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
Information: 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)