Changes

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Performance of filter strips has also been evaluated based on the Roadside Vegetated Treatment Sites Study <ref name='Barrett2003'/> and the BMP Retrofit Pilot Study <ref>California Department of Transportation (Caltrans). 2004. BMP Retrofit Pilot Program, Final Report, CTSW-RT-01-050. Sacramento, CA.</ref>. These studies concluded that concentration reductions consistently occur for TSS and total heavy metals and frequently for [[heavy metals|dissolved metals]]. [[Water quality#Nutrients|Nutrients]] concentrations remained generally unchanged. When vegetation cover on the filter strip is below 80% water quality performance declines.

Performance of filter strips has also been evaluated based on the Roadside Vegetated Treatment Sites Study <ref name='Barrett2003'/> and the BMP Retrofit Pilot Study <ref>California Department of Transportation (Caltrans). 2004. BMP Retrofit Pilot Program, Final Report, CTSW-RT-01-050. Sacramento, CA.</ref>. These studies concluded that concentration reductions consistently occur for TSS and total [[heavy metals]] and frequently for dissolved metals. [[Water quality#Nutrients|Nutrients]] concentrations remained generally unchanged.  

'''NOTE''' When vegetation cover on the filter strip is below 80% water quality performance declines.

[[Category:Water quality]]

[[Category:Water quality]]