DMS questions, smells linger near landfill 

An air-monitoring station at the end of Lincoln Avenue in Val Verde operates on Monday. Perry Smith/ The Signal
An air-monitoring station at the end of Lincoln Avenue in Val Verde operates on Monday. Perry Smith/ The Signal

Since January, Castaic and Val Verde residents have filed 1,092 complaints about smells coming from Chiquita Canyon Landfill, according to data from the South Coast Air Quality Management District through Aug. 7. 

During a Thursday evening meeting hosted on Zoom, two of the more pressing questions about the stench, which Waste Connections officials couldn’t immediately answer, were, what is dimethyl sulfide, or DMS, the gas that officials believe is behind the smell, and are there risks associated with prolonged exposure? 

A worksheet on dimethyl sulfide from the Occupational Safety and Health Administration notes the chemical is not classified as a carcinogen. Also of note, the World Health Organization’s International Chemical Safety Program website did not have information available on the effects of long-term exposure to dimethyl sulfide. 

“Dimethyl sulfide is an industrial contaminant released from pulp and paper, oil refineries and sewerage treatment plants,” according to a fact sheet from Safe Work Australia, which is that nation’s OSHA equivalent. “Dimethyl sulfide is also produced by bacteria in periodontal pockets and is an intermediary from methionine metabolism. It is found in fragrance formulations and in several food substances, including butter, oil and bread.” 

The South Coast Air Quality Management District referred questions about any potential health concerns to the Department of Public Health.

In an email sent Monday evening, DPH officials reported that they’ve asked Chiquita to expand its monitoring program “to include other landfill gases, including but not limited to dimethyl sulfide,” and “enhance and expand its current ambient air sampling program.” 

“Short-term exposure to landfill gases can include nausea, headache, coughing, irritation of the eyes, nose and throat and difficulty breathing,” according to an email from Becky Schlikerman Sernik, director of external communications for DPH. “Exposure to landfill gases can worsen health conditions related to respiratory conditions, such as asthma, or conditions where people are prone to nausea.” 

When asked about the potential health risks associated with dimethyl sulfide, Professor Neil Garg of UCLA shared a safety worksheet on the chemical — and a caveat: It’s all about the levels. 

“So yeah, it doesn’t immediately alarm me,” said Garg, an organic chemistry professor at UCLA whose specialty is understanding how chemical reactions occur, “but if I was living there, I would want more information, for sure.” 

Without knowing the exact levels, as well as whether DMS is the only sulfur-containing compound that’s being created, it’s hard to quantify what a health risk would be.  

“That’s my bottom line for something like this,” Garg said, “I think without more information, one shouldn’t jump to conclusions about what may be happening.” 

Another observation Garg shared is that sulfides and thiols, which refer to organic compounds that contain sulfides, are “really stinky, even in extremely low quantities.” 

As part of a developing problem, definitive information has been a bit hard to come by, but Chiquita Canyon Landfill officials have said they’re working to better understand the causes of the smell themselves, saying they believe the stench is being caused by previous operators prior to Waste Connections, and a natural release of gases involved in decomposition that has exceeded levels the landfill anticipated. 

District Manager Steve Cassulo said the landfill is hiring a toxicologist he hopes will help them better understand the risks, as well as improve local monitoring techniques. 

Right now, the landfill doesn’t have ways to detect the levels of DMS — it only knows it’s occurring through scent and relative levels of other gases, Cassulo said Thursday.    

Abigail Desesa Ordway, who lives about one mile “as the crow flies” from the landfill, off Lexington Drive, discussed feeling nauseous, disoriented and suffering from headaches — concerns, she said, that go away when she leaves her house for longer stretches.  

Cassulo said the landfill is treating the smell as a nuisance odor while doing its best to abate the smell for residents. The landfill created a program in response to the smell that provides air filters rated for about 300 square feet. He also said Thursday that the company was working to make more of the filters available once all of the affected residents received one. 

