The city of West Memphis, Arkansas, has a motto, “Beautiful from Every Direction,” which could also apply to the 500,000 gallon potable water tank featuring a visually appealing protective coating system from Tnemec. “This tank is very close to one of the largest service centers operated by Utility Service Co., Inc. (USCI), the nation’s leading supplier of water storage tank maintenance,” according to Tnemec coating consultant Arthur Valentine. “This is one of several tanks Utility Service was doing for the city of West Memphis.”
Utility Service was chosen for the projects after they were opened for bidding by the city’s engineer. Specifications called for the tank’s exterior steel to be prepared in accordance with SSPC-SP6/NACE No. 3 Commercial Blast Cleaning prior to receiving a roller-applied coat of Series 91-H2O Hydro-Zinc, a moisture-cured, zinc-rich aromatic urethane. Next, an intermediate coat of Series 20 Pota-Pox, a polyamide epoxy, was roller-applied, followed by a topcoat of Series 1074 Endura-Shield II, an aliphatic acrylic polyurethane that meets the requirements of The Society for Protective Coatings (SSPC) Paint 36 standard. Coatings meeting this standard provide excellent color and gloss retention and weathering resistance.
The tank’s interior steel received a spray-applied prime coat of Hydro-Zinc following surface preparation in accordance with SSPC-SP10/NACE No. 2 Near-White Metal Blast Cleaning. Two coats of Pota-Pox in tank white and beige colors were spray-applied to complete the interior coating system. “Two different colors are always used to make sure they get the right number of coats applied and to ensure complete coverage of the second application,” Valentine confirmed. Both Hydro-Zinc and Pota-Pox are certified by NSF International in accordance with ANSI/NSF Standard 61.
“The tank is in a city park and surrounded by homes, so it’s highly visible,” Valentine added. “We heard good reviews of the coating system from the city engineer and Utility Service.”
Treatment capacity for the city of West Memphis is approximately 11 million gallons per day. Treated water is stored in two finished water ground storage tanks from which water is pumped into the pipeline distribution system and into four elevated storage tanks with a combined capacity of 3 million gallons.