The repairs were meant to resolve, at least for now, areas of deteriorating runway pavement identified by federal aviation officials in January, as well as safety concerns that have been raised by the airport’s own operations specialists for more than a year.|
EMMA MURPHY AND MARTIN ESPINOZA
THE PRESS DEMOCRAT
After months of planning, construction crews and engineers on Tuesday executed what some officials described as a “surgical” operation to repair deteriorating sections of the main runway at Charles M. Schulz-Sonoma County Airport.
The repairs were meant to resolve, at least for now, areas of deteriorating runway pavement identified by federal aviation officials in January, as well as safety concerns that have been raised by the airport’s own operations specialists for more than a year.
The work, which began Monday at 11 p.m., forced the closure of Runway 14/32, which is the main airstrip used by commercial air traffic. Throughout Tuesday, commercial flights used the airport’s shorter, alternate runway.
The extensive repairs included replacing a failing World War II-era culvert underneath the northern end of the runway and a concrete-encased electrical conduit on the southern end that had caused pavement to sink around it.
The work, scheduled to conclude at 7 p.m. Tuesday, capped a frantic month of repairs on the runway, including three rounds of emergency patchwork that also required the runway to close for shorter periods.
By Tuesday morning, most of the 84-year-old culvert had been replaced.
“It was fast. It was like watching an orchestra,” said Johannes Hoevertsz, director of the county’s Department of Public Infrastructure, which oversees the airport.
The corrugated metal storm drain — buried 13 feet under the runway — was long past its life span.
Nearly a month before the scheduled work, several sinkholes appeared on the runway pavement above the failing storm drain, forcing airport officials to order overnight emergency repairs three times in a six-day period.
Inspections showed parts of the decades-old culvert had corroded and buckled, causing the metal pipe to sink and destabilize the earth above it. That deterioration caused voids to appear below two layers of runway pavement in a stretch of the runway where commercial and general aviation flights touch down.
In January, the Federal Aviation Administration ordered county officials to repair the culvert following the federal agency’s annual inspection of the airport. In March the airport announced plans to complete the work in June and described officials’ efforts as “proactive.”
But some airport operations and safety employees have been raising concerns about the condition of the runway as far back as late 2022, a Press Democrat Investigation found in April.
The repairs on the two sections of the main runway were expected to take 20 hours. Representatives of Alaska, American and Avelo said Monday and Tuesday they expected no impact on their flight schedules.
“Our crew used another available runway for operations departing and arriving STS to avoid impacts to our flight operations,” Madison Jones, communications manager for Avelo Airlines wrote in an email.
“Avelo is working closely with the airport to continuously monitor field conditions,” she said.
On Tuesday morning, the day’s first commercial flights were departing from the alternative runway at about 7 a.m. The heavy construction equipment and crews on the main runway were visible to passengers as the planes lifted off.
The first arrivals were about two hours later. By that time, crews were tamping down the soil over the new culvert.
Hoevertsz said the repair work went off quickly and without any problems.
The work kicked off Monday night with a management/contractor meeting at 9 p.m., he said. Excavation started at 11 p.m. and by 2 a.m. workers had dug down to 13 feet and started pulling out the old culvert.
By 3:30 a.m. the culvert had been completely removed. By 4:30 a.m., crews were back filling soil. Hoevertsz said he noticed no voids or cavities in the earth during the work.
Voids that formed from rusted and sinking sections of the culvert had been responsible for pockets of empty space forming just under the runway. Those voids caused potholes to form in late May and earlier this month.
At the southern end of the Runway 14/32, crews milled or ground down a section of sinking pavement where an underground electrical conduit traverses the runway. The uneven pavement resulted in standing water during periods of heavy rain.
Monday and Tuesday’s repairs, estimated to cost $667,115, address areas of the runway impacted by the culvert and conduit.
Most of the runway, however, has not been repaved since 2001.
A major repaving job, estimated at $42 million, is at least four years off, officials say.
Editor’s Note: This story has been revised from a previous version to correct a list of the airport’s commercial carriers. They are Alaska Airlines, Avelo Airlines and American Airlines.
You can reach Staff Writer Emma Murphy at 707-521-5228 or emma.murphy@pressdemocrat.com. On Twitter @MurphReports.
You can reach Staff Writer Martin Espinoza at 707-521-5213 or martin.espinoza@pressdemocrat.com. On Twitter @pressreno.