BEsT MANAGEMENT PRACTICEs HANDbooK - Tahoe BMP

Three performance monitoring studies conducted on a single Lake TahoeRegion media filter are cited below.• StormFilter Performance Analysis 14 and Lake Tahoe BMP MonitoringEvaluation Process 15 noted the following performance for the media filtertreating stormwater runoff from the Ski Run Marina in South Lake Tahoe,California:• The media filter demonstrated variable (typically poor) ability to removedissolved nutrients from stormwater, including nitrate, nitrite,orthophosphate, and dissolved phosphorus.• The media filter consistently reduced particulate pollutants in urbanstormwater.• Event mean concentrations of total nitrogen were reduced on averageby 13 percent.• Event mean concentrations of total phosphorus were reduced onaverage by 45 percent.• Event mean concentrations of total suspended sediment were reducedon average by 80 percent.• Focused Stormwater Monitoring to Validate Water Quality Source Control andTreatment Assumptions 16 noted the following performance for the mediafilter treating stormwater runoff from the Ski Run Marina in South LakeTahoe, California. While the data are very limited, this study provides someof the first performance monitoring data for fine sediment particles:• Roughly a 65 percent reduction in the fine sediment particle loading wasobserved.142NDNATURE, 2005, Storm Filter Performance Analysis prepared for the City of South LakeTahoe.ftp://2ndnaturellc.com/2ndnature/2NDNATURE_Reports/Lake%20Tahoe/CSLTStormFilterPerformanceAnalysis_FinalReport.pdf152NDNATURE, 2006, Tahoe Basin BMP Monitoring Evaluation Process: Synthesis of Existing Researchprepared for USFS Tahoe Basin Management Unit.162NDNATURE and Northwest Hydraulic Consultants, 2010, Focused Stormwater Monitoring toValidate Water Quality Source Control and Treatment Assumptions prepared for US Army Corps ofEngineers, Sacramento District.ftp://2ndnaturellc.com/2ndnature/2NDNATURE_Reports/Lake%20Tahoe/PLRM%20Refinement_FinalPhaseI_TechnicalReport.pdfChapter 4: BMP ToolkitTRPA BMP Handbook4.4.2.5-Media Filter 2012Page 6