5 Colo. Code Regs. § 1002-42.26
SPECIFIC STATUTORY AUTHORITY
The provisions of C.R.S. 25-8-202; 25-8-203; and 25-8-204 provide the specific statutory authority for adoption of these regulatory provisions. The Commission has adopted in compliance with C.R.S. 24-4-103(4) the following statement of basis and purpose.
BASIS AND PURPOSE
As a result of this hearing, the Commission applied the classification of limited use and quality to the ground water contained within the following specified areas:
Weld County (Figure 46) The Permian aged Lyons Sandstone within a specified area of Weld County, Colorado in which extensive oil and natural gas exploration and development have occurred. The specified area includes approximately 25 square miles in Weld County, Colorado.
Weld County (Figure 47) The Upper Cretaceous aged Parkman Sandstone within a specified area of Weld County, Colorado in which extensive oil and natural gas exploration and development have occurred. The specified area includes approximately 12 square miles in Weld County, Colorado.
Weld County (Figure 48) The Upper Cretaceous aged Sussex Sandstone within a specified area of Weld County, Colorado in which extensive oil and natural gas exploration and development have occurred. The specified area includes approximately 14 square miles in Weld County, Colorado.
Adams, Arapahoe, Morgan, Washington, and Weld Counties (Figures 49A, 49B, 49C) The Lower Cretaceous aged D and J Sandstones within specified areas of Adams, Arapahoe, Morgan, Washington, and Weld Counties, Colorado in which extensive oil and natural gas exploration and development have occurred. The specified areas include approximately 186 square miles in Adams, Arapahoe, Morgan, Washington, and Weld Counties, Colorado.
The adoption of this Limited Use and Quality classification by the Commission does not preclude the need for obtaining an aquifer exemption under the Underground Injection Control (UIC) program, if future applicants wish to inject fluids into portions of the subject formations within each specified area for which an aquifer exemption would be needed. That is, the adoption of this classification does not preclude the need for compliance with the specific requirements of the UIC program.
Site-specific classification of ground water begins with the identification of the use of the water within the four specified areas as follows:
Weld County (Figure 46) The ground water in the Permian aged Lyons Sandstone is coproduced with oil and gas and is considered a waste. Within the specified area, ground water in the Lyons Sandstone is not currently used nor can it reasonably be expected to be used in the future for domestic or agricultural purposes. The ground water is not in communication with any surface water bodies within the specified area so that the water quality standards of any classified surface water bodies are not affected by this ground water. More specific evidence of the limited use and quality of this ground water follows:
Within the specified area there are approximately 126 water wells permitted with the Office of the State Engineer. Division of Water Resources data indicates that there are no public water systems, or domestic, agricultural, commercial, or industrial water wells completed in the Lyons Sandstone within the specified area.
The Lyons Sandstone contains or has contained naturally occurring accumulations of crude oil and natural gas, in addition to ground water in many portions of this specified area. These oil and gas resources have been developed and produced since the 1950's.
Within the specified area approximately 40 oil and gas wells or tests have been drilled to or completed in the Lyons Sandstone.
Within the specified area the Colorado Oil and Gas Conservation Commission (COGCC) has not granted any aquifer exemptions for UIC projects under Rule 324(B) of the Rules and Regulations, Rules of Practice and Procedure (2 CCR 404-1), pursuant to the Colorado Oil and Gas Conservation Act, Title 60, Article 34, C.R.S. (1982). Two injection projects have been permitted within the specified area; however, these did not require aquifer exemptions, because the total dissolved solids (TDS) concentrations of the injection zone exceeded 10,000 milligrams per liter (mg/l). These three injection projects contain a total of approximately 14 injection wells completed in the Lyons Sandstone.
Within the specified area the Lyons Sandstone lies between 8,800 - 9,500 feet below the ground surface (fbgs).
Based on information available to the COGCC, within the specified area the TDS concentration of the Lyons Sandstone ranges from 27,228 mg/l to 95,867 mg/l with an average of 61,548 mg/l.
Hydrogeologic data including produced water quality and depths of the Lyons Sandstone and other COGCC data indicate that the ground water in these formations meets the criteria in Regulation 41 for classification as "Limited Use and Quality" . The Commission, therefore, concluded that the application of the "Limited Use and Quality" classification to the ground water within the Lyons Sandstone in the specified area is appropriate. This classification and the application of site-specific standards for organic chemicals assure consistency between implementation of the UIC Program requirements and WQCC Standards and Classification.
