The U.S. Department of Energy (DOE) is issuing a National Environmental Policy Act of 1969 (NEPA) revised draft environmental assessment (EA). The revised draft EA evaluates the potential environmental impacts of closing the Nonradioactive Dangerous Waste Landfill and Solid Waste Landfill. The Washington State Department of Ecology (Ecology) is a cooperating agency on this revised draft EA. This revised draft EA assesses the impacts of the proposed action and alternative actions. The proposed action is to install a permanent engineered surface barrier (also referred to as a final, permanent cover) over these two landfills to protect human health and the environment and to meet Washington State regulatory requirements for closed landfills.  A 45-day public comment period for this EA will run from August 29 – October 13, 2011. DOE welcomes the public’s comments and suggestions.

Proposed Action and Alternatives
The proposed action is to close NRDWL and SWL by installing a final, permanent engineered surface barrier that would meet the state’s regulations in WAC 173-303. Final grade of the cover would be completed to blend in with the existing surroundings to the extent practical. The site would be re-vegetated with native plants consistent with the Hanford Biological Resource Management Plan (BRMaP).

DOE would monitor the performance of both landfills long term. Post-closure care would include:

• Maintaining the integrity of the final, permanent cover
• Conducting periodic inspections
• Implementing a state-approved, regulatory compliant groundwater monitoring program; including installing six new monitoring wells
• Preventing run-on and run-off
• Filing a record in the Notice of Deed that will include steps to implement institutional controls to mitigate future human intrusion

Through the natural processes of evaporation and transpiration, DOE expects the final, permanent cover to prevent more than 98% of the average annual precipitation from percolating into the underlying waste.

Please submit comments by October 13, 2011 to:

Kevin D. Leary
NEPA Document Manager
NRDWL/SWL EA
U.S. Department of Energy
P.O. Box 550, Mailstop A6-38
Richland, Washington 99352
Or email: NRDWLSWLEA@rl.gov

Fact Sheet

Environmental Assessment for Closure of the Nonradioactive Dangerous Waste Landfill (NRDWL) and Solid Waste Landfill (SWL)

Appendix

Fact Sheets

• Evapotranspiration Cover Systems for Waste Containment
• Alternative Landfill Cover Project Profiles

Supporting Documents

• NRDWL/SWL Closure/Postclosure Plan (DOE/RL-90-17 Rev. 2)
• Groundwater Monitoring Plan for NRDWL and SWL (DOE/RL-2010-28 Rev. 1)