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D21 Ground gas collection and venting systems
GENERAL
110 GROUND GAS COLLECTION AND VENTING SYSTEMgenerally
• Site investigation: Submit risk assessment and report .
• Gases to be collected and vented: As note in the site investigation report.
• Gas collection:
- Venting layer and membrane: to suit gases idnetified in the site investigation
report.
- Pipework: to suit gases idnetified in the site investigation report.
• Depressurization sumps: to suit gases idnetified in the site investigation report.
- Type: to suit gases idnetified in the site investigation report.
- Size: to suit gases idnetified in the site investigation report.
• Gas venting and outlets: to suit gases idnetified in the site investigation report.
• Accessories: Submit proposals.
SYSTEM PERFORMANCE
210 RISK ASSESSMENT AND REPORT
• General: Undertake and submit report.
- Copies: 2.
- Timing: Before starting work on site.
• Contents:
- Identification of gas contaminants and their source.
- Extent and level of gas contamination.
- Evaluation of the consequences of the contamination not being treated.
- Assessment of potential or unacceptable risks.
- Other information: Any considered relevant.
230 DESIGN
• Design: Complete the design of the ground gas collection and venting system.
• Location: site specific.
• Performance criteria: site specific.
• Gas measurements: At any location throughout the site up to 5 m above ground
level should not exceed recomendations for the gases identified in the site
investigation.
• Proposals: Submit drawings, technical information, calculations and manufacturers'
literature.
• Builder's work: Submit requirements.
PRODUCTS
320 VENTING HARDCORE LAYER
• Fill: Clean granular material, well graded, passing a 75 mm BS sieve but retained on
a 20 mm BS sieve. In each layer only one of the following:
- Crushed hard rock.
- Crushed concrete, crushed brick or tile, free from plaster, timber and metal.
- Gravel.
RotF generic (intermediate) NBS 2014 6118-AEW-XX-XX-NBS-A-01
