02-18410. Underground Injection Control Program Revision; Aquifer Exemption Determination for Portions of the Lance Formation Aquifer in Wyoming

AGENCY:

Environmental Protection Agency.

ACTION:

Final rule.

SUMMARY:

The State of Wyoming Department of Environmental Quality (WDEQ) has requested Environmental Protection Agency (EPA) approval of a revision to the State Underground Injection Control (UIC) Program, specifically that EPA approve an aquifer exemption from classification as an underground source of drinking water (USDW) for portions of the Lance Formation within the Powder River Basin in Johnson County, Wyoming.

Until August 2000, COGEMA Minerals was mining uranium from the Wasatch Formation under a UIC Class III in-situ leaching permit, issued by WDEQ. A previous Lance Formation aquifer exemption, approved by EPA in the Federal Register on March 26, 1999, allowed COGEMA to inject mining and mineral processing waste fluids from the Wasatch into the Lance Formation through two Class I Non-Hazardous deep injection wells permitted in 1997. COGEMA, after closing its mining operations, is extending its large-scale ground water restoration throughout the entire mined portion of the Wasatch Formation.

During the active mining process, the disposal capacity of the two existing Class I wells were adequate for the smaller scale restoration waste stream as COGEMA mined, then closed each Class III well field sequentially. However, now that COGEMA is restoring the entire mine site, large-scale restoration will produce a larger volume of waste fluid. WDEQ issued the final permit to COGEMA for the operation of two additional wells on November 3, 2000. However, COGEMA cannot inject any fluids into these wells until EPA approves this aquifer exemption.

Today's approval of this new aquifer exemption will allow COGEMA to use the newly permitted Class I injection wells to inject ground water restoration waste fluids from the Wasatch Formation into the Lance Formation. As a result of this increased disposal capacity, COGEMA will be able to restore the Wasatch ground water more quickly and pump and treat less ground water. The rate of pumping out of the Wasatch will prevent any negative impact to the adjacent portions of this USDW.

EPA published a notice of the aquifer exemption request and asked for comments from the public in the Federal Register on January 30, 2001. EPA did not receive comments and after careful review of the exemption request, EPA has determined that the designated portions of the Lance Formation meet the requirements for an aquifer exemption. EPA is approving this aquifer exemption as a revision of the Wyoming UIC program. This final rule contains a table listing approved aquifer exemption areas for Class I wells on Wyoming State lands within the Lance Formation approved since January 1, 1999.

DATES:

This rule shall become effective on August 21, 2002. In accordance with 40 CFR 23.7, this rule shall be considered promulgated for the purposes of judicial review at August 5, 2002.

FOR FURTHER INFORMATION CONTACT:

Valois Shea, US EPA Region 8, Mail Code 8P-W-GW, 999 18th Street, Suite 300, Denver, CO 80202; [phone].

SUPPLEMENTARY INFORMATION:

 

I. Regulated Entities

COGEMA Mining, Inc. is the only regulated entity affected by today's action. COGEMA will derive some economic benefit as a result of this approval because the accelerated restoration will reduce the volume of waste being disposed and close the site more quickly. There is no other impact on regulated entities.

II. Introduction

The Safe Drinking Water Act (SDWA) established the Underground Injection Control (UIC) Program, which protects underground sources of drinking water ^[1] (USDWs) from potential contamination from injection well practices. The UIC program regulations also provide for exempting aquifers from the definition of USDWs stated in 40 CFR 144.3. The UIC regulations, specifically 40 CFR 144.7 and 146.4, define and provide criteria for exempting aquifers.

