If ever a scheme needs a good euphemism, it’s the Beneficial Use of Digester Gas. Nevertheless, the plan passed its first smell test. The City presented it to the local planning board at its July 19, 2007 meeting, explaining the venture as another way for San Diego to capitalize on renewable energy. The undertaking calls for a private company to truck compressed methane gas from the wastewater plant at Point Loma to remote sites, where “ultra clean” fuel cells can burn the gas to produce electricity. One fuel cell will be located near the City’s South Bay Water Reclamation Plant, where the power can be used. Qualcomm Stadium, UCSD, and the San Diego Zoo have also been identified as potential users of the energy.
The Point Loma treatment plant uses an anaerobic digestion process to break down biodegradable material that’s removed from sewage before sending it out to sea. In the oxygen-free interior of digester tanks, microorganisms go to work on sludge. A by-product of the process is methane gas. Small portions of the gas are used in Caterpillar engines on-site to produce electricity to run the plant. But according to the City, “the plant generally produces between one to two million standard cubic feet…per day of excess digester gas, which is 63 percent methane. This excess gas is flared by [the plant] in low emission, temperature controlled, state of the art gas flares.” Flaring the methane produces a significant amount of greenhouse gas.
Instead, Linde Merchant Production, Inc., will lease approximately 31,000 square feet at the plant’s southern end. The company will build a facility where impurities can be removed from the methane, which can then be pumped into long cylinders and loaded onto trucks. From there, the trucks must first head south on Gatchell Road and negotiate a sharp switchback onto Cabrillo Road. They are then to enter the Cabrillo National Monument before joining Cabrillo Memorial Drive, which becomes Catalina Boulevard heading north. The trucks will turn right onto Canon Street and snake down the hill to Rosecrans Street. There they find a straight shot to Interstates 5 and 8. An alternate plan has the trucks turning from Catalina onto Chatsworth Boulevard to Lytton Street for an eventual left turn onto Rosecrans. There will be six round-trips a day.
The City will even make money from the private firm’s purchase of the gas. The plan, according to the City, will also lower the creation of carbon dioxide in “fossil fuel power plants by over 7000 tons per year.” It will produce 3.9 megawatts of renewable energy. The City’s goal is to install “50 kilowatts of renewable electricity generation by 2013.…”
Members of the Peninsula Community Planning Board were impressed. During the 2007 board meeting, Metropolitan Wastewater Department and Linde officials asked the planners to devote their facilities subcommittee to assisting “with issues of transport, routes, safety, etc.” The board chose Katheryn Rhodes, a civil engineer, to chair the subcommittee. In return, Wastewater promised to return periodically with Linde officials for updates and elaboration of the program. But within 12 days, and without an update, the digester-gas plan appeared as a “consent” item at a city council meeting. The consent agenda consists of routine items not requiring discussion. Citizens can request the council to discuss consent motions, and that’s what Rhodes did. On September 4, 2007, in a unanimous vote, the council authorized the City to carry out the plan.
I ask Rhodes, who no longer serves on the board, if she wanted to give the council information on the safety of trucking methane gas through residential neighborhoods. “No,” said Rhodes, who has often testified before the council on downtown earthquake issues. “I have no expertise in gas safety. I only wanted to hold Wastewater to their promise to keep us informed. After the council meeting, they did come back several times, and I have to say, they made a very sophisticated case. There were always numerous presenters. I left the safety issues to Mr. Gilhooly,” who is not a planning board member but was asked to join the subcommittee because of his background.
Jim Gilhooly, who is critical of the project, is a retired construction engineer with 40 years of experience at petroleum facilities and managing the building of several nuclear power plants. He also worked as head of quality control during construction of the San Onofre nuclear plant. His insistent questioning of presenters appears to have irritated some members of the Peninsula planning board. From conversations with several of them, I get the impression they think of him as a crank. They say the board unanimously supports the project. One of them told me, on condition of anonymity, that Gilhooly objects to every project that comes before the board.
But Gilhooly tells me he has objected only to Beneficial Use of Digester Gas and a plan by the Navy to truck heavy equipment through the peninsula for construction of new fuel tanks at the Naval Base Point Loma. “It’s very densely populated out here,” he says, “and these projects are 2 of 10 to 15 that are new or just beginning and, in the next few years, will cripple our traffic.”
