TROUBLED WATERS
Salton Sea now emitting bad smells year round
It assailed Jessica Perez on Friday evening as she left her job as receptionist for the Desert Recreation District at the North Shore Beach and Yacht Club by the Salton Sea. She hurried to her car to escape.
The next day, she walked out the door to take her 2-yearold son to the neighborhood park in Mecca. It hit her again. The smell.
Perez went back inside and made sure the windows were shut. She’s gotten nauseous from the stench in the past, and she also worries about how it might impact her toddler.
“It smelled really, really bad. I have to go back inside because I can’t have my kid be out in that,” she said.
Humidity, hot winds and the decaying Salton Sea have long been been a recipe for nostril and stomach misery during the summer across large swaths of the eastern Coachella Valley.
But now, an analysis of 20 years worth of records by a UC Riverside laboratory shows a disturbing new trend: The noxious odor is hanging around at detectable lower levels yearround.
For her entire life, Perez, 22, and her neighbors in Mecca and other portions of the eastern Coachella Valley have lived with hydrogen sulfide occasionally rising off the decaying Salton Sea on sticky days In July and August, blanketing their neighborhoods in a fetid stench.
But lately, with higher temperatures, she says, “I might have to move because of the smell . ... it’s definitely getting worse. I’ve been here like forever, and I like living here, but I don’t know if I can stay.”
She’s not imagining it.
Since Friday, hydrogen sulfide levels have repeatedly exceeded the state recommended level of 30 parts per billion average per hour, in some cases more than double that recommended limit. Air regulators issued an extended odor advisory for the eastern Coachella Valley through Wednesday evening, citing shifting winds off the Salton Sea.
And while humid summer weather and desert winds have long created ripe conditions for the smell, new research by a UC Riverside biogeochemistry lab shows that as the massive water body dries, the noxious odor is actually now persisting at lower levels year round.
You’re not imagining it, the Salton Sea smell is year round now
“The Salton Sea is experiencing a ‘regime shift’ that affects sulfide emissions and, consequently, the surrounding communities,” said doctoral student Caroline Hung of the Lyons Biogeochemisitry Lab at UCR’s Department of Earth and Planetary Sciences in an email. She is currently preparing an academic manuscript on the group’s findings.
While South Coast Air Quality Management District regulators have long said the stink is the result of “natural processes occurring at the Salton Sea,” it’s actually a complex mix of long-running water pollution and the rapid loss of those contaminant-laden waters that’s creating year-round odors.
More than a century’s worth of pesticide and fertilizer runoff combined with less of that runoff as water is diverted to urban areas makes for a potent mix.
“The mechanism of the sulfide release from the Salton Sea polluted water is important,” said Hung, and the current trend is predicted to increase as it dries more rapidly.
“Here’s what’s happening,” she said in an email listing the processes at work:
Lake level drop: Since the early 2000s, the Salton Sea has lost about 4 meters (nearly 15 feet) of depth.
Thermal stratification breakdown: The lake used to have distinct layers of water at different temperatures. Now, due to its shallower depth, these layers are breaking down and mixing more frequently.
Nutrient overload: Agricultural run-off has led to extremely high nutrient levels in the lake, causing rapid algae growth.
Oxygen depletion: When algae die, bacterial decay consumes oxygen. This process has left more areas of the lake with very low oxygen levels.
Sulfide production: In oxygenpoor conditions at the lake bottom, bacteria produce sulfide, which causes a rotten egg smell.
Changing sulfide emission patterns.
She noted that previously hydrogen sulfide would accumulate at the lake bottom and “be released in one big, smelly burst when the lake turned over in late summer” due to a combination of a “very windy” seasonal transition to autumn, big day and night temperature differences and a known wind tunnel effect in the valley.
“Now, due to frequent mixing in the shallower lake, there’s a constant, lowlevel release of sulfide.” wrote Hung, who along with colleagues analyzed two decades worth of measurements, and slogged through increasingly mucky lakeside conditions to even launch their research boat.
South Coast air regulators said in the odor advisory that hydrogen sulfide levels at their near-shore and Mecca monitors rose from 28 to 70 parts per billion just on Monday morning between 8 a.m. and 11a.m.
At the state standard for outdoor levels of 30 ppb averaged over one hour, the news release said, “most individuals can smell the odor and some may experience symptoms such as headaches and nausea. However, the symptoms associated with this level of exposure are temporary and do not cause any long-term health effects. Humans can detect hydrogen sulfide odors at extremely low concentrations, down to a few parts per billion.”
The air district monitors hydrogen sulfide at three locations in the southeastern Coachella Valley:
along the shoreline at an Imperial Irrigation District site on the Torrez Martinez reservation;
at Saul Martinez Elementary in Mecca; and at
Amistad High School in Indio, which has not seen elevated levels this week.
Residents can see daily measurement data at saltonseaodor.org and sign up for alerts at the same link, to be notified when levels exceed the state maximum.
Salton Sea odor isn’t pleasant, but health risks are low
Hung said the levels are still not high enough to cause what federal public health and occupational safety regulators say are dire health impacts from hydrogen sulfide exposure. They’d need to be in parts per million rather than billion, according to federal fact sheets.
But the changes might impact habitat restoration plans at the water body’s edge, with too little oxygen for yearround use by wildlife, Hung said. And they definitely impact humans..
“While the sulfide levels aren’t high enough to cause serious health issues, they create a persistent, unpleasant odor that affects the quality of life for nearby residents,” said Hung. “The smell can be constant” and can worsen under certain conditions, like recent high winds.
‘It was a great place to be... and now it’s not’
Perez has little hope that anything will be done to lessen the smell or improve lakeside conditions, because nothing’s been done about it her entire life.
The thought of moving to escape the smell “kind of makes me sad because (otherwise) it’s a pretty nice place to be; very nice,” said Perez. She recalls how in high school a teacher talked often about the odor, and wanted to do a student project before COVID cancelled his plans.
“They would always say that back in time, people would come over here from far away, and it was a great place to be,” she recalls. “And now it’s just not.”
Janet Wilson is senior environment reporter for The Desert Sun and co-authors USA Today Climate Point. She can be reached at jwilson@gannett.com