Gridtech SuStainable urban Drainage SyStemS Gridtech Source control and Surface water treatment train Source control techniques include:

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1 Sustainable Urban Drainage Systems w w w.gridtech. c o m

2 Gridtech Sustainable Urban Drainage Systems The reduction of natural surfaces and subsequent increased usage of hard impermeable surfaces (roads, parking areas, roofs etc.) throughout the last century has contributed to the increasing incidence of localized and regional flooding and pollution of rivers, estuaries and coastal waters. Rainfall that once infiltrated through natural ground is now typically drained over impermeable surfaces containing oil, grease, rubber, silt, cleaning fluids etc., creating increasingly polluted surface water runoff. Sustainable Urban Drainage Systems (SUDS) contain a series of alternatives to paving, cost effective techniques that are designed to manage surface water runoff as close to the source as possible in a more sustainable manner than traditional drainage systems. The SUDS concept takes into consideration long term environmental and social factors, the quantity and quality of runoff and the amenity value of surface water in the environment. The utilization of SUDS techniques within a development project can provide the following benefits: Reduce the potential for flooding on new and existing developments Protect and enhance river and groundwater quality Provide habitats for wildlife Encourage natural groundwater recharge Minimize environmental damage: bank erosion and damage to habitats Enhance amenity and landscape quality Reduce the use of potable water by rainwater utilization Gridtech Source control and surface water treatment train Source control is the preferred infiltration and attenuation technique. By controlling runoff at its source, site runoff, outfall volumes and pollution are all reduced. Source control techniques include: Porous surfacing Permeable paving systems Infiltration/attenuation trenches Swales Regional or site control techniques include: Detention Basins Retention Ponds Bioretention Areas Wetlands and Sand Filters The treatment train concept, which should be incorporated into all SUDS designs, is based upon the combination of a series of complimentary treatment techniques to achieve enhanced water quality. Typically a minimum of two treatment stages are required to provide adequate cleansing prior to discharging from a site. A review of the required level of treatment is important and should be undertaken on a project specific basis. 1

3 Gridtech SUDS Solutions Gridtech ATS Netlon ATS 400 reinforced rootzone Gravel Drain reinforced rootzone High void content aggregate sub-base/storage layer blinded with fine aggregate Subgrade Soil Water to on-site retention Permeable concrete block pavers Geotextile Filter High void content aggregate sub-base/storage layer Gridpave 50 with gravel fill Gravel Bedding Geotextile Filter High void content aggregate sub-base/storage layer blinded with fine aggregate Gridpave 50 with rootzone fill and grass cover Consolidated Rootzone Geotextile Filter High void content aggregate sub-base/storage layer blinded with fine aggregate Gravel fill Gravel Bedding Gravel Drain Water to on-site retention 2

4 Gr i d t e c h Gr a s s Pa v i n g Sy s t e m & In s t i l a t i o n Gu i d e T y p e A T y p e B T y p e C T y p e D G r a s s - f i l l e d G r a v e l - f i l l e d S e l e c t i o n Gu i d e Incorporates a ATS300 stabilized Rootzone 1 which provides optimum conditions for grass growth; Type A being more suitable for light vehicle use and firm subgrade conditions Appropriate where the quality of the grass cover is not considered critical but where economy of construction is important Utilizes a gravel fill for a low maintenance architectural surface CBR (%) D Th i c k n e s s (m m ) > F i r e t r u c k o r o c c a s i o n a l HGV a c c e s s 4-6 x x x > Li g h t Ve h i c l e a c c e s s o r o v e r s p i l l c a r p a r k i n g x x I n s t a l l a t i o n a. Place paver units (with dimpled face uppermost) onto the prepared base. b. Connect the pavers using the lugs and slots, progressing over the area in rows. Use protective gloves to avoid abrasions. c. Pavers can be cut, using a hand or power saw, to fit around obstructions and contours. Pieces which are less than half of the original size should not be used. 1 Gridtech ATS300 Rootzone (see instructions page) 3

