Orange County NC Website
Browse       Search
Table 1 : Inspection and Maintenance Provisions for Sand Filters <br /> Upon <br /> completion of <br /> • If a pretreatment grass filter strip has been built, water twice a week until the <br /> construction <br /> grass become established ( commonly ii weeks ) , depending on rainfall . <br /> • Maintain any grass at the perimeter of the sand filter to a height of <br /> approximately six to eight inches . <br /> • Check inlet, outlet, and conveyance system for any obstructions or clogging . <br /> Once every Remove accumulated grit, leaves, and debris and dispose off-site . <br /> quarter . Remove any trash present on the sand filter surface . <br /> • Inspect for prolonged ponding and bare or eroding areas and make adjustments <br /> as necessary . <br /> Twice during .the growing Remove any vegetation growing on the surface of the sand filter preferably by <br /> hand . <br /> season <br /> • Skim the first inch of sand media . <br /> Annually . If a sedimentation chamber is present, pump out oil and grit . <br /> Structural Integrity <br /> • Replace or repair any cracked , separated or damaged inlet pipes , outfalls , or <br /> other structural elements . <br /> • Remediate bare soils or erosive gullies by regrading the soil to remove the gully, <br /> plant ground cover and water until it is established . <br /> • If erosion has occurred within the forebay or pretreatment area , provide <br /> additional erosion protection such as reinforced turf matting or riprap . <br /> Functionality <br /> • Sediment Accumulation <br /> As Needed o Maintain stable ground cover in the drainage area . <br /> (Typical o Sweep or vacuum sediment on pavement in the contributing drainage area . <br /> Problems ) o If sediment has accumulated in the pre -treatment area to a depth greater <br /> than six inches, remove the top few inches of drainage media and dispose of <br /> it in a location where it will not cause impacts to the SCM or a stream . <br /> Search for the source of the sediment in the drainage area and remedy the <br /> problem . <br /> • Filter Media Failure <br /> o If water is ponding on the surface for more than 24 hours after a storm <br /> event, check to see if the underdrain collection system is clogged and flush <br /> if necessary . It water still ponds , remove the top few inches of filter bed <br /> media and replace . If water still ponds , consult an appropriate professional . <br /> All the sand filter media may need to be replaced . <br /> Will <br /> OEM= <br />