UST + Site Investigation + Remediation
A historical underground storage tank containing heating oil was leaking from a residential property onto a City of Vancouver (the City) owned laneway. Ambleside Environmental (Ambleside) was engaged to complete an onsite underground storage tank remediation and subsequent offsite Updated Stage 2 Preliminary Site Investigation, and subsequent Remediation.
Ambleside was initially engaged to provide supervision and soil sampling of an underground storage tank remediation on a residential property. The soil sample results found that the tank had leaked and hydrocarbon contamination in soil was evident at the property boundary indicating offsite migration onto the City lane.
The sale of the residential property triggered the requirement for an offsite delineation program. The investigation included drilling soil bores for soil sample collection and conversion to groundwater monitoring wells. Soil vapour probes were installed in select locations. The investigation identified a hydrocarbon plume in the soil and groundwater on the lane and prompted remediation to more stringent Residential Land Use standards (as required by the City).
The remediation Site crew was made up a multidisciplinary team consisting of: environmental technicians, scientists and engineers; geotechnical engineers; materials engineers; drillers; traffic controllers; machine operators and labourers; service locators; City inspectors; pavers; and hydrovac operators. Remediation works were complicated by the presence of multiple utility lines including fibre optic, gas, catch basin and hydro. Lines were daylighted using non-destructive digging methods. Contaminated soil and groundwater were disposed of at an approved facility. Ambleside collected closure results and documented the findings in a report for submission to the City, the Client (previous property owner) and the current property owner.
All works were conducted under the City’s Street Use Permit and Traffic Special Zone Permit. Ambleside also submitted a “Notice of Independent Remediation”, “Site Risk Classification Report” and “Notice of Offsite Migration” to the BC Ministry of Environment (BC MOE).
Ambleside’s selection of a committed and experienced Site crew meant additional requirements by the City inspectors and variable subsurface conditions were handled efficiently and professionally. Changes were managed onsite through a strong communication plan with select site staff and office support to provide the Client with new strategies while minimizing any cost increases or project delays. Site machinery were directed to continue working to avoid machine downtime. Once Client approval was granted, the adjustments were successfully implemented. Ultimately, due to the quick thinking nature of the Site crew and immediate communication to the Client, each work program was completed on time without the need for City permit extensions.
As part of City permit requirements, Ambleside worked closely with the residential property manager to distribute flyers and conduct a door knock to all residents and immediate neighbours. This explained the project work planned and physical restrictions to the work area. This allowed the majority of questions to be answered prior to Site work and minimized interactions with the public during the operation of heavy machinery around the open excavation, ensuring a safer workplace for Site crew and the public.
Successful completion of the remediation has ended the Client’s environmental liability associated with the Site.