Prince George looks to groundwater to beat summer heat

Hydrology Study for Non-mechanical Cooling of a Proposed LEED Silver Municipal Police Building

The City of Prince George investigated the possibility of cooling its new RCMP headquarters with groundwater. This could reduce energy use and greenhouse gas emissions, and the water would be returned to the aquifer.

A pump test on an 80.8-metre deep test well suggested the aquifer could provide the flow rates and yields needed for the proposed open-loop geothermal cooling system. The water was, however, slightly warmer than would be ideal for cooling. As the water was found to be quite hard, the well would need to be refurbished every two to three years to prevent scaling and clogging.

The groundwater system would be backed up by a small conventional system.

Results

Challenges

• Initial groundwater testing showed high levels of contaminants, requiring a thorough flushing of the well.
• Rainfall and capacity limitations of the municipal sanitary system, which received the purged water, made it difficult to schedule the pump test.
• High levels of bacteria suggested the well would need regular maintenance to avoid clogging.

Lessons learned

• Review all available information about the suitability of an aquifer for thermal energy extraction before drilling.
• Avoid drilling twice by making the test well large enough to serve as the permanent well.
• Despite the added cost, run the pump test long enough to thoroughly flush the well before testing for contaminants.

Partners and Collaborators

• City of Prince George
• FCM's Green Municipal Fund
• SNC Lavalin

Project Contact

Greg Anderson
Civic Facilities Manager
City of Prince George, BC
T. 250-561-7615