Posted on July 30, 2025 by Brent Phillips

Surface preparation is the foundation of durable, compliant coatings for potable water storage tanks. Sandblasting vs. water blasting are two leading surface preparation methods, each with unique benefits and challenges. In rural municipalities, the stakes are exceptionally high. Proper surface prep prevents corrosion, ensures safe drinking water, and aligns with strict regulatory demands for protective coatings in potable water systems.

Understanding the Methods: Sandblasting and Water Blasting

Sandblasting uses high-pressure streams of abrasive grit—commonly sand—to strip old coatings, rust, and contaminants from tank surfaces. That method is efficient and has a powerful cleaning effect. However, sandblasting can pose health and environmental risks, particularly when lead-based coatings or silica dust are present, necessitating strict containment and permit requirements.

Water Blasting (hydroblasting), by contrast, uses high-pressure jets of water, often exceeding 10,000 psi, to dislodge and wash away surface materials. Water blasting produces less hazardous dust and can be highly effective on newer coatings or when minimizing airborne debris is essential. However, it generates a significant volume of contaminated wastewater that requires proper disposal to prevent environmental contamination.

Regulatory Compliance and Protective Coating Standards

In the debate over sandblasting vs. water blasting, regulatory compliance is non-negotiable. Protective coatings inside water tanks must comply with NSF/ANSI 61, which ensures that no harmful contaminants leach into drinking water supplies. From Environmental Protection Agency (EPA) to state agencies and public water system supervisors, these standards are monitored for compliance.

Key compliance requirements in rural municipalities include:

• Use of NSF/ANSI 61-certified coatings for all tank interiors and potable water contacts.
• Strict adherence to AWWA (American Water Works Association) standards for tank design, surface preparation, painting, and disinfection.
• Exhaustive documentation and testing, including leachate testing for more than 150 contaminants under NSF/ANSI 61.
• Rejection of any coatings containing lead, hazardous solvents, or other restricted chemicals.

Failure to comply can result in tank out-of-service notices, financial penalties, and, most importantly, risks to public health.

Comparing Sandblasting vs. Water Blasting: Practical Considerations

Choosing between sandblasting vs. water blasting involves more than technical efficiency. Rural systems must weigh safety, regulatory requirements, environmental impact, and maintenance realities:

Sandblasting

• Surpasses water blasting for removing heavy corrosion and legacy coatings
• Generates high amounts of dust and requires significant containment and worker protections
• May demand environmental permits, especially if hazardous materials are present

Water Blasting

• Ideal for routine maintenance when coating buildup or corrosion is light
• Reduces airborne dust but requires the containment and proper treatment of wastewater
• Sometimes less effective on hardened or multilayer coatings, necessitating possible retreatment

Best Practices for Compliance and Cost Efficiency

Across rural America, funding for infrastructure and technical capacity can be limited. Still, compliance remains vital. Small systems can streamline their approach by:

• Prioritizing certified coatings for all immersion surfaces
• Scheduling recoating to align with infrastructure upgrades
• Pursuing technical assistance and training for surface prep crews
• Using digital records to remain audit-ready for regulatory inspections

Plan Your Next Water Tank Project

The choice between sandblasting and water blasting for surface preparation of water tanks or towers is influenced by technical and regulatory factors unique to rural potable water systems. By staying well-informed about the latest standards and investing in compliant practices, rural municipalities can secure their infrastructure while also ensuring the safety and trust of their communities.

When it’s time for your municipality to schedule routine water tank or tower maintenance, contact the tank and tower experts at Cunningham Sandblasting & Painting Co. at (620) 848-3030.