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FAQ - Clean Pools, Healthy Community

Why are non-functional swimming pools a risk to public health?

Mosquitoes grow in stagnant water. An unmaintained, non-functional swimming pool can produce up to 3,000,000 mosquitoes in one month. This staggering number is more than enough to impact the public health of an entire neighborhood. Reducing the population of mosquitoes helps reduce the incidence of mosquito-borne diseases such as West Nile virus and Zika.


Why are empty swimming pools especially dangerous?

The condition of an empty swimming pool is extremely volatile and can go from a clean, empty, and dry state to a mosquito breeding habitat in a matter of days. As soon as water is introduced, either from rain or irrigation, mosquitoes will begin to lay eggs and grow in the stagnant water.


How do I prevent my swimming pool from becoming a public health nuisance?

Any stagnant water on your property that can grow mosquitoes is deemed a public health nuisance by the California Health and Safety Code. The best way to prevent your swimming pool from becoming a public health nuisance is to keep it clean and functional, with a working filtration system and a regular chemical treatment schedule.

If you are unable to return the pool to a clean and functional state then you must work with vector control to develop a longterm management strategy to reduce the risk of mosquito development.


What does the vector control district do to prevent a non-functional pool from becoming

a mosquito habitat?

The District monitors thousands of non-functional pools in the San Gabriel Valley and works closely with residents to ensure their pools do not become a public health nuisance. We do that in two ways. The first is by helping residents develop a practical, longterm, and sustainable plan to prevent mosquito breeding; as well as providing convenient ways to confirm compliance. The second way is by providing short term support, through chemical management and control, while residents make necessary repairs or decide on a longterm strategy.


What is a Request for Confirmation?

As part of the Districts monitoring program, we need to confirm that the condition of a nonfunctional swimming pool, at any given time, is not growing mosquitoes. Throughout the year, the District will request that residents provide confirmation that the condition of their pool is acceptable. Residents can comply with the confirmation request by providing photo verification or by scheduling a physical inspection by a vector control technician.


How often will vector control request confirmation of my empty and dry pool?

If a resident decides to keep their pool empty and dry, the resident must accept the responsibility of keeping it clean and dry year-round. The District may request confirmation up to four times a year to ensure the pool stays empty.


Why does the District need confirmation so often?

California’s mild climate allows mosquitoes to grow year-round and during the rainy season it becomes very difficult for residents to keep the pool empty and dry. Fall and spring create a dangerous combination of rain and warm weather that make empty pools a prime habitat for mosquitoes.


What is the Photo Confirmation Program?

To make confirmation as easy as possible for the resident, the District has a photo confirmation program that allows residents to communicate with the District via text or email and submit photo confirmation at their convenience within a specified amount of time. This program replaces the need for physical inspections and site visits.


How do I register for photo confirmation?

To enroll in the program, text REGISTER with a picture of your pool (completely empty and dry) to (626) 314-6006. Residents can use email if they prefer, The District will respond to confirm enrollment and let you know when the next confirmation request will be sent. All of the pools registered in the program are on the same confirmation cycle.


What should I expect once I am registered for the photo confirmation program?

Up to four times a year, the District will send a confirmation request that will include a unique confirmation code and a confirmation deadline. Write the confirmation code on a piece of paper and take a picture of the swimming pool (completely empty and dry) with the confirmation code in the foreground. Send the photo to the District before the confirmation deadline. The District will confirm receipt of the photo and your obligation will be fulfilled.


How long will vector control continue to monitor my swimming pool?

The District monitors any pool that is not in a clean and functional state. As long as the pool is non-functional the District will need regular confirmation that it is being maintained in a way that prevents the development of mosquitoes.