Underground Storage Tanks
Permitting & Compliance
Effective May 26, 2017, a release must be reported within 24 hours
DHEC's 24-hour Emergency Response Line for Accidental Spills:
Walkthrough inspections can be done in conjunction with A/B operator requirements. A person knowledgeable in
tank systems (does not have to be the A/B operator) must complete the inspection form. Walkthrough inspections
include two components: monthly requirements and annual requirements. Walkthrough inspections must begin no
later than May 26, 2020.
The monthly walkthrough inspections need to include the following:
- Single wall spill buckets-checking for visual damage; removing liquid and debris; checking and removing
obstructions in the fill pipe.
- Double wall spill buckets-checking for leaks in the interstitial area.
- Release detection equipment- checking for proper operation; checking for alarms or other unusual operating
conditions; checking and reviewing records.
The annual walkthrough inspections need to include the following:
- Containment sumps-checking for visual damage, checking for leaks to the containment areas or releases to the
environment; removing liquid and debris.
- Double wall sumps-checking for leaks in the interstitial area.
- Handheld release detection equipment-checking devices such as tank gauge sticks and groundwater bailers for
functionality; calibrating equipment as needed; replacing damaged or inoperable equipment that cannot be
- Within 30 days after repair, overfill prevention equipment must be tested for proper function, and spill
containment and secondary containment areas of tanks and piping used for interstitial monitoring must be
tested for tightness.
- Internally lined tanks that fail the internal lining inspection and cannot be repaired in accordance with
nationally recognized code of practice must be permanently closed.
- No vent line flow restrictors (Ball Float Vent Valves) may be installed at new facilities or installed at
any existing facility. Ball Float Vent Valves that cannot be repaired according to the manufacturer's
specifications, must be replaced with another method.
Tank owners have four options for documenting the requirements of the walkthrough inspections as well as the
items required by the A/B operator log. All forms must be maintained and provided upon request. These forms are
available from the Department.
- Option 1: Use both a walkthrough inspection form and A/B operator log.
- Option 2: Use a combined form that reflects both the monthly and quarterly A/B operator requirements
as well as the walkthrough inspection requirements. A tank owner will be responsible for maintaining the
completed form in their records.
- Option 3: A tank owner may create their own specific form provided that it meets the criteria set by
the A/B operator log and walkthrough inspections. This form would need to be submitted, reviewed and
approved by the Department prior to being used.
- Option 4: A tank owner may use Petroleum Equipment Institute Publication RP 1200, "Recommended
Practices for the Testing and Verification of Spill, Overfill, Leak Detection and Secondary Containment
Equipment at UST Facilities" to comply with the walkthrough inspection requirements. A separate A/B operator
log would still need to be used to meet the B operator requirements.