CADD based details for pond systems are contained in the section on drawings. The following details, with specifications, have been created for infiltration systems:

  • infiltration basin
  • infiltration trench
  • subsurface infiltration system
  • inlet/outlet structures

Construction specifications

Given that the construction of infiltration practices incorporates techniques or steps which may be considered non-standard, it is RECOMMENDED that the construction specifications include the following format and information.

Temporary erosion control

  • Installation prior to site disturbance
  • Catch basin/inlet protection
  • Use of BMP as temporary sedimentation basin

Excavation, backfill and grading

  • Timing of grading of infiltration practices (relative to total site development)
  • Use of low-impact, earth moving equipment
  • Controls to ensure site is not over-excavated
  • Restoration in the event of sediment accumulation during construction of practice
  • Gravel backfill specifications
  • Gravel filter specifications
  • Filter fabric specifications
  • Observation well specifications

Native plants, planting and transplanting

  • Site preparation of planting areas
  • Timing of native seeding and native planting
  • Weed control
  • Watering of plant material
Warning: It is REQUIRED that infiltration systems not be excavated to final grade until the contributing drainage area has been constructed and fully stabilized.

Construction sequence scheduling

  • Temporary construction access
  • Location of silt fence installation to protect BMPs and downgradient receiving waters
  • Removal and storage of excavated material
  • Installation of underground utilities
  • Rough grading
  • Seeding and mulching disturbed areas
  • Road construction
  • Final grading
  • Site stabilization
  • Installation of semi-permanent and permanent erosion control measures
  • Silt fence removal (often forgotten but an essential step)

Construction observation

  • Adherence to construction documents
  • Verification of physical site conditions
  • Erosion control measures installed appropriately

Related pages

This page was last edited on 11 December 2022, at 14:46.