On September 25, 2000, the EPA Regional Office in Denver, Colorado (Region 8) received a request from the Wyoming Department of Environmental Quality (WDEQ), dated September 9, 2000, submitted on behalf of COGEMA Mining, Inc. (COGEMA), for EPA to grant an aquifer exemption for the Lance Formation. This exemption surrounds two Class I ^[2] Non-Hazardous deep injection wells in Johnson County, WY. The exemption area includes two cylindrical volumes with centers in the wells COGEMA DW No. 2 and COGEMA DW No. 3 respectively, and a radius of 1320 feet. These volumes were determined to be required to protect adjacent portions of the USDW from contamination from the injection activity. Traditional algorithms were used to determine the minimum distance from the wells that would be affected by the injection of the restoration waste. Both wells are located in the Christensen Ranch, in Johnson County WY. The COGEMA DW No.2 is located at approximately 2,290 feet from the North line and 1130 feet from the East line SW1/4 SE1/4 NE1/4 of Section 7, Township 44 North, Range 76 West. The COGEMA DW No. 3 is located approximately 3300 feet from the North line and 1340 feet from the West line center of SW1/4 of Section 5, Township 44 North, Range 76 West. The upper boundary of the exemption is at 3800 feet below ground surface and the lower boundary is at 6500 feet below ground surface.

EPA has reviewed this aquifer exemption request and approves the request to exempt the designated portions of the Lance Formation from classification as a USDW. The technical review done by EPA included the verification of the volume of the Lance formation that would be affected by the waste. Part of this verification included determination that all contaminants injected in the wells would be precipitated out of solution, neutralized, diluted or adsorbed by the formation matrix within the volume of the exemption. The January 30, 2001 Federal Register document (66 FR 8234, January 30, 2001) contains a detailed discussion of the justification of this aquifer exemption approval. Today's approval exempts two cylindrical volumes with centers in the wells COGEMA DW No. 2 and COGEMA DW No. 3 respectively, and a radius of 1320 feet (approximately one square mile of the Lance Formation, at depths between approximately 3,800 to 6,500 feet below the surface). On March 26, 1999, EPA approved a similar exemption of an nearby portion of the Lance Formation for two other COGEMA Class I wells located within 2 miles of the Class I wells involved in today's final rule. EPA published a Request for Public Comment on a Substantial Modification to the Wyoming 1422 Underground Injection Control Program in the Federal Register on August 27, 1998 (63 FR 45810). EPA received no public comment and subsequently published approval of the aquifer exemption in the Federal Register on March 26, 1999 (64 FR 14799).

The procedures to follow for approval or disapproval of State program revisions in the UIC program are codified in 40 CFR 145.32 and described in UIC Guidance #34, Guidance for Review and Approval of State UIC Programs and Revisions to Approved State Programs. EPA UIC Guidance #34 also identifies criteria that EPA generally uses to determine whether or not a State program revision is substantial. The Lance Formation ground water contains less than 3,000 milligrams per liter total dissolved solids (TDS), and the aquifer exemption is associated with a Class I injection well permit. For these two reasons this aquifer exemption is a substantial revision of the Wyoming UIC program as approved under section 1422 of the Safe Drinking Water Act.

WDEQ determined that the Lance Formation in the exemption area is located at such a depth below the surface so as to make its use economically impractical as a possible source of drinking water. Previously, WDEQ's request for public participation in issuing the well permits focused on the poor quality of the water in the Lance formation to justify the exemption. Subsequent analysis of the water quality and geological data by EPA determined that this criterion was not adequate and was replaced with the * * * (2) It is situated at a depth or location which makes recovery of water for drinking water purposes economically or technologically impractical; * * * § 146.4(b)(2)). The depth of the Lance Formation in the exemption area is between approximately 3,800 to 6,500 feet below ground surface, based on its depth at the nearer of the two other COGEMA Class I Non-Hazardous deep injection wells. WDEQ issued a public notice in local newspapers, the Casper Star Tribune and the Johnson County Buffalo Bulletin on October 2, 2000 inviting public comment on its intent to issue a permit for the two new wells. The public comment period began October 2, 2000, and ended October 31, 2000, but WDEQ did not receive any public comments or requests for a public hearing.

On January 30, 2001, EPA published a notice in the Federal Register (66 FR 8234, January 30, 2001) requesting public comment on the aquifer exemption request by COGEMA, based on both the contamination (§ 146.4(b)(3)) and the location (§ 146.4(b)(2)) criteria.^[3] EPA did not receive comments or requests for a public hearing.

