Section 096-543-2 - Classification of wellsThe classification of a particular well is determined by the department based upon the following categories and discharge characteristics. The applicable regulatory category and rule section for each well type is indicated in parentheses.
A. Class I wells. Wells that discharge fluids under the following circumstances: (1) Wells used by generators of hazardous waste or owners or operators of hazardous waste management facilities to discharge hazardous waste beneath the lowermost formation containing groundwater;(2) Other industrial and municipal disposal wells that discharge fluids beneath the lowermost formation containing groundwater; or(3) Radioactive waste disposal wells that discharge fluids below the lowermost formation containing groundwater. (Note: Prohibited, see § 3C)
B.Class II wells. Wells that discharge fluids: (1) That are brought to the surface in connection with natural gas storage operations, or conventional oil or natural gas production and may be commingled with wastewaters from gas plants that are an integral part of production operations, unless those waters are classified as a hazardous waste at the time of discharge;(2) For enhanced recovery of oil or natural gas; or(3) For storage of hydrocarbons that are liquid at standard temperature and pressure. (Note: Prohibited, see § 3C)
C.Class III wells. Wells that discharge fluids for extraction of minerals including: (1) Wells used for the mining of sulfur by the Frasch process;(2) Wells used for in situ production of uranium or other metals, limited to the in-situ production from ore bodies which have not been conventionally mined; or(3) Wells used for solution mining of salts or potash. (Note: Prohibited, see § 3C)
NOTE: Solution mining of conventional mines, such as stopes leaching, is included in Class V. See Section 2(E)(9)(b). Stopes leaching is not considered in-situ leaching, but is considered mining for the purposes of 06-096 Chapter 200.
D.Class IV wells. Wells that discharge fluids under the following circumstances: (1) Wells used by generators of hazardous waste or of radioactive waste, by owners or operators of hazardous waste management facilities, or by owners or operators of radioactive waste disposal sites to dispose of hazardous waste or radioactive waste into or above a formation which contains groundwater (Note: Prohibited, see § 3D );(2) Wells used by generators of hazardous waste or owners or operators of hazardous waste management facilities to dispose of hazardous waste that cannot otherwise be classified under Section 2(A)(1) or Section 2(D)(1) (Note: Prohibited, see § 3D); or NOTE: Subsurface disposal of drinking water filter backwash containing radionuclides below concentrations determined to be radioactive waste is included in Class V. See Sections 2(E)(2)(d) and 2(E)(11)(c).
(3) Wells used to discharge solutions to remediate contamination in situ or to discharge contaminated groundwater that has been treated and is being discharged into the same formation from which it was drawn, pursuant to provisions for cleanup of releases under CERCLA, RCRA or 38 M.R.S.A. Chapters 11-A, 11-B, and 13-B. (Note: Authorized by meeting conditions of LBR, see § 5A)E.Class V wells. Wells not included in Class I, II, III, IV or VI. Class V wells are divided into the following subclasses. (1) Motor vehicle waste disposal wells, which consists of wells that receive fluids discharged from areas in which vehicular repair or maintenance activities occur, including, but not limited to, activities performed at such businesses as automotive and auto body repair shops; new and used car and truck dealerships; aircraft, outboard engine, snowmobile, lawnmower, and ATV sales and repair shops; specialty repair shops; and any person that does gasoline- or diesel-engine repair work, whether those services are offered to the public or not. (Note: Prohibited, see § 3E)(2) Industrial wells that receive discharges of non-domestic wastewater. Industrial wells include, but are not limited to: (a) Wells that receive wastewater from automatic, tunnel, roll-over, and hand-held car washes;(b) Wells that receive wastewater from egg washing facilities;(c) Wells that receive wastewater from commercial fish or shellfish processing facilities excluding home occupation fish or shellfish processing facilities;(d) Wells that receive public drinking water treatment plant filter backwash water, except filter backwash from surface water sources with no chemical additions; and except as provided in Section 2(E)(11)(c);(e) Wells that receive wastewater from septage storage and dewatering facilities and Type IC, Type II, and Type III residual processing facilities;(f) Wells that receive water from secondary containment dikes and berms at Aboveground Storage Tank facilities that has the potential to contain concentrations of oils and hazardous materials (OHM). This includes wells that receive stormwater from catch basins within loading and off-loading racks at bulk oil facilities, gas stations, or other facilities that have the potential to receive OHM spilled during loading and off-loading activities; or NOTE: For information on residuals and processing facilities, see 06-096 CMR 400, 409, 419 and 420. In general, Type IC residuals come from a known source that does not contain hazardous substances and have a carbon to nitrogen ratio of 15:1 or less. Type IC residuals include mussels, shrimp, fish, crab, and lobster wastes; poultry carcasses; and hen manure. Type II residuals come from a known source that does not contain hazardous substances but may contain human pathogens. Type II residuals include sewage sludge, dewatered septage and disposable diapers. Type III residuals may contain hazardous substances. Type III residuals include non source-separated residential wastes and petroleum contaminated soils.
