Board approves modified permit conditions for Kernan yard after creek impacts, orders berm setback and noise steps

The Humboldt County Board of Supervisors on April 15 approved changes to the conditional use permit (CUP) for Kernan Construction’s Glendale rock-aggregate yard after staff found unpermitted grading and a berm within the streamside management area along Noisy Creek.

The board voted 4-1 to adopt modified permit conditions that include relocating portions of a berm away from the creek, restoring vegetation along the riparian edge and new noise-reduction measures for on-site operations. The action follows complaints that parts of the Northern Yard were regraded and a stormwater detention feature was created without prior permits.

The vote came after a lengthy hearing in which county planning staff described a sequence of complaints and site inspections going back to 2023. Planning Director John Ford told the board: “This is not a recommendation or consideration to at all remove the ability for Kernan to operate.” Ford said staff’s approach was to stop the unpermitted elements in the Northern Yard, bring the site back toward its originally approved footprint and add conditions to prevent future impacts.

County staff and the California Department of Fish and Wildlife (CDFW) recommended a 25-foot setback from the outer drip line of the riparian zone at Noisy Creek for any berm or new structures. CDFW field staff and biologists who inspected the site in January documented fish use and recommended revegetation with a planting palette to restore riparian function.

Kernan’s attorney, Brad Johnson, said the company considers the original CUP a long-standing vested right and pushed back on a broad revocation approach. Johnson said the company had operated on the site for more than two decades and that “there is no substantial evidence in the record that Kernan has operated in violation of the permit’s terms” regarding hours and crushing operations. He asked the board to rely on engineering and measured noise studies during its decision.

Applicant representatives and consultants presented engineering, noise and flooding analyses. Northpointe Consulting’s Praj White and Dr. Angie Dodd said long-term sound monitoring found the site met the permit’s 60 LDN (day–night average) threshold; Dodd added that spot dB(A) readings can be misleading and that the LDN/CNEL metric is the appropriate standard for land-use decisions. Kernan agreed to equip much of its yard equipment with quieter “white-noise” backup alarms (often called “quackers”) and to pursue enclosures or operational steps to reduce night-time shop noise.

Board members and neighbors disputed how much nighttime work had occurred. Supervisor Carla Madrone, who moved the set of amended conditions the board ultimately adopted, said the extended 24/7 activity in 2023 prompted many of the complaints and made the situation urgent for nearby residents. Supervisor Eileen Arroyo and others pressed staff and the applicant for measurable steps the company would take to limit noise and sediment delivery while retaining the site’s industrial operations.

The final conditions the board approved require, among other things, the relocation of portions of the berm out of the streamside management area to meet a 25-foot riparian setback where feasible; a revegetation plan coordinated with CDFW; clarification of allowable hours for rock-crushing and yard operations in the permit documents; and a requirement that equipment that is regularly stored or maintained in the yard be fitted with quieter backup alarms within a defined timeline. The applicant told the board it would complete many of those items and asked for time to retrofit equipment; the board specified deadlines and follow-up reporting to staff.

The decision preserves Kernan’s ability to operate the aggregate yard while adding formal, enforceable conditions to address sediment control, riparian protection and community noise. A 4-1 tally approved the motion; one supervisor opposed the package and expressed concern it did not go far enough to restrict overnight activity.

Neighbors and environmental reviewers will monitor implementation. Staff said future compliance work will include verifying the location of the property line, reviewing as-built grading plans, and monitoring revegetation and stormwater controls.

The board also directed staff to continue coordination with the Regional Water Quality Control Board and CDFW and to return to the board with follow-up reports on implementation progress and compliance.