Gas Leak Lawsuit Settlements, Charges, and Penalties

A gas leak lawsuit is a civil action brought by residents, property owners, or workers against a utility or facility operator whose escaped natural gas caused health harm, property damage, forced relocation, or, in some cases, an explosion. Recent U.S. cases show what these suits can produce: SoCalGas and Sempra Energy agreed to pay up to $1.8 billion to roughly 35,000 plaintiffs after the 2015 Aliso Canyon blowout, the Los Angeles Department of Water and Power settled a Sun Valley methane case for nearly $60 million, and CPS Energy in San Antonio is now facing multiple suits after twin house explosions in April 2026.¹²

Who Has Standing to Sue

The plaintiffs in these cases have generally been people who lived, worked, or owned property near the leak. Proximity drives eligibility, and it also drives how much a claimant recovers.

In the Southern California Gas Leak Cases (JCCP 4861), more than 380 lawsuits were consolidated in Los Angeles Superior Court on behalf of approximately 48,000 people who alleged health effects from the Aliso Canyon blowout, and a separate property class covered no fewer than 23,000 properties within a five-mile radius of the well.¹³ Symptoms residents reported included headaches, nausea, nosebleeds, respiratory irritation, and dizziness, along with oily mists on cars and playgrounds. The Los Angeles County Department of Public Health directed the temporary relocation of more than 8,000 households during the four-month leak.⁴

The Sun Valley case involved roughly 1,200 plaintiffs from the Sun Valley and Pacoima neighborhoods near the LADWP Valley Generating Station, where compressors leaked methane continuously between 2015 and 2020 without public notification for 1,699 days. Residents reported nausea, dizziness, headaches, and rashes.⁵²

In the San Antonio explosions on April 21, 2026, two homes on Preston Hollow Drive were destroyed, five residents and one CPS Energy employee were seriously injured, and both destroyed households have filed suit.⁶

Common Legal Theories

Plaintiffs in these gas leak cases have pursued a mix of personal injury, property damage, negligence, and gross negligence claims. The specific allegations track what the operator did or failed to do.

In the Sun Valley case, a judge found that LADWP failed to perform adequate equipment inspections and did not notify the surrounding community about the leak.²

In San Antonio, two separate lawsuits target CPS Energy. Survivors Mayte Terrie Reeves and Jose Ochoa filed suit in Bexar County’s 131st Civil District Court on May 5, 2026, alleging gross negligence and claiming CPS Energy personnel falsely told them it was safe to return home after the first explosion. Each is seeking $1 million.⁷ The Nowell family filed the next day, alleging CPS Energy failed to inspect, maintain, and repair aging gas infrastructure and adopted a “reactive, wait-and-see approach” to known leaks, seeking more than $1 million for medical expenses, pain and suffering, lost income, and exemplary damages.⁸

The pattern across all three matters: failure to inspect, failure to warn, failure to shut down quickly. NTSB findings in San Antonio show a CPS Energy worker identified a gas leak in a service line at 6:50 p.m., about 46 minutes after the first explosion, but the second home exploded at 8:25 p.m. with people inside. CPS Energy did not isolate and plug the leak until 1:40 a.m. the following morning.⁶

How Damages Are Calculated and Paid

Mass gas leak cases usually run through a claims administrator who applies a formal allocation system rather than paying each plaintiff the same amount. BrownGreer PLC served as claims processor for the Aliso Canyon personal injury settlement, administering a points-based system. Base points were assigned according to a claimant’s residential or workplace proximity to the leak, with adjustments for age, health conditions, medical treatment received, whether the person relocated, economic losses, and other factors.⁹

The Aliso Canyon deal was contingent on roughly 97 percent of plaintiffs accepting the terms; if fewer agreed, the $1.8 billion total could be reduced.³ BrownGreer also administered a $40 million property settlement program for the property class, which a Los Angeles Superior Court judge approved in April 2022.¹⁰

In the Sun Valley matter, the City of Los Angeles agreed to a $59,892,000 payout, and a judge will determine how the money is distributed among the roughly 1,200 plaintiffs.²

SoCalGas recorded an after-tax charge of approximately $1.1 billion in September 2021 to cover its civil settlements and stated the costs would not be passed on to ratepayers.³

