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mineral build-up or corroded metal from refrigeration system and piping located within the refrigeration room. There is no evidence of this happening other than in the accumulation of sediments in the compression tank located in the mechanical room and the higher level of residual metals shown in the brine testing. It would be appropriate to keep an eye on the potential of this occurrence which would result in a decrease in cooling capabilities of the rink slab. From discussions with the City of Roseville ice system operating staff, it does not appear the ice rink cooling slab has seen any decrease in performance to date. Brine Pumps The brine pumps, motors and associated piping and headers in the refrigeration room were all replaced in 2005. The pump impellers were trimmed down some at that time to better match the pumping head. Since that reconstruction occurred, one pump motor was replaced, and occasional pump seals and bearings replacements have been made. The metal pump bases have been corroding badly where they come in contact with the concrete equipment pad. It appears the corrosion is the result of brine leakage which gets trapped next to the pump bases on the equipment pad and causes accelerated corrosion to the pump-base metal. With almost fifteen years of service since the pumps were reworked, these could use some upgrading. Whether or not the pumps are fully replaced or partially replaced could be evaluated at the time of replacement. Three of the five pump bases are badly corroded but not to the point of being structurally compromised. We feel the pumps, motors, and bases, could be cleaned up, painted, and kept in service for another five years when full or partial replacement should occur. Expansion Tanks The original two large bladder expansion tanks were provided primarily to take up the brine system expansion resulting from the winter-to-summer fluid expansion from the seasonal temperature changes. Another expansion tank, specifically a compression tank, was more recently added at the high point of the brine piping to allowing operating personnel to monitor air levels in the brine piping system more easily. At the current time only one bladder expansion tank is functional since the bladder in one tank has failed and not been replaced. The use of only one bladder tank could cause a release of brine from the high-pressure relief valve if temperatures reach a level where fluid expansion exceeds the available capacity of one tank. While this will not harm the system, the released brine must be monitored along with the air levels in the brine piping system to understand if losses in brine are significant enough to require replacement for proper and safe operation. Certainly, low levels of brine should be avoided for low levels allow excess air to accumulate in the brine circulation system where corrosion of the iron piping systems in the refrigeration room is accelerated. Refrigerated Rink The key components of the refrigerated rink are the refrigerated concrete slab and the rink floor insulation. Refrigerated Concrete Slab 161616