Protective materials and methods for prevention of anything but clear rainwater runoff entering the stormwater system must all be in place before any soil disturbance occurs.
Protect natural vegetation and trees. Use vegetated buffers where possible. Before soil disturbance or grading, mark clearing limits and sensitive areas for protection. Provide recognized and commonly-used construction barrier materials to secure the work site. Direct surface drainage around the work area.
2. Establish Construction Access
Minimize vehicle access points and the amount of vehicular traffic. Stabilize the vehicle entrance access point with crushed rock or similar material.
Crushed materials such as limestone are not allowed under any circumstance. Clean the road surfaces on a regular basis and, at a minimum, at the end of each work day/shift. Minimize mud and dirt tracked onto paved roads. Shovel and sweep mud off the roadway.
Do not rinse away dirt or mud with water to the storm drains! A muddy ramp is NOT a good access point for vehicles. The mud tracked onto streets will wash out in stormwater.
3. Control flow rates
It is our intent to reduce site impacts where specific flow controls will be required. In the event that flow control is required, only proven methods will be approved for use.
Protect properties and waterways downstream from the site from impacts of stormwater runoff. Always seek a resolution that reduces flow to the absolute minimum and prevents erosion at all costs.
4. Install sediment controls specific to the site topography
Any information specific to the site topography, drainage, soils and vegetation must be noted and planned for before commencing work.
Provide alternative Best Management Practices (BMPs) for difficult sites where most standard BMPs may not provide the protection required. Pass stormwater through a sediment pond, sediment trap, filter, or another equivalent measure before it leaves the site or enters drain inlets.
5. Stabilize soils
Soil stabilization measures include temporary and permanent seeding, mulching, geotextiles, erosion control fabrics and sod stabilization. Identify any potential erosion problem areas and report them to your engineer.
6. Protect slopes
Design and construct cut-and-fill slopes to minimize erosion. Methods may include terracing and diversions, and reducing steepness. Divert runoff around slopes and disturbed areas with pipe slope drains. Provide recognized and commonly-used construction barrier materials to secure the work site.
7. Protect drain inlets
Inspect drains, catch basins and other stormwater sewer components routinely. Protect all storm drain inlets from sediment. Install catch basin filters according to Best Management Practices. Clean and remove sediment from inlet protection devices when they fill to 1/3 of their capacity.
8. Stabilize channels and outlets
Stabilize drain outlets, adjacent stream banks, slopes and channels with armoring such as rocks or gravel. Install silt fencing along creeks during construction. No work can take place within 15m from the top of the bank without a valid Environmental Development Permit.
9. Control Pollutants
Follow the District of West Vancouver Waterworks Protection Bylaw:
Prevent chemicals and other pollutants from coming into contact with stormwater.
Handle and dispose of prohibited substances properly.
Prohibited substances include: pesticides, herbicides, fertilizers, soap, detergents, household and commercial grade cleaning compounds, paints, solvents, chemicals, chlorinated water, waste oil or any material or substance which is a hazardous product, contaminant, toxic substance, deleterious substances, special waste, dangerous goods or reportable substance including any substance whose discharge to the watercourse system would violate the Environmental Management Act.
Prevent or treat contamination of stormwater runoff by alkaline sources such as: bulk cement, cement kiln dust, fly ash and water used to wash and cure concrete.
Obtain written approval from The District of West Vancouver prior to using chemical treatment other than CO2 to adjust pH.
10. Control de-watering
Carefully control de-watering. Extreme care needs to be taken when doing this task. If you have muddy or contaminated de-watering water, then treat it separately from other stormwater runoff.
11. Maintain Best Management Practices
Inspect erosion and sediment control Best Management Practices (BMPs) at least once every seven days and within 24 hours after any discharge from the site.
Cleanup and maintenance is a critical element for success. Cleanup activities: remove or stabilize on-site trapped sediment. Follow BMPs for proper disposal.
12. Manage the project
When possible, plan to construct projects in phases. Sequencing will reduce the impact to soils and surrounding stormwater systems. Record data. Whether conducting stormwater investigations, inspections, preventive maintenance work, recording flow levels or repairing stormwater system components, it needs to be documented.
See Confirmation of Commitment Letter for the required inspection schedule to be submitted from your engineer. Reports are to be sent to: