Recheck to determine if there is standing water after 72 hours Remove any sediment buildup If standing water is present longer than 5 days, report to Standing water is present after mosquito commission. the design drain time Y__ 1 Replace the sand layer (volume The observed drain time is N__ of replacement sand is approximately _________ hours. specified in the Basin Configuration Targets in the Basic Design Information Section of this Manual) Work Order # ______________ Clean pretreatment system Y__ Excessive sediment, silt, or trash 2 accumulation on basin bed Remove silt, sediment, and N__ B trash Sand Bed Check whether the flow bypass or diversion device is clogged Y__ Erosion or channelization is 3 present Re-grade the infiltration bed N__ Work Order # ______________ Pest control Y__ Animal burrows/rodents are 4 present Work Order # __________ N__ Use light equipment to Y__ resurface the bed 5 Uneven bed N__ Work Order # _________ Y__ Evidence of sinkholes or Monitor for sinkhole 6 subsidence development N__ Note:
B Sand Bed 1 Standing water is present after the design drain time The observed drain time is approximately _________ hours. Y__ N__ Recheck to determine if there is standing water after 72 hours Remove any sediment buildup If standing water is present longer than 5 days, report to mosquito commission. Replace the sand layer (volume of replacement sand is specified in the Basin Configuration Targets in the Basic Design Information Section of this Manual) Work Order # ______________ 2 Excessive sediment, silt, or trash accumulation on basin bed Y__ N__ Clean pretreatment system Remove silt, sediment, and trash 3 Erosion or channelization is present Y__ N__ Check whether the flow bypass or diversion device is clogged Re-grade the infiltration bed Work Order # ______________ 4 Animal burrows/rodents are present Y__ N__ Pest control Work Order # __________ 5 Uneven bed Y__ N__ Use light equipment to resurface the bed Work Order # _________ 6 Evidence of sinkholes or subsidence Y__ N__ Monitor for sinkhole development Note:
04-surface-sand-filter-infiltration-main-field-manual-april-2015.docx