Discovery Problems and Sanctions

Winning or settling a gas leak case can take years, and the record from Aliso Canyon shows how contested the evidence process becomes. During six years of litigation, Los Angeles Superior Court Judge Carolyn B. Kuhl found that SoCalGas and its outside counsel, Morgan Lewis & Bockius LLP, engaged in what she described as willful, intentional, and bad-faith discovery misconduct. The companies withheld more than 150,000 documents from plaintiffs and violated court orders governing the production of evidence.¹¹

At a February 2020 hearing, Kuhl said her prior trust in defense counsel to properly produce documents had been “a mistake.” Morgan Lewis attorney David L. Schrader apologized for “missteps” but denied the firm had acted in bad faith.¹² Total discovery sanctions imposed on the defense exceeded $5.7 million.¹¹

Government Suits and Regulatory Penalties

Civil litigation by residents is only one track. Attorneys general, air quality regulators, utility commissions, and local governments often bring their own actions, and the money from those suits generally does not go to individual plaintiffs.

SoCalGas reached a $119.5 million settlement with the California Attorney General, the California Air Resources Board, and city and county officials in Los Angeles. A Los Angeles Superior Court approved the consent decree on February 25, 2019, and SoCalGas did not admit liability.¹³¹⁴ The funds were split across supplemental environmental projects, methane mitigation, civil penalties, response costs, and a reserve fund. Notable allocations included:

$25 million for a long-term health study overseen by the County Department of Public Health
$7.1 million for air filtration in schools in environmental justice communities
$5.2 million for lead paint abatement in Boyle Heights and Maywood
$3 million for air monitoring around Porter Ranch
$26.5 million in loans to build methane digesters at 12 San Joaquin Valley dairies to offset released methane
$21 million in civil penalties to the city, county, and Attorney General’s Office

SoCalGas was also required to maintain a fenceline methane monitoring system with public data access for at least eight years and to hire an independent safety ombudsman.¹³

On top of that, the California Public Utilities Commission adopted a separate $71 million settlement on August 10, 2023, payable to the state-legislated Aliso Canyon Recovery Account. The CPUC order also barred SoCalGas from recovering a wide range of leak-related costs through customer rates, including the $1.8 billion civil settlement, roughly $126 million in government settlements, $462 million spent relocating and housing displaced residents, $109 million for the root cause analysis, and $377 million in outside counsel and litigation expenses. SoCalGas must include a senior executive attestation with every future cost-recovery application for five years confirming these expenses are excluded, and the settlement required $18.2 million in refunds to commercial customers.¹⁵

Together, SoCalGas and Sempra have paid over $2 billion across settlements, fines, and penalties related to the Aliso Canyon leak, and the state has barred the company from passing any of these costs on to ratepayers.¹⁶

Criminal Exposure for the Utility

Criminal charges are possible but rare, and when they come, they tend to hit the company rather than individual employees. In February 2016, the Los Angeles County District Attorney’s Office filed a misdemeanor complaint against SoCalGas, charging the company with three counts of failing to report the release of hazardous materials and one count of discharging air contaminants.¹⁷

SoCalGas later pleaded no contest to one misdemeanor count of failing to immediately report the leak to the California Office of Emergency Services. The remaining counts were dismissed at sentencing on November 29, 2016. The company paid $307,500 in fines and penalty assessments and roughly $247,000 to reimburse the Los Angeles County Fire Department’s investigation costs. It was also required to install an infrared methane monitoring system (estimated at $1.2 to $1.5 million), install real-time pressure monitors at each well, and hire six full-time employees to operate leak detection equipment at an estimated cost of $2.25 million over three years.¹⁸

What the Health Evidence Now Shows

Health evidence often lags settlement, and later findings can matter for people still deciding whether to pursue claims or evaluate their exposure. The largest long-term study of Aliso Canyon residents, funded by the $119.5 million government settlement, is UCLA’s five-year Aliso Canyon Disaster Health Research Study, running from December 2022 through October 2027.¹⁹