III. Background

Until August 2000, COGEMA operated the Christensen Ranch in-situ leaching uranium mine within the Wasatch Formation in Johnson and, Campbell Counties WY. The mining operation included five well fields operating under a UIC Class III ^[4] permit. The mining process contaminated ground water within the mined portions of the Wasatch Formation. To fulfill the mine permit closing requirements, COGEMA is engaging in large-scale ground water restoration throughout the entire mined portion of the Wasatch Formation.

COGEMA must conduct ground water restoration upon completion of mining activities to return the ground water affected by mining to baseline condition or to a condition consistent with its pre-mining or potential use. Once the ground water within the Wasatch is restored, the concentrations of contaminants in the ground water will be below drinking water standards. Complete restoration of the ground water quality within the mined-out areas of the Wasatch Formation will require a wastewater disposal capacity of 300 to 500 gallons per minute (gpm) over the next 4 to 6 years.

While mining was active, COGEMA used two Class I Non-Hazardous deep injection wells permitted in 1997 to inject mining, mineral process and ground water restoration waste fluids into the Lance Formation. Under the previously planned mining closure and aquifer restoration process, the disposal capacity of the two previously permitted Class I wells (and the volume of the previously granted aquifer exemption) would have been adequate for the long-term (18 years) restoration waste stream as COGEMA sequentially mined, then closed each Class III well field. However, now that COGEMA is restoring all areas of the mine site simultaneously, large-scale, accelerated restoration will produce a larger volume of waste fluids more quickly than the existing two Class I wells can inject it into the Lance Formation at the permitted injection rate.

Limiting the rate of the restoration process results in the generation of a bleed stream (discussed below) which constitutes an additional volume of waste fluids. Much of the mined portion of the Wasatch is on “standby” until either (a) the two new wells increase the disposal capacity, or (b) COGEMA sequentially restores each well field and completes the restoration process in other mined-out areas. In the standby areas, it is necessary to keep underground water flow directed into the mined portions until COGEMA can begin the restoration process there. Ground water flowing into the unrestored mined areas prevents contaminated water migration from the mined part of the aquifer outward into the surrounding high water quality areas of the Wasatch Formation. In order to allow underground water to flow into the standby areas, COGEMA must continuously pump ground water out of them. The term “bleed stream” refers to the ground water that COGEMA extracts for this purpose.^[5]

The injected wastewater consists of the bleed stream described above and fluids from the restoration of the Wasatch Formation. The injectate also includes yellow cake wash water from washing any residual uranium recovered during the restoration process, laboratory wastewater, reverse osmosis brine, and ground water sweep solutions.^[6] The bleed streams are non-hazardous, beneficiation ^[7] wastes exempt from regulation as hazardous waste under the Resource Conservation and Recovery Act as stipulated by the Bevill Amendment (40 CFR 261.4(b)(7).

Bringing the two new Class I wells on line to handle an increased volume of restoration waste water will increase the rate of the restoration process and will allow restoration to begin more immediately in the standby areas. These two new injection wells will decrease the time these mined areas will have to remain in standby mode, producing a continuous bleed stream. Use of the two new Class I injection wells will prevent the production of an additional 31 million gallons of bleed stream requiring disposal.^[8] The increased rate of restoration will allow COGEMA to complete the restoration of the Wasatch Formation two years sooner than without the two additional wells.

IV. Basis for Approval of the Aquifer Exemption

EPA approves the exemption of the designated portions of the Lance Formation because the formation meets the following criteria for exempted aquifers:

§ 146.4

Criteria for exempted aquifers

An aquifer or a portion thereof which meets the criteria for an “underground source of drinking water” in 146.3 may be determined under 40 CFR 144.8 [sic—should read 144.7(b)] to be an “exempted aquifer” if it meets the following criteria:

(a) It does not currently serve as a source for drinking water;

There are no drinking water wells, public or private, extracting water from the Lance Formation in the exemption area or within 30 miles of the exemption area.

