Floodplain and wetlands protection; environmental review determinations; availability, etc.: Shiprock, NM; Uranium Mill Tailings Site,

[Federal Register: September 25, 1998 (Volume 63, Number 186)]

[Notices]

[Page 51342-51343]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr25se98-48]

[[Page 51342]]

DEPARTMENT OF ENERGY

Grand Junction Office; Floodplain/Wetlands Statement of Findings for Site Characterization Activities at the Uranium Mill Tailings Site Located Near Shiprock, NM

AGENCY: Grand Junction Office, Department of Energy.

ACTION: Floodplain/wetlands statement of findings.

SUMMARY: This Floodplain/Wetlands Statement of Findings is prepared pursuant to Executive Orders 11990 and 11988 and 10 CFR Part 1022, Compliance with Floodplain/Wetlands Environmental Review Requirements. The U.S. Department of Energy (DOE) is proposing to conduct site characterization activities at the Uranium Mill Tailings Site near Shiprock, New Mexico. The purposes of the activities are to determine the extent of ground water contamination and to investigate flow patterns in the ground water system; this information will assist DOE in selecting a ground water remediation strategy for the site in accordance with 40 CFR 192, Health and Environmental Protection Standards for Uranium and Thorium Mill Tailings. Portions of the proposed field activities would occur on the 100-year floodplain of the San Juan River and in a nearby wetland. Approximately 18,000 square feet (0.4 acre) of the 100-year floodplain and approximately 120 square feet (0.003 acre) of the wetland area would be temporarily disturbed by these field activities. A floodplain/wetlands assessment was prepared that described the effects, alternatives, and measures designed to avoid or minimize potential harm to or within the affected floodplain/ wetlands. The assessment found that the proposed action would have minimal temporary or long-term impacts on the floodplain and associated wetland.

DATES: Written comments are due to the address below no later than October 13, 1998.

ADDRESSES: Written comments should be addressed to Audrey Berry, U.S. Department of Energy-Grand Junction Office, 2597 B3/4 Road, Grand Junction, Colorado; or transmitted electronically by E-mail via Internet to Audrey.Berry@gjpomail.doegjpo.com; or by facsimile at (970) 248-6040.

FOR FURTHER INFORMATION ON THIS PROPOSED ACTION, CONTACT: Don Metzler, Project Manager, U.S. Department of Energy, Grand Junction Office, 2597 B3/4 Road, Grand Junction, Colorado 81503, Telephone 1-970-248-7612 or 1-800-399-5618, E-mail Don.Metzler@ gjpomail. doegjpomail.doegjpo.com.

FOR FURTHER INFORMATION ON GENERAL DOE FLOODPLAIN/WETLANDS ENVIRONMENTAL REVIEW REQUIREMENTS, CONTACT: Carol M. Borgstrom, Director, Office of NEPA Policy and Assistance (EH-42), U.S. Department of Energy, 1000 Independence Avenue, SW, Washington, DC 20585, (202) 586-4600 or (800) 472-2756.

SUPPLEMENTARY INFORMATION:

Background

The Notice of Floodplain/Wetlands Involvement for the Shiprock site characterization activities was published in the Federal Register on June 23, 1998 (63 FR 34153). The Floodplain/Wetlands Assessment was completed in August 1998.

Project Description

The Shiprock site is located on the Navajo Nation in northwestern New Mexico, approximately 1 mile (1.6 kilometers) south of Shiprock, New Mexico, and about 30 miles (48 kilometers) west of Farmington, New Mexico. The proposed action would involve (1) installing monitoring wells to characterize ground water quality and other hydrologic properties, and (2) constructing a surface water distribution system consisting of a 30-foot-long, 4-foot-high, concrete intake structure on Bob Lee Wash; a connecting 6-inch diameter, 2,000-foot-long pipeline along the upper limit of the 100-year floodplain; and a 1- to 2-foot deep, gravel-filled infiltration trench underneath the last half of the pipeline. Most of the pipeline would be outside the wetlands, in higher-elevation areas. The intake structure would divert a portion of the flow in Bob Lee Wash into the pipeline and infiltration trench and increase ground water flow in the floodplain alluvial aquifer. The purpose of the surface water distribution system would be to flush ground water contaminants towards the San Juan River and decrease contaminant concentrations within the aquifer. Features of the surface water distribution system would be in place for two to three years. Because contaminated ground water is present in the floodplain alluvial aquifer, the monitoring wells and surface water distribution system must be located on the floodplain.

Alternatives

No alternative sites or actions exist for the proposed characterization activities; the only other alternative would be no action. Under a no action alternative, no impact to the floodplain or wetland would occur. The ground water contamination, however, would remain in place, and no additional characterization would be performed.

Floodplain and Wetland Effects

Installation of the monitoring wells, pipeline, and infiltration trench would directly affect approximately 18,000 square feet (0.4 acre) of floodplain. Present vegetation consists primarily of inland saltgrass (Distichlis spicata) and salt cedar (Tamarix ramosissima). The areas disturbed by installation activities would be more susceptible to wind and water erosion until vegetation became reestablished. None of the proposed characterization activities would be expected to affect lives, property, or any natural and beneficial floodplain values. In addition, the construction of an intake structure across Bob Lee Wash would directly affect approximately 120 square feet (0.003 acre) of wetland. This construction within a wetland would require regulation under Section 404 of the Clean Water Act. The U.S. Army, Corps of Engineers has been consulted and a Nationwide Permit will be required before construction begins.

Diversion of water from Bob Lee Wash through the intake structure and into the pipeline could potentially affect the downstream emergent wetland over time by reducing the amount of water supplied by the wash. Temporary displacement of birds, small mammals, and other wildlife in adjacent areas may occur during installation of the intake structure and the associated pipeline and trench. Wildlife use of the wetland would be expected to return shortly after construction work is complete. No threatened or endangered species would be affected.

Floodplain and Wetland Mitigation Measures

Potential adverse effects within floodplain and wetland areas would be mitigated by (1) installing monitoring wells only in higher- elevation areas (2) reseeding floodplain areas where vegetation has been disturbed as a result of characterization activities (3) avoiding wetland areas whenever possible by constructing most of the pipeline and all of the infiltration trench outside wetlands (4) diverting a minimal amount of flow from Bob Lee Wash (5) using access routes that are well outside wetlands, and (6) monitoring emergent wetland boundaries annually for the duration of the proposed activities to ensure wetlands are not permanently reduced. With the implementation of these mitigation measures, the proposed action would be protective of the 100-

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year floodplain and associated wetland at the Shiprock site and would conform to the Navajo Nation's floodplain protection standards.

Issued in Albuerque, N.M. on September 16, 1998. Constance L. Soden, Director, Environmental Protection Division, U.S. Department of Energy, Albuquerque Operations Office.

[FR Doc. 98-25688Filed9-24-98; 8:45 am]

BILLING CODE 6450-01-P