There are multiple levels of air monitoring during Pit F work, including in the work zone, perimeter of Ascon, and offsite in neighborhoods and schools near Ascon.

In addition to 24/7 air monitoring conducted at the perimeter of the Site and at neighborhood stations, a telemetry-based air monitoring network is collecting additional air quality data during work hours during Pit F cleanup.

Community members can view near real-time air monitoring data from the Pit F area on the Pit F Telemetry Air Monitoring  webpage. By selecting the calendar icon, you can view cumulative data, or from a specific time period. DTSC is at the Ascon Site every day during Pit F work and include their independent air monitoring in DTSC inspection reports under the Ascon “site activities” tab on DTSC’s online database, EnviroStor.

community alert system


  • MAINTENANCE: Regular maintenance will be conducted within the Site and around the perimeter fence areas, including gate areas.

  • Current work: Workers inside and around the large white tent the east side of Ascon near Magnolia Street are conducting Pit F excavation work. The air treatment system is currently operating 24/7 during excavation. As of the week ending August 13, 2021, the excavation phase is over 50 percent complete.

    You may see: Workers arriving before 7 a.m. for safety briefings. Workers, materials, and large equipment, like manlifts, small cranes, excavators, water trucks, forklifts, street sweepers, material hauling trucks, and waste hauling trucks, may be arriving and leaving the Site, Monday through Friday, and Saturdays if necessary.

    You may hear: A low-level hum for the air treatment system, which has been mitigated with 20-foot and 8-foot sound panels and sound blanketing in addition to the 16-foot sound wall along Magnolia Street. Acoustical engineers have conducted sound metering in multiple neighborhood locations to confirm compliance with local ordinances for residential areas. This system is required to operate 24/7 during the duration of Pit F work to maintain a vacuum environment and treat air inside the tent for workers and our neighbors.

    Construction sounds during work hours, like vehicle backup signaling required for worker safety and noises from equipment, such as the grout plant, supporting excavation within the tent. Workers will minimize backing up vehicles when possible and when it is safe for workers and equipment.

  • SECURITY: 24-hour onsite security continues. Security is not always visible at the entrance gates. In addition to 24/7 onsite security, there are regular visits by air quality technicians, Site inspectors and Site maintenance personnel. During Pit F active work there is overnight equipment monitoring personnel onsite.

    You may see: You may see flashlights or headlights from a limited number of vehicles at night conducting inspections and providing security at the 38-acre Site.


    • DTSC continues its ongoing weekly inspections of Ascon. DTSC plans to be present for key Pit F mobilization activities and daily during Pit F excavation work.
    • City of Huntington Beach continues its regular stormwater inspections of Ascon.
    • Regular inspection of the “Pit F” tent will be conducted.
    • Regular inspections are conducted by Orange County Mosquito and Vector Control District of the onsite detention basins and other areas of the Ascon Site where water may be detained.
  • NEARBY ACTIVITIES: Bonfires in fire pits at Huntington State Beach have increased with summer activity, which periodically can generate a noticeable fire or smoky odor at and around Ascon. Please note there currently is a large mural painting project at the AES power facility southwest of Ascon. There are automobile storage activities that may generate noise or dust unrelated to Ascon at the former tank farm property, south of Ascon and adjacent to Magnolia Street. There is planned renovation work occurring at Eader Elementary School this summer, which includes construction and painting.


Air monitoring continues both on the Ascon Site and at community locations, which includes dust data at upwind (offsite sources) and downwind stations on the Ascon Site documenting effective dust control measures.

Where to find Pit F telemetry air monitoring data: Near real-time air monitoring data during working hours from the Pit F area is being shared during excavation work on the Pit F Telemetry Air Monitoring webpage.

Where to find 24/7 air monitoring data and live stream weather: Sitewide and neighborhood air monitoring data and live streaming weather conditions from the Ascon site are found on the Actively Monitoring Air Quality page on asconhb.com. Data are submitted to DTSC and shared on their online document archive, Envirostor. To view archived air monitoring results posted by DTSC on Envirostor, click on “Community Involvement Documents” and scroll to “Updates and Information.”


DRONES: The community is asked to not fly drones over the Ascon Site and over the Pit F tent during this work. This could create worker and Site safety issues. We appreciate the community’s assistance by preventing drone flights over the occupied tent structure, sensitive equipment onsite, and moving vehicles and workers conducting work onsite, as well as the power lines along the perimeter of Ascon.

ENTRANCE AND EXIT GATES: The community is asked to keep a safe distance from both entrance and exit gates at Ascon, and refrain from parking, walking, or standing in these areas. The exit gate on Magnolia Street may open unexpectedly for departing vehicles during Pit F work. There will be a flag person at the gate when vehicles are departing, as a public safety practice.

PEDESTRIANS: Pedestrians have been observed walking next to Ascon along Magnolia and Hamilton streets next to the concrete fence base where there currently is no sidewalk. We encourage pedestrians to use the sidewalks on the east side of Magnolia and the north side of Hamilton to avoid walking near or in front of entrance and exit gates.

PHYSICAL DISTANCING: Work at Ascon is being conducted under Site safety protocols regarding COVID-19 and ongoing protocols and procedures to maintain job safety. These practices apply to air quality professionals and other team members who may be outside the fence conducting work. We ask for the community’s support of these safety practices by maintaining physical distancing to allow these professionals to focus on their work and stay safe.

Recent Posts