Sec. 26.13.05.06-1. Ground Water Protection — Program Elements

A. Ground Water Protection Standard.

(1) During the compliance period established under §E of this regulation, the owner or operator shall comply with conditions specified in the facility permit to ensure that, in the uppermost aquifer underlying the waste management area beyond the point of compliance, hazardous constituents detected in the ground water from a regulated unit do not exceed the concentration limits established under §C of this regulation. The hazardous constituents to which this applies are determined under §B of this regulation. The point of compliance is set under §D of this regulation.

(2) The Secretary shall establish this ground water protection standard in the facility permit when hazardous constituents have been detected in the ground water.

B. Hazardous Constituents.

(1) The facility permit shall specify the hazardous constituents to which the ground water protection standard of §A of this regulation applies.

(2) For the purposes of this regulation, "hazardous constituents" means constituents identified in COMAR 26.13.02.24 that have been detected in ground water in the uppermost aquifer underlying a regulated unit and that are reasonably expected to be in or derived from waste contained in a regulated unit, unless the Secretary has excluded them under §B(3) of this regulation.

(3) The Secretary may exclude a constituent identified in COMAR 26.13.02.24 from the list of hazardous constituents specified in the facility permit if he finds that the constituent is not capable of posing a substantial present or potential hazard to human health or the environment based on the following considerations:

(a) Potential adverse effects on ground water quality considering:

(i) The physical and chemical characteristics of the waste in the regulated unit, including its potential for migration;

(ii) The hydrogeological characteristics of the facility and surrounding land;

(iii) The quantity of ground water and the direction of ground water flow;

(iv) The proximity and withdrawal rates of ground water users;

(v) The current and future uses of ground water in the area;

(vi) The existing quality of ground water, including other sources of contamination and their cumulative impact on the ground water quality;

(vii) The potential for health risks caused by human exposure to waste constituents;

(viii) The potential damage to wildlife, crops, vegetation, and physical structures caused by exposure to waste constituents;

(ix) The persistence and permanence of the potential adverse effects; and

(b) Potential adverse effects on hydraulically connected surface water quality, considering:

(i) The volume and physical and chemical characteristics of the waste in the regulated unit;

(ii) The hydrogeological characteristics of the facility and surrounding land;

(iii) The quantity and quality of ground water, and the direction of ground water flow;

(iv) The patterns of rainfall in the region;

(v) The proximity of the regulated unit to surface waters;

(vi) The current and future uses of surface waters in the area and any water quality standards established for those surface waters;

(vii) The existing quality of surface water, including other sources of contamination and the cumulative impact on surface water quality;

(viii) The potential for health risks caused by human exposure to waste constituents;

(ix) The potential damage to wildlife, crops, vegetation, and physical structures caused by exposure to waste constituents; and

(x) The persistence and permanence of the potential adverse effects.

(4) In making any determination under §B(3) of this regulation about the use of ground water in the area around the facility, the Secretary shall consider any identification of underground sources of drinking water and exempted aquifers made by the Approving Authority for the State's Underground Injection Control Program.

C. Concentration Limits.

(1) The facility permit shall specify concentration limits in the ground water for hazardous constituents established under §B of this regulation. The concentration of a hazardous constituent:

(a) May not exceed the background level of that constituent in the ground water at the time that limit is specified in the permit;

(b) For any of the constituents listed in Table 1, may not exceed the respective value given in that table if the background level of the constituent is below the value given in Table 1; or

(c) May not exceed an alternate limit established by the Secretary under §C(2) of this regulation.

