All of the approximately 34,000 manholes are treated twice a year for infestation. The product used to control the roaches is boric acid. About one pound of boric acid is sprayed into each manhole through a hole in the center of the cover. The process does not require lifting the cover. While boric acid is very effective in killing cockroaches, it is not toxic to humans or animals. If you would like to request treatment for cockroaches in the sewer system in your neighborhood, please follow the link below.
The Water Authority engages in an ongoing effort to prevent cockroaches in its network of sanitary sewer manholes.