Performance of compost filter socks and conventional sediment control barriers used for perimeter control on construction sites

Abstract

The objective of this study was to compare the sediment removal efficiency, peak flow rate, and cost of straw bales, mulch filter berms, compost filter socks, and compost filter socks + polymer used as perimeter sediment control devices under high intensity/duration single storm event conditions to assist environmental regulators and design professionals in choosing an appropriate best management practice for their construction site or storm water pollution prevention plan. A simulated rainfall intensity/duration was chosen in order to produce a direct runoff (Q) per linear unit length of treatment equivalent to that generated in 24- hour 5-year return for north Georgia (11.25 cm [4.5 in]) using the maximum drainage area allowed for silt fence on a 10% slope. All sediment control treatments restricted peak runoff flow rates relative to the bare soil (control). All treatments discharged significantly lower total solids (concentration and load) than the bare soil, while all compost sock treatments were significantly lower (concentration and load) than the mulch filter berm and straw bale. Removal efficiency for total solid load ranged from 63.5% to 88.2%. Single-event P factor (soil loss ratio) was determined for all treatments and ranged from 0.118 to 0.365. All treatments were significantly lower than the bare soil, and all compost filter socks were significantly lower than the mulch filter berm. All treatments discharged significantly lower total suspended solids (concentration and load) than the bare soil, and all compost sock treatments were significantly lower (concentration and load) than the mulch filter berm and straw bale. Removal efficiency for total suspended solid load ranged from 60.4% to 89.5%. All compost filter socks had significantly lower turbidity relative to bare soil, and the addition of the polymer to the compost filter sock treatments had significantly lower turbidity relative to the compost filter socks without the polymer. Percent turbidity reduction ranged from 8.1 to 49.1. Total cost of installation was estimated for each sediment control device based on product + freight from distributor + staking materials + labor to install. Total cost for sediment control devices ranged from $1.75 to $2.87 per linear 30 cm (1 ft).