5 Gr i d t e c h S pecification It e m T y p e A T y p e B T y p e C T y p e D P a v e r Fi l l ( s e e d b e d ) 70:30 sand soil blend such as Gr i d t e c h R300 rootzone 70:30 gravel:soil or 70:30 sand:soil 2-6 mm sized select gravel G r a s s Se e d 35 gm/m 2 low-maintenance amenity blend or as specified N/A F e r t i l i z e r Pre-seeding fertilizer mix followed up with appropriate spring & autumn fertilizer (advise available from Netlon Limited) N/A B e d d i n g La y e r N/A N/A N/A Ro o t z o n e Ty p e ATS300 Rootzone 2 ATS300 Rootzone 2 70:30 gravel:soil G300 Rootzone 25mm of 2-6mm sized crushed aggregate N/A Ro o t z o n e Th i c k n e s s (m m ) D N/A Su b-b a s e Ty p e 3 Type 1x Type 1x Type 1x Type 1x GRIDTECH Grass Paver Specification Material Paver size Internal cell size Weight Load-bearing capacity Connection detail Colour 100% recycled polyethylene 500mm x 500 mm x 50 mm deep 63mm x 63 mm 11kg/m2 200tonnes/m2 T lugs and slots Black GRIDTECH 2 ATS300 Ro o t z o n e This pre-blended permeable and compaction resistant material is designed to provide optimum agronomic conditions for root development which results in improved grass recovery and improved moisture retention. The mixture incorporates unique GT mesh elements which stabilize the Rootzone and provides support to the pavers. GRIDTECH 3 Type 1x Sub-Base This shall comply with DOT Type 1 sub-base specifications except that the fines content shall be limited to: Passing: 5mm 20-35% 4

6 Gridtech Advanced Turf System The Netlon Advanced Turf system comprises a specially prepared rootzone into which is blended thousands of small interlocking, polypropylene mesh elements. Grass roots penetrate down through the mesh to form a deep anchored root system and a very stable load bearing rootzone. Flexing of the mesh elements under traffic resists compaction and enhances infiltration properties. These characteristics make it particularly suitable as a porous paving solution for: Overspill car parks Occasional access roads Fire service routes Events and amenity areas Gridtech Reinforcement of granular materials Traditionally subgrade soils below paved surfaces are protected from surface water infiltration. This, combined with the use of an appropriate drainage system improves subgrade strength. Conversely SUDS source control applications incorporating porous surfacing, encourage runoff to infiltrate into the subgrade reducing subgrade strength. The aggregate layer in such systems must perform the dual function of storage reservoir and load bearing sub-base layer to protect the subgrade. Gr i d t e c h Geogrids are designed to reduce the required sub-base depth by up to 40%; contributing to sustainability by reducing excavation depths, aggregate requirements and overall costs. Gr i d t e c h SS Ge o g r i d s Gr i d t e c h SS geogrids are manufactured from durable polymers to form a unique high strength grid structure with strong junctions and high in-plane stiffness. When an aggregate is compacted over the geogrid it interlocks within the apertures. The geogrid reinforces the aggregate and reduces subgrade deformation. GRIDTECH SS geogrids reduce whole life costs for: Sub-base and capping layers Reinforcement of the aggregate layer in source control systems Foundations Erosion protection of swales and retention ponds Swales and retention ponds provide temporary storage for storm water reduce peak flows to receiving waters and facilitate the filtration of pollutants. The performance characteristics of Gridtech Mat make it an ideal erosion solution in this type of source control technique. Gridtech Ma t Gr i d t e c h Mat is designed to control soil erosion. Manufactured from polyethylene it provides an array of pockets and traps for topsoil retention and an ideal medium for anchorage and reinforcement of a root system. It offers a permanent solution for erosion protection of: Underground tanks and storage structures Retention ponds Swales Flood bunds 5

7 Advanced Turf Netpave 50 Netpave 25 Turf Guard Application Multiuse- Events/ sports, occasional use access routes Car parks, pathways, cycle routes Overspill car parks, drives, verges, occasional use of grassed areas Occasional use access routes and car parks Surface Grass Grass or Gravel Grass Grass Load Bearing To HGV To HGV Light Traffic Light Traffic Ruttin Resistance Yes (on prepared base) Yes (on prepared base) Yes (on firm ground) Yes (on firm ground) Installation Prepared Ground Prepared Ground Existing or new grass Existing or new grass Start Using Immediately Immediately Immediately on existing grass Grass must befully established Reinforcement Location Sub-surface (no visible structures Surface Surface Surface 6

8 Gridtech Arthur Erhardt AErhardt@gridtech.com