Network of pipes and blowers tames toxic gas below Cesar Chavez Park

The flow of methane gas through the decomposing landfill beneath the park has dropped over the years, but it still requires continual maintenance.

The flare station on the east side of Cesar Chavez Park, October 2021. Credit: Kelly Sullivan

With stunning views of the Golden Gate Bridge, Alcatraz and the San Francisco skyline, few visitors who run their dogs or fly their kites at historic Cesar Chavez Park may never even notice the small tower at the east side of the park. Few would have reason to suspect that beneath that tower is a vast, 90-acre network of burners, blowers and miles of piping built to tame a constant flow of poisonous methane gas.

EDITOR’S NOTE: This is part of a series of stories about the Berkeley Marina written by UC Berkeley journalism graduate students in partnership with Berkeleyside.

This industrial installation was built amid controversy in 1989 after the city’s almost three-decade-old municipal dump was covered with earth and transformed into a park. The little tower is a flare station on the site of the former landfill, which holds an estimated 1.6 million tons of garbage, mostly from households, that was dumped there between 1961 and 1983. The methane gas is a result of trash that decomposed over the years. There are 42 landfill wells that extract the methane gas in the park and 10 others just to the south, around the DoubleTree Hotel complex, two long trench wells in each of the parking lots and four at the boat complex. 

To burn off the methane, the flare station’s two blowers pull the gas out of the landfill along 4,000 feet of vertical and horizontal extraction well piping. The extracted gas is then passed through approximately 8,000 feet of below-grade transfer piping from the wells to the flare. There, it is burned and cooled before the remnants are released into the air through the tower.  

Around 2003, SCS Engineers, an environmental firm Berkeley contracts with to maintain the site, found methane around the hotel. Tests revealed the gas wasn’t from the landfill but was naturally occurring from bay mud, and SCS added a series of 16 horizontal collectors around the hotel complex in 2006. 

A map of the gas control system below Cesar Chavez Park. Credit: SCS Engineers

The flow of gas at the marina has dropped steadily over the years, from 400-500 cubic feet per minute to around 60 now, according to Art Jones, vice president and senior project manager at SCS Engineers. The original flare station, built in 1989, required a minimum gas flow to operate and the reduced flow is what led it to be replaced by a smaller incinerator in 2016 at an initial cost of $721,000 and an annual monitoring and maintenance cost of $150,000.

The gas flare station has its critics. 

John N. Roberts, a landscape architect, was among a group of environmental activists who opposed building the station in the first place. Although no leakage of methane has been reported so far, Roberts raises concerns about the operations of the station and argues that a flare station incinerating gas from garbage to release other greenhouse gases into the atmosphere needs to be investigated. He also notes that the marina itself is vulnerable to rising sea levels and earthquakes, and a solution must be reached.

But Jones said the landfill’s effect on the environment would be worse without the work of his firm. 

 “Yes, there is an increase in the carbon dioxide,” Jones said, “because you’re burning the methane, but of the two greenhouse gases, carbon dioxide is almost 30 times less toxic than methane. Back in 1980, when the system was designed, landfills weren’t being designed to prevent greenhouse gases, but now we have to deal with this and be more environmentally friendly and responsible to burn before releasing it.” 

Cesar Chavez Park as seen in mid-October 2021. Credit: Kelly Sullivan
People take a stroll in Cesar Chavez Park at the Berkeley Marina in October 2021. Credit: Kelly Sullivan

With gas levels dropping, is it possible that the gas flow will one day drop to zero and the station that costs the city of Berkeley $150,000 a year will no longer be necessary?

Jones said it’s unclear. 

“We’re still learning,” he said. “We’re just looking at it in a different way now as opposed to just looking at public health and safety. We’re looking at our environmental responsibility.”


Iqra Salah is a student at the UC Berkeley Graduate School of Journalism, where she covers economic development.