Chelsea Soldiers Homes Community Living Center Geothermal System

Challenge

GZA supported the design team for geothermal in these four phases: 1) geothermal feasibility study, including conceptual wellfield design with cost estimates; 2) geothermal test well, to obtain thermal design parameter; 3) geothermal wellfield design by a specialty geothermal mechanical designer; and 4) construction, including review on contractor submittals and observation/documentation of well installation, surface piping and pressure testing.

Solution

Working with architect Payette, GZA provided consulting services and performed a geothermal feasibility study for the Chelsea Veterans’ Home Community Living Center on behalf of the Massachusetts Division of Capital Asset Management and Maintenance (DCAMM). The project involved evaluating the proposed geothermal well area atop Powder Horn Hill, at the edge of Malone Park in Chelsea, Massachusetts. GZA reviewed available hydrogeological information, applicable regulations, and permitting requirements, and published estimates of thermal capacity for bedrock at the site to prepare a conceptual well field design and solicit cost estimates form wellfield installation contractors. GZA recommended closed-loop wells based on regulatory requirements, overall cost, and long-term operations and maintenance requirements.

For the testing phase, GZA teamed with Skillings and Sons (S&S), a well drilling contractor, to install a test well to evaluate the drilling conditions at the site and estimate the thermal parameters for actual design of the well field. GZA’s team coordinated the drilling of a closed loop test well by S&S and conducted a 48-hour thermal conductivity test for use in obtaining site-specific information regarding drilling conditions, groundwater quality, groundwater temperature, and thermal characteristics at the site.

For the construction phase of the project, GZA provided construction oversight and engineering consulting services during the installation of 80 productions wells and geothermal piping to confirm compliance with the project plans and specifications. GZA team members provided daily updates for the drilling, grouting, pipe fusion and pressure testing by the geothermal contractor. The project exceeds LEED Silver certification requirements.

Benefit

GZA was able to resolve with the production driller several quality issues during drilling, grouting and pressure testing that should prevent later potential operational issues with geothermal system. The system was installed and is operational today.