To hear what the City is telling the public, I act as a private citizen and call Tom Asplaugh, a mechanical engineer at Wastewater. Asplaugh is the department’s point man for the gas-transport project. He tells me that the trucks will make their six trips per day in the middle of the night or early morning, before most drivers are on their way to work. The Peninsula planners helped ensure that the routes avoided schools.
What about the trucks? Asplaugh says the U.S. Department of Transportation has certified them as exceedingly safe, and they have a perfect track record. The cylinders that hold the gas, he says, are similar to those used currently by city buses. But when loaded to capacity, the trucks will weigh 38 tons. “No loads that heavy have ever been driven on Point Loma streets,” says Gilhooly, “not to mention six trips per day.”
Gilhooly found on Talbot Street and several other roads nearby a sign forbidding trucks over five tons, according to a standard “gross vehicle rated capacity.” At meetings of the planning board through this past April, he pressed gas-transport presenters to state the gross vehicle capacity of streets such as Catalina and Chatsworth. “They gave no answer,” he says. “When I asked them to name places where their trucks have operated safely, they cited major highways in Nevada. Well, Point Loma neighborhoods are quite a different matter.”
Cynthia Conger is a local real estate agent and former planning board member. She sides with Gilhooly. “I was representing a house on the market whose sewer backed up,” Conger tells me by phone. “Our pipes out here are so old, the water went into the house next door. So imagine what those trucks mean for our roads and the pipes underneath them. There’s no comparison of their effects on the open highway to what they’ll do here.”
The difference is the thick concrete that engineers use to build freeways versus the thinner and weaker asphalt of city streets, says Gilhooly. But the City says the trucks’ 18 wheels distribute the weight. “It doesn’t matter,” says Gilhooly. “Big garbage and other trucks already cause street vibrations that are breaking the pipes below.” He reminds me of a recent breakage at Rosecrans and Nimitz Boulevard. It caused a major tie-up of the intersection.
Let’s come back to safety. Suppose one of the tank trucks gets into an accident or hits a sinkhole on a Point Loma street. “Somebody at one of those meetings,” says Gilhooly, “stated that if a gas tube sprang a leak, the methane would go straight up in the air. Not at 2400 pounds per square inch it won’t. That’s the pressure the methane will be under in those tubes. Pressure in the city-bus tanks is only 2.5 pounds. At 2400, the gas is going in whatever direction the opening points. Someone close enough could be asphyxiated because the methane would suddenly suck all the oxygen out of the air. And if there’s a spark around, look out.
“Before the gas leaves the Point Loma treatment plant,” according to Gilhooly, “equipment will increase the purity of the methane from 63 to over 90 percent. So it’s basically natural gas. You remember what happened at a downtown hotel last year when that natural gas explosion occurred. With this project out here, the City doesn’t even have a disaster management plan. Remember, there are no hospitals in Point Loma. And they’ve got an exemption from having to do an environmental impact report. They say it’s because the gas transport is technically not ‘a project.’ ” (The ordinance that went before the city council said that “this activity is exempt from the California Environmental Quality Act…because [it] does not have the potential for causing a significant effect on the environment.”)
Gilhooly has been arguing that, instead of trucking methane out of Point Loma, fuel cells should be built at the treatment plant to send electricity out. Last year, he asked the Navy if it was interested in receiving power from the plant and showed me a reply letter he’d received from Captain M.D. Patton, commanding officer of Naval Base Point Loma. On April 2, 2008, Patton wrote: “I…noted your suggestion of in-situ development of methane reuse and fuel cell technology as an alternative to transportation of the methane to a secondary market. We have also looked into that idea, but the City has been unwilling to enter into a long-term agreement (10 years or more) that would make our necessary investment worthwhile.”
In its written report to the city council, the wastewater department said only that “due to a number of constraints, [the] renewable fuel can not be economically used at the [Point Loma treatment facility], the main reason being that the plant’s SDG&E power line is at its maximum rated export capacity.”
According to the City’s Tom Asplaugh, Beneficial Use of Digester Gas is about to enter the permitting process. Construction will start at the Point Loma Wastewater Treatment Plant in January 2010, and trucks will start transporting methane approximately a year later.