Council approves 46% change order to speed construction of new leachate pond at Horn Rapids landfill

The Richland City Council on June 17 approved Resolution 2025-95 authorizing Change Order No. 1 to the Phase 2A site-works contract for the Horn Rapids landfill expansion, adding excavation of a new leachate pond and related fence relocation.

City staff said the change order was driven by detection of a leak in the primary liner of the existing leachate pond and by a Department of Ecology recommendation to test the secondary liner as soon as possible. The work was added to the existing Phase 2A contract with Apollo Inc. to accelerate the pond construction and save about eight weeks compared with rebidding the work, staff said.

The city’s presentation said the excavation already completed at the site totals about 700,000 cubic yards, with roughly 300,000 cubic yards remaining. The proposed new pond will be about 7–9 feet deep and include aeration sprinklers to increase evaporation, staff said. City staff described the change order as a 46% increase over the current Phase 2A contract value and noted a standard 15% markup allowance for field change orders under the contract specifications.

Project consultant representatives told council that the primary liner leak was reported to the health district; staff have been pumping the interstitial sump between the liners and engaging Ecology. Ecology recommended a leak test of the secondary liner, which staff said can be most effectively completed once the existing pond is drained and its contents and connections are transferred to a new basin. Because the new pond’s design was completed earlier than the rest of Phase 2B’s liner work, staff sought a quote from Apollo to add excavation work to the active Phase 2A contract rather than wait for Phase 2B.

Council members asked how the secondary liner test is performed, environmental risk if a leak were confirmed, and how the city ensures value for money given the size of the change order. Staff explained that testing requires draining the pond and creating an electrical leak-detection circuit in the interstitial space; locating an actual breach typically requires drawing down the pond and cutting into liners. Staff said the currently observed leak is in the primary liner only and that the closed, older landfill cell has had higher nitrate levels historically but no documented off-site groundwater impacts. The presenter said Ecology’s recommendation was advisory, not a formal order with an immediate fine threat.

On financial oversight, staff said they reviewed Apollo’s equipment rates and methods and found them within industry standards; the primary cost differential between issuing a competitive bid vs. issuing a change order is the contractor markup. Council members expressed support for accelerating the work to reduce schedule and potential environmental risk. Council member Witten moved approval; the motion passed by unanimous voice vote.

Votes at a glance (items referenced on the agenda and acted on at the June 17 meeting): - Resolution 2025-95 — Authorize Change Order No. 1 to Phase 2A (Horn Rapids landfill expansion leachate pond excavation). Outcome: approved (unanimous voice vote). Yes: 5; No: 0; Abstain: 0; Absent/excused: Van Dyke, Kent. - Consent calendar items approved earlier by roll call (unanimous): Ordinance 2025-18 (first reading; minors and alcohol-related municipal code amendment) noted for first reading; Ordinance 2025-17 (second reading and passage; 2025 budget amendment to include 2024 carryovers) passed; Resolution 2025-93 (construction contract award to Apollo Inc. for Horn Rapids landfill Phase 2B) adopted as part of consent; Resolution 2025-94 (agreement with Visit Tri Cities for tourism promotion 2026–2030) adopted; Appointment of Casey Anderson to the Planning Commission approved; expenditures for 05/01/2025–05/31/2025 of $43,853,486.32 approved.

The council did not specify a dollar amount for Change Order No. 1 during the meeting beyond the percentage increase; staff said their review indicated the excavation cost would be similar whether included in Phase 2A or Phase 2B and that adding it to the active contract would save schedule time. Staff also described the later Phase 2B work (lining and piping) that will enable pumping existing pond contents into the new pond and complete leak-testing procedures.

The resolution requires the city to complete Phase 2B lining work before full transfer of leachate, and staff said follow-up work will include rerouting leachate piping and pumping while managing the ongoing inflow from the landfill cell. Council members asked for further historical detail on landfill financing and oversight, which staff said they would provide separately.