From Pasadena Now
December 17, 2018
City authorities and staff from the San Gabriel Valley Mosquito and Vector Control District identified a total of 93 dirty swimming pools in Pasadena that could be breeding places for mosquitoes, including those that carry the West Nile virus and other diseases.
The owners of these swimming pools were notified and advised to clean them and restore them to a functional state, or to empty the water and keep the pools dry.
A report by Michael Johnson, the City’s Director of Public Health, said the dirty or “green” pools – green because of algae – were identified in the spring. The owners were given Swimming Pool Notices, and by August all the pools have been cleaned, Johnson said.
According to the San Gabriel Valley Mosquito and Vector Control District, a dirty and unmaintained swimming pool can produce up to three million mosquitoes in a month, contributing to the spread of mosquito-borne diseases.
The District said only two conditions could guarantee that mosquitoes don’t grow in the swimming pools: they should either be “clean and functional,” with a working filtration system, or “empty and dry.”