California has become the newest battleground state in the fracking fight that is already being waged in states like Pennsylvania and New York. Why?

The short answer is the Monterey Shale. It’s a massive oil deposit that is trapped in the shale formations underneath Los Angeles and most of California’s Central Coast and Central Valley regions (as well as all of the sources of drinking water for the people living in those regions). It was considered too difficult to reach to be worth it until fracking technology came along.

The rush to exploit the Monterey Shale’s reserves has spurred three bills moving through the California state legislature that would halt all fracking in the Golden State until its impacts can be studied more fully, not unlike what has happened in New York and New Jersey. Unlike New Jersey’s ban, which expired in January, the California legislation would require further legislative action to lift. It also stipulates that fracking cannot be done close to valuable water sources, and that all chemicals used in the process must be disclosed.

Environmentalists oppose fracking because of the many dangers, known and unknown, that it poses to the environment and human health. Contamination of water supplies is the major concern, as is the amount of fresh water required by fracking operations, and the fact that injecting water and chemicals to fracture the ground is maybe not a great idea in earthquake-prone California.

Despite several studies suggesting toxic emissions from refineries are underestimated, the Environmental Protection Agency (EPA) continually failed to review and revise emissions factors for health and life-threatening pollutants.

Now, five environmental justice groups are suing the agency for failure to comply with the Clean Air Act. The groups, the Environmental Integrity Project, Air Alliance Houston, Texas Environmental Advocacy Services (TEJAS), Community In-power and Development Association, Inc. (CIDA), and Louisiana Bucket Brigade, assert that EPA failures are leading to undue health and safety risks for the Gulf Area population.

Under the Clean Air Act, the EPA Administrator is required to review and (if necessary) revise the emissions factors used to estimate emissions of carbon monoxide (CO), volatile organic compounds (VOCs), and oxides of nitrogen (NOx) from emission sources at least once every three years. However, according to the notice of intent preceding the lawsuit, “EPA has not reviewed emission factors for flares since 1991,” for wastewater treatment systems since 1998, and emission equations for tanks since 2006.

Said TEJAS executive director Juan Parras, “EPA needs to protect public health and the environment, and there are no excuses to further delay long overdue action to revise inaccurate emission factors consistent with scientific studies.”