Walk-through Inspections

Walk-through Inspections

New UST Walk-through Inspections Coming Soon to Montana!

By Seth Hendrix

New Underground Storage Tank (UST) regulations are coming, including periodic operation and maintenance walk-through inspections.  The U.S. Environmental Protection Agency (EPA) published revisions to the Federal UST regulations on July 15, 2015. In accordance with these new regulations, the State of Montana Department of Environmental Quality (DEQ) will require UST owners and operators to begin implementation of periodic operation and maintenance walk-through inspections no later than October 13, 2021.   Montana DEQ is currently updating its UST regulations to incorporate the new walk-through inspection requirements and maintain consistency with the 2015 updates to the federal regulations set forth in 40 CFR 280.36.  

Currently, UST facilities receive a compliance inspection by a State-licensed inspector at least once every three years, and these will continue. The periodic 30-day walk-through inspection must be performed by UST owners and operators and a record of these inspections must be documented and maintained for at least 12 months, just like the previously-required monthly leak detection recordkeeping. The 30-day walk-through inspection is intended to help owners and operators find and address possible leak sources before they enter the environment. 

A federal checklist is already available and Montana is planning on creating a checklist, as well.  Additionally, the “Petroleum Equipment Institute Recommended Practice 900: UST Inspection and Maintenance”, provides a checklist, if the owner/operator chooses to utilize the code of practice to satisfy the walk-through requirement. (If utilizing PEI/RP-900, the code of practice must be used in its entirety.)   In accordance with the checklists, owners and operators must check the following when conducting a walk-through inspection:

  • Designated equipment that must be inspected on a 30-day basis. 
  • Other equipment such as containment sumps and hand-held release detection equipment. 
  • Spill prevention equipment (i.e. spill buckets) and release detection equipment including associated records. 

If done correctly, there will be tremendous benefits to the 30-day inspection requirement, including:

  • Heavily-used UST equipment found to be degraded, damaged or malfunctioning will be required to be repaired or replaced in a timely manner.
  • Small UST compliance problems can be discovered early and addressed.
  • Spills, leaks, releases and equipment alarms may be caught sooner.
  • Regular inspections facilitate and reinforce operator training for conducting inspections of UST equipment each month.
  • Inspections will occur on items not currently on the routine three-year UST compliance inspection schedule such as dispensers with attached cracked dispenser hoses.

Each inspection will include three principle areas of an UST facility:

  1. Tank pad area,
  2. Impressed current rectifier/voltage area (if applicable), and
  3. Tank monitor and/or release detection equipment area.

All components on the 30-day inspection checklist must be inspected unless not present or applicable. Checklist records must be kept by the owner/operator and provided to the State-licensed UST inspector during State-required UST compliance or oversight inspections.

When conducting a walk-through inspection, spill buckets must be inspected for damage and replaced if necessary. Liquids and debris in the spill bucket must be promptly removed.   Check for fill pipe obstructions and ensure caps are properly secured. Replace damaged fill caps that don’t seal properly and inspect all interstitial monitoring devices on-site.

Example of the Federal Walk-through Inspection Checklist

A couple examples of cracked and damaged spill prevention devices (i.e. spill buckets) that are not liquid tight.  Both spill prevention devices shown above require replacement.

Release detection equipment and associated records must also be inspected during walk-through inspections every 30 days to ensure proper functioning. Confirm no unusual operating conditions are present. For most UST sites in Montana, checking the release detection equipment includes:

  • Visually inspecting the tank monitor.
  •  Ensuring each tank shows passing 0.2 gallons per hour (gph) tank test results.
  •  Ensuring each piping run shows passing 0.2 gph pressure line leak test results if your facility has Electronic Line Leak Detectors (ELLDs).
  • If facility has double-walled tanks with interstitial sensors and/or piping liquid sensors and secondary pumps, ensuring each liquid sensor shows normal/passing liquid status test results.
  • Printing out passing/normal tank and piping test results and keeping monthly records to demonstrate compliance.

For automatic tank gauge and other leak detection controllers:

  • Test the alarm.
  • Verify the system configuration.
  • Test the battery backup.

