For contractors, project managers and/or landowners, the risks of uncontrolled runoff are project delays and increased costs. These can occur due to:
- Sediment transport: Loose soil from construction activity such as grading, excavation, or stockpiled materials can be washed offsite resulting in clogged storm drains and pressure on local streams.
- Water quality impacts: Suspended solids (TSS), turbidity, pH changes, and other pollutants in runoff can harm natural environments and aquatic life.
- Regulatory non-compliance: The effects of the movement of soil and sediment can violate municipal bylaws and other provincial and even Federal regulatory guidelines.
How ESC Tanks Help
ESC tanks, such as the ones manufactured by Canwest Tanks, are engineered units that can be installed on-site to capture and retain runoff during construction storms. Their advantages are:
- Sediment settling: Slower flow within the tank allows heavier particles to precipitate out before discharge.
- Modular capacity: Canwest Tanks offers various sizes suitable to the specific site and expected rainfall.
- Integration with filtration: The tanks can be fitted with filters, sand or geotextile cartridges, or flocculation systems for finer treatment.
- Better control during dewatering: When pumping groundwater or excavations, tanks act as holding vessels.
- Reduced turbidity risk: By moderating discharge, ESC tanks help you meet turbidity or TSS limits set by municipalities.
BC & Municipal ESC Standards & Guidelines
The following are some resources for determining a reliable ESC tank strategy:
Provincial / Guideline Documents
- BC Erosion and Sediment Control Manual (Nov 2022). The provincial reference manual for ESC in highway, infrastructure, and civil works in BC. (Province of British Columbia)
- BC Joint Professional Practice Guidelines ESC (2024). These provide guidelines for ESC planning, monitoring, and professional accountability in BC. (cab-bc.org)
- Many municipal ESC bylaws (e.g. Surrey’s bylaw) reference specific TSS or turbidity limits. (surrey.ca)
Municipal / Local Bylaws & ESC Programs
- City of North Vancouver / Stream & Drainage System Protection Bylaw No. 7541. Key requirements include turbidity limits and prohibition of sediment, concrete wash, or other “prohibited substances” entering the drainage system. (City of North Vancouver)
- City of Vancouver — ESC for large lot developments (≥ 1,000 m² or deeper excavation) — Projects of this scale must submit an ESC Plan with measures to treat runoff, specify discharges, control pH, protect inlets, schedule phases, and monitor discharge. (City of Vancouver)
- City of Abbotsford, ESC Bylaw (2010). This bylaw prohibits discharge of sediment or sediment-laden water into the drainage system, with turbidity limits that are stricter than municipal or Fisheries Canada limits. (laws.abbotsford.ca)
- District of West Vancouver, Watercourse Protection Bylaw (4364, 2005) This bylaw requires ESC planning and periodic inspections. (West Vancouver)
Call to Action
For contractors in BC, installing ESC tanks is a necessary practise for risk mitigation, regulatory compliance and environmental stewardship. Canwest Tanks & Ecological Systems, specializes in custom ESC Tank solutions so that our motto, “Totally Safe Water” can extend to your construction site.
Resources: You may wish to check full municipal rules at the links provided below or on your own municipality’s website.
- BC Erosion & Sediment Control Manual (Nov 2022) (Province of British Columbia)
- BC Professional Practice ESC Guidelines (2024) (cab-bc.org)
- City of North Vancouver ESC & Bylaw No. 7541 (City of North Vancouver)
- Vancouver’s ESC Plan requirements for large sites ≥ 1,000 m² (City of Vancouver)
- Surrey’s ESC bylaw & threshold of 75 mg/L TSS (surrey.ca)
- Abbotsford ESC Bylaw 2010 (turbidity, discharge limitations) (laws.abbotsford.ca)
- West Vancouver’s ESC requirements and inspection schedule (West Vancouver)