Stormwater Source Control Design Guidelines 2005 - Waterbucket

Stormwater Source Control Design Guidelines 2005Pervious Paving16. Avoid utility or other crossings of the pervious pavementarea. Where utility trenches must be constructed crossingbelow the reservoir, install trench dams at exits to avoidinfiltration water following the utility trench.Guideline SpecificationsMaterials shall meet Master Municipal Construction Document2000 requirements, and:1. Pavers: Permeable Interlocking Concrete Pavers meetingCSA A231.2, designed and tested by the manufacturer foruse as part of a permeable unit paving system with a initialinfiltration rate >280mm/hr. and a maintained>28mm/hr infiltration rate over the pavement life (usually20 years) (Smith, 2001).2. Paver bedding course (50mm thick) and joint fillingmaterial shall be open-graded crush 5mm aggregate (orASTM No.8 - no sand). A surface finish of 3mm cleancrush aggregate (or ASTM No 89) should be applied tothe finish surface and brushed in (Formpave, 2003; Smith,2001).3. Reservoir Base course shall be clean crushed stone gradedfrom 5mm to 20mm (approximately 100mm deep orgreater – varies with design) (Formpave, 2003). In caseswhere this finer base is not required for water qualitytreatment, the Reservoir Base may be the same material asthe Reservoir Subbase.4. Reservoir Subbase shall be clean crushed stone gradedfrom 10mm to 63mm, with void space ratio >35% (orASTM No. 57 – approximately 250mm deep or greater –varies with design) (Formpave, 2003; Smith 2001).5. Pipe: PVC, DR 35, 150 mm min. diameter, with cleanouts.Practical depth of cover over the pipe may be adeterminant in depth of base courses.6. Geosynthetics: as per Section 02498, select for filtercriteria or from approved local government product lists.Greater Vancouver Sewerage & Drainage District57