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Table 1. Cost Estimate to Change Oval's S stem to Ethylene Glycol Ite.�u I r..� � � �t��=��t I�i i ��._��ti�7 il�, ;,�I �;_.� tit7s[ � � f r�ts�m invncled i}� i.i� �}rk�Fl� i�a-narrts) _— —�__,t]Ii0 �;I r! r_�t !Ck^�L�; iti -�5 �[l5 ��!3'i�:n� � I��;i i1 ��f��ivu +�QH1 a� I�: iti titi' �'��'1� i I•�'i�� I .�e f a.�}�Itll ��15;1� �y�in��i��il i'�}l'kl«•ill��'1 L�751k --- --- �� — � �4fi��L� r-: - • • — - — � — ..�S�Ill:i.t, I�cwi e e. .}i71.1 r:'�:u�t= �ti iL:n +C •�,uc:asku-nc u{ I l��.J" ! �9,9�10 � � � fl[:i� �tili1lilaV4� � i7�.' �II}�y11�� }�•k— — — — — �.11.+�.4'I]I} f`r��'��t:-:r_„�I ��.�nd k f;i��i;s�.r,�iut-(�v'•=�` _ �-- --- --. . _�_ ��6,�i1{1 : 3,�tis5F.ste:er;�t.+`�'P��i",nsta — — - - �-- — `�R��}�i �s:C��•.�,.:.,—:irna�r'�;�:r•.��,,.�ti�_.ti..�nUiil�.:•�� — Recommendations far Secondary Refrigerants The existing 6rine solution in the oval's refrigeration system is contaminated with ammonia. The Minnesota Pollution Control Agency classifies all ammonia solutions with a pH of less than 2.0 ar greater than 12.0 as a hazardous waste, After the chemical tests of this solution is perfor�ned within the next week ar so we can discuss possibly diluting the solution to lower the pH if required. if the solution can not be diluted and is within the stated pH range, it must fl�e� be disposed of under the Minnesota hazardous waste regulations. I�the pH falls between these two levels then the solution may be disposed of through the sanitary sewer system if approved by the Metropolitan Council. The existing brine solutions should be tested to determine how to properly dispose of it. Consideration was given to switching from a calcium chloride mixture to a glycol mixture. This would have reduced the capacity ofthe oval's refrigeration system but would reduce future concerns of corrosion and reduce the monitoring and maintenance requirements. However, after talking with a local chemical supplier about the options available for secondary refrigerants, they stated that at least one n�ajor glycol manufacturer would not warranty their product if assurance could not be made that all of the existing calcium chloride was removed from the oval's piping system. Calcium chloride will break down the ethylene glycol and weaken its effectiveness. lt may be possible to flush the system clean of calcium chloride but given the construction of the oval's floor piping system it will be difficult. ln addition the cost to switch is substantial as stated in the above table and there are increased environmental concerns if there is a leak. When a new refrigeration system is installed in the RSVC Arena, either calcium chloride mixture or ethylene glycol mixture could be used if an indirect system is selected. STEP 1-COLLECT INFORMATION infarmatron was collected on-site on March 22 and '�,r''' During our last site visit on April 21" it was noted that two of the bolts holdi��g the support system for the brine piping were broken off. This indicates greater than i�onnal stresses on the support system. This should be looked into immediately before a failure occurs. One solution is lo remove and dispose of the contaminated brine to lessen the weight of the piping system. The brine is contaminated with ammonia and can not be reused.