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Exhibit C 7.1.H. - Page 36 <br /> Table 1.Street sweeper assignment to various permeable pavements <br /> PavementType Schmutzdecke Depth Preventive Sweeper Restorative•Sweeper <br /> Concrete Grid Pavers filled with sand 0.5 inches Mechanical Mechanical <br /> MCP filled with aggregate 1;5 to 2,0 inches Regenerative Air Vacuum <br /> If Sand:<1 inch If Sand: Vacuum? <br /> Pervious concrete Regenerative Air <br /> If Silt/Clay:>3 inches if Silt/Clay:Not known <br /> If Sand:<1 inch If Sand: Vacuum? <br /> Pervious asphalt Regenerative Air <br /> If Silt/Clay:>3 inches If Silt/Clay:Not known <br /> tively old permeable pavements located along the North <br /> Carolina barrier islands and in the NC sandhills, both <br /> very sandy soil regions,demonstrated that despite being <br /> clogged, infiltration rates usually exceeded I in/hr.This , <br /> is because the pavement was clogged by sand. Designers <br /> and regulators should consider whether an infiltration rate <br /> of 1 to 2 inches per hour is acceptable. If so,the frequen- }� <br /> cy of required street sweeping in some(albeit limited) <br /> parts of the U.S. is reduced.A recent analysis of rainfall , .>- . 3k <br /> • <br /> �� <br /> intensities in NC demonstrated that less than 2 percent of <br /> all rainfall intensities(as measured hourly)exceed 1 in/hr. <br /> PICP related specifics =" ��° - Y" s= 40:' 14 <br /> Street sweepers will remove fill aggregate that could =� . . = ..z:f � <br /> then pose a tripping hazard (Figure 8). So every time <br /> PICP is machine swept, aggregate refill is mandatory ,Y <br /> (Figure 8). Be mindful that not every aggregate may `° � ;� <br /> be appropriate for the landowner and application. The ,, 00. <br /> aggregate's color or hue and that of the PICP block <br /> could be important to the landowner. Refilling gaps is <br /> 4+ 1 <br /> a very easy process and is usually achieved by broom <br /> sweeping. , - za <br /> Vacuum sweepers are powerful and, if not carefully <br /> operated, can suction too much aggregate from the gaps ' s ', ` d ¢, <br /> and beneath the pavers. Care must be taken to verify that .a�A f ` '� Y �� ..°rtrt.2,6: <br /> the amount of suction provided by the vacuum sweeper is m 4 P440, <br /> not removing portions of the gravel base layer. This can 43;7;4'". 41' �'�, <br /> be quickly checked by sticking a pencil down the vacu- Figures.PICP gaps must be filled with aggregate to <br /> umed gap to verify the depth of gravel suctioned is less prevent a tripping hazard(top).Gravel replacement is <br /> than the depth of the block. simple and done with a push broom(bottom). <br /> OTHER MAINTENANCE ISSUES: REMOVING structure, and its removal can be more destructive to the <br /> UNWANTED VEGETATION structure of the pavement. <br /> Vegetation is often a sign that too much sediment has One cautionary note: some permeable applications <br /> accumulated, because the excess sediment provides an are meant to be grassed. Mowing may actually be the <br /> environment for vegetation to survive. Weeds should be appropriate maintenance activity. If a parking lot is to <br /> removed using a systemic herbicide such as glyphosate be mowed, please remember to catch the grass clippings <br /> and then returning within the week to pull the weeds. before they are deposited on the pavement.Accumula- <br /> It is imperative to not let unwanted vegetation persist. tion of grass biomass (clippings)could further limit <br /> As weeds mature, it becomes harder to remove the root infiltration. <br /> 6 Urban Waterways <br />