Stormwater Quality Design Manual (May 2007) - City of Sacramento ...

Technical RequirementsSand FilterLong-Term MaintenanceThe local permitting agencies in the Sacramento and South Placer areas will require execution of amaintenance agreement or permit with the property owner for projects including a sand filter. Check withthe local permitting agency about the timing for execution of the agreement. Such agreements willtypically include requirements such as those outlined in Table SF-3. The property owner or his/herdesignee will be responsible for compliance. See Appendix B for additional information aboutmaintenance requirements and sample agreement language.Table SF-3. Inspection and Maintenance Recommendations for Sand FiltersActivityRemove trash and debris collected in the sedimentation basin inlet area to maintain theinflow capacity of the sand filter and avoid bypassing of the unit.Remove cover grates or precast lids on the sedimentation basin and inspect todetermine if the system is functioning properly. Inspect for standing water, sediment,grass/vegetative debris, and trash on the trash racks at the outlet pipe or elsewhere inthe unit. Schedule removal of observed materials and correct any other observedproblems. Sediment removal should be scheduled when the sediment occupies 10percent of the basin volume.Inspect sediment trap (if applicable) and clean when full.Inspect the facility after large rain events to determine whether the facility is drainingcompletely within 48 hours. Look for discoloration of the filter, which may be anindication of clogging.If drawdown time exceeds 40 hours, remove top two inches of sand. Restore sand layerdepth to 18 inches when overall depth drops to 12 inches.ScheduleBefore significant storm eventsduring wet season (October 1 –April 30)Inspect quarterly during first year ofoperation; semiannually after firstyear of operationMaintain as needed based onobservationsSame as aboveAt least once during the wet season(October 1 – April 30)As required.Add maintenance recommendations/methods for geotextile fabric, gravel bed,underdrains, as needed.Dispose of sand, gravel, or filter fabric contaminated with petroleum hydrocarbons inaccordance with all applicable laws.Reconstruct or replace the control measure when it is no longer functioning properly.As requiredSee projected lifespan in Appendix Bfor informational purposes.References• California Stormwater Quality Association (CASQA). Stormwater Best Management PracticeHandbook – New Development and Redevelopment. January 2003.• Urban Drainage and Flood Control District (UDFCD), Denver, Colorado. Urban DrainageCriteria Manual, Volume 3 – Best Management Practices. 1999.Stormwater Quality Design Manual for the Sacramento and South Placer RegionsMay 2007SF-11