Construction requirements for compost filter sock.
Link to this table

Parameters1, 4 Reported as (units of measure) Vegetated Filter Sock5 Unvegetated Filter Socka6
pH2 pH units 5-8.5 6-8
Soluble Salt Concentration2(electrical conductivity) dS/m (mmhos/cm) Maximum 5 NA
Moisture content %, wet weight basis 30-60 30-60
Organic matter content %, dry weight basis 25-65 25-65
Particle size % passing a selected mesh size, dry weight basis
  • 3 in. (75 mm), 100% passing
  • 1 in. (25 mm), 90– 100% passing
  • 0.75 in. (19 mm),70 – 100% passing
  • 0.25 in. (6.4 mm), 30 – 75% passing
  • Maximum particle size length of 6 in. (152 mm)
  • Avoid compost with less than 30% fine particle (1 mm) to achieve optimum reduction of total suspended solids
  • No more than 60% passing 0.25 in. (6.4 mm) in high rainfall/
  • 2” (50 mm), 100% passing
  • 3/8” (10mm), 10% to 30% passing
Stability3 Carbon Dioxide Evolution Rate mg CO2-C per g OM per day <8 <8
Physical Contaminants (man-made inerts) %, dry weight basis <1 <1

1Recommended test methodologies are provided in Test Methods for the Examination of Composting and Compost (TMECC, The US Composting Council)
2Each specific plant species requires a specific pH range. Each plant also has a salinity tolerance rating, and maximum tolerable quantities are known. When specifying the establishment of any plant or turf species, it is important to understand their pH and soluble salt requirements, and how they relate to the compost in use.
3Stability/Maturity rating is an area of compost science that is still evolving, and as such, other various test methods could be considered. Also, never base compost quality conclusions on the result of a single stability/maturity test.
4Landscape architects, plant specialists and project (field) engineers may modify the allowable compost specification ranges based on specific field conditions and plant requirements. 5Alexander, 2003
6Personal communication, B. Faucette, R. Tyler, N. Goldstein, R. Alexander, 2005

This page was last edited on 4 August 2022, at 19:08.