A vast canyon of buried garbage has been smoldering inside a landfill in the Santa Clarita Valley, inducing geysers of liquid waste onto the surface and noxious fumes into the air.

In the Inland Empire, several fires have broken out on the surface of another landfill. In the San Fernando Valley, an elementary school has occasionally canceled recess due to toxic gases emanating from rain-soaked, rotting garbage from a nearby landfill. And, in the San Francisco Bay Area, burrowing rodents may be digging into entombed trash at a landfill-turned-park, unloosing explosive levels of methane.

These are just a few of the treacherous episodes that have recently transpired at landfills in California, subjecting the state’s waste management industry to growing scrutiny by residents and regulators.

Landfill emissions — produced by decaying food, paper and other organic waste — are a major source of planet-warming greenhouse gases and harmful air pollution statewide. But mismanagement, aging equipment and inadequate oversight have worsened this pollution in recent years, according to environmental regulators and policy experts.

This week, the California Air Resources Board will vote on adopting a new slate of requirements to better identify and more quickly respond to methane leaks and disastrous underground fires at large landfills statewide.

The proposal calls for using satellites, drones and other new technologies to more comprehensively investigate methane leaks. It also would require landfill operators to take corrective action within a few days of finding methane leaks or detecting elevated temperatures within their pollution control systems.

In recent years, state regulators have pinpointed at least two landfills in Southern California experiencing “rare” underground landfill fires — largely uncontrollable disasters that have burned troves of buried garbage and released toxic fumes into the air. More recently, a new state satellite program has detected 17 methane plumes from nine landfills between July and October, potentially leaking the flammable gas into unwanted areas and contributing to climate change.

Proponents of the proposed rule say the added oversight could help reduce California’s second-largest source of methane, a potent greenhouse gas that warms the atmosphere much more than carbon dioxide. It could also bring relief to hundreds of thousands of people who live nearby landfills and may be exposed to toxic pollutants like hydrogen sulfide or benzene.

“Curbing methane emissions is a relatively quick and cost-effective way to reduce the greenhouse pollution that’s wreaking havoc with our climate,” said Bill Magavern, policy director at the Coalition for Clean Air. “But [we’ve] also been involved in updating and strengthening the rule because we’re seeing the community impacts of leaking landfills, particularly at places like Chiquita Canyon, where we have a landfill fire that is making people in the community sick.”

Nearly 200 landfills statewide would be subject to the proposed requirements — 48 are privately owned and 140 are government-owned.

Many landfill operators oppose the rule, saying the new requirements would saddle the industry with an untenable workload and millions of dollars each year in added costs. These costs could be passed on to residents, whose garbage fees have already risen significantly in recent years.

Sacramento County officials, who operate the Kiefer Landfill, said the proposed protocols were not feasible.

“As a public landfill, Kiefer cannot quickly adapt to regulatory shifts of this magnitude, and these increased costs would ultimately burden the community it serves,” Sacramento County officials wrote in a Nov. 10 letter to the state Air Resources Board.

The vast majority of landfills are already required to monitor for leaks and operate a gas collection system — a network of wells that extend deep into the layers of buried waste to capture and destroy methane.

A hot mess

Chiquita Canyon Landfill in Castaic has become the poster child for the issues plaguing California’s waste management system.

A blistering-hot chemical reaction began inside the landfill’s main canyon in May 2022, roasting garbage in a roughly 30-acre area.

Starting in April 2023, residents of Castaic and nearby Val Verde began to take notice. They called in thousands of odor complaints to the South Coast Air Quality Management District, with many citing headaches, nausea, nosebleeds and difficulty breathing.

Later that year, state regulators learned that the landfill’s temperatures had risen above 200 degrees, melting plastic pipes used to collect landfill gases. An air district inspector also witnessed geysers of liquid waste bursting onto the surface and white smoke venting from large cracks spreading across the reaction area.

Air sampling found elevated levels of lung-aggravating sulfur pollutants and cancer-causing benzene. Air samples in 2023 detected benzene concentrations more than eight times higher than the state’s short-term health limit at Hasley Canyon Park, which abuts Live Oak Elementary School, alarming local parents.

“I personally have transferred my children to different schools further away,” said Jennifer Elkins, a Val Verde resident whose children attended Live Oak. “I spend three hours a day driving my kids to and from school. The commute has been a sacrifice, but it’s also been well worth it, because I know my children are breathing cleaner air, and I have seen their health improve.”

The landfill, owned by Texas-based Waste Connections, installed new heat-resistant equipment to extract liquid waste in an attempt to reduce broiling temperatures. It also installed a large covering over the affected area to suppress odors. It permanently closed and ceased accepting waste this year.

Still, the reaction area has tripled in size and could consume the entire 160-acre canyon for many more years. During other underground landfill fires, elevated temperatures have persisted for more than a decade.

The issue is, once these broiling temperatures start consuming landfill waste, there’s little that landfill operators can do to snuff them out.

The fumes from Chiquita Canyon have pushed some longtime residents to consider moving. After more than 25 years in Val Verde, Abigail DeSesa is contemplating starting anew somewhere else.

