This assessment evaluates whether the San Gabriel Valley Mosquito and Vector Control
District's ("District") mosquito control activities are exempt under the California Environmental Quality Act ("CEQA"). This assessment is prepared under CEQA Guidelines sections 15060 and 15061 to evaluate the application of CEQA and the CEQA categorical exemptions to the District's integrated mosquito management program.

The District was formed in 1987 to protect the public in the San Gabriel Valley in Los Angeles County from mosquitoes and other vectors. The District’s vector control program continuously surveilles mosquitoes and the diseases they may transmit to ascertain the risk of disease transmission and annoyance, and uses safe, integrated methods to manage vectors (discussed below) below levels where they may compromise public health.

CEQA was adopted by the California Legislature in 1970 and generally requires state and local agencies to prepare an environmental document (either an environmental impact report (EIR) or negative declaration) assessing the potential environmental impacts of discretionary projects that may affect the environment CEQA exempts from this requirement certain projects and activities which are declared exempt by the Legislature ("statutory exemptions"; listed in CEQA Guidelines sections 15260-15282) and other classes of projects that the State Secretary for Resources has determined do not have a significant effect on the environment ("categorical exemptions"; listed at CEQA Guidelines sections 15301-15329). This preliminary analysis focuses on certain categorical exemptions as applied to the District’s integrated vector management program.

The District previously concluded that its vector control activities were exempt from CEQA (District Resolution 98-05). This CEQA preliminary assessment re-evaluates the exempt status of the District’s vector control program in light of its current operations, activities, and conditions.

To accomplish long-range, intelligent, and environmentally sound mosquito control, mosquitoes must be managed with an integrated vector management (IVM) program. The District uses IVM by first surveying populations of mosquito larvae and adults to determine which species are present. Mosquitoes which pose a threat to public health are controlled with the most effective and environmentally sensitive means possible. Sometimes, sources of water can be modified or eliminated to reduce breeding areas.

The District also may consider using biological control such as mosquitofish if there is no impact to the environment. When these approaches are not practical or effective, pesticides may be applied in specific areas.