The
San Diego County Air
Pollution Control District
(SDAPCD) provides monitoring
updates for the communities
potentially affected by
hydrogen sulfide (H₂S)
odors, a gas that can cause
a “rotten egg” smell,
produced by the
transboundary wastewater and
sewage flows near the
Tijuana River Valley. SDAPCD
has placed community
monitoring sites to measure
H₂S and has captured the
following information:
|
|
| |
Locations
|
Date
|
Time
|
H2S
Levels
|
Berry
Elementary
School | 08/30/25
| 7
AM - 8 AM |
38.6
ppB
[1]
|
Berry
Elementary
School | 08/30/25
| 6
AM - 7 AM |
60.3
ppB
[1]
|
[1]
"parts per
billion" or
ppB is a unit of
measurement used
to describe the
concentration of a
substance in the
air, water, or
soil.
Specifically, one
part per billion
means one part of
a substance per
one billion parts
of the medium
(such as
air). |
|
|
|
|
The California Office of
Health Hazard Assessment
has established a
threshold of 30 parts per
Billion of hydrogen
sulfide (H₂S) emissions to
protect sensitive groups,
including children, older
adults, and people with
certain health conditions.
Some individuals may
experience odor-related
symptoms such as headaches
and nausea. H₂S can cause
strong odors even at low
concentrations.
For current H₂S levels,
visit
Air
Quality
Monitoring.
Precautions if odors
persist:
- Limit
outdoor activities.
-
Create a Cleaner Air
Space inside your home
by closing windows and
doors and use air
conditioning if available
and/or indoor air
purifiers.
-
Households most
impacted by odors
may qualify for a
FREE home air
purifier. Visit
sdapcd.org/AIRE
for more
information.
- 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.
- If
possible, it’s recommended
businesses run the HVAC
system for 1-2 hours
before business
hours.
These
precautions are part of the
Community Hydrogen
Sulfide Guidance, a
document developed in
partnership with multiple
agencies to help interpret
hydrogen sulfide
(H₂S) threshold
levels, about what to expect
and recommended actions for
each level range. |
|
|
|
For more information, please visit
www.sdapcd.org/TJRiver
Last Updated: 08/30/2025 at 9:47 a.m.