NFPA 25 Fire Water Tank Inspections: What Facility Managers Should Know

Why Fire Water Tank Inspections Matter

Fire protection storage tanks may contain surfaces and components that are difficult to assess from outside. Internal corrosion, coating deterioration, sediment and damaged fittings can require closer examination to understand their significance.

Fire water tank inspections provide evidence about the areas included in the scope. They can help owners plan cleaning, investigate observations and develop maintenance priorities before committing to repairs or a shutdown.

An internal visual survey is one part of the wider inspection, testing and maintenance programme. It does not replace required checks of pumps, valves, alarms, water levels or other fire protection components.

Explore Ven-Tech’s NFPA 25 fire water tank services to discuss the internal inspection support appropriate for your facility.

1. Confirm the Requirements for Fire Water Tank Inspections

NFPA 25 is the Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems. Its water-storage tank requirements are addressed in Chapter 9.

Before scheduling fire water tank inspections, confirm the edition applicable to your facility, the tank construction, previous findings and any requirements established by the authority having jurisdiction, insurer or owner.

The newest published edition is not automatically the edition adopted at every site. Inspection frequencies and required activities should be checked against the applicable requirements rather than assumed from a general checklist.

For background, review NFPA’s official information about NFPA 25 and its explanation of water storage tanks for fire protection systems.

2. Define Which Surfaces and Components Will Be Examined

Effective fire water tank inspections begin with an agreed scope. Identify the inspection areas, required evidence and any components that need particular attention.

• Floor: accessible surface condition, deposits and visible deterioration.
• Walls: observable corrosion, coating condition and other surface changes.
• Joints and seams: visible irregularities requiring closer investigation.
• Internal components: accessible piping, fittings, ladders and supports.
• Obstructions: debris or deposits affecting access and visibility.
• Above-water areas: confirm separately whether and how these are included.

ROV and diver access may not cover every surface. Drawings and previous inspection reports help identify likely limitations before the team mobilizes. The final report should distinguish completed coverage from areas not examined.

3. Choose ROV, Diver or Drained Inspection Methods

Fire water tank inspections can involve remotely operated vehicles, commercial divers or drained access, depending on the task and applicable requirements. Each method provides different access and testing capabilities.

An ROV can collect underwater video and photographs from accessible areas without placing a person inside the tank. Its suitability depends on the entry opening, internal geometry, water clarity, equipment configuration and recovery arrangements.

Divers may provide hands-on access for selected inspection, cleaning or measurement tasks. Draining may be necessary where the required examination, testing or repair cannot be completed adequately underwater.

Ven-Tech’s ROV inspection services and commercial diving capabilities support method selection around the asset and agreed deliverables.

4. Address Sediment Before Drawing Conclusions

Sediment can limit fire water tank inspections by covering the floor and obscuring its condition. A camera may document the deposit without revealing the surface underneath.

If the floor is obscured, the report should state that it was not fully examined. Cleaning may be needed before the inspection can answer questions about coating condition, corrosion or other underlying observations.

The presence of sediment alone does not establish structural failure. Equally, clear images of the walls do not prove that a sediment-covered floor is in acceptable condition.

Where needed, our reservoir inspection and cleaning services can be scoped to expose accessible surfaces for further examination.

5. Identify Testing Beyond a Visual Survey

Some fire water tank inspections require more than camera footage. Depending on the applicable requirements, tank material and findings, additional examination or testing may be necessary.

Ultrasonic thickness testing can collect measurements at suitable locations when performed with appropriate equipment, surface preparation and procedures. It should not be assumed included in every ROV or diver inspection.

Coating assessment, leak investigation and other testing also require a defined scope. Some activities need drained access. Confirm the method, coverage, personnel qualifications and acceptance criteria before mobilization.

Inspection measurements support technical assessment. A visual observation or isolated thickness reading does not automatically establish the structural fitness of the entire tank.

6. Coordinate Access and Fire Protection Availability

Planning fire water tank inspections requires coordination with the facility’s operations and fire protection personnel. Keeping a tank filled is different from confirming that the connected system can remain operational during the work.

The team should review pumps, suction arrangements, water movement, required isolation and site operating restrictions. If the work creates an impairment, the responsible parties must manage it through the applicable site and regulatory procedures.

• Confirm hatch dimensions and the available launch or entry point.
• Review roof access, platforms and equipment lifting arrangements.
• Identify connected equipment and necessary isolation.
• Assess applicable fall protection and confined-space requirements.
• Establish communications, supervision and emergency arrangements.
• Confirm the work window and responsibility for restoring operations.

For diving in British Columbia, review the applicable WorkSafeBC occupational diving requirements. Other jurisdictions and work methods require their own assessment.

7. Request a Report That Supports Maintenance Decisions

Reports from fire water tank inspections should identify the asset, method, date, scope and areas examined. Findings should be supported by photographs, video references or measurement records where applicable.

For a multi-tank programme, each tank should have a clearly identifiable record. This helps facility managers track findings, compare conditions and assign follow-up work to the correct asset.

• Tank identification and relevant construction information.
• Inspection method, equipment and agreed coverage.
• Observed conditions and referenced supporting evidence.
• Sediment, visibility and access limitations.
• Results of separately specified measurements or testing.
• Items needing cleaning, further assessment or maintenance review.

The report should explain what remains unconfirmed. It should not imply that an internal survey certifies the complete fire protection system or replaces an engineering assessment where one is needed.

What Information Is Needed for a Quote?

To price fire water tank inspections, send the site location, number of tanks, dimensions, construction material, access photographs and previous reports. Include the applicable inspection requirements if known.

Also identify water depth, operating restrictions, expected sediment conditions and any requested cleaning or testing. Information about roof access, power, lifting support and site orientation helps establish a realistic field schedule.

Ven-Tech supports industrial clients across Canada, including energy, mining, forestry and manufacturing facilities. Availability, mobilization and scope are confirmed for each project location.

Frequently Asked Questions

Can the tank be inspected without draining?

In some cases, an underwater survey is suitable. The required scope, tank condition and applicable requirements determine whether an ROV, diver or drained inspection is appropriate. Repairs and certain tests may still need drained access.

How often are fire water tank inspections required?

The schedule depends on the applicable NFPA 25 edition, tank type, inspection activity and other governing requirements. Confirm the programme with the responsible fire protection professional and authority having jurisdiction.

Does a visual inspection include ultrasonic testing?

Only if it is specifically included. Ultrasonic testing requires suitable instruments, access, surface conditions and a defined measurement scope. A camera survey alone does not measure remaining steel thickness.

Can you provide an overall pass or fail?

Conclusions must be supported by the completed scope and applicable criteria. Where sediment, access or visibility prevents assessment, the report should identify the limitation and required next steps.

Why Work with Ven-Tech Subsea?

Ven-Tech combines robotic inspection and commercial diving capabilities with project-specific planning and clear reporting. Our credentials include DCBC-certified diving personnel, BCCSA COR certification and $5 million in commercial general liability insurance.

We coordinate the proposed inspection approach with the client’s asset information, access arrangements and required deliverables. Where additional cleaning, testing or engineering input is needed, those requirements are identified for review.