8525 EVERGREEN WAY BURGER KING 2021-05-10

No. 21 (continued)-Maintenance Standards and Procedures for Bioretention Facilities. Maintenance Recommended Frequency• Condition when Maintenance is Needed Action Needed Component Inspection Routine Maintenance (Standards) (Procedures) Facility Footprint(coned) Ponded water B,S Excessive ponding water:Water overflows during storms Determine cause and resolve in the following order: smaller than the design event or ponded water remains in 1) Confirm leaf or debris buildup in the bottom of the facility is not impeding infiltration.If necessary,remove leaf litter/debris. the basin 48 hours or longer after the end of a storm. 2) Ensure that underdrain(if present)is not clogged.If necessary,clear underdrain. 3) Check for other water inputs(e.g.,groundwater,illicit connections). 4)Verify that the facility is sized appropriately for the contributing area.Confirm that the contributing area has not increas ed. If steps#1-4 do not solve the problem,the bioretention soil is likely clogged by sediment accumulation at the surface or has become overly compacted.Dig a small hole to observe soil profile and identify compaction depth or clogging front to help determine the soil depth to be removed or otherwise rehabilitated(e.g.,tilled).Consultation with an engineer is recommended. Bioretention soil As needed Bioretention soil media protection is needed when •Minimize all loading in the facility footprint(foot traffic and other loads)to the degree feasible in order to prevent compaction media performing maintenance requiring entrance into the facility of bioretention soils. footprint •Never drive equipment or apply heavy loads in facility footprint. •Because the risk of compaction is higher during saturated soil conditions,any type of loading In the cell(including foot traffic) should be minimized during wet conditions. •Consider measures to distribute loading if heavy foot traffic is required or equipment must be placed in facility.As an example,boards may be placed across soil to distribute loads and minimize compaction. •If compaction occurs,soil must be loosened or otherwise rehabilitated to original design state. Inlets/Outlets/Pipes Splash block inlet A Water is not being directed properly to the facility and Reconfigure/repair blocks to direct water to facility and away from structure away from the Inlet structure Curb cut inlet/outlet M during the Weekly during fall Accumulated leaves at curb cuts Clear leaves(particularly important for key inlets and low points along long,linear facilities) wet season leaf drop and before severe storm Is forecasted Pipe inlet/outlet A Pipe is damaged Repair/replace W Pipe Is dogged Remove roots or debris A,S Sediment,debris,trash,or mulch reducing capacity of •Clear the blockage inlet/outlet •Identify the source of the blockage and take actions to prevent future blockages Weekly during fall Accumulated leaves at inlets/outlets Clear leaves(particularly important for key inlets and low points along long,linear facilities) leaf drop A Maintain access for inspections •Clear vegetation(transplant vegetation when possible)within 1 foot of inlets and outlets,maintain access pathways •Consultation with a landscape architect is recommended for removal,transplant,or substitution of plants Erosion control at A Concentrated flows are causing erosion Maintain a cover of rock or cobbles or other erosion protection measure(e.g.,matting)to protect the ground where inlet concentrated water enters the facility(e.g.,a pipe,curb cut or Swale) Volume V—Runoff Treatment BMPs—December 2014 4-55