Code of Maine Rules
10 - DEPARTMENT OF HEALTH AND HUMAN SERVICES
144 - DEPARTMENT OF HEALTH AND HUMAN SERVICES - GENERAL
Chapter 232 - WELL DRILLERS AND PUMP INSTALLERS RULES
Chapter 5 - OPEN-LOOP GEOEXCHANGE WELLS
Section 144-232-5-501.0 - SPECIFIC REQUIREMENTS

501.1 Return water quality: Any water returned to an open loop well shall be the same water that was pumped from that well, or another well in the same aquifer, modified only by a change in temperature due to the heat pump and a reduction in particulates using generally accepted means of filtration. No other form of water treatment, filtration or any addition of chemical or biological substances is allowed.

501.2 Bleed water discharge: An open-loop well for a single-family, residential, detached home should have a bleed rate of no more than one (1) gallon per minute (gpm) per acre for lots greater than one (1) acre in size that discharges to a point other than the aquifer from which it came. For lots less than one (1) acre in size, bleed water that discharges to somewhere other than the aquifer from which it came is not recommended. All other water must be returned back into the same aquifer from which it was produced.

501.3 Return Water: Any water from an open-loop well that is returned back into a ground water aquifer shall be returned back into the same aquifer from which it was produced.

501.4 Bedrock return wells: If the water from a bedrock well is returned to another bedrock well, it will be considered that the water is being returned to the same aquifer.

501.5 Gravel return wells: If the water from a "gravel" well is returned to another "gravel" well, it will be considered that the water is being returned to the same aquifer.

501.6 Return well/geoexchange well separation: Return wells for single-family detached homes shall not be more than 200 feet away from the pumped well.

501.7 Return line depth: All return lines installed in open-loop wells shall be installed so they will always be submerged below the lowest pumping water level in the well so as to prevent the cascading of return water back into the well.

501.8 Coastal zones: Any open-loop well drilled within a defined coastal zone shall always have 100% of the water that is pumped from it (for geothermal purposes) returned into the exact aquifer from whence it originated. This may be in the exact same well or in a different well. No bleed shall be allowed unless it is returned back into the same aquifer.

501.9 Coastal zone definition: The "coastal zone" is defined as the land area bounded by the medium high water mark along all ocean front property and all saltwater or brackish marshes or inland rivers, extending 600 feet inland.

501.10 Chloride levels: If the driller encounters water in an open-loop well which is drilled within the coastal zone, with a chloride level of more than 1,500 mg/l, the driller must suspend drilling and seal off the salt water fracture with a neat cement grout.

501.11 Chloride level measurements: For any well drilled within the coastal zone, a driller must perform a field measurement of the chloride content of the water produced from the well after encountering each water-bearing fracture and shall record the results on a permanent driller's log.