6522 WETMORE AVE 2025-08-19 - Laserfiche WebLink

Table V-A.22: Maintenance Standards - Permeable Pavement (continued) Recommended Frequency a Condition when Maintenance is Needed Component (Standards) Action Needed (Procedures) Inspection Routine Maintenance Aggregate is clogged: Ponding on surface or Ab water flows off the permeable pavement surface Rehabilitate per manufacturer's recommendations. during a rain event (does not infiltrate) • Remove pins, pry up grid segments, and replace grass A Paving grid missing or damaged • Replace grid segments where three or more adjacent rings are broken or damaged • Follow manufacturer guidelines for repairing surface. A Settlement of surface May require resetting • Restore growing medium, reseed or plant, aerate, and/or amend vegetated area as needed A Poor grass coverage in paving grid • Traffic loading may be inhibiting grass growth; reconsider traffic loading if feasible As needed None (routine maintenance) Use a mulch mower to mow grass • Sprinkle a thin layer of compost on top of grass surface (112" top dressing) and sweep it in A None (routine maintenance) • Do not use fertilizer • Manually remove weeds A Weeds present • Mow, torch, or inoculate and replace with preferred vegetation Inlets/Outlets/Pipes Inlet/outlet A Pipe is damaged Repair/replace pipe A Pipe is clogged Remove roots or debris Clean orifice at least bian- Plant roots, sediment or debris reducing caps- • Jet clean or rota cut debris/roots from underdrain s rotary ( ) Underdrain pipe Clean pipe as needed nually (may need more fre- quail cleaning during wet city of underdrain (may cause prolonged draw- • If underdrains are equipped with a flow restrictor (e.g., orifice) to attenuate flows, the orifice must be cleaned season) down period) regularly Clean orifice at least bian- • Jet clean or rotary cut debris/roots from under-drain(s) Raised subsurface overflow pipe Clean as needed pipe nually (may need more fre- quent cleaning during wet Plant roots, sediment or debris reducing capa- city of underdrain If underdrains are equipped with a flow restrictor (e.g., orifice) to attenuate flows, the orifice must be cleaned season) regularly Outlet structure A, S Sediment, vegetation, or debris reducing capa- • Clear the blockage cityof outlet structure Identify the source of the blockage and take actions to prevent future blockages Overflow g Native soil is exposed or other signs of erosion Repair erosion and stabilize surface damage are present at discharge point Aggregate Storage Reservoir Water remains in the storage aggregate longer If immediate cause of extended ponding is not identified, schedule investigation of subsurface materials or other Observation port A, S than anticipated by design after the end of a potential causes of system failure. storm 2019 Stormwater Management Manual for Western Washington Volume V - AppendixA - Page 1028