2023 Trenchless Technology Project of the Year Rehab Honorable Mention: Asbestos Abatement UV CIPP Rehabilitation Through Protected Environments in Santa Maria, California

This project consisted of trenchless rehabilitation via UV cured-in-place-pipe (UV CIPP) lining of 20,000-plus ft of 21- and 24-in. diameter asbestos cement sewer pipe (ACP) after inspections showed significant deterioration.

The sewer is owned and operated by the Laguna County Sanitation District. The District provides wastewater services to the Orcutt and southern Santa Maria area and serves a population of 35,000 with a total of 129 miles of sewer pipes.

Also included were pre- and post-rehabilitation cleaning and video inspection, sewage bypassing, chemical grouting of joints prior to lining due to groundwater intrusion, and asbestos abatement through the environmentally protected Central Coast region in Santa Maria, California.

The rehabilitation involved removal of damaged, exposed and friable asbestos debris from degraded pipe. Asbestos controls were implemented to comply with regulatory criteria, which included a filtration system to capture waste streams from pre-rehabilitation cleaning and the removal, transportation, and disposal of the asbestos. Material had to be decanted into sealed filtration bins and pumped through two more micron filters before the water could be pumped into a sealed truck and the remaining debris removed from the filters and sent to an asbestos disposal site.

Asbestos measures were approved by a certified asbestos consultant and monitoring was conducted by a certified site surveillance technician. Licensed asbestos personnel were employed to prevent worker exposure to asbestos fiber emissions, and visual inspections and air monitoring were conducted to document safe workplace conditions.

The project required considerable sewage bypass operations, including bypassing three separate pipes into one main header pipe and installing vehicular ramps to ensure employee and fuel tanker access to the nearby Santa Maria Airport. Pumps were sized for peak flows of over 2,000 gpm and multiple standby pumps were implemented to ensure accommodation – the specifications required 100 percent backup of all major pieces of equipment.

Environmental avoidance and minimization measures were undertaken to comply with the District’s Habitat Conservation Plan and State and Federal incidental take permits for associated endangered and threatened species (California tiger salamander and red-legged frog). These measures included worker awareness training, burrow inspection surveys, delineating all construction access routes and staging areas, and daily biologist monitoring.

Why Project Is Outstanding

The Laguna County Sanitary District Asbestos Abatement Rehabilitation Project originally underwent feasibility exploration over a decade ago — ultimately conventional replacement and rehabilitation methods were deemed too high risk. Through the recent recommendation, testing and demonstration of innovative technologies, in addition to unprecedented coordination across many specialist groups with a singular mindset towards sustainable trenchless solutions, the successful delivery of this unique market defining project was finally realized in November 2022.

Among the unique considerations:

• Thousands of pounds of asbestos safely processed and responsibly disposed of through novel filtration solutions and coordination with specialized asbestos personnel
• Sophisticated, redundancy backed sewage bypass configurations through all project phases
• High-risk project in sensitive areas required considerable cooperation with the community; local property owners and tenants, operations crews from nearby airport, farmers with commercial operations (livestock pastures, strawberry and broccoli fields), and even local fauna (grazing cows, badgers, ground squirrels)
• Rigorous environmental protections observed, especially regarding Federal and State Endangered and Protected species
• Due to environmental and site restrictions, extremely limited jobsite footprints, access points, and weight considerations despite project complexity and variety of specialized personnel and equipment
• IMPREG UV CIPP liners chosen to fully encapsulate remaining residual asbestos (after testing proved no post-project material migration). UV cure prevented heating of friable asbestos matter, and the ability for onsite staging without refrigeration trucks eased site footprint, transit timeline, and coordination concerns
• Coordination of Independent Specialists: sewer cleaning crews, CCTV crews, asbestos remediation contractors, bypass contractors, biologists, industrial hygienists, district engineers.

Owner: Laguna County Sanitation District
Engineer: Santa Barbara County Public Works
Contractor: Performance Pipeline Technologies; subcontractors Qwik Response Restoration & Construction and Charles King Co.
Manufacturers/Suppliers: IMPREG and United Rentals
Value of Trenchless Project (US$): $4,100,000