Ballast Environmental provided the following to achieve project goals:
- completion of a Phase I and Phase II ESA in accordance with CSA standards
- delineation of the impacted material
- development and implementation of a remediation plan including an onsite groundwater treatment system and treatment cell construction
- liaison with regulatory bodies regarding compliance issues and remediation options
- project management and supervision of the remediation plan
- development and implementation of a Risk Management Plan
- monitoring as per the Risk Management Plan
Phase I ESA: Ballast Environmental conducted a Phase I ESA on an industrial property that manufactured wire products (subject site). The subject site was approximately 16,000 m2 in size and had been an active industrial site since the 1950’s. The site was complex in that there were five different sources of contamination caused by adjacent properties and previous on-site tenants (fuel station, card lock site, metal foundry and transformer). The Phase I ESA was instrumental in determining the sources of contamination and assigning the liability for the remediation to the responsible parties.
Phase II ESA: A Phase II ESA was completed to compliment previously completed subsurface investigations. The Phase II ESA confirmed the soils were contaminated with hydrocarbons (from underground storage tanks, aboveground storage tanks, adjacent main rail line and solvents) and metals. The groundwater was contaminated with hydrocarbons and metals. The soils in the area of the previous underground storage tank contained a flashpoint that was considered hazardous and as such could not be hauled off site. It was also discovered the majority of the site was backfilled with spent foundry sand and debris from the previous foundry located adjacent to the site. The spent foundry sand was contaminated with polycyclic aromatic hydrocarbons (PAHs), chromium and nickel with some pockets of copper and molybedenum and there was estimated to be a volume of approximately 70,000 tonnes.
Phase III ESA: Remediation
Several remediation options were evaluated for this site: recycling of the foundry sand, two stage ex-situ soil treatments (thermal and soil washing) and the traditional soil relocation. A combination of recycling and soil relocation was the chosen method of remediation for all soil contaminants. The spent foundry sand (sand) was excavated and run through systems of screeners and sorters to allow for retrieval of recyclable materials.
Another layer of marginally contaminated soils was separated and hauled to an alternative landfill at significant cost savings.
The hazardous, hydrocarbon contaminated soils were placed in a treatment cell and treated onsite until it met Hazardous Waste Criteria and could safely be hauled off site to an appropriate landfill.
Groundwater Treatment: The water table was between 2 and 3 metres below surface. It became necessary to pump contaminated groundwater during portions of the excavation. An additional effect of removing this contaminated groundwater was to encourage the infiltration of non-impacted groundwater and promote natural attenuation processes within the local hydrogeological system. A passive treatment system was designed and used using a new and innovative product: virgin coconut shells. The treated groundwater was then discharged to the City of Calgary storm-water system. The entire groundwater treatment process was completed in winter.
Additional potential sources of impacts were identified during on-site remedial activities. Contaminated soil and groundwater was still present on adjacent properties and as such, environmental geo-membrane liners were installed to reduce the potential for contaminant migration from these adjacent properties. The geo-membrane liners were hydrocarbon resistant and safe for potable water aquifers. The remediation was successfully completed in conjunction with other stakeholders who were also remediating impacted areas within the same property. Our client’s portion of this multimillion dollar project included removal of 62,000 tonnes of contaminated material and recycling of 3,500 tonnes of concrete and 1,700 tonnes of metal.
A Risk Management Plan (RMP) was developed and approved by regulatory bodies to address impacted groundwater located upstream and downstream of the subject site. The purpose of the RMP is to collect and analyze representative groundwater samples to confirm that the concentrations of the contaminates of concern were stable or decreasing. The site was monitored on an annual basis as per the RMP and regulatory closure was achieved after 4 years of monitoring.
The clients objectives were successfully achieved shortly after remediation was completed. The work completed by Ballast Environmental made it through the due diligence process, the property was sold (multi-million dollar property) and successfully re-development by the new property owner.