The landfill’s website also mentions a number of efforts that have been undertaken in order to clean up the smell, including giant misters, and a flare application with the AQMD that’s intended to help the landfill process more of the DMS gas believed to be responsible for the smell. 

Cassulo mentioned some of the other ways Chiquita is trying to make the odor less noticeable, which was his main goal right now, he said.  

Ordway, who also runs a tortoise rescue, describes the smell as well beyond a nuisance, adding it’s also made her dog sick. 

It was so bad Monday morning, she wasn’t able to stay and visit with the residents she helps out with the Meals on Wheels deliveries she makes to what she calls “the President streets” — an area the Castaic Town Council member describes as “ground zero” for the smell — a community directly northwest of the landfill and east of Chiquita Canyon Road, from Lincoln Avenue in the south to Taylor Street in the north. 

Jillian Graves, who lives off Roosevelt in Val Verde, essentially on the other side of a canyon wall from the landfill, said she and her sister have smelled it for the last four months or so, but their parents only started noticing it more recently. 

The smell wasn’t there Monday afternoon, but it’s “very pungent” in the morning and the evenings, Graves added. 

“It smells like what it is,” said Graves, who just finished her environmental sciences studies at College of the Canyons. “It smells like … if you left your trash bag outside of your dumpster,” she said, likening it to the artificial scent added to methane. She added that, on windy days, she’s also been frustrated by trash blown from the landfill onto their property. 

Not everyone surrounding the “President streets” reported being bothered by the smell Monday, and the prevalence seemed to depend on where the home was and which way the wind is blowing.  

Gina Court works from home near the intersection of Monroe and Lincoln and said she hasn’t really been bothered by it. However, around the corner off Taft, the Mirons have noticed the smell is much worse lately and said they received notices from the landfill operators about the free air filter program. 

One thing is certain: The overall number of complaints has risen exponentially in response to the recent increase in smells, for which Chiquita has taken conditional responsibility, with its website using language such as “most likely source of any odors that may be coming from the Chiquita Canyon Landfill.” 

The AQMD confirmed this week it has taken in nearly 1,100 complaints in 2023, according to data from the agency: eight in January; six in February; 14 in March; 46 in April; 108 in May; 139 in June; 550 in July; and 221 so far for August, through Aug. 7, which means the agency received an average of more than 30 complaints a day for the first part of the month. Once the agency substantiates six, a notice of violation is issued.  

L.A. County 5th District Supervisor Kathryn Barger authored a motion last week giving a county task force she authorized 30 days to come back to the board with a root-cause report on the smell and an update on remediation efforts. 

Desesa Ordway says it’s not as noticeable during the day where she is, perhaps because it migrates with the wind, she said, as she’s recently started noticing Facebook posts from residents to the northeast, including the Hasley Canyon area, who are logging complaints and questions such as, “Is this real?” on social media. 

Graves added that she’s been seeing more reports from that neighborhood as well, and another resident of Lincoln Avenue, who asked not to be named, felt the only way something would get done is if it affects the residents in the area’s newer, more affluent neighborhoods. 

Desesa Ordway said the smell was so bad outside of one of the 91-year-old resident’s homes that she just had to tell the woman they’re dropping off the food and leaving. 

“Oh,” DeSesa Ordway added Monday answering the Facebook posts rhetorically, “it’s very real.” 

The next public discussion of the landfill is the Chiquita Canyon Landfill Community Advisory Group meeting scheduled for 6 p.m. Tuesday at Castaic Library (27971 Sloan Canyon Road, Castaic).  The landfill was approved for a 30-year extension of its operations in April 2017, with a number of conditions that included continued meetings of the landfill’s CAG. The next discussion after that is during the Castaic Area Town Council meeting, which is hosted virtually on Zoom at 6 p.m. Wednesday. The webinar ID for the Zoom is 896 7408 5265 and the passcode is 211269. 

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