(b) It cannot now and will not serve as a source of drinking water because:

* * * (2) It is situated at a depth or location which makes recovery of water for drinking water purposes economically or technologically impractical.^[9]

The depth of the Lance Formation within the aquifer exemption area ranges from 3,800 to 6,500 feet. The Powder River Basin is a deep syncline ^[10] and the aquifer exemption area occurs very near the center of the syncline, which is the deepest occurrence of the Lance Formation within this syncline. Retrieval of water from an aquifer at these depths is very expensive.

In addition to the great depth of the Lance Formation within the exemption area, it is also a low-yielding aquifer and does not produce a sufficient volume to supply drinking water to a public system. Verification that the Lance Formation is unable to provide a public drinking water system with a sufficient supply of water is presented by the towns of Midwest and Edgerton, WY, which depended on the Lance Formation for drinking water until 1997. These towns are located 30 miles southwest of the exemption area where the Lance Formation occurs near the surface at the western edge of the Powder River Basin. In 1997 these wells were abandoned because of low water productivity (40 gallons per minute (gpm) sustainable flow). At that time the towns of Midwest and Edgerton determined that piping in pre-treated water 50 miles from Casper, WY is more economically feasible than continuing operation of the drinking water wells completed in the Lance Formation, even at the relatively shallow depth of 1,500 to 2,000 feet. (The Wasatch formation is not present near these two towns.) Another factor in this decision was the expense of treatment that would be required to continue using the Lance wells as a public water supply (COGEMA, 1998).

Alternatively, the Wasatch Formation occurs 2,600 feet above the Lance Formation in the mining restoration area and provides a shallower, more prolific, better quality water supply source available for use in the area. Given this abundant, shallower supply of high quality ground water, EPA concludes that the deeper Lance Formation will never be required to provide drinking water in the area of the aquifer exemption. (Please note that the Wasatch is the same aquifer that COGEMA will restore to drinking water quality more quickly if these disposal wells are available to increase capacity for disposal of aquifer restoration waste fluids into the Lance Formation.)

As indicated before, neither the State of Wyoming nor EPA received comments or a request for a public hearing in response to several public notices including the January 31, 2001 notice published in the Federal Register (66 FR 8234) for this aquifer exemption.

V. Regulatory Impact/Administrative Requirements

A. Paperwork Reduction Act

This action does not impose an information collection burden under the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. This action does not establish new monitoring and reporting requirements. Reporting by this facility, involving the injection wells, is already required by the State UIC program and it is not affected by the approval of this exemption. The approval of this aquifer exemption does not impose any additional information collection burdens.

Burden means the total time, effort, or financial resources expended by persons to generate, maintain, retain, or disclose or provide information to or for a Federal agency. This includes the time needed to review instructions; develop, acquire, install, and utilize technology and systems for the purposes of collecting, validating, and verifying information; processing and maintaining information, and disclosing and providing information; adjust the existing ways to comply with any previously applicable instructions and requirements; train personnel to be able to respond to a collection of information; search data sources; complete and review the collection of information; and transmit or otherwise disclose the information.

An Agency may not conduct or sponsor, and a person is not required to respond to a collection of information unless it displays a currently valid OMB control number. The OMB control numbers for EPA's regulations are listed in 40 CFR part 9 and 48 CFR chapter 15.

B. National Technology Transfer and Advancement Act

Section 12(d) of the National Technology Transfer and Advancement Act of 1995 (NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272 note) directs EPA to use voluntary consensus standards in its regulatory activities unless to do so would be inconsistent with applicable law or otherwise impractical. Voluntary consensus standards are technical standards (e.g., material specifications, test methods, sampling procedures, business practice) that are developed or adopted by voluntary consensus standard bodies. The NTTAA directs EPA to provide Congress, through the Office of Management and Budget (OMB), explanations when EPA decides not to use available and applicable voluntary consensus standards.

This action does not involve technical standards. Therefore, EPA did not consider the use of any voluntary consensus standards.

