Post-fire Pool Water Tests Show Low Contamination Levels

By Laurel Busby

News & Information Editor

Researchers collected post-fire water from 100 pools, split between the Eaton and Palisades Fire areas, and found relatively low levels of pollutants, according to a Community Action Project L.A. study led by Dr. Caitlin Proctor or Purdue University.

“Overall, metal contaminant concentrations in pool waters sampled were unremarkable and test results indicated limited health risk,” according to a press release from CAP LA. “Results were generally similar to drinking water metal concentrations, which can also be found in consumer confidence reports released by drinking water providers.”

In addition, most of the 73 tested semi-volatile organic compounds (SVOCs) were not detected, had low concentrations, or were below levels that posed a health risk.

“The exception was benzyl butyl phthalate (BBP), which often exceeded the recommended ambient water quality limit,” according to the press release. “No chemicals exceeded the more stringent drinking water limits.”

A CAP LA researcher gathering a pool sample for testing.

Of the tested pools, 60 percent had not received any chemical remediation after the fire and before the testing. Both dirty and non-operational pools were among this group.

The levels of 22 heavy metals were tested, including arsenic, aluminum, antimony, barium, beryllium, cadmium, chromium, copper, cobalt, iron, lead, lithium, manganese, mercury, molybdenum, nickel, selenium, silver, tin, thallium, vanadium, and zinc.

None of these tested metals exceeded recreational standards, but four, arsenic, antimony, lithium, and selenium, exceeded drinking water standards, which are based on drinking such water daily for ears, according to an August webinar on the study. Arsenic and antimony exceeded drinking water levels in 10 percent of the pools, lithium in 40 percent, and selenium in 5 percent. The Palisades, in particular, had higher levels of arsenic in both pool water and comparison water from the area’s utility.

Seven of the 73 tested SVOCs were detected in 10 or more pools, but none exceeded drink water standards, according to the webinar.

The low level of contaminants likely stems from three reasons, according to the researchers. The pool water may have been diluted by rainfall or other water, particulates may have settled to the bottom, or chemicals may have transferred from the water to the air.

A pdf of the webinar can be viewed here. Previous Canyon News articles about environmental testing by CAP LA can be found here and here.

Questions about the findings can be directed to info@cap.la or the Pool StudyTeam at LAPoolStudy@gmail.com.

Recommendations:

For residents with affected pools, CAP LA researchers suggest the following:

1. Wear correct safety gear. Watch for sharps, hazmat, animals, etc.

2. Have an electrician check electrical connections.

3. Remove debris from the top and bottom of the pool and pool deck.

4. Maintain and/or replace pool water filters.

5. Remove particulates and discoloration from the pool walls and deck. Scrubbing with safe surfactants may be helpful. This may require pool draining. The water refill may cost $100s to $1000s of dollars. If pool draining with explicit approval from a wastewater utility, discharge pool water to their sanitary sewer (not storm sewer).

6. Run filters to remove particulates.

7. Disinfect the pool and achieve proper water pH to help reduce microbial growth. Maintain water quality within proper ranges. This helps limit mosquito populations.

Special Concerns:

• If high particle loading, you may ruin your filters. Remove debris first.

• Adding large amounts of bleach to the pool produces chemical reaction byproducts and a chemical exposure hazard.

• Overdosing chemicals or having too high/too low water pH can excessively corrode stainless steel

• Discharging pool water to the sanitary sewer without approval may cause sewer backups into nearby buildings. Get approval first.

• Do not discharge pool water into a septic tank. You can plug and ruin the leaching field and tank.

Pool remediation actions will vary based on how impacted the pool is.

Not all pools will be treated the same for the same fire.