“This is our life’s investment — our forever home that we were building for retirement and on the verge of paying off,” DeSesa said. “And we may have to start over.”

“I don’t know that I can outlast it,” DeSesa added.

Chiquita Canyon is not alone.

Earlier this year, the South Coast air district learned about another fiery chemical reaction brewing inside El Sobrante Landfill in Corona. In August, Waste Management, the landfill’s owner and operator, acknowledged there was a two-acre “area of concern” where landfill staff had observed temperatures climbing above 200 degrees. Riverside County inspectors also found several fires had ignited on the landfill’s surface in recent years, according to public records.

Environmental advocates fear that many more landfills may be on the precipice of these largely unmanageable disasters.

According to an analysis by California Communities Against Toxics, there are 18 landfills in California that have had prolonged heat signatures detected by NASA’s Fire Information for Resource Management System, an online tool using satellite instruments to detect fires and thermal anomalies.

At least 11 of these landfills requested and received permission from either federal or local environmental regulators to continue operating with higher temperatures than currently allowed, according to public records obtained by the environmental organization.

These regulatory exemptions are part of the problem, said Jane Williams, the group’s executive director.

“We have 11 landfills across California that have been granted waivers by the government to basically ‘hot rod’ the landfill,” Williams said. “We would really like EPA and state agencies to stop granting landfill waivers. It’s a permission slip to speed in a school zone.”

Under newly proposed revisions to state rules, operators must be more transparent in disclosing the temperatures in their gas collection systems. If operators detect elevated temperatures, they must take action to minimize the amount of oxygen in the landfill.

While these rule changes might be coming too late to fix the issues near Chiquita Canyon, locals hope it will help others who live in the orbit of the nearly 200 other large landfills in California that could be subject to these rules.

“While there’s still a fight here to try to address the concerns at Chiquita Canyon Landfill, we know that there’s an opportunity to really prevent this kind of disaster from happening anywhere else in our state,” said Assemblymember Pilar Schiavo.

Dangerous leaks

Meanwhile, many other landfills are releasing unsafe amounts of methane, an odorless gas produced by bacteria that break down organic waste.

These emissions present two critical issues.

First, methane is a powerful greenhouse gas — capable of warming the atmosphere 80 times more than the same amount of carbon dioxide over 20 years. Following California’s large dairy and livestock operations, landfills emit the second-most methane statewide.

Second, methane is the primary constituent in natural gas. It can ignite or explode at certain concentrations, presenting a serious safety risk in the event of uncontrolled releases. Several times over the last few years, regulators have detected potentially explosive concentrations in the air and shallow soil near several landfills.

Under current landfill regulations, operators are required to monitor for excessive methane leaks four times a year. Many operators hire contractors to walk across accessible portions of the landfill with a handheld leak-monitoring device, an approach that some environmental advocates say is unreliable.

In addition, some areas of the landfill are not screened for methane leaks if operators consider them to be unsafe to walk across, due to, for example, steep hills or ongoing construction activities.

“Landfills have to monitor surface emissions, but they do that in a very inefficient way, using outdated technology,” Magavern said.

Starting this past summer, California has partnered with the nonprofit organization Carbon Mapper to use satellites to detect methane leaks, and already has found 17 coming from landfills. In one case, researchers saw a large methane plume appear to emanate from Newby Island Landfill in San José and drift into a nearby residential neighborhood.

Although the state has notified these landfill operators, it currently cannot require them to repair leaks detected via satellite. That would change under the proposed amendments to the state’s landfill regulations. Operators would also have to use state-approved technology to routinely scan portions of their landfills they deem inaccessible.

The proposed amendments seek to prevent the most common causes of methane emissions. A series of surveys of landfill operators found 43% of leaks in recent years were caused by one or more of a facility’s gas collection wells being offline at the time.

The new rules would require that such wells can only be offline for up to five days at a time for repairs. Operators would also be required to install gas collection systems within six months of when garbage is first placed in a new part of a landfill — rather than the 18-month time frame currently allowed.

In addition, landfills would be forced to take actions to fix a leak within three days of detection, rather than 10 days. In theory, that should help reduce the risk of leaks from things like cracks in landfill covers (typically a layer of soil or plastic covering) and damaged components of gas collection systems — two other major sources of leaks that landfill operators have reported.

The amended landfill rules could collectively cost private companies and local governments $12 million annually.

Some say that’s well worth the cost.

A contingent of residents who live near Chiquita Canyon Landfill are flying to Sacramento to attend the state Air Resources Board meeting. They are expected to testify on how the fire and landfill emissions have unraveled the fabric of the semi-rural community.

Elkins, the Val Verde resident, appreciated the area’s natural beauty — picturesque hillsides, wildlife and opportunities for stargazing without bright city lights. However, now her family hardly spends any time outdoors due to the noxious odors.

Some of her neighbors have moved away, but Elkins and many other longtime locals cannot, no matter how they fear for their health and safety. “The homes are not selling,” she said. “Other homes sit vacant, and community members are paying two mortgages just to get away. And for many of us, it would be financial suicide to move away and start over somewhere new.”