After reports of an influx of mosquitos on the west side of town, City staff began working diligently with Hyperion and County Public Health staff to locate the sources of mosquitos and make every effort to resolve the issue.

Jan. 2 Update: Hyperion staff initiated efforts on Jan. 1 to combat the mosquito influx by making physical inspection of the Hyperion site. As a result of this inspection, they located several mosquito breeding areas and immediately treated them. City staff is coordinating efforts with Hyperion staff and the LA County Vector Control District in an attempt to eradicate all the breeding sources for these mosquitos.

Jan. 5 Update: As City staff have been coordinating efforts to address the influx of mosquitoes, Hyperion staff indicated that LA County Vector Control District staff would be inspecting the Hyperion site and setting up mosquito traps as early as Jan. 5. Vector Control will return soon after the installation to check the traps and provide Hyperion with a report of their findings by Jan. 9.

Jan. 9 Report from Hyperion:

This report is intended to document the mosquito abatement actions undertaken at the Hyperion Water Reclamation Plant (HWRP) in response to concerns raised by the neighboring El Segundo community regarding an increase in mosquito activity.

In coordination with the Los Angeles County Vector Control District, Hyperion staff conducted a comprehensive inspection of the plant facilities, the adjacent greenbelt area separating the plant from the residential community, and portions of the nearby neighborhood. The inspection focused on identifying potential mosquito breeding sources, including standing water, vegetation density, drainage conditions, and operational structures that could retain water.

On January 5th, HWRP staff met with William McDougal, General Field Operations Manager of the Los Angeles County Vector Control District, to review inspection findings and discuss the action plan for mosquito abatement moving forward.

As a result of these inspections and discussions, the following actions were taken:

• Identification and mitigation of standing water sources within the facility.
• Adjustments to maintenance practices to improve drainage and reduce water retention.
• Coordination with Vector Control to apply appropriate larvicidal treatments where necessary.
• Evaluation of the greenbelt area to ensure it is not contributing to mosquito breeding conditions.
• Continued collaboration with Vector Control to monitor conditions both on-site and in surrounding areas.

These proactive measures identified one area on the north end of Hyperion property that may have contributed to elevated mosquito counts. This area was immediately addressed and mitigated. In addition, new mosquito traps that were set earlier this week are expected to reflect the effectiveness of these corrective actions, and the Los Angeles County Vector Control District anticipates a significant reduction in mosquito activity. County Vector Control also indicated that recent rainfall combined with unusually warm December temperatures was a major contributing factor to the elevated mosquito counts observed in the area. Inspections further identified multiple mosquito breeding sources within the El Segundo residential neighborhood that were contributing to the increased numbers, and these areas were treated directly by County Vector Control personnel.

Additionally, County inspectors determined that some specimens submitted as mosquitoes were in fact midge flies, which closely resemble mosquitoes in appearance and can congregate in large numbers at a fast rate. County Vector Control indicated that these insects are commonly associated with wet grass conditions and may be related to moisture present within the greenbelt area, particularly following recent rainfall.

https://www.glamosquito.org/midges

Ongoing coordination with Los Angeles County Vector Control will continue to ensure early detection and prompt response to any future mosquito-related issues. These efforts support not only regulatory compliance but also the health and quality of life of neighboring communities, including El Segundo.

Jan. 13 Update: At the request of City staff, the Hyperion Superintendent and his staff are going to immediately contact the LA County Vector Control District to:

• Set up additional and possibly more efficient mosquito traps
• Apply chemicals in addition to the treatments Hyperion staff have already applied
• Take any other mitigating measures possible

City staff also directly contacted the LA County Vector Control Manager's office and requested his full cooperation with Hyperion staff in an attempt to eradicate the mosquitos.

Jan. 15 Update: Yesterday, LA County Vector Control staff re-inspected Hyperion’s green belt area and informed City staff that there were no mosquito larvae or adult mosquitos. As a preventative measure, the area was still chemically treated.

LA County Vector Control has a follow-up meeting with Hyperion staff Jan. 15 to discuss progress made.

City staff and LA County Vector Control staff have received positive feedback from residents indicating that some are seeing a significant decrease in mosquitos.

Jan. 16 Update:

•  Hyperion staff met with Orkin Pest Control Service yesterday to assess the conditions on the Hyperion site.
• Hyperion and LA County Vector Control staff applied pesticide yesterday in the identified breeding areas.
• Hyperion staff are purchasing additional traps that will address both mosquitos and medflies.
• Hyperion is continuing their efforts to eliminate standing water and identify potential additional breeding areas within the Hyperion footprint.
• Hyperion upper management has approved overtime for their staff to work this weekend, if needed.
• Hyperion’s latest Mosquito Report reflects that the numbers have decreased significantly.

Jan. 20 Update:

LA County Vector Control has tested samples collected in the area and found no evidence of West Nile virus.

The following report was provided by LA County Vector Control to Hyperion yesterday, Jan. 19:

This report is a summary of mosquito surveillance and inspection activities in coordination with Hyperion and LA County Vector Control District personnel:

On Jan. 15, 2026, mosquito source inspection was carried out on the south side of the Hyperion facilities. LA County Vector Control and Hyperion staff targeted areas that had been identified earlier. During the inspection, LA County Vector Control staff observed that Hyperion had done a good job in pumping and clearing out standing water and have multiple submersible pumps located in large sump pumps with pesticide treatment.

Further, three clarifiers and one emergency final clarifier experienced overflow during that period. All offline facilities were monitored by Hyperion staff and mosquito abatement contractors, drained and pesticide treated. Also, multiple above-ground mosquito breeding and potential mosquito breeding sites were observed during this period, including flooded sites that were created by recent rainfall events. These areas are being addressed by either treatment or by draining. Screen mesh is being implemented at access points throughout the facility to ensure mosquitoes cannot enter.

LA County Vector Control staff continue to attend regular meetings with Hyperion staff to address these issues. LA County Vector Control will continue monitoring mosquito activity to protect public health.

Jan. 20, 3 p.m. Update:

The City just received the following info from Mara Luevano, the Director of Public Works in the Office of Los Angeles Mayor Karen Bass:

• LA County Vector Control and Hyperion staff will set out six additional traps along the greenbelt area between Hyperion and El Segundo this Wednesday, Jan. 21.
• Hyperion staff has been working with the County since this issue was raised in mid-December. Last Thursday, Jan. 15, staff met with LA County to address this issue. County staff returned today, Jan. 20, to continue the mitigation work.
• LA County Vector Control staff have been applying pesticides as needed. Hyperion also has a private contractor on standby to apply pesticide, if needed. Hyperion will purchase and use non-toxic BTI Mosquito Dunks as suggested by the County.

Updates will be provided as more information becomes available.