The Pit F tent has been cleaned and prepared for demobilization. The interior surface over the former pit is now sealed with hardened concrete-like slurry and Posi-shell. Interior air quality is confirmed as safe and consistent with outdoor ambient air. Starting the week of September 13, the cleaned Pit F tent fabric and structure will be dismantled and removed from the Site. Telemetry air monitoring for Pit F continues through the demobilization phase. Onsite perimeter and offsite neighborhood air monitoring continue 24/7, including after the Pit F demobilization phase is completed.

Trucks leaving the Site with dismantled Pit F tent materials and large equipment may depart the Magnolia Street exit gate turning right to Pacific Coast Highway, after being cleared by gate personnel.


ascon demobilization small equipment

Workers onsite are using small vehicles like the equipment pictured above for demobilization activities.


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

  • Current work: The Pit F active excavation phase was completed August 24, and all Pit F waste has been removed for disposal. The excavation area is now sealed with a hardened concrete-like slurry material between two to three feet thick. The surface area over and around the former pit also is covered with Posi-Shell®, a clay-based sealant that, when mixed with cement, dries to form a hard crust to prevent erosion and potential odor. There will be no more haul trucks with Pit F waste material leaving the Site. There is continued Pit F activity expected through September as part of equipment cleanup and demobilization. This activity includes cleaning, dismantling and removal of the Pit F tent from Ascon.

    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 and material hauling trucks arriving and leaving the Site, Monday through Friday, and Saturdays if necessary.

    You may hear: The air treatment system was turned off Friday, August 27, after decontamination of the Pit F tent material and air quality was confirmed to be safe inside the tent. Acoustic monitoring for the Pit F air treatment system has been removed.

    Periodic construction sounds during work hours, like vehicle backup signaling required for worker safety and noise from equipment. 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. Unannounced visitors without official business or agency oversight of Ascon are not permitted to enter the Site.

    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 demobilization activities.
    • City of Huntington Beach continues its regular stormwater inspections of Ascon. The latest inspection occurred Thursday, 8/26.
    • 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.


The California Department of Toxic Substances Control (DTSC) permitted a brief pause on daily air sampling and monitoring both onsite and at offsite locations over the holiday weekend to allow our personnel to be with their families. The pause began Friday, September 3, at approximately 7 a.m. and the air sampling and monitoring will resume at approximately 7 a.m., Tuesday, September 7. There is no field activity, earth movement, or Pit F demobilization activity during this pause.

Following the holiday weekend pause, 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 through the demobilization phase 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 through the demobilization phase of Pit F, 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