Erosion and Sediment Control

Builders must follow best practices to prevent sediment runoff; streets must stay clean, and no silty water should leave the site.

Please refer to PLI Bulletin: Erosion and Sediment Control

All builders must ensure:

• No mud, silt, or silty water leaves the site
• Vehicle tires stay on pavement or clean gravel
• No discharge of dirty water into drains, creeks, ditches, or neighbouring properties
• Discharged water must meet the quality limit of 25 NTU or less

• ESC Plan: Must be prepared by a Qualified Professional and cover all phases of development until 90% final completion (paving, landscaping and building construction).
• ESC Permit: Required before any land clearing, grading, or grubbing. No building permit or pre-construction meeting will be issued without it.
• Compliance Monitoring: A Qualified Professional must monitor site conditions and water quality. The Township also conducts audits.

1. Submit Required Documents
   • ESC Schedule 'A' Control Permit Application
   • ESC Schedule 'C' Letter of Appointment
   • ESC Plan prepared by a qualified professional
2. Estimate ESC Costs
   • Your ESC designer submits a cost estimate for review
   • The Township calculates your permit fee and security deposit
3. Pay Fees and Security
   • Application fee
   • Security = 120% of your ESC estimate
   • Permit is typically issued within one week after payment
4. After Issuance
   • Valid for one (1) year; extensions available upon request if received prior to the expiry date
   • Allows you to undertake temporary works for ESC purposes only. It does not mean you have received approval from any other Township departments

Obtaining a permit requires hiring a Qualified Professional monitor. The monitor’s duty is to:

• Observe, record and report any ESC issues to the permit holder and contractor for their attention.
• Inspect all erosion and sediment control related works at minimum once per week, or after each Significant Rainfall Event whichever is greater
• Conduct water sampling when discharging to Township infrastructure
• Immediate reporting of all ESC permit violations 
• Maintain a logbook
• Schedule inspection with ESC Coordinator and ESC Designer, once primary ESC measures are installed. Construction may not continue until this meeting has been held.
• Upload monitoring reports via Erosion and Sediment Control Inspection Report

Water leaving your site must meet these turbidity limits:

• Normal Conditions: ≤ 25 NTU
• Significant Rainfall (25 mm+ in 24 hrs): ≤ 100 NTU (for 24 hrs post-event)

To determine whether your site can discharge up to 100 NTU, visit the Township’s rainfall gauge indicated on your permit:

• Langley Rainfall Gauge – FlowWorks

What to look for

• Red Triangle on the “Langley Municipal” gauge = 100 NTU limit is active
  (Valid during and for 24 hours after a significant rainfall event of 25 mm+)
• Green Line = Rainfall has slowed. If the red triangle is still visible, the 100 NTU limit may end soon unless more rain falls.
• No Red Triangle = Your site must meet the 25 NTU limit

This visual indicator helps you stay compliant with ESC discharge requirements in real time. The red triangle is shown for up to 48 hours following the SRE. Users need to be aware and confirm the SRE occurred within the last 24 hours.

• DFO Sediment Limits
• Erosion and Sediment Control Bylaw (No. 4381)
• Erosion and Sediment Control Inspection Report
• ESC - Chemical Treatment Checklist
• ESC Sched 'A' Control Permit Application
• ESC Sched 'C' Letter of Appointment