A containment inspection should answer a practical question: if liquid escaped here today, where could it go?

That question leads beyond the most visible crack in a berm. It takes the inspector around pipe penetrations, across changes in materials, toward drainage valves and through the records showing whether last month's repairs were finished.

For oil facilities subject to the federal SPCC rule, EPA guidance considers the whole secondary containment system, including its walls and floor, and whether it can retain discharged oil until cleanup occurs. The assessment depends on the facility and stored product; it is not a claim of indefinite impermeability. EPA secondary containment guidance

The route below is a practical way to organize observations. Adapt it to the facility's engineering documents, operating procedures and applicable requirements. It does not replace a qualified engineering evaluation or a required inspection program.

Prepare the route before walking it

Bring the current containment layout, previous inspection findings and open maintenance orders. Identify which vessels, transfer points and equipment the area serves. Confirm the liquids involved and note any recent change in product, concentration, temperature or cleaning chemistry.

Assign simple location references: north wall, pump penetration P-2, drain D-1. The references should mean the same thing to operations, maintenance and the repair contractor. A photograph marked “crack” is much less useful than one connected to a specific location and earlier photographs.

Set safe access boundaries before starting. This is a planned inspection, not authorization to enter an unsafe area or handle an unknown release. Follow the site's emergency arrangements if a release is discovered. OSHA distinguishes workers who summon trained responders and evacuate from personnel authorized and trained to perform response activities. OSHA HAZWOPER preparedness

Start at the release points

Stand at each identified potential release point and trace the intended flow route on the layout. Compare the drawing with what is physically present. Has a new equipment pad changed the route? Has a temporary hose been routed beyond the boundary? Is an opening hidden behind stored materials?

Record differences for review rather than assuming the original plan still represents today's arrangement. Where you cannot see a section, label it “not inspected” and explain why. Do not turn missing access into a satisfactory finding.

This exercise is especially useful after equipment installation or a change in site traffic. Ask the responsible engineer or plan preparer to assess modifications affecting containment, rather than treating them as minor housekeeping decisions.

Inspect the barrier as a connected assembly

Follow the wall-to-floor junction, construction joints, penetrations and changes from one lining material to another. Then examine the accessible floor and wall surfaces. EPA inspection materials identify conditions such as cracking, erosion, corrosion, penetrations, standing liquid and valve condition as relevant observations. EPA field inspection checklist

For a coated area, record visible splits, lifting edges, blisters, exposed substrate and damage around supports or traffic routes. Describe what you can actually see. A blister is an observation; a conclusion about its cause requires further evaluation.

At each finding, take one photograph showing its position and another showing detail, with a scale where safe and practical. Compare repeat locations over time. A repair that repeatedly opens at the same joint deserves a review of the detail and service conditions before another patch is specified.

Make drainage a separate checkpoint

Identify each outlet, sump and drain control. Verify its required normal position against the operating procedure, and record its observed state. Confirm that the outlet destination matches the drawing and that the responsible staff can explain the drainage process.

For covered onshore facilities, 40 CFR 112.8 includes specific controls on drainage from diked areas. Where its rainwater-bypass provision applies, it requires a normally sealed-closed bypass valve, inspection of retained rainwater, supervised drainage and resealing, and records. The regulation also addresses manually activated pumps or ejectors and inspection before pumping. 40 CFR 112.8

Do not open a drain just to demonstrate that it works. Arrange any functional check through the approved procedure, with the appropriate controls. Clear-looking water should not become an improvised discharge authorization; use the facility's established evaluation, treatment and disposal requirements.

Check available space against the design basis

Record accumulated water, sediment, debris and newly stored equipment. Ask whether anything has changed the usable containment volume or the ability to move liquid toward its intended collection point.

Avoid treating “110 percent” as a universal federal SPCC sizing rule. EPA's guidance explains that the rule does not prescribe that percentage for precipitation allowance; relevant site conditions and the applicable containment provision matter. Some arrangements need different capacity considerations, and state requirements may also apply. EPA guidance on freeboard

Use the documented design capacity and operating limits for the actual installation. If the calculations are unavailable, or the arrangement has changed, raise a technical-review item. A quick estimate during a walkdown should not silently replace the engineering basis.

Connect lining condition with chemical exposure

If a coating has softened, changed appearance or deteriorated, record the location and known exposure history. Ask whether it experienced a spill, extended pooling, a new cleaner or elevated temperature. Do not infer chemical compatibility from the generic label “polyurea,” “epoxy” or “chemical resistant.”

For polymer materials, ASTM D543 emphasizes that useful chemical-resistance evaluation depends on relevant reagents, concentrations, contact conditions and temperatures. That principle makes the exposure history valuable when a supplier evaluates a damaged lining. ASTM D543

Send that history with photographs and the original system identification. Ask the manufacturer or qualified specialist for an appropriate investigation and repair recommendation.

Finish with a repair decision and verification

A useful finding needs more than a checked box. Record the location, observed condition, responsible person, required review, interim controls and target completion date. Escalate an apparent loss of containment capability through the site's established process immediately; do not leave it in an ordinary maintenance queue without evaluation.

Before repair, agree on the approved preparation, materials, detail and verification method. Afterward, retain completion photographs, relevant application records and the required inspection or test results. Record who accepted the work and any restrictions on return to service.

Finally, revisit the location during the next appropriate inspection. The practical measure of a good inspection program is whether identified weaknesses are understood, corrected and checked again. Following the liquid gets you to the finding. Following the repair gets you to a documented resolution.