The most significant published finding to date appeared in Science Advances on September 12, 2025. Researchers found that women in their third trimester who lived within about six miles of the blowout had a 45 to 100 percent higher-than-expected chance of delivering low-birthweight babies, with the effect strongest for those living closest to the well.²⁰ An earlier UCLA analysis found that exposure during early pregnancy was associated with a 20 percent increase in male births, suggesting a possible increase in miscarriage of female fetuses.²¹ Cancer and neurodevelopmental analyses remain in progress, and clinical assessments involving lung function tests, neurological exams, and blood and urine sampling for benzene traces are planned for roughly 2,400 participants.²²

What Stays Open While Cases Proceed

A gas leak lawsuit closes the money question for the plaintiffs who sign on, but it does not necessarily close the facility or the underlying dispute. Aliso Canyon remains operational after being shut down following the blowout and reopening in 2017 at reduced capacity. As of the CPUC’s August 31, 2023 determination, the facility is capped at a maximum operating pressure of 2,926 psi, corresponding to a storage limit of 68.6 billion cubic feet of natural gas.²³ In November 2024 the CPUC issued a proposed decision setting a path to consider reducing and eventually eliminating reliance on the facility, but in December 2024 Governor Gavin Newsom declined to order its closure.²⁴

In San Antonio, both civil suits are active, CPS Energy has said it cannot comment on pending litigation, and the NTSB investigation into the two-inch high-density polyethylene main and one-inch polyethylene service lines, installed in 1993, may take one to two years.²⁵²⁶ Anyone weighing a claim should expect a long timeline: filing, consolidation, discovery, sanctions fights, health study results, and settlement can span the better part of a decade.

1
NPR. Gas Leak Los Angeles Aliso Canyon Settlement
2
KTLA. Nearly $60 Million Settlement Reached Over Toxic Gas Leak Sun Valley
3
Sempra. SoCalGas Announces Agreements to Resolve Aliso Canyon Litigation
4
Los Angeles County Department of Public Health. Aliso Canyon Disaster Health Research Background
5
PARRIS Law Firm. Parris Law Firm Reaches Multi-Million Dollar Settlement Over Sun Valley Gas Leak
6
KSAT. NTSB Releases Initial Findings of Investigation Into 2 North Side House Explosions
7
KSAT. North Side House Explosion Survivors Pull Original Lawsuit Refile New Suit Against CPS Energy
8
News 4 San Antonio. Second Lawsuit Filed Against CPS Energy Over Northeast Side Gas Explosions
9
BrownGreer. Porter Ranch Personal Injury and Property Class Settlements
10
Keller Rohrback. Southern California Gas Leak
11
Panish Law. Sempra SoCalGas Agree to Settle Aliso Canyon Gas Well Blowout Litigation
12
PorterRanchLawsuit.com. Trusting Morgan Lewis Attys Mistake Gas Leak Judge Says
13
California Attorney General’s Office. Aliso Canyon
14
Los Angeles County Counsel. Lawsuit Against SoCalGas for Aliso Canyon Gas Leak Results in Safety Upgrades and $119.5 Million Settlement
15
CPUC. CPUC Issues Presiding Officers Decision Adopting Settlement Penalizing SoCalGas for Aliso
16
NENC-LA. SoCalGas Paid Over $2 Billion in Aliso Canyon Gas Leak Settlements
17
KTLA. DA Files Criminal Charges Against SoCal Gas Over Aliso Canyon Gas Leak
18
Los Angeles County District Attorney’s Office. SoCal Gas to Pay $4 Million for Failing to Immediately Report Aliso Canyon Gas Leak
19
UCLA Aliso Canyon Study. Aliso Canyon Disaster Health Research Study
20
PubMed. Investigating the Aliso Canyon Gas Blowout Disaster and Adverse Birth Outcomes
21
Inside Climate News. California Aliso Canyon Gas Leak Harmed Babies
22
Daily News. Residents Still Waiting for Full Results of Aliso Canyon Disaster Health Study a Decade Later
23
CPUC. Aliso Canyon Well Failure
24
CalMatters. Aliso Canyon Decade Gas Leak
25
San Antonio Express-News. NTSB Preliminary Report House Explosions
26
San Antonio Report. Lawsuit Filed Against CPS Energy Northeast Side Explosions