(g) Wells that receive wastewater from any other commercial, industrial or manufacturing processes that contains constituents unlike that or of significantly higher strength than that of domestic wastewater. (Note: WDL required, see § 4A)
(3) Large-capacity cesspools which consist of those that receive solely domestic wastewater and have the capacity to serve 20 or more persons per day or dispose of 2,000 gallons or more of domestic wastewater per day. This definition includes multiple-dwelling, community or regional cesspools of all sizes but does not apply to single-family cesspools or to non-residential cesspools that serve fewer than 20 persons per day and dispose of less than 2,000 gallons of domestic wastewater per day. (Note: Prohibited, see § 3E)(4) Stormwater drainage wells that are used for the disposal of rain water and melted snow. (Note: Authorized by meeting conditions of LBR, see § 5B)(5) Other drainage wells that are used to drain surface and subsurface fluids other than stormwater. These wells include, but are not limited to: (a) Agricultural drainage wells that receive irrigation runoff;(b) Construction dewatering wells that are used to lower the water table and keep foundation excavation pits dry; or(c) Swimming pool drainage wells that receive chlorinated water from swimming pools and hot tubs, including pass-through analyzer water from public drinking water treatment plants. (Note: Authorized by meeting conditions of LBR, see § 5B )
(6) Beneficial use wells that receive fluids to improve either flow of aquifers or some other groundwater management benefit. Beneficial use wells receiving stormwater runoff are regulated as stormwater drainage wells. Beneficial use wells include, but are not limited to: (a) Aquifer recharge wells used to replenish the water in an aquifer;(b) Aquifer storage and recovery wells used to place excess water in the subsurface during periods of high flow and then withdraw the water later when it is needed;(c) Subsidence control wells used to inject fluids to prevent the land surface from sinking or settling; or(d) Wells that inject water to control the intrusion of salt water in coastal areas into freshwater aquifers. (Note: Authorized by meeting conditions of LBR, see § 5B )
(7) Fluid return wells that receive discharges of water that has been used for heating or cooling a heat pump or water extracted for the recovery of geothermal energy for heating, aquaculture, and the production of electrical power. (Note: Authorized by meeting conditions of LBR, see § 5B)(8) Non-contact cooling water wells that receive discharges of non-contact cooling water that contains no additives and has not been chemically altered. Wells that inject contact cooling water or non-contact cooling water that contains additives, such as corrosion inhibitors or biocides, or is contaminated compared to the original source water are considered industrial wells, as defined in Section 2(E)(2). (Note: Authorized by meeting conditions of LBR, see § 5B)(9) Mining and recovery wells that receive discharges of fluids used in the production of energy or minerals; or for subsidence prevention, disposing of wastes and fire control in mining operations. These include, but are not limited to: (a) Sand backfill and other backfill wells used to discharge a mixture of water and sand, mill tailings or other solids into mined out portions of subsurface mines, whether what is discharged is a radioactive waste or not;(b) Wells used for solution mining of conventional mines such as stopes leaching;(c) Wells used to discharge spent brine into the same formation from which it was withdrawn after extraction of halogens or their salts; or(d) Wells used for in situ recovery of lignite, coal, tar sands, and oil shale. (Note: WDL required, see § 4A)
(10) Experimental technology wells used as an integral part of an unproven subsurface injection technology other than waste disposal. (Note: WDL required, see § 4A)(11) Other injection wells that receive non-hazardous, industrial and commercial wastes which have constituents similar in type and concentration to domestic wastewater. Other injection wells include, but are not limited to, wells that receive: (a) Snowmelt from cars, trucks, snowmobiles and other motor vehicles;(b) Filter backwash from swimming pools and hot tubs;(c) Drinking water system filter backwash including those containing radionuclides provided the radioactive material is below concentrations considered to be radioactive waste as listed in 10 CFR Part 20, Appendix B, Table II, Column 2, and provided the applicant can demonstrate that all other pollutants are de minimis;(d) Boiler blowdown, provided that the applicant has demonstrated that no other acceptable disposal option exists. (Note: Authorized by meeting conditions of LBR, see § 5B )
NOTE: Some Class V wells located at single-family homes are exempt from some requirements under this rule. Please see Section 5(D) for more information.
F.Class VI wells. Class VI wells include all wells designed, installed, and operated in conformance with the "Maine Subsurface Waste Water Disposal Rules," 10-144 CMR 241, and used for the disposal of domestic wastewater or other wastewater from commercial, industrial or residential sources that is of similar quality (constituents and strength) to that of domestic wastewater. Class VI wells include, but are not limited to: (1) Single-family, other residential and non-residential septic systems including, but not limited to, large-capacity septic systems that have the capacity to serve 20 or more persons per day and engineered disposal systems with design flows in excess of 2,000 gallons per day;(2) Single-family cesspools used solely for the disposal of domestic waste and non-residential cesspools provided their layout and use complied with the subsurface waste water or plumbing code provisions prevailing when the system was first put into use; they are used solely for the disposal of domestic waste; and they have the capacity to serve fewer than 20 persons per day and dispose of less than 2,000 gallons per day;(3) Wells receiving wastewater from home occupation fish or shellfish processing;(4) Wells receiving wastewater from laundromats where no on-site dry cleaning is performed and where no organic solvents are used for laundering;(5) Wells receiving wastewater from funeral homes; or(6) Wells receiving wastewater from hospitals, restaurants, nursing homes, schools, hotels, motels, dental and veterinary facilities and other commercial and industrial establishments provided the wastewater does not contain constituents unlike that of or in significantly higher strength than found normally in domestic wastewater. (Note: Covered under State Plumbing Code, see §6 )
06-096 C.M.R. ch. 543, § 2