Secondary containment – geo fabric
In 2011 the bureau of reclamation was installing new electrical sub stations at davis dam in arizona. The sub stations are used to collect and distribute power generated at the dam. The transformers for the sub stations hold oil for cooling so a secondary containment was required incase the units leaked. Exposure to extreme temperature swings and chemical resistance to the oils were special considerations for the coating selection.
Freedomtuff™ 2202 polyurea
Freedomtuff™ 2202 polyurea was chosen as the membrane since its phyisical properties provide flexibility across varying temperature ranges seen the in desert. The membrane would have to be installed over loose soil so an 8 oz geo fabric was used as a substraight. Then freedomtuff™ 2202 polyurea was applied at 100 mils . Per freedoms recommendations, ¼” keyway terminations were used in areas over concrete. Consideration was given to the rapid and extreme temperature swings. Therefore, appropriate slack was left to accommodate for expansion and contraction of the coating system.
The selection of the freedomtuff™ 2202 polyurea over the geo fabric left the owners with a durable and seamless secondary containment membrane. The system has seen 2 full summers of arizona’s extreme temperatures and has shown no signs of premature failure.
