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Anaerobic digester rehabilitation project wins inaugural Impact Award


Short Elliott Hendrickson Inc., Champion Coatings, and Wapasha Construction took top honors in the inaugural Sherwin-Williams Impact Award program for their rehabilitation of a domestic anaerobic digester for the city of Austin, Minnesota.

The challenging project impressed the program’s judges, who were looking to recognize notable projects featuring coating and lining materials from Sherwin-Williams Protective & Marine Coatings. The company announced the Impact Award winners at the Water Environment Federation’s WEFTEC conference on September 26, 2016, in New Orleans, Louisiana.

Their winning project addressed the challenges of restoring two nearly 60- and 80-year-old domestic anaerobic digesters for the city of Austin. The city operates three domestic anaerobic digesters that were constructed between 1938 and 1959, including two with concrete covers. The original structural concrete was still sound, but concrete used in the 1980s to rebuild the digester mixer bases had become severely deteriorated.

The winning project addressed the challenges of restoring two old anaerobic digesters operated by the City of Austin, Minnesota.

The contractors experienced several challenges related to operating and weather conditions, as well as the age of the digesters. Due to numerous cracks in the digester cover prior to repairs, fluid in the lower tank was escaping and reducing the tank pressure. Therefore, crewmembers had to confirm that the tank would hold pressure after completing the repairs. It didn’t after the first repair application, so they reapplied the SherFlex Elastomeric Polyurethane and tested the pressure. Again, the tank didn’t hold pressure.

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After much troubleshooting, crewmembers discovered a difficult-to-access cold joint that needed to be filled. They carefully repaired the cold joint and realized success, with the tank holding pressure on the next test.

Due to the climate and a cold winter, it took nearly six months to adequately coat the first tank and get it ready for service. With the lessons learned from that tank, the contractors made some adjustments and were able to repair the second tank faster and without issues.

“We created the Sherwin-Williams Impact Award to honor demanding water and wastewater projects and recognize those professionals who contribute to improving public health and safety by enhancing water and wastewater infrastructure,” said Kevin Morris, market segment director, water & wastewater, Sherwin-Williams Protective & Marine Coatings.

For more information on the Impact Awards, visit: www.sherwinblogs.com/impact-award

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