As the California Energy Commission grapples with how state gas utilities can make more use of biogas\u2014a byproduct of landfills, animal farms, and sewage treatment plants\u2014the ghost of the notorious BKK landfill in the Los Angeles area still looms. \tThe Energy Commission\u2019s May 31 workshop on challenges in procuring biomethane comes almost 25 years after former state Sen. Tom Hayden in 1988 put a legislative end to sending landfill gas into natural gas pipelines. \tWhile the Energy Commission is developing technical information about the potential and economics of tapping biogas, the California Public Utilities Commission is setting health standards. The Utilities Commission is set to require monitoring and treatment to make sure contaminant levels do not pose an unacceptable health risk, much the same way that natural gas from wells is monitored and treated for contaminants and quality. \tHayden\u2019s legislation was in response to health concerns about the BKK landfill dating back 30 years in the quiet bedroom community of West Covina east of downtown Los Angeles. \tBKK accepted hazardous materials beginning in 1963 amid the larger flow of conventional solid waste from households and businesses. The California Department of Health Services estimates at least 3 million tons of predominantly liquid hazardous waste was buried at the site by 1984, when the landfill closed. \tBy that time, a developer had built and sold homes within 500 feet of the landfill and residents became concerned about what appeared to be a high incidence of infant deaths and low birth weights in the vicinity. \tStudies by environmental authorities, such as the South Coast Air Quality Management District, detected 35 volatile organic compounds in the air around the landfill, including indoors. One was the carcinogenic compound vinyl chloride, which also causes a variety of short-term health effects, including irregular heart beat and breathing difficulty. \tVinyl chloride vapor and other gases from the landfill were traveling through the soil and infiltrating into homes. More than 500 residents sued BKK and the housing developer, W & A Builders. They collected $43 million in a settlement in 1986. \tSome studies indicated there were a rash of infant deaths and low birth weights in the area, but a nine-year state investigation ruled it out. \tToday, in its quest to move to renewable energy, state energy agencies are pushing to tap gas from landfills up and down the state to feed conventional natural gas pipelines for use in power plants, businesses, and homes. \tAB 1900, enacted in 2012, would allow use of the gas as long as it meets health standards the CPUC is developing (Current, May 17, 2013). \tA report by the Office of Environmental Health Hazard Assessment and California Air Resources Board earlier this month listed 11 contaminants that commonly occur in landfill gas as key concerns. It recommended maximum concentration levels aimed at protecting health. \tWhen it comes to cancer, the standards seek to limit lifetime risk of the general population to one in a million and for workers in the gas industry to 30 in a million. \tThe contaminants include carcinogens and non-carcinogens. Carcinogens include not only vinyl chloride, but also arsenic, p-Dichlorobenzene, Ethylbenzene, and n-Nitroso-di-n-propylamine. Non-carcinogens include hydrogen sulfide\u2014which smells like rotten eggs and can cause nausea and fainting\u2014mercaptans\u2014which is added to natural gas to give it an odor so leaks can be detected\u2014toluene, Methacrolein, antimony, copper, and lead, a heavy metal that can cause learning disabilities. \tWhile these are the contaminants of chief concern, OEHHA noted that up to 300 contaminants have been detected in biogas, particularly from landfills. \tThe contaminants stem not only from permitted disposal of hazardous materials in landfills, such as BKK, but also the legacy of poor regulation in the past, as well as the breakdown of a wide variety of materials buried in landfills\u2014from plastics to metals.