Aluminum air pipes

A network of pipes and blowers tames toxic gases under Cesar Chavez Park

The torch 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 lead their dogs or fly their kites in Cesar Chavez Historical Park may never even notice the small tower from the side. east of the park. Few would have reason to suspect that beneath this tower lies a vast 90-acre network of burners, blowers and miles of pipes built to control a constant flow of poisonous methane gas.

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

This industrial facility was built amidst controversy in 1989 after the city’s nearly three-decade-old municipal landfill was covered with earth and turned into a park. The small tower is a flare on the site of the old landfill, which contains around 1.6 million tonnes of garbage, mainly from households, which was dumped there between 1961 and 1983. Methane is the result of waste that have decomposed over the years. There are 42 landfill wells that extract methane gas in the park and another 10 just to the south, around the DoubleTree resort, two long trench shafts in each of the parking lots and four at the nautical complex.

To burn off the methane, the two flaring station fans extract gas from the landfill along 4,000 feet of vertical and horizontal extraction well pipes. The extracted gas then passes through approximately 8,000 feet of underground transfer piping from the wells to the flare. There it is burnt and cooled before the remains are released into the air through the tower.

Around 2003, SCS Engineers, an environmental company with which Berkeley contracted to maintain the site, found methane around the hotel. Tests revealed that the gas was not coming from the landfill but was naturally coming from the mud in the bay, and SCS added a series of 16 horizontal collectors around the resort in 2006.

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

Gas flow to the marina has dropped steadily over the years, from 400 to 500 cubic feet per minute to around 60 now, according to Art Jones, vice president and senior project manager at SCS Engineers. The original torch station, built in 1989, required a minimum gas flow rate to operate and it was this reduced flow rate that led to it being 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 flare station has its detractors.

John N. Roberts, a landscape architect, was one of a group of environmental activists who opposed the construction of the station in the first place. Although no methane leaks have been reported so far, Roberts is concerned about the station’s operation and maintains that a torch station incinerating garbage gas to release other greenhouse gases in the atmosphere must be studied. He also notes that the marina itself is vulnerable to sea level rise and earthquakes, and a solution must be found.

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

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

Cesar Chavez Park seen in mid-October 2021. Credit: Kelly Sullivan
People stroll through Cesar Chavez Park at Berkeley Marina in October 2021. Credit: Kelly Sullivan

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

Jones said it was not clear.

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

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