For probes and sensors:

  • Inspect for residual buildup.
  • Ensure all floats move freely.
  • Ensure all shafts are not damaged.
  • Ensure the cables are free of kinks and breaks.
  • Test the alarm operability and communication with the controller.

For automatic line leak detector (ALLD):

  • Ensure the device activates (alarms, restricts flow, or shuts off product flow) within an hour when simulating a release equivalent to 3.0 gph at 10 pounds per square inch.

Visually inspect your tank monitor at least once every 30 days. 

Containment sumps must now be inspected at least once a year. This requirement includes under-dispenser containment sumps and all tank top containment and transition sumps. During the inspection, check each containment sump for damage, leaks in the containment area and releases to the environment. Remove liquid and debris found inside the sump. Check for interstitial leaks in double-walled containment sumps with interstitial monitoring equipment installed. Replace or repair compromised sumps.

Remove all liquid and debris and have your service provider repair or replace the sump if damage is discovered

Check UST hand held release detection, such as tank gauge sticks, at least once per year. Ensure equipment is functional and in good condition. Gauge sticks must be able to measure product over the full range of the stick to the nearest 1/8 of an inch. They must also be legible and not worn down or damaged at the end. Replace all hand-held release detection equipment that is not functional or is worn out.  All tank and piping leak detection methods must meet minimum Department standards. Any method of leak detection must have the ability to detect a leak rate of 0.2 gph with a probability of successful detection of 95 percent and probability of failure of detection of 5 percent or less. To confirm if your tank and piping leak detection method meets this requirement, contact DEQ UST program staff or check with the at NWGLDE.org. National Work Group on Leak Detection Evaluations (NWGLDE) website

A gauge stick used to disable the overfill flapper valve (overfill prevention device) in a UST drop tube. Remove the stick and confirm that the flapper valve is still functioning properly.

Inspections should always be done in a safe manner. With proper preparation, safety equipment, training, and common-sense potential hazards conducting 30-day UST inspections are lessened.  However, individuals conducting inspections must be aware of inherent risks associated with working at an UST site. Potential hazards of UST inspections may include:

  • Traffic safety hazards. Lots of vehicle accidents occur at gas stations. Use safety cones. 
  • Exposure of skin and eyes to liquid petroleum.
  • Exposure to petroleum vapors.
  • Potential injuries related to opening UST access points.
  • Potential slips, trips, and falls associated with UST facility surface conditions.

The 30-day inspection should take about 30 minutes to complete, but the time it takes to finish the inspection checklist depends largely on how many tanks a facility has and how accessible the UST systems are. A large truck stop inspection may take most of a day to complete properly. Be aware of safety hazards during each inspection and utilize professional assistance when needed. The Montana DEQ UST program website provides owners and operators of UST systems with a complete list of State licensed UST professionals at  http://deq.mt.gov/Land/ust/licensees Montana DEQ will provide UST owners and operators with more information on walk-through inspections as new regulations and inspection requirements are developed.






Directors Office
Christine Mandiloff (Public Information Officer): 444-6469

Underground Storage Tanks
1520 East Sixth Avenue | P.O. Box 200901 | Helena, MT 59602-0901
Phone: 406-444-5300 | Fax: 406-444-1374
Email: dequstprogram@mt.gov  
UST Web: http://deq.mt.gov/land/ust
Leanne Hackney (Program Manager): 444-0485

Petroleum Tank Cleanup Section Federal Facilities and Brownfields
1225 Cedar Street | P.O. Box 200901 | Helena, MT 59601
Phone: 406-444-6444 | Fax: 406-444-6783
Remediation Web: http://deq.mt.gov/Land/rem
Aimee Reynolds (Bureau Chief): 444-6435
Amy Steinmetz (Section Supervisor): 444-6781

Petroleum Tank Release Compensation Board
1225 Cedar Street | P.O. Box 200901 | Helena, MT 59601
Phone: 406-444-9710 | Fax: 406-444-9711
PTRCB Web: http://deq.mt.gov/deqadmin/pet
Terry Wadsworth (Executive Director) 444-9712