The two winning projects are shining examples of how advanced protective coatings from Sherwin-Williams can extend the life and performance of essential water and wastewater infrastructure.
Sherwin-Williams Protective & Marine has announced two water storage tank rehabilitation projects as the winners of its 2026 Sherwin-Williams Impact Award program. The restored tanks include a steel potable water storage tank operated by the Aquarion Water Authority that serves the Stamford (Connecticut, USA), market and an underground concrete tank used to feed cooling system infrastructure for Arizona State University’s (ASU) West Valley campus in Glendale (Arizona, USA).
Restoration of the Connecticut water tank’s exterior coatings and interior lining earned the project team, consisting of Aquarion, coatings applicator R.J. Forbes Painting, and engineering and construction firm CDM Smith, the 2026 Sherwin-Williams Water Impact Award. The team selected the highly cleanable Sher-Loxane® 800 polysiloxane coating
for the 2.2-million-gallon tank’s exterior topcoat to enable easy cleaning of biological growth. The water authority just needs to use a low-pressure wash to remove mold and mildew. Applicators also restored the tank’s interior using a Sherplate® PW system for the tank’s immersed floor and walls and a Sherplate® 600 system to protect the numerous hard angles and edges that make up the tank ceiling’s structure.
Rehabilitating the lining for a large underground water storage tank earned the project team of ASU, applicator Professional Piping Systems (PPS), inspection firm Industrial Inspection Group (IIG), and general contractor Chasse Building Team the 2026 Sherwin-Williams Wastewater Impact Award, covering non-potable water infrastructure. The tank, which is 250 feet long, 50 feet wide and 40 feet high, feeds chilled water to the campus’s air conditioning systems. Following extensive testing and the preparation of multiple system mock-ups, PPS successfully relined the tank using a moisture-mitigation system for the floor consisting of cementitious resurfacer Dura-Plate® 2300, Poly-Crete® MDB applied at 3/16 inch, an aggregate broadcast and Dura-Plate® 6100 topcoat. The tank’s walls and ceiling received spot resurfacing with Dura-Plate 2300, a coat of Macropoxy® 5000 as a penetrating primer/sealer, followed by a thick coat of Dura-Plate 6100 at 125 mils DFT.
“Protective coatings are an essential element of water and wastewater infrastructure, delivering extended service lives to keep assets online and help owners reduce operational costs. Efforts like these tank restorations show how a combination of careful specification planning and the application of advanced coating technologies can breathe new life into assets and help owners maximize their investments,” has stated Paul Trautmann, Marketing Director for Infrastructure at Sherwin-Williams Protective & Marine.
The Sherwin-Williams Impact Awards honour contractors, specifiers and asset owners for outstanding performance on water and wastewater infrastructure projects across North America. The program recognises initiatives that protect vital assets while also extending service life and improving operational reliability for the communities those systems serve. Eligible submissions for the 2026 awards included projects completed the year prior that incorporated high-performance coating and lining technologies from Sherwin-Williams Protective & Marine.
The Aquarion Water Authority manages more than 100 storage tanks across 60 Connecticut municipalities. To keep these tanks operating to their full potential, the authority needs a 30- to 35-year cycle out of its tanks before engaging in necessary maintenance. Reaching that long service life, while avoiding the unscheduled cost of premature restoration, requires robust, long-lasting coating systems both inside and outside the tank.
When restoring the exterior of a potable water reservoir tank located in the North Stamford, Aquarion had mold and mildew in mind while selecting a new coating system. The authority needed a long-lasting coating that could resist biological growth and also be highly cleanable to help the authority maintain aesthetics and avoid the incorrect perception that mold and mildew on the tank’s exterior is a public health concern. As a side benefit, the coating’s ease of cleanability would also help to protect the coating system itself from wear, helping the water authority maintain its necessary maintenance cycle.
Restoration of the water tank’s exterior coatings and interior lining earned the project team of Aquarion, coatings applicator R.J. Forbes Painting, and engineering and construction firm CDM Smith the 2026 Sherwin-Williams Water Impact Award.
The 2.2-million-gallon tank, which is 130 feet in diameter with a 24-foot shell height, is surrounded by a retaining wall and nearby vegetation, making it prone to organic surface growth. In fact, the grimy material covered the tank’s exterior coating system before its rehabilitation.
For the restoration, the Bridgeport, Connecticut-based water authority’s engineering and specifying team chose Sher-Loxane® 800, a polysiloxane topcoat from Sherwin-Williams Protective & Marine. The glossy coating readily enables cleaning of biological growth from tank surfaces, which can potentially add extra years of service life to the system. Just a low-pressure wash is required to remove mold and mildew, prompting Aquarion to consider moving to a regular cleaning cycle for the tank.
Applicators from R.J. Forbes blasted the tank’s entire exterior surface before building a system featuring a primer coat of Corothane® I GalvaPac 1K. A stripe coat of Macropoxy® 646 Fast Cure on welds, seams and irregular surfaces followed by a full intermediate coat, and a full topcoat of Sher-Loxane 800.
