Prohibited Subsurface Wastewater Discharges


Floor drains in motor vehicle repair areas/ Class V Motor vehicle waste disposal wells  

Floor drains in motor vehicle maintenance areas are prohibited from discharging to a subsurface wastewater disposal system or to a pipe that discharges on top of the ground ("daylighted).  A motor vehicle maintenance area is any area in which vehicular repair or maintenance activities occur, including, but not limited to, activities performed at such businesses as automotive and autobody 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 are solely for the person's own vehicle or fleet).

If you have a floor drain in a motor vehicle repair area, your options are to (1) seal the drain, (2) connect the floor drain to a municipal sewer system (with permission of the local sewer district) or (3) connect the floor drain to a non-domestic, wastewater holding tank (See Floor Drains for more information).  The DEP will not issue a license this discharge.  When you seal or re-direct the floor drain, you must dispose or otherwise manage any soil, gravel, sludge, liquids or other materials removed from the drain in accordance with all applicable federal, state and local regulations.

Thirty (30) days prior to sealing your floor drain or otherwise disconnecting it from a system that discharges onto or below the ground, federal law requires you to notify the DEP of your intended action.  Pre-closure notification includes:

  • the name and address of the business, 
  • the name and address of the owner, 
  • the number of floor drains to be sealed or re-connected,
  • the type of surface or subsurface system to which the floor drains are presently connected, and
  • whether the floor drain(s) will be sealed or the new connection location for the drain (municipal sewer or holding tank).

If you are closing a floor drain in a motor vehicle repair areas as the result of an inspection by DEP, you do not need to file pre-closure notification.  

Please send pre-closure notification to:

Underground Injection Control Program
Maine Dept. of Environmental Protection
Bureau of Land and Water Quality
17 State House Station
Augusta, ME  04333-0017

Fax:  (207)287-7191
Phone: Bureau of Land and Water Quality (where the UIC program is located), (207)287-3901

Unless you are directed by the DEP to keep your floor drain open, you may seal or re-direct the drain after 30 days.  The DEP will attempt to respond to all pre-closure notifications within 7 days.  Once you have gotten approval from DEP, you may proceed immediately and need not wait the full thirty days.  

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Floor drains in other areas with a "significant potential" for discharge

Section 205.3 of the Maine Subsurface Waste Water Disposal Rules states:

205.3 Floor drains.  Floor drains may be connected to a subsurface waste water disposal system if (1) the disposal area is properly sized to handle the potential flow from the drains; (2) there is no significant potential for discharge of industrial, hazardous or toxic liquids; (3) the floor drain is necessary for the discharge of wash water or other waste water which has constituents similar in volume or concentration to domestic waste water (including animal or vegetable matter, soap solutions, and diluted domestic-use cleaning solutions); and (4) connection to a public sewer is not available.  Floor drains shall not be connected to a subsurface waste water disposal system if there is a significant potential for industrial, hazardous or toxic liquids (including gasoline, oils and degreasers) to drip, be spilled or washed into the floor drains. (emphasis added) 

Look around your place of business: Are there areas in which there is a "significant potential" for hazardous materials to discharge to floor drains?  Are there floor drains in the same room as your hazardous materials storage?  Waste oil or heating oil tank?  

Floor drains in these areas present a unique risk to ground water and should be sealed if not used.   If you must have floor drains in these areas, choose a HIGH RISK connection option from the Floor Drain guidance or make sure there is adequate secondary containment below or around any hazardous material or oil container.  

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Large-capacity cesspools

A large-capacity cesspool is a dry well that receives solely untreated domestic wastewater and serves 20 or more persons per day or disposes of 2,000 gallons or more of domestic wastewater per day.  This term does not include single-family, other residential or non-residential cesspools below the capacity or flow limits specified.

If you operate a business such as a camp ground, mobile home park or summer camp that is still utilizing a large-capacity cesspool, federal and state law require that you close the cesspool by April 5, 2005.  Your closure options include (1) installation of a septic system, (2) connection to a municipal sewer system or (3) installing a treatment system and being granted a waste discharge license for disposal in surface water or to the land.  

Thirty (30) days prior to closing the cesspool, notification of your intended action must be sent to two state agencies.  Pre-closure notification includes:

  • the name and address of the business, 
  • the name and address of the owner, 
  • the dimensions, flow and capacity of the cesspool, and
  • the type of wastewater disposal system that will be taking its place.

If you are closing a cesspool as the result of an inspection by DEP, you do not need to file pre-closure notification.  

Please send pre-closure notification to:

Underground Injection Control Program
Maine Dept. of Environmental Protection
Bureau of Land and Water Quality
17 State House Station
Augusta, ME  04333-0017

Fax:  (207)287-7191
Phone: Bureau of Land and Water Quality (where the UIC program is located), (207)287-3901

Waste Water and Plumbing Control Program
Maine Dept. of Human Services
10 State House Station
Augusta, ME  04333-0010

Fax:  (207)287-3165

Unless you are directed by the DEP or the DHS to keep your cesspool open, you may close and re-direct the domestic wastewater after 30 days.  Both agencies will attempt to respond to all pre-closure notifications within 7 days.  Once you have gotten approval, you may proceed immediately and need not wait the full thirty days.  

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Subsurface discharge of hazardous or radioactive wastes

The subsurface discharge of hazardous waste or radioactive waste into a dry well, cesspool, septic system or through any other subsurface fluid distribution system is prohibited.  The DEP will not issue a license for this discharge.

How do you know if you have a hazardous or radioactive waste?  Hazardous wastes are those substances identified as hazardous in 06-096 CMR, Chapter 850, Section 3(C).  Questions about the hazardous waste should be directed to the Bureau of Remediation and Waste Management at (207)287-2651.

A radioactive waste is any waste which contains radioactive material in concentrations which exceed those listed in 10 CFR Part 20, Appendix B, Table II, Column 2.  Further information about radioactive waste is also available from the Dept. of Human Services, Radiation Control Program.. 

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