Code of Maine Rules › 06 - DEPARTMENT OF ENVIRONMENTAL PROTECTION › 096 - DEPARTMENT OF ENVIRONMENTAL PROTECTION - GENERAL › Chapter 405 - Solid Waste Management Rules: Water Quality Monitoring, Leachate Monitoring, and Waste Characterization › Section 096-405-2 - Water Quality Monitoring

Current through 2024-29, July 17, 2024
The monitoring program approved for a solid waste facility
				  must be capable of detecting any changes in ground water quality in the
				  vicinity of the solid waste facility and/or any changes in surface water
				  quality in the vicinity of the solid waste facility.
A.
Standards for Ground Water
				Monitoring.
The objective of a ground water monitoring program is to
				detect changes in the quality of ground water due to a solid waste facility. To
				accomplish this, downgradient and upgradient (or background) ground water
				monitoring wells must be placed in sufficient numbers to meet the standards of
				this chapter as determined through a hydrogeological investigation of the
				facility site. Areas where public health concerns or nearby sensitive receptors
				are threatened or have been affected may be subject to more intensive ground
				water monitoring requirements than provided below.
(1)
Number and location of ground water
				monitoring wells
. The number and placement of ground water monitoring
				wells at new or altered solid waste facilities, or existing active, inactive or
				closed solid waste facilities required to implement a new ground water quality
				monitoring program or add additional monitoring wells, must conform to the
				standards listed below. Where the location of existing active, inactive or
				closed solid waste facilities (including alterations) make it impossible to
				locate wells upgradient of the waste handling area, other locations for
				characterizing background ground water quality may be proposed for review by
				the Department:
(a) Horizontal well spacing
				must be based on site-specific conditions including ground water flow direction
				and rate, estimated dispersion, proximity to sensitive receptors and the nature
				of wastes disposed of, stored, processed or beneficially used at a solid waste
				facility. For landfills, it must also be based on the proposed or existing
				design of the landfill liner and leachate management systems. The number and
				location of the downgradient monitoring wells or well clusters will depend on
				the size of the waste handling area and the length of its downgradient
				perimeter. Monitoring wells must be established in sufficient numbers to detect
				any contamination emanating from the waste handling area.
(b) Vertical well locations must be chosen to
				ensure that each hydrogeologic unit is monitored.
(c) At new or expanded landfills, a minimum
				of two upgradient and three downgradient wells or well cluster locations must
				be provided. At landfills where more than five wells or well clusters are
				necessary, the ratio of upgradient (or background) wells to downgradient wells
				must be sufficient to support valid statistical analyses.
(d) At existing facilities, or where ground
				water contamination is suspected, the Department may require the use of
				geophysical techniques to aid in establishing appropriate well locations and
				screen elevations for additional ground water monitoring points.
(e) The downgradient monitoring wells must be
				located as close as practical to the solid waste boundary(s) of landfills, or
				the waste handling area of solid waste facilities that are not landfills, but
				in no case greater than 100 feet away, unless placing some of the wells at
				greater distances enhances the ability to detect a release from the facility.
				In such a case, placement of wells more than 100 feet distant may be proposed
				for approval by the Department
(f)
				All upgradient and background monitoring wells must be placed so as to avoid
				any facility-derived impacts both during the operating life of the facility and
				after closure.