DRINKING WATER AND ENVIRONMENTAL HEALTH DIVISION – ENVIRONMENTAL ASSISTANCE CENTER 800-662-9278
PLUGGING ABANDONED WELLS WHEN COMMUNITY WATER LINES ARE EXTENDED
The Department of Environment, Great Lakes, and Energy (EGLE) advises property owners to hire registered water well drilling contractors to plug abandoned wells. Registered water well drillers have the specialized training and equipment necessary to properly plug abandoned wells.
Properly plug the well
· Properly plugging the old well is the preferred option. Plugging the well protects the drinking water aquifer and limits the property owner's liability for ground water contamination.
· The Groundwater Quality Control Act, Part 127, 1978 PA 368 (state well code) requires “A well that is abandoned when municipal water is installed shall be plugged.”
· Some county, local, and municipal jurisdictions have ordinances that prohibit the retention of private wells when structures are connected to municipal water service.
Restore the well to operational condition
· To retain the existing well for irrigation, car washing, or other uses, it must be restored to operational condition.
· Plumbing changes are required to physically separate the structure’s domestic water piping served by the municipal water system, from the piping connected to the well.
· A cross connection inspection and approval from the public water utility, the plumbing inspector, or the local health department is required when water service is initiated.
· Where existing wells will be retained for non-potable purposes, well construction upgrades are recommended, but are not mandatory.
The property owner is responsible for assuring that all abandoned wells on his or her property are properly plugged.
· A property owner may plug a well only at his or her residence.
· A registered water well drilling contractor or his or her supervised employee may plug a well at any residence, farm, industry, business, or other public water supply.
· pipes sticking above ground
· pipes sticking through wall or floor in the basement
· electrical switch boxes out in the yard
· cement pits in or under sheds
· old crock, brick, or stone structures
For locating buried wells:
· Metal detectors may be used to find buried steel well casings. First, look in the basement for where the old water line penetrates the foundation wall. Go outside on that side of the structure and locate the pipe. From that point, survey the ground with the metal detector, moving away from the structure. Use a marker to designate the location of any “readings.” Usually, well casings will be four (4) to five (5) feet below grade and will be located between three (3) and 25 feet from the home.
· Neighbors and senior citizens who have lived in the area for a long time often know where old wells are located. If you take advantage of their input you may save yourself a lot of work.
· Pumps, drop pipe, pump rods, packers, wire, check valves, and all other debris or obstructions must be removed from the well before plugging.
· Due to the equipment necessary, this often requires the services of a registered well drilling contractor.
· Failure to remove obstructions from the well can result in void spaces in the column of plugging material.
· The depth and diameter of the well must be measured before plugging to allow the drilling contractor or well owner to calculate the amount of plugging material necessary to fill the entire depth of the well.
Methods used to plug wells depend on the well type and site geology.
Dug Wells: These large (12 to 48 inch diameter) wells are made of cement crock, brick, stone, or tile. A six (6) inch layer of bentonite chips or pellets shall be placed at the bottom of the well. The remainder of the well shall be plugged by placing clean soil backfill* layers that are not more than ten (10) feet thick, with a six (6) inch layer of bentonite chips between backfill layers. The upper three (3) to four (4) feet of stone, brick, cement crock, or curbing must be broken up and removed. A final six (6) inch layer of bentonite must be placed three
(3) feet below finish grade, then the remainder of the hole backfilled and crowned to prevent settling and ponding of water over the old well. Clean, dry soil backfill may be loam, clay, silt, or sand obtained from commercial sources or from the site. Clean backfill may not contain trash, wood, roots, sod, construction debris, or chemical contaminants.
Drilled Wells in Sand or Gravel Formations: Bentonite grout slurry, neat cement slurry*, or dry bentonite chips or pellets may be used to plug wells with screens in sand and gravel formations. All slurry grouts must be placed using a tremie pipe which runs to the bottom of the well. The slurry may be pumped or poured using a funnel into the tremie pipe. Plugging is complete when the grout appears at the surface. Neat cement slurry is a mixture of one 94 pound bag of Portland cement and not more than six (6) gallons of water.
Wells in Bedrock Formations: Neat cement must be used when plugging bedrock wells. A pump and a tremie pipe (run to the bottom of the well) are used to deliver the grout to the bottom of the well. The tremie pipe is removed as the neat cement is pumped into the well or after thick cement appears at the surface. Bedrock wells should be plugged by registered well drilling contractors.
