County Notifies South Bay Residents Of Elevated 'Sewer Gas' Levels

SAN DIEGO, CA — High levels of hydrogen sulfide in the South Bay near the Tijuana River Valley Tuesday prompted county public health officials to offer guidance to deal with possible noxious smells.

An increase in the gas, which has a rotten egg smell and is associated with untreated wastewater, came after a pipe in Tijuana experienced a break last weekend.

The San Diego County Air Pollution Control District monitors reported average hydrogen sulfide emissions in the Tijuana River Valley exceeded the 4- hour Level 1 Federal Acute Exposure Guideline Level threshold of 360 parts per billion for a period between 10 p.m. and 4 a.m. earlier Tuesday and reached a one-hour average of 915 parts per billion between 1 and 2 a.m.

The U.S. International Boundary and Water Commission said repairs are being expedited, and is "pressing Mexico to complete them as quickly as possible," a county statement read. "While Mexican authorities have indicated repairs could be completed as soon as the end of the week, USIBWC continues to urge an accelerated timeline to halt excess flows to the Tijuana River."

"We are working closely with our partners at the USIBWC, SDAPCD and others and staying in close communication," said Dr. Sayone Thihalolipavan, county public health officer.

"We really want to people who live, work or go to school in the area to know where they can find up-to-date information on H2S levels and what steps they can take to reduce their exposure to H2S."

According to the Environmental Protection Agency, emissions exceeding the Acute Exposure Guideline Level 1 for the gas can cause "notable discomfort, irritation, or certain asymptomatic non-sensory effects. However, the effects are not disabling and are transient and reversible upon cessation of exposure."

The broken line, the Parallel Gravity Line, is being rehabilitated under a binational agreement as part of the U.S.-Mexico commitment to a permanent solution to transboundary flows.

To reduce exposure, those in the area can limit outdoor activities, keep windows and doors closed when odors are present, use fans to circulate air inside buildings and an air purifier with a high efficiency particulate air filter and activated charcoal with potassium permanganate.

"We are continuously monitoring hydrogen sulfide levels in the Tijuana River Valley to ensure residents are informed and safe," said Paula Forbis, air pollution control officer for the San Diego County Air Pollution Control District.

"We encourage residents to visit our website for the latest information on hydrogen sulfide levels. Our monitoring network provides current data so you can stay informed and take the necessary precautions to protect your health."

According to the county, people who are more sensitive to air pollution like those with asthma, chronic obstructive pulmonary disease, or other chronic lung conditions should keep rescue medication(s) readily available. Anyone with persistent, worrisome, or worsening, symptoms should reach out to their medical care provider or seek emergency care if symptoms feel life-threatening.

Members of the public can sign up to receive updates when gas particulates reach 30 parts per billion at public.govdelivery.com/accounts/CASDCAPCD/subscriber/new, where you can also monitor current levels and other pollution data.

— City News Service