3003 W CASINO RD BLDG 40-YD 2019-11-27

STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Table 1114.4 Specific Maintenance Requirements for Detention Ponds Maintenance Defect Conditions When Maintenance Results Expected When Component is Needed Maintenance is Performed I.Ponds- Trash end debris Any trash or debris which exceeds 1 ft/1000 ft2(equal to Trash and debris cleared from General the volume of a standard size office garbage can). In site. general,there should be no evidence of dumping. Poisonous vegetation Any poisonous vegetation which may constitute a hazard No danger of poisonous to maintenance personnel or the public.e.g.tansy,poison vegetation where maintenance oak,stinging nettles,devils club. personnel or the public might normally be. Coordinate with the local county health dept. Pollution I gallon or more of oil,gas or otter contaminants or any No contaminants present other amount found that could:I)cause damage to plant, than a surface film.Coordinate animal or marine life,2)constitute a fire hazard,3)be with the local county health dept. flushed downstream during storms or 4)contaminate ground water. Unmowed grass/ground cover In residential areas,mowing is needed when the cover When mowing is needed,grass exceeds 18 inches in height. Otherwise,match facility or ground cover should be cover with adjacent ground cover and terrain as long as mowed down to 2 inches.A there is no decrease in facility function. dense grass cover must be maintained on slopes,and in dry ponds on the bonom as well. Rodent holes Any evidence of rodent holes if facility is acting as a dam Rodents destroyed and dam or or berm,or any evidence of water piping through darn or berm repaired. Coordinate with berm via rodent holes. the local county health dept. Insects When insects such as wasps or hornets interfere with Insects destroyed or removed maintenance activities. from site. Coordinate with people who remove wasps for anti-venom production. Tree growth Tree growth does not allow maintenance access or Trees do not hinder maintenance interferes with maintenance activity. If trees are not activities. Selectively cultivate interfering with access,leave trees alone. trees such as alders for firewood. Side Slopes of Erosion Eroded damage>2 inches deep where cause of damage is Slopes should be stabilized with Pond still present or where there is potential for continued appropriate erosion control erosion. BMPs e.g.seeding,plastic covers,riprap. Storage Area, Sediment Accumulated sediment that exceeds 10%of the designed Sediment cleaned out to designed Forebay forebsy depth,or every three years. pond shape and depth;reseeded if necessary to control erosion. Pond Dikes Settling Any part of dike which has settled 4 inches lower than the Dike should be built back to the design elevation. design elevation. Emergency Rock missing Only I layer of rock above native soil in an area a 5 ft2 Replace rock to design Overflow, or any exposure of native soil. standards. Spillway IL Debris Trash end debris Trash or debris that is plugging X20%of the openings in Barrier clear to receive capacity Barrien-General the barrier. flow. III-4-22 FEBRUARY, 1992