City webinar spotlights compost "filter socks" as a durable, cost-saving stormwater control

Holly Thorne, Community Relations Coordinator for the City of Oklahoma City Stormwater Quality Division, opened the webinar and introduced presenters Terry Craighead of Fertile Ground Cooperative and Jack Eaton of Karaf Engineered Fabrics, who described how compost-based products can be used as stormwater best-management practices.

Craighead, founder of Fertile Ground Cooperative, said compost products are used across the stormwater spectrum—from temporary construction perimeter control to longer‑term bioretention—and cited an industry graphic suggesting compost can filter “60 to 95%” of urban stormwater pollutants. He described the material’s benefits for infiltration, soil function and water retention and said compost supports local jobs and reduces landfill disposal costs.

“[Compost] serves as both a filter and a sponge, immobilizing and degrading pollutants to improve our water quality,” Craighead said, summarizing the material’s role in trapping and treating runoff.

Eaton, who supplies tubular mesh products for erosion control, said modern “compost filter socks” are filled with coarse wood fiber media rather than finished bagged compost and that the mesh must balance containment and flow. He described design details—mesh opening targets of roughly 1/8 to 3/8 inch—and said properly sized socks can hold substantial sediment volumes, with the presenters estimating up to two‑thirds or more of captured sediment stored inside the sock.

“We’ve seen compost socks under a foot of water that never moved,” Eaton said, citing field experience to illustrate the products’ durability. He also noted that wood-fiber media, sometimes amended with biochar or other additives, has been used to reduce hydrocarbons and certain metals; Eaton said in some cases wood fiber has removed “85 to 90%” of particular hydrocarbons.

Presenters gave practical guidance on sizing and installation: 8‑inch socks are usually sufficient for typical house‑lot sites, while 12‑inch socks may be preferred on larger slopes; staking behind the sock (not piercing it) improves hold-down; and blower trucks or simple pallet forks can speed installation of blankets and large socks. For disposal, the presenters said crews commonly cut away the fabric and spread the wood‑fiber media into vegetated areas or send materials to an appropriate landscape facility if contaminated.

During Q&A, speakers addressed common barriers. Craighead and Eaton said compost products often have lower life‑cycle maintenance costs than silt fence, but Holly Thorne relayed a caveat from a colleague, Joel Dixon: some jurisdictions’ erosion‑control specifications still require silt fence and may not permit compost socks. The presenters recommended checking local erosion‑control requirements before specifying an alternative BMP.

The webinar concluded with Thorne sharing City resources (newsletters, training, the OKC Action Center) and announcing that a recording and slides will be posted to the City’s website and OKC’s YouTube channel. Attendees were invited to future sessions on March 27 and April 21.

What the webinar showed: local suppliers and erosion‑control specialists argued compost‑based socks and blankets can be effective, durable and cost‑competitive stormwater controls when sized and installed correctly, but their use depends on local specifications and site conditions. The presenters’ performance claims and removal percentages were presented as field experience and industry references rather than independently verified in the webinar; jurisdictions or project owners should confirm specifications and disposal rules before deployment.