WESTERVILLE, Ohio — The National Ground Water Association (NGWA) has announced plans to develop an American National Standards Institute third-party accredited standard for the construction of vertical boreholes used in closed-loop ground source heat pump systems, a decision reached by the NGWA board of directors.
“This effort will use our now nearly 15-year-old guidelines document on this topic as the basis from which to develop the standard,” explained Kevin McCray, CAE, NGWA executive director.
NGWA’s Guidelines for the Construction of Vertical Closed Loop Heat Pump Systems, first published in 1997, have been revised by NGWA twice in the intervening years, most recently in 2010.
“NGWA’s motivation is to strengthen our contributions to this important drilling market segment heavily served by water well drilling contractor firms,” McCray said.
“We want to help assure that the drilling of loop wells — the vertical boreholes of many ground source heat pump systems — is done in a way that protects the groundwater from contamination risk. The number of boreholes typically drilled for such systems makes groundwater protection especially important,” McCray continued. “We also want to assure that loop wells are drilled to the design specifications so these systems operate effectively over their lifetime. This will strengthen customer satisfaction and customer support.”
The guidelines cover topics such as loop wellfield design, test loop wells and samples, borehole construction, loop tube installation, loop well grouting, loop wellfield identification, and permanent loop well decommissioning. NGWA anticipates the standard will ultimately cover similar interests.
“Having much of the standard completed by way of the guidelines we hope will lead to rapid development of the standard and introduction to the required public comment periods on the draft,” McCray said. “However, the ANSI process is very deliberate and thoughtful, with an aim toward consensus agreement. We will follow the procedures to produce our best possible work.”
Publication date: 12/19/2011