Posted on July 28, 2026 by Brent Phillips

Every water district manager assumes the coating inside their water tank is safe once installed. But safety and compliance aren’t the same. If your lining hasn’t been verified against NSF/ANSI 61, you may be operating a non-compliant tank without knowing it—and that gap carries real regulatory and health consequences.

What NSF/ANSI 61 Means for Tank Coatings

NSF/ANSI 61 is the national standard covering the health effects of components that contact drinking water, including tank coatings, pipes, and fittings. NSF International maintains the standard alongside the American Water Works Association (AWWA) and the Environmental Protection Agency (EPA), which enforces requirements under the Safe Drinking Water Act. For a water district, certification isn’t optional: It applies to the exact product used in your water tank lining, not the coating type in general terms.

The Compliance Gap Districts Don’t See

Many districts inherited their water tank system from a previous contractor or a decades-old capital project. Records get lost. Product formulations change. A tank lining applied years ago may never have carried NSF 61 certification, or the certification may have lapsed when the manufacturer reformulated the product. Because the interior of a water tank isn’t visible daily, a non-compliant lining can sit undetected for years, surfacing only during a sanitary survey, a complaint, or a failed inspection.

How to Verify Your Tank Coatings

Verifying compliance takes more than trusting a past invoice. Water district staff should:

• Confirm the exact coating brand, formulation, and batch appear on NSF’s certified product listing, not just the manufacturer’s marketing claims
• Request current NSF/ANSI 61 certification documentation directly from the coatings applicator or manufacturer
• Check the certification date against the actual application date of the tank lining
• Schedule a physical interior inspection if documentation is missing, outdated, or unclear

An experienced tank coatings contractor documents every application against the current NSF 61 listing before, during, and after the work is complete.

The Cost of Non-Compliant Coatings

The cost of a non-compliant water tank isn’t hypothetical. A failed sanitary survey can trigger mandatory retesting, public notification, and emergency remediation timelines that cost more than a planned recoating project. Left untreated, a failing tank lining allows corrosion to advance, introducing metals and coating byproducts into drinking water—a direct violation of protections the EPA enforces under the Safe Drinking Water Act. Districts that wait until a lining fails outright, rather than verifying tank coatings proactively, consistently pay more in emergency repairs than in scheduled maintenance.

Choosing a Certified Coatings Partner

Not every contractor who applies a coating understands the certification requirements that a water district requires. The right partner treats tank coatings as a compliance discipline, not a maintenance task, verifying product certification before application and documenting the process for your records. For a water asset manager or city water manager, that distinction is the difference between a tank lining that meets NSF/ANSI 61 today and one that quietly falls out of compliance next year.

Cunningham Sandblasting Inc., headquartered in Joplin, Missouri, has spent years helping water districts nationwide verify, recoat, and document water tank systems in compliance with current NSF/ANSI 61 standards. If your district can’t confirm the certification status of your tank lining, don’t wait for a failed inspection. Call Cunningham Sandblasting today to schedule an on-site inspection and receive a detailed quote for recoating your town’s water assets, so your community stays safe and compliant.