C. Unfunded Mandates Reform Act

Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public Law 104-4, establishes requirements for Federal agencies to assess the effects of their regulatory actions on State, local, and Tribal governments and the private sector. Under section 202 of the UMRA, EPA generally must prepare a written statement, including a cost-benefit analysis, for proposed and final rules with “Federal mandates” that may result in expenditures to State, local, and Tribal governments, in the aggregate, or to the private sector, of $100 million or more in any one year. Before promulgating an EPA rule for which a written statement is needed, section 205 of the UMRA generally requires EPA to identify and consider a reasonable number of regulatory alternatives and adopt the least costly, most cost-effective or least burdensome alternative that achieves the objectives of the rule. The provisions of section 205 do not apply when they are inconsistent with applicable law. Moreover, section 205 allows EPA to adopt an alternative other than the least costly, most cost-effective or least burdensome alternative if the Administrator publishes with the final rule an explanation why that alternative was not adopted. Before EPA establishes any regulatory requirements that may significantly or uniquely affect small governments, including Tribal governments, it must have developed under section 203 of the UMRA a small government agency plan. The plan must provide for notifying potentially affected small governments, enabling officials of affected small governments to have meaningful and timely input in the development of EPA regulatory proposals with significant Federal intergovernmental mandates, and informing, educating, and advising small governments on compliance with the regulatory requirements.

Today's rule contains no Federal mandates (under the regulatory provision of Title II of the UMRA), for State, local or Tribal governments, or the private sector. This rule imposes no enforceable duty on any State, local or Tribal governments or the private sector. This final rule merely approves the exemption of a portion of the Lance aquifer from the definition of a USDW. Thus, today's rule is not subject to the requirements of sections 202 and 205 of the UMRA. For the same reasons, EPA has also determined that this rule contains no regulatory requirements that might significantly or uniquely affect small governments.

Thus, today's rule is not subject to the requirements of section 203 of UMRA.

D. Regulatory Flexibility Act (RFA), as amended by the Small Business Regulatory Enforcement Fairness Act of 1996 (SBREFA), 5 U.S.C. 601 et seq.

The RFA generally requires an agency to prepare a regulatory flexibility analysis of any rule subject to notice and comment rulemaking requirements under the Administrative Procedure Act or any other statute unless the agency certifies that the rule will not have a significant economic impact on a substantial number of small entities. Small entities include small businesses, small organizations, and small governmental jurisdictions.

For purposes of assessing the impacts of today's rule on small entities, we defined small entities as (1) a small business based on Small Business Administration (SBA) size standards; (2) a small governmental jurisdiction that is a government of a city, county, town, school district or special district with a population less than 50,000; and (3) a small organization that is any not-for-profit enterprise which is independently owned and operated and is not dominant in its field.

After considering the economic impacts of today's final rule on small entities, I certify that this action will not have a significant economic impact on a substantial number of small entities. This final rule will not impose any requirements on any small entities. Further, EPA received information with the exemption request and confirmed that there are no entities of any size currently using the Lance Formation as a source of drinking water within 30 miles of the aquifer exemption area.

E. Executive Order 13175 (Consultation and Coordination with Indian Tribal Governments)

Executive Order 13175, entitled “Consultation and Coordination with Indian Tribal Governments” (65 FR 67249, November 6, 2000), requires EPA to develop an accountable process to ensure “meaningful and timely input by Tribal officials in the development of regulatory policies that have Tribal implications.” “Policies that have Tribal implications” is defined in the Executive Order to include regulations that have “substantial direct effects on one or more Indian tribes, on the relationship between the Federal government and the Indian tribes, or on the distribution of power and responsibilities between the Federal government and Indian tribes.”

This final rule does not have Tribal implications. It will not have substantial direct effects on Tribal governments, on the relationship between the Federal government and Indian tribes, or on the distribution of power and responsibilities between the Federal government and Indian tribes, as specified in Executive Order 13175. This rule does not apply to any Tribal government and there are no Tribal jurisdictions on or near the area of this aquifer exemption. Thus, Executive Order 13175 does not apply to this rule.

