Time-Critical Removal Action for Phase II of UXO Site 00141 (Small Arms Range Complex B), Naval Air Station North Island, Coronado, California
Client: NAVFAC Southwest, Environmental Core Team
Project Overview: The primary objective of this Time-Critical Removal Action (TCRA) was to reduce imminent ecological risk to birds and small mammals known to inhabit the site by preventing exposure to sediment containing lead and polycyclic aromatic hydrocarbons [PAHs] at concentrations levels determined to be non-protective of potential human and ecological receptors. ERRG performed excavation of contaminated sediment, pre-excavation optimization and post-excavation confirmation sampling, transportation and off-site disposal of contaminated soils, importation of backfill material that matches the physical characteristics of the surrounding sediment and is protective of ecological receptors, and restoration of habitat to facilitate the re-establishment of federally protected species.
Distinctive/Unique Features: Naval Air Station North Island (NASNI) consists of 2,500 acres of contiguous land and is located on the northern end of the Silver Strand Peninsula in southwestern San Diego County. The UXO Site 00141 is located in the center of the southern coastline of NASNI and is approximately 37 acres.
UXO Site 00141 was formerly a skeet and trap range. It is currently an undeveloped beachfront area covered with thick non-native invasive ornamental species (i.e., ice plants) and an undeveloped beach/sand area along the coastline. It is also home to several bird species including two special-status bird species: the burrowing owl (Athene cunicularia) and the Western Snowy Plover (Charadrius alexandrinus nivosus).
NASNI UXO Site 00141 has these constraints and considerations:
Active small arms training range at the NASNI base
To ensure the small arms range can remain in operation, the Navy requested that fieldwork be performed at night between 3:30 pm and midnight, Friday through Tuesday, and on weekends during the day.The breeding and nesting seasons of two special-status bird species
To avoid impacts on the two special-status bird species identified at UXO Site 00141, fieldwork was scheduled to be completed outside the avian nesting season, between 15 September 2022 and 15 March 2023.Proximity to the NASNI Runway
The NASNI UXO Site 00141 is located adjacent to the flight operations on base. Actions needed to be taken to ensure night lighting did not create glare interference and impair the visibility of flight operations for air traffic.Proximity to the Port of San Diego (and associated supply chain issues)
Significant financial impacts to the overall cost of the project were encountered due to a change in market conditions affecting the availability and cost of trucking.
Challenges/Solutions: This project operated on a non-standard work schedule (i.e., nights and weekends) which was intended to eliminate disruption to weekday training. At night, the work areas needed to be illuminated, while at the same time, adjacent runways remained in operation. The considerations of glare interference affecting operations on the runway and/or the control tower limited our work areas and the ability to set up lighting as needed, which reduced production rates. To eliminate these challenges, ERRG coordinated with the Range Chief to identify and secure a clear area outside of their range safety limits which would allow us to safely perform fieldwork during normal daytime operations Monday through Friday. Normalizing the schedule improved the safety of the field crew and increased our production productivity, resulting in fewer days in the field required for project completion.
End Result/Customer Satisfaction: As a result of these actions, ERRG resolved potential significant financial impacts for the Navy, improved the schedule and safety of the field crew, facilitated the protection of the Western Snowy Plover’s nesting season by shortening the schedule, and eliminated any operational interference with the small arms training range and the base runway operations. The Navy was very pleased that ERRG was able to solve the problem with a series of thoughtful and effective solutions.
