Rule 3745-535-805 | Groundwater monitoring system.
(A) The groundwater monitoring system shall consist of a sufficient number of monitoring wells, installed at appropriate locations and depths in both the uppermost aquifer system and any significant zones of saturation to produce groundwater samples that represent the following:
(1) The background groundwater quality that has not been affected by past or present operations at the solid waste landfill.
(2) The groundwater quality passing directly downgradient of the limits of solid waste placement.
(B) The director may order or otherwise authorize an owner or operator to conduct surface water monitoring as part of the groundwater monitoring system in areas where it may not be practical to place a well in order to collect a sample representative of groundwater quality passing directly downgradient of the limits of solid waste placement.
[Comment: The director's authorization to conduct surface water monitoring under this rule will include sampling procedures in accordance with rule 3745-535-810 of the Administrative Code, as applicable.]
(C) If the top of the uppermost aquifer system exists more than one hundred fifty feet beneath the recompacted clay liner of the solid waste landfill, the owner or operator shall ensure that the groundwater monitoring system consists of a sufficient number of monitoring wells, installed at appropriate locations and depths, to produce groundwater samples from an adequate number of significant zones of saturation above the uppermost aquifer system, in accordance with paragraphs (A)(1) and (A)(2) of this rule.
(D) All monitoring wells shall be designed, installed, and developed in a manner that allows the collection of groundwater samples that are representative of groundwater quality in the geologic unit being monitored, and that are in accordance with the following criteria:
(1) Monitoring wells are cased in a manner that maintains the integrity of the monitoring well boreholes.
(2) The annular space above the sampling depth is sealed to prevent the contamination of the samples and the groundwater.
(3) The casing is screened or perforated and surrounded by sand or gravel in such a way that allows for the following:
(a) For the minimization of the passage of formation materials into the well.
(b) For the monitoring of discrete portions of the uppermost aquifer system or any significant zones of saturation above the uppermost aquifer system.
(4) The monitoring wells, piezometers, and other measurement, sampling, and analytical devices are operated and maintained to perform to design specifications throughout the life of the monitoring program.
(E) The number, spacing, and depth of groundwater monitoring wells shall be as follows:
(1) Based on site specific hydrogeologic information including that information listed in paragraphs (C)(3)(a) to (C)(3)(g) of rule 3745-27-06 of the Administrative Code.
(2) Capable of detecting a release from the solid waste landfill to the groundwater at the closest practicable location to the limits of solid waste placement.
(F) The owner or operator shall document the design, installation, development, maintenance and abandonment of the following in accordance with rule 3745-27-09 of the Administrative Code:
(1) Monitoring wells.
(2) Piezometers.
(3) Any other measurement, sampling, and analytical devices.
Last updated March 1, 2026 at 9:33 AM
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