NOTICE OF SUBMITTAL FINAL DESIGN REPORT AND OPPORTUNITY FOR REVIEW ADA COUNTY LANDFILL NORTH RAVINE CELL STAGE 5 On behalf of the Ada County Board of Commissioners, Jacobs Engineering Group has submitted the Ada County Landfill North Ravine Cell Stage 5 Final Design Report to the Director of the Idaho Department of Environmental Quality (Department) for review of the proposed development of the Ada County Landfill North Ravine Cell, a municipal solid waste landfill facility. Copies of the report are available for inspection and copying in the following libraries: Boise Public Library 715 S. Capitol Blvd., Boise Garden City Library 6015 Glenwood Blvd., Garden City Ada County Community Library 5868 W. Hidden Springs Dr., Boise Library! at Collister 4724 W. State St. Boise The Stage 5 design includes a 30-acre landfill liner expansion and a new leachate evaporation pond within the landfill property boundaries. The 30-acre landfill liner design is consistent with the previously approved design for the entire 260-acre landfill approved in 2005. Therefore, the landfill cell design is subject to Administrative Review by the Department, as specified in Idaho Code, Section 39-7422. The design of the new leachate evaporation pond is consistent with the design and construction of the two existing leachate evaporation ponds at the Ada County Landfill. The Department has determined that the addition of a third leachate pond constitutes a Major Modification because it adds surface area and volume beyond those included in the original North Ravine Cell leachate pond cell design. A Major Modification requires the public review and approval process in accordance with Idaho Code Section 39-7419, as amended by House Bill 555 (2026). The public is invited to review the Ada County Landfill North Ravine Cell Stage 5 Project as it relates to the new leachate evaporation pond. The public comment period extends for 35 days from the date of the second publication of this notice. Comments or questions should be submitted by email to Ben Jarvis (ben.jarvis@deq.idaho.gov) or Rebecca Blankenau (rebecca.blankenau@deq.idaho.gov). All comments must be received by DEQ within the 35-day comment period. Additional information regarding the public comment period may be obtained from the Idaho Department of Environmental Quality Boise Regional Office at (208) 373-0550. The Final Design Report contains design plans and specifications prepared by a qualified professional engineer addressing the criteria specified in Idaho Code Section 39-7421 for design review of municipal solid waste landfill facilities. IPL0363518 Aug 10,17 2026