SUISUN CITY — Making room at Potrero Hills Landfill for more garbage involves more than just moving around some dirt and tossing in the trash.
Dirt did get moved to create the latest trash disposal area or cell – 450,000 cubic yards. But the project also involves putting down a polyethylene liner and installing drains to comply with environmental laws.
“Nothing leaks out,” said David Jappert of Waste Connections Inc., the company that owns the landfill. “It’s kind of like a bathtub.”
Potrero Hills Landfill takes garbage from Fairfield and Suisun City, as well as other counties such as Napa County. It is located a few miles southeast of Suisun City in the hills of Suisun Marsh.
The landfill over the years has grown in sections, or cells. It has a couple dozen cells and has room for a few more in the existing landfill footprint.
Preparing sections of the landfill with liner as needed makes more economic sense for Waste Connections than lining the entire landfill at once. The landfill has existed since 1986.
But this latest cell is different from the others. It is on the edge of the landfill. Workers moved that 450,000 cubic yards of dirt to create a berm along the landfill’s southern end. The berm is about 40 feet tall with a vertical slope of 80 feet. It is a quarter-mile long.
The berm and the flank of an existing landfill cell on the opposite side create a small canyon. As trash gets poured in, the canyon will turn into a hillside.
“It’s going to give us about two years of capacity,” Jappert said.
Jappert said the new cell should be finished this month and perhaps will begin taking in trash in September or October. It depends when the San Francisco Regional Water Quality Control Board approves the work.
A key part of construction happened this past week. Workers took rolls of black, high-density polyethylene liner that Jappert compared to rolls of paper towels. Then they unrolled the liner down the 80-foot-long vertical face of the berm.
The polyethylene liner gets protected by a geotextile material and topped by fine-grained sand. All of this is done to protect the polyethylene liner. Only then will the discarded items from daily life get poured on top, with a layer of the softer trash going first.
Visible from the new landfill cell is a valley covered by brush. This area is targeted for the future Potrero Hills Landfill expansion, beyond the footprint of the present-day landfill. That brushy valley is to allow the landfill to continue to operate once the present-day landfill has no more room for garbage.
Potrero Hills Landfill has worked for more than a decade to secure the expansion site, fending off several court challenges. Opponents said a bigger landfill could hurt environmentally sensitive Suisun Marsh and discourage recycling by making relatively cheap landfill space available to communities in other counties.
The state Court of Appeal in April took up the final legal case and decided in favor of the landfill expansion. Expansion opponents’ final legal hope is that the state Supreme Court agrees to review the case.
Garbage flow to the landfill has slowed with the recession. The state reports that Potrero Hills Landfill takes in about half of its annual capacity of 1 million tons to 1.4 million tons.
“It’s still about half, I would say,” Jappert said. “We’re not seeing a big upturn. We’re anticipating it, because the economy seems to be getting better.”
Solano County also sees more economic activity generating more trash. The 2014-15 county budget for the fiscal year that started July 1 calls for $1.2 million more in disposal fee revenue for county coffers, an increase from $2.7 million to $3.9 million.
As garbage continues to flow into Potrero Hills Landfill, the landfill will continue to make room for it – one cell at a time.
Reach Barry Eberling at 427-6929 or firstname.lastname@example.org. Follow him on Twitter at www.twitter.com/beberlingdr.