As the United States Army Corps of Engineers expanded its footprint in the Eaton fire area to more than 120 crews this week as part of a massive debris-removal process, a much smaller operation is attempting to curtail a potential public health crisis brewing in Altadena’s pools.

The San Gabriel Valley Mosquito and Vector Control District is going pool to pool inside the fire perimeter and just outside to treat unmaintained pools, which if left alone, could breed 3 million mosquitoes in one month.

“We’re already seeing a lot of breeding within these pools, so we have a very short window to get as much work done before we start to see disease activity,” Communications Director Anais Medina Diaz said. “Mosquitoes are not just a very annoying pest, we’re really concerned about West Nile virus, other mosquito transmitted diseases like dengue. So this is really a public health concern for us.”

Through a combination of aerial imaging and having crews on the ground, the district identified about 2,900 pools that could need treatment. So far, about 980 have been cleared, meaning the pool was deemed functional, empty and dry, non-existent or been treated by pesticide or mosquito fish.

@the.socal.local

There’s a public health crisis brewing in the area burned by the Eaton fire and it has to do with Altadena’s pools and mosquitoes. A lot of mosquitoes. The San Gabriel Valley Mosquito and Vector Control District is going pool to pool inside the fire perimeter and just outside to treat unmaintained pools which if left alone could breed 3 million mosquitoes in one month. That’s a public health concern, as mosquitoes are known to carry a multitude of diseases – including West Nile virus and Dengue. To read more about the problem, tap the link in our bio. : David Wilson, SCNG #altadena #eatonfire #pasadena #sangabrielvalley #mosquito #socal #losangeles #publichealth #psa

♬ Noticias – yagobeats

From the 2,900 pools, 1,411 are inside the burn scar and the remainder are outside. Mosquito breeding typically occurs when overnight temperatures are closer to 60 degrees for five or more days at a time.

This week the district, an agency with 33 full-time employees, had two crews of three people working in Altadena on pool treatments. An additional crew placed mosquito fish in pools, which is a longer-lasting solution than chemical treatments. But it is possible only if the water quality is good enough for the fish to survive. For many of the pools, the district will have to return in the coming weeks to reassess the water quality before being able to use mosquito fish.

To help keep up with the demand, the district received support from the Greater Los Angeles County Vector Control District, which provided three technicians.

One of those technicians, Vector Control Specialist David Lopez, sat in the bed of a vector district truck as it made its way around Altadena on a recent Tuesday afternoon.

Covered head to toe in personal protective gear, Lopez traversed the destroyed remains of homes on Beverly Way, near Mendocino Street, and threw a larvicide treatment into two pools surrounded by nothing but rubble. The larvicide is effective for 90 days.

The treatment targets mosquito larvae and is held in a net with pool noodle like material inside to help it float on the surface of the water. A mosquito can go from larva to flying adult in five to seven days in the right conditions.

Diaz said the district expects to complete the first round of treatments inside the burn area within the next four weeks.

“Our district has a scheduled aerial surveillance update at the end of the month/early May at which point technicians will take another look at flagged properties,” Diaz said. “We can determine if the number of pools we need to treat has decreased or increased.”

Technicians have observed mosquitoes breeding in most of the pools they’ve treated so far. However, technicians are not looking for signs of mosquitoes to determine whether to treat impacted pools.

“We can assume that if there is stagnant water in the pool, there is active breeding of mosquitoes. They are prioritizing getting to as many pools as possible rather than verifying if the pool is breeding at each visit,” Diaz said. “Whether it’s this week or next week, the pool will breed mosquitoes as long as it has stagnant water.”