Weld County (Figure 47) The ground water in the Upper Cretaceous aged Parkman is coproduced with oil and gas and is considered a waste. Within the specified area, ground water in the Parkman Sandstone is not currently used nor can it reasonably be expected to be used in the future for domestic or agricultural purposes. The ground water is not in communication with any surface water bodies within the specified area so that the water quality standards of any classified surface water bodies are not affected by this ground water. More specific evidence of the limited use and quality of this ground water follows:
Within the specified area there are approximately 176 water wells permitted with the Office of the State Engineer. Division of Water Resources data indicates that there are no public water systems, or domestic, agricultural, or industrial water wells completed in the Parkman Sandstone within the specified area.
The Parkman Sandstone contains or has contained naturally occurring accumulations of crude oil and natural gas, in addition to ground water in many portions of this specified area. These oil and gas resources have been developed and produced since the 1970's.
Within the specified area approximately 39 oil and gas wells or tests have been drilled to or completed in the Parkman Sandstone.
Within the specified area the Colorado Oil and Gas Conservation Commission (COGCC) has not granted any aquifer exemptions for UIC projects under Rule 324(B) of the Rules and Regulations, Rules of Practice and Procedure (2 CCR 404-1), pursuant to the Colorado Oil and Gas Conservation Act, Title 60, Article 34, C.R.S. (1982). Three injection projects have been permitted within the specified area; however, these did not require aquifer exemptions, because the total dissolved solids (TDS) concentrations of the injection zone exceeded 10,000 milligrams per liter (mg/l). These three injection projects contain a total of three injection wells completed in the Parkman Sandstone.
Within the specified area the Parkman Sandstone lies between 2,600 - 4,700 fbgs.
Based on information available to the COGCC, within the specified area the TDS concentration of the Parkman Sandstone ranges from 11,078 mg/l to 24,400 mg/l with an average of 14,272 mg/l.
Hydrogeologic data including produced water quality and depths of the Parkman Sandstone and other COGCC data indicate that the ground water in these formations meets the criteria in Regulation 41 for classification as "Limited Use and Quality". The Commission, therefore, concluded that the application of the "Limited Use and Quality" classification to the ground water within the Parkman Sandstone in the specified area is appropriate. This classification and the application of site-specific standards for organic chemicals assure consistency between implementation of the UIC Program requirements and WQCC Standards and Classification.
Weld County (Figure 48) The ground water in the Upper Cretaceous aged Sussex Sandstone is co-produced with oil and gas and is considered a waste. Within the specified area, ground water in the Sussex Sandstone is not currently used nor can it reasonably be expected to be used in the future for domestic or agricultural purposes. The ground water is not in communication with any surface water bodies within the specified area so that the water quality standards of any classified surface water bodies are not affected by this ground water. More specific evidence of the limited use and quality of this ground water follows:
Within the specified area there are approximately 96 water wells permitted with the Office of the State Engineer. Division of Water Resources data indicates that there are no public water systems, or domestic, agricultural, or industrial water wells completed in the Sussex Sandstone within the specified area.
The Sussex Sandstone contains or has contained naturally occurring accumulations of crude oil and natural gas, in addition to ground water in many portions of this specified area. These oil and gas resources have been developed and produced since the 1970's.
Within the specified area approximately 180 oil and gas wells or tests have been drilled to or completed in the Sussex Sandstone.
Within the specified area the Colorado Oil and Gas Conservation Commission (COGCC) has not granted any aquifer exemptions for UIC projects under Rule 324(B) of the Rules and Regulations, Rules of Practice and Procedure (2 CCR 404-1), pursuant to the Colorado Oil and Gas Conservation Act, Title 60, Article 34, C.R.S. (1982). Two injection projects have been permitted within the specified area; however, these did not require aquifer exemptions, because the total dissolved solids (TDS) concentrations of the injection zone exceeded 10,000 milligrams per liter (mg/l). These two injection projects contain a total of three injection wells completed in the Sussex Sandstone.
Within the specified area the Sussex Sandstone lies between 4,300 - 4,850 fbgs.
Based on information available to the COGCC, within the specified area the TDS concentration of the Sussex Sandstone ranges from 12,645 mg/l to 21,862 mg/l with an average of 18,238 mg/l.
