“In House”, Resurfacing of Hatchery Raceways at National Fish Hatchery

1. “In House”, Resurfacing of Hatchery Raceways at National Fish Hatchery Casey Mitchel, Jeremy Sommer, Ira Wilson Nez Perce Tribe, Production Division, Dworshak National Fish Hatchery 276 Dworshak Complex Dr., Orofino, ID 83544 Preparations included installing inflatable bladders into our re-use system using a marine sealant to ensure that the raceways were bone dry. The grip strut walkways and aluminum channel was removed and labeled. The ponds were then pressure washed to remove loose concrete and debris. Sheets of Visqueen were placed on pond bottoms to determine moisture content of the concrete. Painters tape was placed over non-movable bolts and channels. In 1982 the Army CORP. of Engineers began construction of thirty raceways at Dworshak National fish Hatchery in Orofino Idaho. For the next thirty-one years these raceways were used to rear Coho and Spring Chinook Salmon. After thirty-one years of extensive use of the raceways they were showing signs of concrete erosion, cracks, rock pits, and heavy ware of fish fins. To extend the life-span of these raceways, resurfacing by employees of the Dworshak Hatchery, began in April of 2013. The purpose of the resurfacing was to prevent degradation of these rearing structures, provide a better rearing environment, reduce abrasions on the fish, and allow easier cleaning. Culture in these ponds has shown successful results for durability, fish health and ease of cleaning. The cost savings and benefits to the facility and fish were such that we have decided to repeat this process in Spring 2014 on 15 more raceways. A crew armed with painter suits, rollers and respirators took less than two weeks to finish the application process. Another week was spent trying to put Humpty Dumpty back together again. Professional resurfacing of these ponds is expensive. Bids for a similar project broke down to costing less than 25% using in house labor. Extrapolating the savings to this project and using our own employees we estimated that we would be able to resurface an entire bank of raceways (15 ponds) for under $40,000. Primer and paint were applied in two coats each using paint rollers and covers. About 300 roller covers and 50 rollers were used during the entirety of the project. During mixing of the two part epoxy and primer as well as applying the product to the ponds, respirators were required with a filter cartridge replacement of once a day. Approximately 20 gallons of primer and hardener were applied to each raceway after which 15 gallons of top coat were put onto each pond per coating. Thanks Nathaniel Weise .