Hand-driven Point Wells: These small diameter wells (normally 1-1/4 inch diameter) are plugged by carefully dropping bentonite chips or pellets into the top of the well casing. Another method is to pour a slurry of neat cement through a funnel and tremie pipe extending to the bottom of the well. If bentonite chips are used, a hardware cloth screen (1/4 inch mesh) shall be used to remove any fine bentonite particles before the chips are poured into the well. If they are not removed, they will swell upon contacting water, bridge in the upper part of the well, and will prevent effective plugging of the lower part of the well.
Flowing Wells: Because of their unique characteristics, flowing wells should only be plugged by registered well drilling contractors. Neat cement must be used to plug flowing wells. Its heavy slurry weight is needed to initially overcome the artesian pressure of flowing wells, and then to provide a solidified permanent seal.
EGLE Environmental Assistance Center Phone: 800-662-9278
Michigan.gov/EGLE (Rev. 08/2020
Soil Dispersal System and Septic Tank Abandonment
The following correspondence has been pieced together from Michigan Department of Environment, Great Lakes, and Energy (EGLE) historical interdepartmental communication regarding the proper abandonment and removal of an onsite wastewater system.
Over time with the replacement of existing onsite wastewater systems, the proper abandonment or removal of septic tanks and the soil dispersal areas must be addressed. In order to ensure the protection of public health and safety it is increasingly important to make sure the abandonment or removal process is done in a manner to reduce pathogen exposure. The following recommendations are ways to reduce public health risks and should be followed as supported through the applicable laws and regulations. Although it is best to leave the onsite wastewater system in place (after proper abandonment) this can only be acceptable if the Local Health Department regulations allow for it. The following recommendations are ways to reduce public health risks and should be followed as supported through the applicable laws and regulations.
For septic tanks:
1. A licensed septage hauler must pump all contents from all of the tanks in the system.
2. The tanks can be crushed in place and backfilled with free sand, granular material, concrete, or any other soil material that has been compacted to prevent settling.
3. If the tanks have to be removed, the tanks can be removed once not containing any free liquids and properly disposed of in a licensed landfill.
The soil dispersal area may be left in place intact. The soil dispersal area cannot be relocated to another location on the property unless it is licensed as a solid waste disposal area.
According to Part 115: Solid Waste Management of Act 451 of 1994 as amended
R 299.4430 Type II landfill operator; prohibited wastes; procedures for excluding the receipt of prohibited waste.
(2) The following wastes shall not be disposed of in a Type II landfill:
(c) Bulk or noncontainerized liquid waste or waste that contains free liquids unless the waste is household waste other than septic waste or the waste is leachate or gas condensate that is approved for recirculation under R299.4432.
(w) “Liquid Waste” means any waste material that is determined to contain free liquids as defined by method 9095, the paint filter liquids test, as described in the publication entitled “Test Methods for Evaluating Solid Wastes, Physical-Chemical Methods” SW- 846, which is adopted by reference in R 299.4133. For purposes of the act and these rules, liquid waste does not include industrial waste sludges that are disposed of at a location other than a Type II landfill.
To ensure the soil dispersal area does not contain excess liquid waste before removal, it is helpful to dig a hole in the four corners of the soil dispersal area along with a hole in the middle to create sump pits that the liquid septage waste can pool and collect to be pumped out by the licensed septage hauler. This process may take numerous days to ensure the surrounding soil, pipes, and dispersal media are drained. This method should be completed prior to the removal of the dispersal area and bringing it to the ground surface. Removing saturated dispersal media to dry at the ground surface will threaten the public health of nearby residents and the contractors removing the material due to potential exposure to pathogens in the process.
Other supporting rules which do not allow spoiled soil dispersal area wastes to be stored onsite is from:
Part 117, Septage Waste Servicers, of Act 451 of 1994 as amended.
324.11710. Requirements to which permit subject
Sec. 11710. A site permit is subject to all of the following requirements:
(a) The septage waste disposed of shall be applied uniformly at agronomic rates.
Since the removed soil dispersal with liquid waste cannot be applied onsite together at a uniform agronomic rate, it would not meet the requirements to be land applied under this septage regulation.
All non-conventional dispersal media and septic tanks should be individually assessed and characterized for proper disposal at the appropriate licensed landfill. The soil dispersal area and tank may be disposed of in a licensed landfill if it is determined that free liquids are not included, and it meets the criteria for solid waste management. If you have any further questions regarding Materials Management including solid waste regulations (EGLE Materials Management Division) or Septage regulations (EGLE Drinking Water and Environmental Health Division) please contact the EGLE Environmental Assistance Center at 1-800-662-9278 or visit the following link at Michigan.gov/EGLE for more information pertaining to each program.