F. Executive Order 12866: Regulatory Planning and Review

Under Executive Order 12866 (58 FR 51735, October 4, 1993), the Agency must determine whether the regulatory action is “significant” and therefore subject to OMB review and the requirements of the Executive Order. The Order defines “significant regulatory action” as one that is likely to result in a rule that may:

(1) Have an annual effect on the economy of $100 million or more or adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, public health or safety, or State, local, or Tribal governments or communities;

(2) Create a serious inconsistency or otherwise interfere with an action taken or planned by another agency;

(3) Materially alter the budgetary impact of entitlements, grants, user fees, or loan programs or the rights and obligations of recipients thereof; or

(4) Raise novel legal or policy issues arising out of legal mandates, the President's priorities, or the principles set forth in the Executive Order.

It has been determined that this rule is not a “significant regulatory action” under the terms of Executive Order 12866 and is therefore not subject to OMB review.

G. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks

Executive Order 13045 (62 FR 19885, April 23, 1997) applies to any rule that: (1) is determined to be “economically significant” as defined under Executive Order 12866, and (2) concerns an environmental health or safety risk that EPA has reason to believe may have a disproportionate effect on children. If the regulatory action meets both criteria, the Agency must evaluate the environmental health or safety effects of the planned rule on children, and explain why the planned regulation is preferable to other potentially effective and reasonably feasible alternatives considered by the Agency.

This final rule is not subject to Executive Order 13054 because it is not “economically significant” as defined in Executive Order 12866. Further, it does not concern an environmental health or safety risk that EPA has reason to believe may have a disproportionate effect on children.

H. Executive Order 13132 (Federalism)

Executive Order 13132, entitled “Federalism” (64 FR 43255, August 10, 1999), requires EPA to develop an accountable process to ensure “meaningful and timely input by State and local officials in the development of regulatory policies that have federalism implications.” “Policies that have federalism implications” is defined in the Executive Order to include regulations that have “substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.”

This final rule does not have federalism implications. It will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132. This final rule does not have any substantial direct effect on the State of Wyoming or local governments in the State of Wyoming, on the relationship between the national government and the State of Wyoming or local governments in the State of Wyoming, or on the distribution of power and responsibilities among the various levels of government. Thus, Executive Order 13132 does not apply to this rule.

I. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small Business Regulatory Enforcement Fairness Act of 1996, generally provides that before a rule may take effect, the agency promulgating the rule must submit a rule report, which includes a copy of the rule, to each House of the Congress and to the Comptroller General of the United States. EPA will submit a report containing this rule and other required information to the U.S. Senate, the U.S. House of Representatives, and the Comptroller General of the United States prior to publication of the rule in the Federal Register. A major rule cannot take effect until 60 days after it is published in the Federal Register. This action is not a “major rule” as defined by 5 U.S.C. 804(2). This rule will be effective on August 21, 2002.

J. Executive Order 13211 (Energy Effects)

This rule is not subject to Executive Order 13211, “Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use” (66 FR 28355, May 22, 2001) because it is not a significant regulatory action under Executive Order 12866.

VI. References

USEPA 1998. Underground Injection Control Program: Substantial Modification to an Existing State-Administered Underground Injection Control Program, 63 FR 45810, August 27, 1998.

USEPA 1999. Underground Injection Control Program Revision; Aquifer Exemption Determination for Portions of the Lance Formation Aquifer in Wyoming; Final Rule. 64 FR 14799, March 26, 1999.

USEPA 2001. Underground Injection Control Program: Substantial Modification to an Existing State-Administered Underground Injection Control Program. 66 FR 8234, January 30, 2001.

COGEMA Mining, Inc. 1998(b). “Submittal of Supplemental Technical Document in Support of Lance Formation Aquifer Exemption; Application for Modification of Class I UIC permit No. 95-241,” Apr 17, 1998, COGEMA Mining, Inc., 935 Pendell Boulevard, P.O. Box 730, Mills, WY 82644.

