7 Del. Admin. Code § 1302-264-F-264.91

Current through Reigster Vol. 28, No. 6, December 1, 2024

Section 1302-264-F-264.91 - Required programs

(a) Owners and operators subject to this subpart must conduct a ground-water monitoring and response program as follows:

(1) Whenever hazardous constituents under § 264.93 from a regulated unit are detected at the compliance point under § 264.95, the owner or operator must institute a compliance monitoring program under § 264.99. Detected is defined as statistically significant evidence of contamination as described in § 264.98 (f);

(2) Whenever the groundwater protection standard under § 264.92 is exceeded, the owner or operator must institute a corrective action program under § 264.100. Exceeded is defined as statistically significant evidence of increased contamination as described in § 264.99 (d);

(3) Whenever hazardous constituents under § 264.93 from a regulated unit exceed concentration limits under § 264.94 in ground-water between the compliance point under § 264.95 and the downgradient facility property boundary, the owner or operator must institute a corrective action program under § 264.100;

(4) In all other cases, the owner or operator must institute a detection monitoring program under § 264.98.

(b) The Secretary will specify in the facility permit the specific elements of the monitoring and response program. The Secretary may include one or more of the programs identified in paragraph (a) of this section in the facility permit as may be necessary to protect human health and the environment and will specify the circumstances under which each of the programs will be required. In deciding whether to require the owner or operator to be prepared to institute a particular program, the Secretary will consider the potential adverse effects on human health and the environment that might occur before final administrative action on a permit modification application to incorporate such a program could be taken.

(c) The owner or operator of a facility which is used to manage hazardous waste must submit to the Department within 120 days of the effective date of these regulations, a hydrogeologic report, except as paragraph (d) of this section provides otherwise. This report must be certified by a qualified engineer or qualified geologist except for (c)(1) of this section which must be certified by a qualified geologist. (See § 260.10 for definitions of qualified engineer and qualified geologist). This report shall include at a minimum the following:

(1) A definition of the geology of the site and the surrounding areas. This shall include:

(i) A description of the various lithologic units including mineralogy, grain size distribution, shape and color to a depth which includes at least the uppermost confined aquifer underlying the site; and

(ii) Isopachous and structural contour maps and cross-sections showing these various lithostratigraphic units.

(2) A description of the ground-water movement in at least the water table and uppermost confined aquifers underlying the site and the surrounding area including:

(i) The rate and direction of flow, both horizontally and vertically; and

(ii) A potentiometric surface map and cross-section of each aquifer.

(iii) A map showing the difference in hydraulic head between the water table and uppermost confined aquifers.

(3) A description of hydrologic characteristics of the lithostratigraphic units to a depth which includes at least the uppermost confined aquifer underlying the site and the surrounding area such as, but not limited to, hydraulic conductivity, porosity, aquifer thickness, transmissivity, and storage coefficient.

(4) A description of the chemical quality of the ground-water of at least the water table and uppermost confined aquifer underlying the site and surrounding area to include the parameters specified in § 265.9 (a) and any other parameters specified by the Department depending on the composition of the waste; a description of the chemical quality of nearby surface water may be required if deemed necessary by the Department.

(5) A prediction of the potential movement of any contaminants that may enter the ground-water underlying the site and the surrounding area including the rate, extent and direction, both horizontal and vertical migration and the potential impact on ground-water and if applicable on surface water.

(6) An estimate of the amount of leachate which may be generated at the site. This shall be done by using methods described in the following publications: "Hydrologic Simulation on Solid Waste Disposal Sites", U.S. Environmental Protection Agency, Office of Water and Waste Management, SW-868, September 1980; or the "Use of the Water Balance Method for Predicting Leachate Generation from Solid Waste Disposal Sites", U.S. Environmental Protection Agency, Office of Solid Waste Management Program, SW-168, October, 1975; or an equivalent method approved by the Department.

(7) A description of the existing ground-water and, if applicable, surface water monitoring program used to detect and determine any contaminant migration at the site and the surrounding area.

(8) A proposal for future monitoring including additional monitoring wells and if applicable surface water monitoring stations, parameters for analysis and monitoring schedule.

(d) All or part of the ground-water monitoring requirements of this section may be waived if the owner or operator can demonstrate that there is a low potential for migration of hazardous waste or hazardous waste constituents from the facility via the uppermost aquifer to water supply wells, (domestic, industrial or agricultural) or to surface water. This demonstration must be in writing, and must be kept at the facility at all times and also must be submitted to and approved by the Department. This demonstration must be certified by a qualified engineer or qualified geologist except in defining the geology and geologic materials in (d)(1)(ii) and d(2)(i) which must be certified by a qualified geologist.

This demonstration must establish the following:

(1) The potential for migration of hazardous waste or hazardous waste constituents from the facility to the upper most aquifer, by an evaluation of:

(i) A water balance of precipitation, evapotranspiration, run-off, and infiltration; and

(ii) Unsaturated zone characteristics (i.e., geology and geologic materials, physical properties, and depth to ground-water); and

(2) The potential for hazardous waste or hazardous waste constituents which enter the uppermost aquifer to migrate to a water supply well or surface water, by an evaluation of:

(i) Saturated zone characteristics (i.e., geology and geologic materials, physical properties, and rate of ground-water flow); and

(ii) The proximity of the facility to water supply wells or surface water.

(Amended August 29, 1988; August 10, 1990; Amended June 19, 1992)

7 Del. Admin. Code § 1302-264-F-264.91