Hydrogeologic data including produced water quality and depths of the Sussex Sandstone and other COGCC data indicate that the ground water in these formations meets the criteria in Regulation 41 for classification as "Limited Use and Quality". The Commission, therefore, concluded that the application of the "Limited Use and Quality" classification to the ground water within the Sussex Sandstone in the specified area is appropriate. This classification and the application of site-specific standards for organic chemicals assure consistency between implementation of the UIC Program requirements and WQCC Standards and Classification.
Adams, Arapahoe, Morgan, Washington, and Weld Counties (Figures 49A, 49B, 49C) The ground water in the Lower Cretaceous aged D and J Sandstones is co-produced with oil and gas and is considered a waste. Within the specified areas, ground water in the D and J Sandstones is not currently used nor can it reasonably be expected to be used in the future for domestic or agricultural purposes. The ground water is not in communication with any surface water bodies within the specified areas so that the water quality standards of any classified surface water bodies are not affected by this ground water. More specific evidence of the limited use and quality of this ground water follows:
Within the specified areas there are approximately 333 water wells permitted with the Office of the State Engineer. Division of Water Resources data indicates that there are no public water systems, or domestic, agricultural, commercial, or industrial water wells completed in the D and J Sandstones within the specified areas.
The D and J Sandstones contain or have contained naturally occurring accumulations of crude oil and natural gas, in addition to ground water in many portions of these specified areas. These oil and gas resources have been developed and produced since the 1920's.
Within the specified areas, approximately 1,367 oil and gas wells or tests have been drilled to or completed in the D and J Sandstones.
Within the specified areas the Colorado Oil and Gas Conservation Commission (COGCC) has granted 25 aquifer exemptions for UIC projects under Rule 324(B) of the Rules and Regulations, Rules of Practice and Procedure (2 CCR 404-1), pursuant to the Colorado Oil and Gas Conservation Act, Title 60, Article 34, C.R.S. (1982). These 25 injection projects contain a total of approximately 108 injection wells; 41 injection wells are completed in the D Sandstone, 66 injection wells completed in the J Sandstone, and one injection well completed in the D and J Sandstones.
Additionally, 6 injection projects have been permitted within the specified areas; however, these did not require aquifer exemptions, because the total dissolved solids (TDS) concentrations of the injection zone exceeded 10,000 milligrams per liter (mg/l). These 6 injection projects contain a total of approximately 13 injection wells; 9 injection wells completed in the D Sandstone and 4 injection wells completed in the J Sandstone.
Within the specified areas the depth to the D and J Sandstones ranges from 3,795 fbgs in the Pod Field of Washington County to 7,415 fbgs in the Quill and Pollen Fields of Arapahoe County.
Based on information available to the COGCC, within the specified areas the TDS concentration of the D Sandstone ranges from 2,899 mg/l in the Little Beaver Field of Washington County to 18,972 mg/l in the Nile Field of Adams County. Additionally, within the specified areas the TDS concentration of the J Sandstone ranges from 1,026 mg/l in the Lindon Field of Washington County to 25,400 mg/l in the Pollen Field of Arapahoe County.
Hydrogeologic data including produced water quality and depths of the D and J Sandstones and other COGCC data indicate that the ground water in these formations meets the criteria in Regulation 41 for classification as "Limited Use and Quality" . The Commission, therefore, concluded that the application of the "Limited Use and Quality" classification to the ground water within the D and J Sandstones in the specified areas is appropriate. This classification and the application of site-specific standards for organic chemicals assure consistency between implementation of the UIC Program requirements and WQCC Standards and Classification.
Consistent with the "Limited Use and Quality" classification, the ground water quality standards in Tables 1 through 4 of the Basic Standards for Ground Water, 41.0 will not apply within the specified area. Additionally, the ground water organic chemical standards included in Table A of Section 41.5.C.3 of the Basic Standards for Ground Water (5 CCR 1002-41) for benzene, toluene, ethylbenzene, xylenes, and benzo(a)pyrene will not apply to certain oil and gas producing formations within the specified areas. However, to provide some protection of the potential future use of water resources in the specified area, the Commission's action provides that the statewide standard for radionuclides, as well as the statewide organic chemical standards (other than those for benzene, toluene, ethylbenzene, xylenes, and benzo(a) pyrene) will continue to apply to this ground water.
PARTIES TO THE RULEMAKING HEARING
5 CCR 1002-42.26