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Table WA.1 c Maintenance Standards - Detention Ponds (continued) - - Maintenance Com- - ponent , Defect , Conditions When Maintenarite is Needed ` . Results Expected 711fhen Maintenance Is Perf"ed LklikCrtApPlk- SUN unerisvisibleandhasmorethanttueel/43nchhdesi61L tine'rrepairedorreplaced.tkus•isfuUycovered.. Any part of 16Mwhich has settled 41nches lowerttan the design elevation if seftlenre4 is apparent, measure berm to detemmineamount of setuemerd Settlements Settling car4be an indication of more seven: problems with the berm oroutlet works. A Dike is built back to the design elevation. licensed engineer In the state of Washington should be consulted to detemmne the source of Ponds Berms (Dikes) ? thesettlement Discemablewaterflox through pond berm. Ongoing erosion with potential forerosion to con - piping _ t ` a (Recommend Goettieclumical engineerbe caged In to inspect and evaluate condition - Piping eflminated. Erosion pote.Mial resolved& . recommend repardcondtion / Tree growth on emergency spillways creates blockage problems and may cause failure ofttie berm due toinconkolledovertopping• Tiees should he removed If mot stem is small ass less than 4lnches the root may be left in system (b ) system Tide Growth �- Tree growth on herons over4 feet in height may lead to piping through the bens which could place_ Otherwise the roots should be removed and the berm restored. A licensed engineer In the state of Emergency Overflow/ lead tofalhxeofthe berm. Washington should be consulted form berm/spillway illw restoration proper P ay Spillway and Berms over4feet in height Discemablewaterflow through pond berm. Ongoing erosionwith potential forerosion to can Piling fine (Recommend a Geotechnicai engineerbe caged into inspect and evaluate condition and Piping eliminated. Erosion potential resolved recommendlepairof condition Emergency Over- Erlie[gency Over- �Y one lajrarof rock exists above native soil in areafive square feet or larger, orany expos- ure of native soil at thetop afoul flow path of spiitway.'. ' flow/Sol 1 way flow/Spillway (Rip -rap on> -Ide slopes need not be replaced.) Rocks and pad depth are mstored to design standards. Erosion See "Side Slopes of Pond" s Table V.A 2: Maintenance Standards Infiltration Maintenance Component'. - Defect : ` ;' Conifill' s When Maintenance Is Needed :: Expects nance is Per- - `Results d When Mainte s formed Trash &Debits SeeTableV-A.1: Maintenance Standards -DetentlonPonds SeeTableV-A.1:Maintenance Standards- Deten- tion Ponds Poisonous/Noxious SeeTa6leV-A:1: Maintenance Standards - Detention Ponds � - - SeeTabieV-A.1:MaintenanceStandards-Deters- General Vegetation m tion Ponds inants and Pot- SeeTabie V-A.1: Maintenance Standards - Detention Ponds SeeTable V-A.1: Maintenance Standards - Deten- 1ullon lotion Lion Ponds RodentHdes SeeTableVy4.l:Maintenance Standar"its- Retention Ponds SeeTable V A.l: Maintenance Standards - Deten- tionPonds Storage Area Sediment Water pondnng in infiltration pond after rainfall ceases and appropriate time allowed forinfiltration. Treatment basins should infiltrate Water Quality Design Storm Volume within 48 hours, and 24 hours most Sediment is removed and/or facility is cleaned so empty within aftercessation of rain events. that InNtration system works according to design