North Vancouver Remediation Site

LOCATION: Burrard Inlet, North Vancouver BC

SCOPE OF WORK: LP6, OR RPE 25 & Actic Liner used in soil and water remediation application

PROJECT PARTNERS: Next Environmental Inc. Safety Kleen Ltd.


Submitted by: Scott Payne

Technical Sales Representative


Geosynthetics used in a soil and water remediation application



A private developer was unable to commence construction on a parcel of land because it contained contaminated soil. Development could not take place until the soil met provincial standards for commercial land use. The contaminated site is on both private and public lands. Access to the larger land parcel requires that the contamination on the public and private land be remediated to facilitate the construction of an overpass.



The project site is located on the shoreline of Burrard Inlet in North Vancouver, B.C. The site was first occupied by a sawmill from 1970 to 1986 which contaminated the soil with non-leaching metals. The soil and ground water has also been heavily contaminated with hydrocarbons, particularly diesel fuel. The source of this contamination is believed to have come from a bulk fuel facility on an adjacent property. The private land is part of a much larger parcel recently purchased by a developer, who in turn hired a project management company to coordinate the development of the proposed commercial complex.



The consulting firm, Next Environmental Inc., of Burnaby B.C. was retained by the project manager to design and oversee the site clean up process. Nine remedial options were considered to expedite the clean up. The need for a fast and conclusive remedial effort was paramount in selecting which technique would be employed. Remediation on this project involved three main operations:

  • Excavation of contaminated soil
  • Extraction and decontamination of contaminated ground water which flowed into the excavation pits
  • Bioremediation of hydrocarbon contaminated soil on the private lands. Heavy metals contaminated soil was handled identically as the hydrocarbon contaminated soil

Remedial technologies are classified into two categories:

1. Ex-situ methods for excavated soil

  • landfill disposal
  • bioremediation ie: bio-cells, land farming , bioslurry
  • solidification/stabilization
  • soil washing
  • solvent extraction
  • low temperature thermal desorption and incineration

2. In-situ methods for soil and ground water

  • soil vapour extraction
  • bioventing
  • air sparging
  • solidification
  • hot-air or steam stripping
  • radio frequency heating

All of these methods were evaluated for this site. The evaluation took into account protection of human health and the environment, technical feasibility/risks, time involved, and cost.

The objective of the remedial technology of choice, would be to remediate the soil and ground water, on site, as quickly as possible. Initial projections for remediation were anywhere from 5 to 10 years. By selecting the Bio-Cells remediation technique, they were able to expedite the remediation process to within a one year period. This has allowed the project management firm to schedule their development plans much sooner than originally anticipated.



Utilizing the bio-cell remediation technique, the contaminated soil is placed in a geosynthetic lined containment area. The soil pile is then protected with an impermeable cover to keep precipitation out of the containment area. The composition of the contaminants and their concentration levels dictate the formula of nutrients and bacteria that is sprayed and entrained into the contaminated soil. This process is done by installing piping in the soil pile and connecting the piping to a blower. A vacuum is applied to the piping system in order to supply oxygen to the hydrocarbon-degrading bacteria.

Containment of Concern in Remediation Site

  1. Polycyclic aromatic hydrocarbons - PAH
  2. Mineral oil and grease - MOG
  3. Light extractable petroleum hydrocarbons - LEPH
  4. Heavy extractable petroleum hydrocarbons - HEPH
  5. Polychlorinated Biphenyls - PCBs
  6. Benzene, ethyl benzene, toluene, and xylene - BETX
  7. Total extractable hydrocarbons - THE
  8. Volatile organic components - VOC


The contaminated ground water that was encountered in the excavations was collected in portable culvert sumps and channelled into holding ponds that were lined with a geomembrane. These containment areas served as both a reservoir and settling ponds. This permitted a steady flow through the treatment system and reduced the quantity of suspended solids which would have otherwise had to go through the system.

Contaminants of Concern in Ground Water

  1. Light extractable petroleum hydrocarbons - LEPH
  2. Total extractable hydrocarbons - THE
  3. Polycyclic aromatic hydrocarbons - PAH


Once the contaminated soil had been excavated to the property line, and placed in the containment cells, there was great concern that hydrocarbons would continue to migrate to the site from the adjacent property. To prevent this, a trench was excavated approximately 8 m deep along the property line. It was then lined with a geomembrane to act as a curtain preventing any contamination from re entering the site at this location.


