Plans take shape for underground drainage system at San Mateo County Event Center

A concrete holding structure, pump station and diversion sewers are among the components of the underground flow equalization system, or UFES, built underneath the southeast corner of the Event Center parking lot. Access hatches, an emergency backup generator and an electrical building will be visible from the ground level, explained Deryk Daquigan, an engineering manager with the city’s Public Works Department, at the Planning Commission meeting to study the draft environmental impact report on the project.

To address resident concerns that have been raised since the UFES project was introduced, a self-cleaning mechanism and carbon odor scrubbers have been included in the plans to minimize the system’s odors and scheduled deliveries and a traffic management plan have also been considered to mitigate the project’s effects on traffic congestion near the site, noted Daquigan.

But for many residents living near the Event Center parking lot along Saratoga Drive where the UFES project is planned, pile driving and the installation of dewatering wells included in the project’s construction plans drew concerns about noise, the structural integrity of nearby homes and the project’s impact on neighbors’ quality of life. Kelly Moran, president of the Bay Meadows Neighborhood Alliance, was among several residents who asked city officials to consider using alternative construction methods creating less noise and vibration adjacent to a neighborhood already affected by the construction of grade separation projects along the Caltrain corridor.

Having found precedents set in the environmental impact report for the noise, vibration and hours of construction to be above the threshold that neighbors found acceptable, Moran hoped officials could consider restricting hours of construction and other construction methods that would be less disturbing to residents than those currently proposed.

“We know that having construction near our homes is going to be a pain,” she said, according to a video of the Planning Commission meeting. “But we don’t want damage in our homes and we don’t want our homes to be unliveable.”

As host to a wide array of events including academic tests and high-profile corporate events, Event Center staff have strived to be good neighbors and are also hoping to minimize the impact of construction noise and traffic during construction of the system, said Dana Stoehr, chief executive officer of the Event Center. With plans to work with county officials to understand the environmental impact report and its implications, Stoehr hoped to ensure the venue could continue to maintain its financial self-sufficiency while simultaneously being a good neighbor to nearby residents.

“We all need to work together to get to outcomes to develop a good clean water system throughout San Mateo, but minimize the impacts of one group over the other in the process of getting this done,” she said.

Planning Commission Chair Dianne Whitaker asked how as many as 206 vehicle trips could be estimated for the site during construction, which a consultant to the project said was the maximum expected traffic expected if the UFES and a diversion pipeline project to take shape nearby are going on simultaneously. Together, the two projects are expected to take 25 months to complete.

Commissioners asked whether more updated trip counts for nearby intersections could be considered in the drafting of the final environmental impact report of the project, which Daquigan said is expected to be released in late summer.

Whitaker and Commissioner Ellen Mallory also requested more information about how Pacifica and Seattle approached similar projects given the technical complexity and proximity of the project to residential neighborhoods.

Because officials received a consistent message from several residents asking for alternative construction methods, Whitaker also advocated for planners to take another look at the construction methods that could be used.

“I agree with the residents,” she said. “I think [those are] unacceptable impacts to those homes especially given the duration of this project.”

On March 26, the commission did not recommend modifications to the design and landscaping of a project to upgrade the wastewater treatment plant bordered by Detroit Drive, Joinville Road and Leslie Creeks. Due to the increasing cost of construction, officials proposed reductions in the size of an administrative building and the treatment structure that do not reduce the treatment capacity of the new facility. The administration building was moved to north of Detroit Drive in the plans so an existing compressed natural gas fueling facility would not have to be moved on the site, and the proposed pedestrian route around the facility is expected to remain the same. The City Council is set to review the modifications April 15.

Email info@cleanwaterprogramsanmateo.org or send mail to the Public Works Engineering PMO at San Mateo City Hall at 330 W. 20th Ave. to submit comments on the draft environmental impact report on the UFES project before May 7.

anna@smdailyjournal.com

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