DEFINITION
A strip or area of herbaceous vegetation that removes contaminants from overland flow.
(Source: NRCS)
Another definition, A long, narrow vegetative planting used tlo retard or collect sediment for the protection of diversions, drainage basins or other structures.
(Source: Florida Department of Environmental Protection)
On the construction site, filter strips are used to reduce the amount of sediment reaching silt fence or sediment traps.
In the agricultural world, filter strips are commonly used to minimize the amount of pollution (e.g. nutrients and animal waste) reaching waterways.

AKA
other names, related ideas, etc.

PERFORMANCE CRITERIA
how is it measured? what are the criteria for its design or planning?
For erosion control, filter strips should be a minimum of 15' wide.
The applicable NRCS Conservation Practice Standard (Filter Strip, Code 393) specifies a minimum width of 20'.
According to a 1992 study conducted by Yu and Kaighn, pollutant removal is summarized as follows:

Total Suspended Soilds	Total Phosphorous	Nitrate	Lead	Zinc	Width of Filter Strip
27%	22%	6%	2%	17%	18'
67%	22%	8%	18%	46%	50'
68%	33%	9%	20%	50%	150'

ILLUSTRATION
a diagram or drawing that demonstrates the basic pattern or concept



CASE STUDIES
Ohio State University Extension Factsheet: Vegetative Filter Strips: Application, Installation and Maintenance (AEX-467-94)
Ohio State University Extension Factsheet: The Economics of Vegetative Filter Strips (AE-0006-99)
U.S. Department of Transportation (Federal Highway Administration) Stormwater Best Management Practices in an Ultra-Urban Setting: Selection and Monitoring; Factsheet - Filter Strips

ADDITIONAL RESOURCES
USDA NRCS - Conservation Practice Standard: Filter Strip http://efotg.nrcs.usda.gov/references/public/SD/393.pdf
University of Tennessee Extension - Filter Strips http://www.sera17.ext.vt.edu/Documents/BMP_Filter_Strips.pdf