County warns work on Border sewage system could temporarily increase flows, odors
CHULA VISTA, Calif. (FOX 5/KUSI) — The International Boundary and Water Commission (IBWC), County of San Diego and the county Air Pollution Control District are warning South Bay residents that wastewater flows and odors might increase in the coming days as the next phase of work on a sewer line in Mexico is expected to begin on Tuesday.
The second and final phase of work on the connection of the new International Collector sewer line in Mexico will begin on May 13 and could temporarily increase wastewater flows to the U.S., according to the IBWC.
The work is expected to take about a week to complete.
The sewer line being worked on moves untreated wastewater to the South Bay International Wastewater Treatment Plant (ITP) in the U.S. and the San Antonio de los Buenos Plant in Mexico.
EPA head discusses visit to San Diego on Tijuana River sewage crisis
The IBWC says the completion of the sewer line is critical for preventing potential catastrophic failures and increasing the reliability of Tijuana's wastewater infrastructure.
If the wastewater flows do increase, it could cause an increase in odors in San Diego's South Bay neighborhoods near the Tijuana River Valley, according to the Air Pollution Control District, and could also increase the pollution levels at South Bay beaches.
The US International Boundary and Water Commission (USIBWC) said it has been working with Mexico to mitigate wastewater spills as much as possible and have coordinated bypass lines to pump as much wastewater as possible to the ITP.
The San Diego County Air Pollution Control District (SDAPCD) monitors odor complaints and hydrogen sulfide levels for communities near the Tijuana River Valley.
County launches new interactive map of Tijuana River sewage impacts
If the odors continue, SDAPCD says South Bay residents near the Tijuana River Valley can take the following precautions to reduce exposure to the hydrogen sulfide (H2S) odors:
Limit outdoor activities if you smell strong odors
Keep doors and windows closed to prevent odor from coming indoors. Air out your home or building when odor is not present
Use air conditioning if available and/or indoor air purifiers. Filters with activated charcoal are recommended.
People with asthma, chronic obstructive pulmonary disease (COPD), or other chronic lung conditions should have their rescue medication(s) readily available.
If symptoms from strong odor persists, are worrisome, or worsen, seek medical care.
Residents in South Bay communities near the Tijuana River Valley impacted by the odors from the sewage flows at the U.S.-Mexico border can apply for a free air purifier part of the San Diego County Air Pollution Control District's (SDAPCD) AIRE Program.
On Friday, EPA Administrator Lee Zeldin took to X following his Earth Day visit to San Diego to say, 'This week, EPA transmitted to Mexico a proposed '100% solution' that would PERMANENTLY END the decades-old crisis of raw sewage flowing in to the U.S. from Mexico. Next, technical groups from both nations will be meeting to work through the details necessary to hopefully reach an urgent agreement.'
Tijuana River the second most endangered river in US in 2025
More information on the ongoing pollution in the Tijuana River Valley and South County beach water is available from the SDAPCD, IBWC and the County's dedicated South Region Health Concerns webpage.
The County also recently launched an interactive online dashboard and map displaying current environmental conditions in South County including beach water quality and sewage odor data.
Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
Hashtags

Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles


USA Today
13 hours ago
- USA Today
A fog-free San Francisco? Scientists ponder California's climate future
A fog-free San Francisco? Scientists ponder California's climate future Nearly 70% of Californians live in coastal counties, which figure to be most impacted by diminished fog. Show Caption Hide Caption Climate change is now impacting where Americans choose to live Many U.S. locales have reached a climate change "tipping point." Populations are declining as flooding becomes unbearable. SAN FRANCISCO – As most of the U.S. sweltered in mid-July 2022 − when temperatures in many major cities reached the high 90s and even triple digits − a national weather map showed San Francisco topping out at 65 degrees. It was just a typical foggy summer day in the city by the bay, which averaged 62 degrees that month, about the same as the next two Julys. Now the advent of climate change raises the question of whether summertime visitors will stop rushing out to buy sweatshirts upon arrival and instead feel perfectly comfortable in shorts and T-shirts. The future of San Francisco's iconic fog has been debated in media stories during recent years, and some experts note a diminished cloud cover along the California coast that could lead to a warming trend. But few if any detect signs that San Francisco's summer chill is going away like the once-celebrated Fog City Diner, which shut down at the end of May. 'From the data, I can't foresee it any time soon,'' said Rachel Clemesha, a project scientist with the Scripps Institution of Oceanography at the University of California-San Diego who studies the state's coastal climate. 'There are years when there's more or less cloud cover. The last couple of years have been within that range. It is a very foggy place, so it would be very dramatic to get you a fog-free city.'' Data on decreasing fog along coast is 'spotty' Clemesha said some decrease has been confirmed in Southern California in what residents there call the marine layer, mostly in highly urbanized areas, but nothing that applies statewide. Peter Weiss, a faculty researcher and lecturer at the UC-Santa Cruz department of environmental sciences, said that despite a growing narrative of waning fog along the California coast, the data to support it is 'very spotty,'' with few academic studies in the last decade. The reasons include the fog's unpredictability – Weiss calls it an 'ephemeral phenomenon'' – and the lack of a standard way to measure it. Some studies, such as the landmark analysis by James Johnstone and Todd Dawson in 2010, rely on airport visibility records. Others use satellite images to determine the extent of the cloud cover, and others yet believe water content is a more valuable gauge. The airport records are the most extensive, going back to 1950, and Weiss said from that year until 2012 they revealed a 5% decrease in fogginess. 'Nobody's quite sure why,'' he said. 'It probably has to do with the ocean's sea-surface temperature, and that goes through various phases. Overall, there's warming due to global warming, but it's episodic. There appears to be some pattern with less fog after the warmer sea-surface temperatures, but this is still an area of research.'' Many California residents, ecosystems would be affected While the scientific community endeavors to figure out the long-range impact of climate change on California's coastal fog, there's a strong consensus that diminished cloud cover would have a harmful effect. Nearly 27 million of California's 39 million residents – close to 70% – live in coastal counties, by far the largest total in the nation, and they generate 80% of the state's gross domestic product. Their lives are certain to be impacted, as would be the state's powerhouse agriculture industry, which totals close to $60 billion a year in revenue. Species such as the widely admired coastal redwoods, which get up to 40% of their yearly water intake from fog, could be threatened if that resource dwindled. Daniel Fernandez, an environmental sciences professor at Cal State Monterey Bay, is part of a group seeking a grant from a private foundation to study how climate change may alter fog and affect various ecosystems. 'You could have significant die-off of species that are dependent on the fog at locations where it gets reduced,'' he said. 'It would also change how people live. When you look a fog zones, you don't need air conditioning. There are a lot of things we don't need that we take for granted. Those things could all change.'' It can feel like living in a cloud The fog, more prevalent in the summer, is created when warm and moist air sweeps over cold waters, which are churned off the California coast by strong winds in what's known as upwelling. The marine cover can be light enough to simply cool down a warm day and thick enough to wet residents' hair and obscure their eyeglasses, giving the impression they're living in a cloud. Some years the fog is thicker than others, but it tends to be more extensive in Northern California than the state's southern coast because of the differences in their ocean temperature (colder in the north), latitude and topography. Ian Faloona, a professor of land, air and water resources at UC Davis, said he and a colleague conducted a study using regional climate models and found a downward trend in cloudiness along the coast, but agrees the overall evidence 'is not going to hit you over the head.'' He compares that to the abundant data indicating California in general is warming quickly, about 1 degree Celsius – 1.8 degrees Fahrenheit – per decade. Even San Francisco is heating up a bit, though not nearly as fast: Its average summer temperature has risen by 1.6 degrees Fahrenheit since 1970, according to the independent research group Climate Central. Two different perspectives on what the future holds But climate scientists are split over whether the increased heat will lead to less fog because the air over the ocean won't be cold enough to condense, or whether stronger winds will atone for that factor. 'Under climate change, we know the land is warming much faster than the ocean, so that temperature difference across the land and ocean interface is increasing, which could drive stronger winds, which could help preserve this cloudiness,'' Faloona said. 'So there are two arguments you could make about what we theoretically think should happen, and which one's winning out I think is still an open scientific question.'' Sara Baguskas, an assistant professor at San Francisco State University with a specialty in coastal fog, said the lack of conclusive evidence that it's ebbing should not induce complacency but rather stimulate funding to study and predict its patterns. She's among the climate researchers who have heard from longtime coastal residents saying the marine layer has subsided over the years. 'So it's not unreasonable to be concerned about coastal fog declining in the future, but it diminishing completely is unlikely,'' she said. 'No coastal fog in California is a scary thought for both people and ecosystems.''


CBS News
a day ago
- CBS News
Canadian wildfire smoke is affecting air quality in Boston. Here's when it will improve.
The air quality in Boston over the last few days hasn't been great, and you may have noticed a foul smell or slight haze in the air. This is a combination of low-level ozone and wildfire smoke making its way through New England on Monday, which leads to that hazy sky and the decreased air quality index. Most of the air quality monitoring stations in our area are showing as "yellow," which corresponds to moderately unhealthy air. This is not enough for any real cause for concern, and there are not currently any air quality alerts in southern New England. There have been a few stations with levels slightly higher than moderate, tipping into the "unhealthy for sensitive groups, " which means older adults, children, people with disabilities, and those with heart or lung disease should avoid outdoor activities, according to the EPA. WBZ-TV weather graphic. CBS Boston Why is the air quality bad in Massachusetts? Again, the reason for this is twofold. First, there is some low-level ozone present on Monday. Second, and more importantly, some of the wildfire smoke from the ongoing Canadian fires continues to spill into New England. This will come and go depending on the wind direction at both upper and lower levels of the atmosphere throughout the next few weeks and perhaps the rest of the summer, should the wildfires continue. The Canadian wildfire season typically spans from May to September. WBZ-TV weather graphic. CBS Boston When will the air quality improve? Luckily, the smoke levels are forecasted to drop off significantly later in the day on Monday and on Tuesday. WBZ-TV weather graphic. CBS Boston We expect the air quality levels to improve and largely be in the "good" or "green" category by Tuesday.


Newsweek
a day ago
- Newsweek
Americans Warned to Avoid the Sun in 11 States
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. Americans across some 11 states are facing high levels of ultraviolet (UV) radiation on Monday, according to the National Weather Service (NWS) and Environmental Protection Agency (EPA). A UV alert forecast graphic from the two agencies showed that parts of Washington, Oregon, Idaho, Montana, California, Arizona, New Mexico, Texas, Alabama, Georgia, and Florida, were expected to experience UV levels that were "well above normal." "If you are within a UV Alert region extra precautions should be taken to protect oneself from the sun's UV radiation," the alert forecast advised. Eleven states—including Texas, Arizona, and California—are bracing for UV radiation levels, according to the EPA. Eleven states—including Texas, Arizona, and California—are bracing for UV radiation levels, according to the EPA. Getty This is a developing news story and will be updated shortly.