment, plans have been approved pursuant to Env-Or 407.01 through Env-Or 407.04 to install replacement piping within the existing secondary piping and the secondary piping passes a tightness test;
7. (g) Perform a site assessment in the area of the tank and piping as specified in Env-Or 408.08 to determine whether any contamination is present; and
8. (h) For any UST system that is closed in place based on (f)(1), above, completely fill each tank with a solid inert material such that no voids remain in the tank.

Source. (See Revision Note #1 at chapter heading for Env-Or 400) #10393, eff 9-1-18; ss by #12643, eff 10-10-18 (See Revision Note #2 at chapter heading for Env-Or 400)