A Polyurea Application Bolsters the Concrete Surfaces of Two Wastewater Tanks
By Juan SagarbarriaWater treatment tanks provide the important function of storing wastewater and turning it into clean water that can subsequently be used for a number of different purposes. This recycling process is a vital example of how we can repurpose our resources for the greater good. However, because the treatment process can be significantly abrasive, sometimes the tanks themselves need maintenance. This was precisely the case with two storage tanks owned by Seneca Foods Corporation, a New York-based food processing and distributing company.
These steel tanks, which store 144,000 and 166,000 gallons respectively, had sustained severe interior damage. The continuous treatment process had caused the tanks’ concrete floor to deteriorate over time, giving way to fractures that caused the substrate to crumble. The continual fracturing of the concrete created a potential risk that could cause the tanks to lose a high percentage of the stored water, altogether hindering the treatment operation that ultimately resulted in the production of food via irrigation. Seneca needed a quick solution to patch the tanks up and get back on track, so they opted for a product that was sure to provide rigidity, longevity, and chemical resistance:
Seneca put their faith in Straight Line Contracting for the tanks’ restoration, which entailed the application of polyurea to the tanks’ compromised concrete floors. Prior to their arrival, the tanks were completely pumped to devoid them from any moisture. Then, a three-man team from Straight Line arrived at Seneca’s facility and went straight to work.
“Polyurea was the correct choice for this particular project,” said Straight Line’s Megan Passarella. “It creates a seamless, self-adherent membrane that can withstand the treatment process and last for a long time versus other epoxy products that require constant maintenance and reapplication. Seneca was looking for a solution that would see those in charge of this operation not having to worry well after their retirement. We gave them that within a short time frame, as the polyurea cures rapidly and works effectively.”
While prepping the concrete surface for both tanks, the crew scraped off the existing rubber tar membrane system and then sandblasted the concrete surface using crushed glass in an 18-inch curb going up the steel wall.
“The purpose of applying the crushed glass up the steel wall was to create a profile for the polyurea to grip and grab to,” said Passarella. “For the concrete surface, the crushed glass blasting cleared off all the debris and allowed us to get a base, clear surface, which was necessary for a smooth application.”
Additionally, the crew applied a polymer-blend, rapid-set mortar to patch up the concrete in both tanks. Passarella explained that the mortar was utilized to fill in the holes and crevices in the concrete floor, achieving a smooth, even surface finish. Since the mortar set rapidly, the crew was able to expedite the entire application by having an event surface in a short time whereas the alternative of re-cementing both structures would have resulted in considerable down time and added expense. Just before the polyurea application commenced, the Straight Line crew spray-applied to the tanks’ concrete surface and steel walls a quick-set primer specified by the manufacturer of the polyurea coating.
The polyurea application for the interior of both tanks consisted of two 40-mil coats of grey, chemical-resistant polyurea coasting blended for abrasive-resistant characteristics. The polyurea was applied using a Graco Reactor H-XP3. For the duration of the application, the Straight Line crewmen were outfitted with PPE that included Tyvek suits and full-face respirators.
Passarella mentioned that the crew had to overcome a few weather issues, mainly consisting of rainy days that contributed to minor delays of the project. The Straight Line Crew pumped the rainwater out as needed before carrying on with the particular phase of the project they were in. It took the Straight Line crew two weeks to complete the project, averaging a week per tank.
Upon completion of the polyurea application, there was a distinct “night and day” contrast from what the tanks had looked like before. According to Passarella, the polyurea not only bolstered the concrete floors’ structural integrity, but it provided a major upgrade to the tanks’ interior aesthetic.
“They look beautiful,“ noted an impressed Passarella. “The aesthetic is just an added bonus to polyurea’s protective properties. As long as the tanks are prepped to their respective manufacturers’ recommendation, the polyurea system isn’t going to go anywhere and it will protect the concrete floor for a long time to come.”
For more information about Straight Line Contracting, visit www.slcsprayfoam.com.