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MIZATION <br />PERVIOUS PAVEMENT <br />4t .1, <br />Grasspave" at Bradshaw Celebration of Life Center -Stillwater, MN <br />Design Criteria: <br />► Pervious pavement is typically used in low <br />traffic areas including overflow parking <br />areas, emergency vehicle lanes, and <br />pedestrian areas. <br />In-situ soils should have field -verified <br />minimum permeability rates greater than 0.3 <br />in./hr. Contributing runoff from offsite should <br />be limited to a 31 ratio of impervious area <br />to pervious pavement area. <br />► The selected systems load bearing surface <br />should be suited to maximum intended <br />loads. <br />► Design storms should be infiltrated within <br />48 hours. <br />Benefits: <br />► Good for highly impervious areas <br />particularly parking lots. <br />► Reduces need for other storm water Bl\/IPs <br />by reducing runoff. <br />Construction costs of some systems are <br />less than traditional paving. <br />► Soil -enhanced turf systems resist <br />compaction, increase infiltration, and <br />provide .soils for healthier vegetation. <br />Limitations: <br />► Construction costs of some systems are <br />more expensive than traditional paving <br />0. Use depends on infiltration rates of <br />underlying soils. <br />► Maintenance costs are higher than <br />conventional paving. <br />Not recommended for high traffic areas <br />because of durability concerns. <br />Definition: <br />Pervious pavements reduce the <br />amount of runoff by allowing water <br />to pass through surfaces that would <br />otherwise be imperious. Water <br />can either infiltrate into the ground, <br />if soil permeability rates allow, or be <br />conveyed to other BMPs or a storm <br />water system by an under -drain. <br />High' k1pri <br />Nater Quality (V,,,l(,) <br />Med <br />Channel Protection (V c1,) <br />[_a:v <br />Overbank Flood Protection (V,,,,,) <br />Wvv <br />Extreme Flood Protection (V,,,,),,) <br />Flighi Musci <br />Recharge Volurne (Re,,,) <br />MECHANISMS <br />Infiltration -:•.rh apU(opmle sd� candmr))s <br />X. Screening/ Filtration <br />Temperature Control <br />Settling <br />Evaporation <br />X' Transpiration Itvenclal:on pry=_,esil <br />X Soil Adsorption <br />XBiological/ Micro, Uptake <br />Total Suspended Solids <br />'pi e.tremnienf lot rss IS ra COM[TICI Ided S7 � d, leen(n reA , <br />C- <br />(Irn+n In ),',ement <br />3 <br />Nutrients - Total Phosphorus/ <br />J�s:1 ✓3ra°-u <br />Total Nitrogen <br />Metals - Cadmiurn, Copper, Le ad, <br />a, <br />l <br />and Zinc <br />Pathogens - Coliform, Streptococci, <br />p <br />E. Coh <br />pr ? <br />Toxins - Chloride, Hydrocarbons, <br />k - _ <br />Pesticides <br />Note: Pollution removal <br />percentages apply to volume of runoff treated, <br />and not to volume of runoff bypassed <br />