“Approval of Programs and Revisions to Approved State Programs, GWPB Guidance #34,” July 9, 1984, US Environmental Protection Agency, Washington, DC.

WDEQ 2000, “Public Notice of Draft Permit 00-340,” Oct 2, 2000, Casper Star Tribune, Casper, WY.

WDEQ 2000, “Public Notice of Draft Permit 00-340,” Oct 2, 2000, Buffalo Bulletin, Johnson County, WY.

List of Subjects in 40 CFR Part 147

• Environmental protection
• Indians—lands
• Intergovernmental relations
• Reporting and recordkeeping requirements
• Water supply

Dated: July 12, 2002.

Christine Todd Whitman,

Administrator.

For the reasons set out in the preamble, 40 CFR part 147 is amended as follows:

PART 147—[AMENDED]

1. The authority citation for part 147 continues to read as follows:

Authority: 42 U.S.C. 300h; and 42 U.S.C. 6901 et seq.

Subpart ZZ—Wyoming

2. Section 147.2555 is amended by revising the table heading and adding an entry to the table to read as follows:

§ 147.2555

Aquifer exemptions since January 1, 1999.

* * * * *

Aquifer Exemptions Since January 1, 1999

Formation	Approximate depth (feet below ground surface)	Location
Lance Formation at indicated depths and locations	3,800—6,500	Two cylindrical volumes with centers in the wells COGEMA DW No. 2 and COGEMA DW No. 3 respectively, and radius of 1320 feet. Both wells are located in the Christensen Ranch, in Johnson County WY. The COGEMA DW No. 2 is located at approximately 2,290 feet from the North line and 1130 feet from the East line SW1/4 SE1/4 NE1/4 of Section 7, Township 44 North, Range 76 West. The COGEMA DW No. 3 is located approximately 3300 feet from the North line and 1340 feet from the West line center of SW1/4 of Section 5, Township 44 North, Range 76 West.
*         *         *         *         *         *         *

Footnotes

1.  An underground source of drinking water (USDW) means an aquifer or its portion: (a)(1) which supplies any public water system; or (2) which contains a sufficient quantity of ground water to supply a public water system; and (i) currently supplies drinking water for human consumption; or (ii) contains fewer than 10,000 milligrams/liter total dissolved solids; and (b) which is not an exempted aquifer.

2.  Injection wells are divided into 5 classes. Class I wells are associated with the disposal of industrial, municipal or radioactive waste into formations below the lowermost underground source of drinking water (USDW). These wells have strict standards for siting, construction and operation.

3.  Final decision to grant the exemption only under the location criterion did not occur until after this notice was published in the Federal Register.

4.  Class III wells are associated with the extraction of minerals, such as uranium, salts and sulfur, by in-situ mining.

5.  The mined volume acts like a vessel, which the “bleed stream” is continually emptying. This makes water drain into the vessel, preventing any contaminated water from flowing outside the mined area.

6.  To restore the Wasatch Formation, COGEMA must pump ground water from the mined portion and treat it by reverse osmosis. The reverse osmosis process cleans most of the water, but also generates a large volume of concentrated brine that COGEMA must inject into the Class I wells. Pumping the ground water out draws clean ground water into the mined area from surrounding areas in the Wasatch Formation and from injection wells used for injecting the previously extracted and treated ground water. This process causes the ground water to “sweep” through and clean the mined area. Eventually this process will restore the water in the formation to a pre-determined baseline quality.

7.  For a list of the processes included under beneficiation, please see 40 CFR 261.4(b)(7).

8.  This volume is the amount of additional bleed off fluids that would have to be disposed in the two years that this action would save.

9.  Originally the State had requested the exemption under a different criterion. Analysis of the request indicated that the stated criterion is more relevant.

10.  A syncline is a geologic structure in which earth's compressional forces deformed originally flat-lying rock strata into a large U-shaped fold where the center of the fold is deeper than the edges.