(2) The Secretary may establish an alternate concentration limit for a hazardous constituent if the Secretary finds that the constituent does not pose a substantial present or potential hazard to human health or the environment as long as the alternate concentration limit is not exceeded. Establishment of alternate concentration limits is based on consideration of the following factors:

(a) Potential adverse effects on ground water quality, considering:

(i) The physical and chemical characteristics of the waste in the regulated unit, including its potential for migration;

(ii) The hydrogeological characteristics of the facility and surrounding land;

(iii) The quantity of ground water and the direction of ground water flow;

(iv) The proximity and withdrawal rates of ground water users;

(v) The current and future uses of ground water in the areas;

(vi) The existing quality of ground water, including other sources of contamination and their cumulative impact on the ground water quality;

(vii) The potential for health risks caused by human exposure to waste constituents;

(viii) The potential damage to wildlife, crops, vegetation, and physical structures caused by exposure to waste constituents;

(ix) The persistence and permanence of the potential adverse effects; and

(b) Potential adverse effects on hydraulically connected surface water quality, considering:

(i) The volume and physical and chemical characteristics of the waste in the regulated unit;

(ii) The hydrogeological characteristics of the facility and surrounding land;

(iii) The quantity and quality of ground water, and the direction of ground water flow;

(iv) The patterns of rainfall in the region;

(v) The proximity of the regulated unit to surface waters;

(vi) The current and future uses of surface waters in the area and any water quality standards established for those surface waters;

(vii) The existing quality of surface water, including other sources of contamination and the cumulative impact on surface water quality;

(viii) The potential for health risks caused by human exposure to waste constituents;

(ix) The potential damage to wildlife, crops, vegetation, and physical structures caused by exposure to waste constituents; and

(x) The persistence and permanence of the potential adverse effects.

(3) In making any determination under §C(2) of this regulation about the use of ground water in the area around the facility, the Secretary shall consider any identification of underground sources of drinking water and exempted aquifers made by the Approving Authority for the State's Underground Injection Control Program.

Table 1
Maximum Concentration of Constituents for Ground Water Protection

Constituent	Maximum Concentration (Milligrams per liter)
Arsenic	0.05
Barium	1.0
Cadmium	0.01
Chromium	0.05
Lead	0.05
Mercury	0.002
Selenium	0.01
Silver	0.05
Endrin (1, 2, 3, 4, 10-hexachloro-1, 7-1 epoxy-1, 4, 4a, 5, 6, 7, 8, 9a-octahydro-1, 4-endo-5, 8-dimethano naphthalene)	0.0002
Lindane (1, 2, 3, 4, 5, 6-hexachlorocyclohexane, gamma isomer)	0.004
Methoxychlor (1, 1, 1-trichloro-2, 2-bis(p-methoxyphenylethane))	0.1
Toxaphene (C10H10Cl8, technical chlorinated camphene, 67-69 percent chlorine)	0.005
2,4-D (2,4-dichlorophenoxyacetic acid)	0.1
2,4,5-TP Silvex (2, 4, 5-trichlorophenoxypropionic acid)	0.01

D. Point of Compliance.

(1) The Secretary shall specify in the facility permit the point of compliance at which the ground water protection standard of §A of this regulation applies and at which monitoring shall be conducted. The point of compliance is a vertical surface located at the hydraulically downgradient limit of the waste management area that extends down into the uppermost aquifer underlying the regulated units.

(2) Waste Management Area.

(a) The waste management area is the limit projected in the horizontal plane of the area on which waste will be placed during the active life of a regulated unit.

(b) The waste management area includes horizontal space taken up by any liner, dike, or other barrier designed to contain waste in a regulated unit.

(c) If the facility contains more than one regulated unit, the waste management area is described by an imaginary line circumscribing the several regulated units.

E. Compliance Period.

(1) The Secretary shall specify in the facility permit the compliance period during which the ground water protection standard of §A of this regulation applies. The compliance period is the number of years equal to the active life of the waste management area (including any waste management activity before permitting, and the closure period), unless extended by order of the Secretary.

(2) The compliance period begins when the owner or operator initiates a compliance monitoring program meeting the requirements of Regulation .06-5 of this chapter.

(3) If the owner or operator is engaged in a corrective action program at the end of the compliance period specified in §E(1) of this regulation, the compliance period is extended until the owner or operator can demonstrate that the ground water protection standard of §A of this regulation has not been exceeded for a period of 3 consecutive years.