Ohlone Community College District
Geothermal Loop Field Repair

Geothermal Loop Field Repair


Newark, California

Project Start: September 2012

Project End: January 2014

Architect: N/A

Owner: Ohlone Community College District

Meline Engineering was hired to provide the District with an engineered plan to repair their Geothermal Loop Field which had begun leaking at the Newark Campus.  This building was the first Community College Building certified LEED Platinum in August 2008.  System performance and the resulting investigation revealed that the underground connections of the ‘geo coils’ to the buried vaults were the points of failure.  The result of this leaking system was that the soil was being pulled into the water loop circulating between the geo coils and the 110+ heat pumps conditioning the building.

The challenges associated with this design included providing a plan that would repair system leaks, would allow the building to continue to operate during construction, and that would be completed over the Winter Break so as to minimize the impact to the students and staff occupying the building.

Because the building is directly connected to the geo coils, there was an added challenge to provide water treatment for the piping system which was acceptable to the local regulators whose responsibility is groundwater protection..

The solution employed was able to satisfy all the Owner’s Project Requirements.  The final design included the removal of the vaults and the replacement of the vaults with shallower piping manifold system which did not include any metallic components and provided surface access through a series of valve boxes.  The entire system was flushed, purged and re-commissioned to its original design.