- Type: Retention basin
- Location: Chevron Willbridge, Portland, USA
- Area: 4,800 m²
- Product: COLETANCHE® ES2
In the United States, the federal government regulates secondary containment systems for aboveground storage tanks (ASTs) at terminals and refineries through the Clean Water Act. This law recommends that the dikes and embankments surrounding the facility be “sufficiently impermeable”.
Chevron Willbridge’s constraints are:
- Sandy gravel soils on site.
- No existing slope or rainwater collection system.
- Existing pipes, numerous penetrations, blocks and footings.
- Limited working space.
- Irregular stop-and-go planning for waterproofing installation.
- Construction during the wet, windy and cold season.
- Work on already sealed areas.
Chevron planned to replace two old riveted reservoirs with two new large reservoirs that complied with the city’s requirements by installing an “impermeable floor” over the gravelly soil. Waterproofing products were compared in order to select the best solution in terms of construction, operation, maintenance, financial performance and compliance with regulatory criteria.
The client chose COLETANCHE® geomembrane for this project because of:
- Its high puncture resistance.
- Its UV resistance.
- The ease of installing around and under obstacles.
- No specialist contractor required for installation.
COLETANCHE® can be installed in wet, windy conditions and cold temperatures of -40°C.
The ability to use vehicles normally used for site maintenance (pick-up trucks and small loaders).