GEO Weighs In on Tough North Carolina Drilling Setback Rules

The Geothermal Exchange Organization (GEO) sent a letter to North Carolina Secretary of Environment and Natural Resources Dee Freeman, urging changes to new Injection Well Construction Standards, charging that they are “onerous new rules with no proven environmental benefit that may largely preclude installation of GHP closed ground loops in various areas in the state.”

GEO copied the letter to, among others, North Carolina Department of Environment and Natural Resources (NCDENR) Division of Water Quality Chuck Wakild, Groundwater Protection Unit Supervisor Debra Watts, Director, NCDENR Division of Water Quality; and Aquifer Protection Manager Thomas Slusser.

According to GEO, “Average lot sizes across North Carolina offer plenty of room for installation of vertical closed loop systems for GHPs, but the new NCDENR standards demand unrealistic setbacks from septic systems and structures. In doing so, the rules effectively deny citizens the use of closed loop GHP systems—which have no significant impact on groundwater, yet save 40 to 70 percent of the energy used to heat and cool buildings.”



  1. Vertical boreholes for GHP closed loop installations must maintain a 50′ setback from any septic tank, septic drain field and any septic drain field repair area. For smaller properties, such setback requirements will often not allow installation of GHP vertical closed loop installations. This rule should be revisited and considered in practical terms, by drastically reducing the setbacks, reconsidering the repair area issue, or striking them altogether.
  2. Vertical boreholes for GHP ground loop installations must maintain a 15′ setback from any structure attached to a house or building. This standard does not address any public health issue. Its blanket requirement is often not practical, depending on the structure and nature of the property. This is an issue of structural integrity that is better left to the common-sense discretion of property owner and contractor.
  3. For all vertical closed loop GHP installations, contractors must provide site plans for all septic tanks, septic drain fields, septic drain field repair areas, water wells and surface waters within 250′ of boreholes. This rule will hamstring small contractors engaged in vertical closed loop GHP installations with determining facts that will make no positive difference for the environment. The rule should be struck.

“The primary problem with each of these rules is that they are not realistic in their approach,” the letter continued. “By their very nature, closed loop geothermal systems do not allow their circulating fluids to come into contact with groundwater. Their installation is accomplished in boreholes which are quickly grouted to increase thermal conductivity and sealed against environmental intrusion.”

The letter discussed variances promised by NCDENR staff, but pointed out: “This does not solve the problem. Indeed, installers are faced with the prospect of subjective, arbitrary and capricious denial of a variance after the effort, time and cost of making a GHP sale to a customer followed by performing all the work needed for a variance application.”

GEO agrees with the North Carolina Plumbing and Mechanical Association that the state’s revised Injection Well Standards may have a detrimental effect on further installation of environment-ally friendly and energy saving GHPs across the state. “This in turn violates the intention of the North Carolina legislature when it approved tax credit incentives for GHP installations at 35% of system cost up to $8,400, plus various electric utility rebate incentives and loan programs for energy efficient, environ-mentally friendly GHP systems.”

The letter concluded: “The Geothermal Exchange Organization calls on your understanding and assistance in correcting the revised rules in a manner that will realistically protect groundwater while promoting energy conservation and economic growth in North Carolina.”