The Bio-Cells' sub grade was first enhanced with a medium weight, non woven geotextile to improve its suitability for geomembrane placement. Like the geomembrane, the geotextile was prefabricated into large panels for a faster and more economical installation. By prefabricating panels it also saved on material by greatly reducing the amount of field overlaps. Each geotextile panel was approximately 1500 m2 in size. The specified product was LP6, a 6 oz/yd2 [205 gms/m2] non woven geotextile. The Bio-Cells were lined with the specified 20 mil Oil Resistant Reinforced Polyethylene [OR RPE 25]. This material selection was chosen for its; high strength to light weight ratio, chemical resistance, and its ability to be fabricated into large one piece liners up to 5,300 m2. The first Bio-Cell had a surface area of 9,900 m2 and was lined with three panels each measuring 28.3 m by 115.2 m. The second Bio-Cell was 11,000 m2 and was lined with two panels each measuring 47 m by 117 m. The ability to supply such large pre fabricated panels reduced the field seams of each cell to two seams and one seam respectively. This allowed the contractor to line each cell in one day and significantly reduced the installation costs.

The installation of the prefabricated liner and geotextile panels was performed by suppling one installation supervisor / technician and eight construction labourers.

Once the contaminated soils were placed in the containment cells, the soil was protected with the specified 15 mil Reinforced Polyethylene [RPE 15]. This material was selected for its; UV light stability, high strength to weight ratio, large one piece panels up to 8,800 m2, and impermeability. In addition to these feature, the material can be custom accessorised to enable the site operator to easily remove and replace the cover over the soil for maintenance.

The holding / settling reservoirs required complete containment for the contaminated water. It was critical that the specified lining material was installed without any leaks and that it performed for the required service life with out breaching. This required a liner that has a low permeability value, very strong and durable, UV light resistance, excellent hydrocarbon resistance, easily field repairable, and one that could be quickly installed by being brought to the site in large prefabricated one piece panels.

The Arctic Liner, 30 mil unsupported, was specified. There was three reservoirs to be lined, having surface area=s of 6,700 m2, 3,500 m2 and 3,300 m2. Custom sized prefabricated panels were supplied to the project site up to 1,800 m2 in one piece. The panels were field welded together using heat welding techniques [wedge welder]. All seams were destructively tested to ensure they met a minimum of 80 ppi bonded strength and 15 ppi peel adhesion with a film tear bond. Each seam was also 100% non destructively tested to ensure the seam continuity.

The sub grade was covered, prior to the Arctic Liner installation, with LP6 non woven geotextile to enhance its suitability for a geomembrane. It was supplied in large prefabricated panels as per the Bio-Cells.

The trench curtain, or "bad neighbour curtain" had to have long term hydrocarbon resistance and be very strong to survive the installation stresses. A 23 oz/yd2 supported [reinforced] polyurethane membrane was custom fabricated to be installed in the open trench. The operator of the site, responsible for constructing the treatment cells, was Safety - Kleen Ltd., a division of Laidlaw Environmental. Both Next Environmental and Safety - Kleen selected Layfield Plastics (1978) Ltd. to supply and supervise the installation of all the geosynthetics. Layfield Plastics offered:

  • the complete material selection
  • custom fabrication capability
  • long standing reputation for high quality products and installation services
  • competitive pricing

All of the above points positioned Layfield Plastics as the best choice for this highly sensitive project.


By selecting the Bio-Cell remediation technique, and incorporating prefabricated geosynthetic products, the site operator was able to construct the cells to treat the contaminated soils and water in a fraction of the time other techniques would have taken. Application can be made for a Certificate of Compliance which will enable the developer to proceed with its development much sooner than originally anticipated.


J. Bud Williams Project Manager Harbey Bains, P. Eng. Safety - Kleen Ltd.

Next Environmental Inc 7483 Progress Way 215 - 2550 Boundary Road Delta, BC Burnaby, BC V4G 1E7 V5M 3Z3 .

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