Digging deeper

The construction project hit a hiccup because of rising steel prices, Gernand said. The City Council recently reduced the construction budget by $5.8 million by modifying the stone exterior, finishings and furniture.

"We're getting back to a working budget. The rest of the project from here on out should go as planned," he said.

Hiccup or not, construction must go on. On Monday, a new team of builders will begin setting up trailers on site and bringing in equipment. Each construction phase is done by different subcontractors hired by Pankow, which oversees the project.

Currently the future library is working in negative space - that is, what's been done so far has been removal of the old building and the ground beneath. From now on, the project will deal with putting in rather than taking away.

Field engineer Siggy Pfendler described the steps to prepare the smooth dirt walls now framing the giant hole.

"These are our temporary shoring walls," she said, pointing to the earthen walls laced with steel beams bounding the subterranean space.

"We had a 40-foot drill rig in here that went around the whole site drilling in the holes and the walls," she said. "[Then they] mixed cement with the soil, making a liquid solution they dropped poles into," Pfendler explained, describing the long beams that line the flat vertical surfaces.

"It was cool to watch them pick [the beams] up with the giant crane and then drop them right into the ground," she said with a laugh.

The giant hole is several stories deep and currently accessible by lightweight scaffolding descending into the earth. For the next phase, the new contractor will have to get many pieces of large equipment into the ground.

"Space is tight but that comes with an urban site," Gernand said. "Our biggest challenge with space was when doing demolition, when we had to modify power lines, but those were all agreements we had set up from last year."

Though San Mateo may not seem like an urban construction site compared to San Francisco, the challenges are the same, Gernand said. And as the library site is bounded on two sides by road and two sides by buildings, the contractors have to negotiate the space carefully.

The next step? Waterproofing the ground and walls so construction within can begin. A concrete slab will be laid at the bottom and the underground levels will be built into a parking garage. When construction reaches the ground level, the plaza entrance will be built as a cap to the garage and a steel building will be constructed on top.

Both the construction process and the finished library are using sustainable resources technology, creating the largest "green" library in northern California that will reduce energy costs by 20 percent.

"Green" measures will be used throughout the various phases of development, including using recycled materials when possible. Leadership in Energy and Environmental Design, a building rating system administered by the U.S. Green Building Council, will measure the project's environmental friendliness.

"We are shooting to be a LEED silver-certified project." Pfendler said. "[A project] accumulates points for doing things like using recycled materials, recycling a certain amount of waste and locally producing materials so they don't create pollution [while transported to the site]."

"We're also doing things like making sure there's plenty of daylight in the building to reduce energy consumption and creating efficient water usage, those sorts of things," she said.

The new library will be 90,000 square feet and is estimated to be complete in 2006. It will feature a bigger collection space, wider aisles and more accessible shelves and added meeting rooms. In addition there will be ample parking and many new study spaces.

In the meantime the San Mateo Public Library is temporarily housed at 1100 Park Place on the fourth floor. A thousand parking spaces are available on-site.

The new library is funded through a voter-approved $35 million bond, a $20 million state grant and $10 million in local fund-raising.