Applicators also restored the tank’s interior lining, removing the previous system and building a new one up from steel repairs to stripe coating to topcoat. They used a primer coat of Corothane I GalvaPac 1K on the entire interior, as well as stripe coat of Sherplate® 600 on all seams, welds, crevices and irregular surfaces to ensure full protection on those areas.
For the lining topcoat, applicators used two different coatings. The immersed floor and wall areas of the tank received a single coat of Sherplate® PW. The edge retentive, 100% ultra-high-solids epoxy amine coating provides corrosion resistance for these vital areas of the tank, as well as excellent edge retention.
To better protect the numerous hard angles and edges that make up the tank ceiling’s structure, applicators applied two coats of Sherplate 600 to ensure greater coverage and longer service. The coating has the highest-performing edge protection per MIL-PRF-23236. Applicators alternated colors for these two coats, providing a helpful contrast for identifying any missed areas when applying the second coat.
Underneath a bare plot of land on Arizona State University’s (ASU) West Valley campus, workers from Professional Piping Systems (PPS) faced a challenging restoration of the lining for a large underground water storage tank. The tank, which is 250 feet long, 50 feet wide and 40 feet high, is one of three massive concrete reservoirs that feed chilled water to the campus’s air conditioning systems to reduce daytime energy demands.
The tank’s existing lining was in poor shape. Hundreds of blisters had formed underneath the coating material, which was also peeling off in large sheets. The lining was only 10 years old and had been delaminating since at least the five-year mark, indicating a faulty installation, material specification or both.
To restore the lining, which is meant to protect the university’s initial investment in the 40-year-old underground concrete tank, ASU needed to get the new application right and avoid repeating the failures of the previous lining. The scope, complexity and successful execution of the coatings work earned the project team of ASU, applicator PPS, inspection firm Industrial Inspection Group (IIG), and general contractor Chasse Building Team the 2026 Sherwin-Williams Wastewater Impact Award, which covers non-potable water infrastructure.
To provide an impermeable lining for the tank, the project team initially specified a universal restoration system across its entire surface. However, high moisture levels in the tank’s floor necessitated a specification change for this area, requiring installation of a moisture-mitigation solution ahead of the liner.
PPS first meticulously prepared the concrete’s surface for the coating applications, achieving a concrete surface profile (CSP) of 3-5 to encourage a strong mechanical bond. Based on the rubber-like properties of the failed lining, which was likely an elastomeric polyurethane system, the restoration crew was unable to effectively blast the material off the concrete. Instead, they removed it mostly by hand, revealing some inadequate surface preparation, smooth surfaces without a sufficient CSP, that contributed to that lining’s poor performance. The polyurethane system itself was another likely factor, as the material is typically hydrophobic and not the best choice for the tank’s moisture-laden concrete.
Following moisture testing and some serious dehumidification efforts, work was ready to begin on the tank’s walls and ceiling. However, the floor’s relative humidity, tested by inserting moisture probes into the floor, was still between 98% and 100%. This finding prompted lengthy discussions and testing to develop a flooring system that would effectively block moisture penetration and enable blister-free adherence of the new lining.
Ultimately, the team coated the tank’s entire floor with Poly-Crete® MDB, 100% solids, cementitious urethane cement that would block out the moisture in the concrete, before applying Dura-Plate® 6100 on top. PPS installers first resurfaced areas of the floor with Dura-Plate 2300 before applying the self-levelling Poly-Crete at 3/16 of an inch for a thick moisture barrier. They broadcast aggregate into the Poly-Crete layer partway through its curing cycle to assist with adhesion before finishing the entire surface with Dura-Plate 6100 at 125 mils dry film thickness (DFT).
Arriving at this new flooring specification required preparing a series of system mock-ups within the tank to ensure success. PPS carefully prepared 10-foot by 10-foot test sections on the tank floor, applying Poly-Crete MDB and broadcasting fine aggregate across the full surface, while applying Dura-Plate 6100 to half the square. This setup allowed the team to test the adhesion of Poly-Crete MDB to the substrate, as well as the adhesion of the other layers, and fine-tune the process.
Applicators were able to use the originally specified system for the tank’s walls and ceiling: spot resurfacing with Dura-Plate 2300, a coat of Macropoxy® 5000, as a penetrating primer/sealer, followed by a thick coat of Dura-Plate 6100 at 125 mils DFT.
Based on the careful mock-up preparation and testing, all parties believed the lining formula would ensure adhesion and completely seal the tank, effectively creating a tank within a tank. IIG’s inspection efforts supported this goal, with high-voltage holiday detection used to identify any pinholes, thin spots, cracks or other discontinuities in the lining. The inspector found very few areas to address. Once they were repaired, the tank was returned to service to assist in providing energy-efficient cooling for the West Valley campus.