City staff told the Brentwood Board of Commissioners that subsurface soils at Wendy Hill Park are too soft and mixed with topsoil to meet the compaction requirements built into the original trail specification, and recommended changing the trail material from asphalt to concrete.

The recommendation follows on-site testing and multiple conversations with Orion, the park contractor. Orion project manager Jason told the commission that asphalt options carried a high risk that newly laid pavement would settle or "wave" under the weight of construction equipment and that any such failures could require costly tear-out and rework after initial paving. "I will be back saying we're gonna like we're gonna need more money for x y z and I can't put a price tag on that," he said during the briefing.

Staff and the contractor presented four technical options: (1) build concrete trails (formwork, rebar/wire mesh and 4 inches of concrete over compacted base), which Orion said it could warranty for two years; (2) build a heavier, roadway-grade asphalt section (higher cost); (3) excavate deeper (18 inches), replace with stone and pave asphalt (no warranty offered by the contractor); and (4) an intermediate deeper stone option. After discussion, city staff recommended option 1 (concrete) because it offered the most certainty of a finished product with a two-year warranty.

The shift increases the project's cost. Staff said removing several nonessential trail spur segments would save about $123,000; however, the net additional expense for the concrete option was described in the briefing as a substantial change order (the contractor's tabled estimate for the concrete option in the discussion was in the neighborhood of $861,000 before contingency). Jason and staff discussed building details such as control joints, steel chairs for wire mesh and the use of rebar at joints to reduce buckling. Parks staff said they would widen a running offset (a gravel shoulder) to 3' or 4' to accommodate runners and maintain a softer surface option alongside the concrete.

Other project details discussed: the pre-purchased gazebo will be relocated within the park rather than discarded; staff identified three short trail segments proposed for removal (315 feet, 105 feet and about 200 feet) and said doing so would preserve the main loop and capture the stated savings; several portions of the planned parking lots and initial utility work are complete and would remain as shown; staff said a contingency of roughly $100,000 would be left in the project budget to cover remaining unknowns.

Next steps: staff asked the commission for informal permission to let Orion begin work to excavate and prepare areas under option 1 and said a formal written change order will be returned to the commission for approval at the Jan. 27 meeting. If the commission approves the change order, staff said trail construction would proceed under the revised scope and warranty terms.

Why it matters: The material choice affects project cost, long-term maintenance and usability by runners and park users; staff emphasized the tradeoff between a higher upfront cost with a warranty (concrete) and a lower initial cost with higher execution risk and uncertain future repair needs (asphalt).

Ending

A formal change-order document and staff recommendation will appear on the commission's Jan. 27 agenda; staff asked commissioners to note that cutting and base work could start shortly if the commission signals preliminary consent to proceed to preserve the construction schedule.