forestconcepts™
Design, Development, and Field Experience with Wood-Strand Erosion Control Mulch for Mine and Pipeline
Projects
Jim Dooley, Dave Lanning, and Mike Perry
Commercially available from:
Forest Concepts - Auburn, WA
Mountain Pine Mfg. - Steamboat Springs, CO
forestconcepts™
• The Issues with Agricultural straw: • Invasive weed species• Farm weeds• Short functional life – 3 months to 2 years• Not wind stable at less than 15 mph• Mats to prevent broadleaf seedlings from emerging• Absorbs/adsorbs rainfall during spring/summer showers• Dusty during application by hand or blowers• Certified “Weed-free” requires use of herbicides
• In 2002, US Forest Service called for development of an all-wood alternative to agricultural straw for use on FS lands
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Why a New Mulch?
forestconcepts™
• Forest Concepts proposed a wood-strand analog of straw that addressed known issues with straw mulch
• USDA NIFA SBIR program supported Forest Concepts• USDA Forest Service provided support to their RMRS erosion research
lab in Moscow, ID in collaboration with Forest Concepts• Interagency BAER team leaders from FS, BLM, NPS, DOD… provided
guidance• Washington Technology Center supported wind erosion research at
Washington State University• USDA ARS contributed use of their soil wind tunnel at Pullman, WA• Plus many contributed test sites across the West
Development Partnership
forestconcepts™
• Functional Objectives• Intercept rainfall• Reduce soil mobilization• Increase infiltration• Trap & store sediment• Stop rill formation & growth• Create soil organic matrix as it decays• Trap seed & provide seed bed• Enable seedling emergence• Reduce surface wind velocity• Wind-stable to 35mph• Applicable to steep slopes• Last 4 years in Western U.S.
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Design objectives for wood-strand mulch
forestconcepts™
• Functional Objectives• Intercept rainfall• Reduce soil mobilization• Increase infiltration• Trap & store sediment• Stop rill formation & growth• Create soil organic matrix• Trap seed & provide seed bed• Enable seedling emergence• Reduce surface wind velocity• Wind-stable to 35mph• Applicable to steep slopes• Last 4 years in Western U.S.
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• Operational Objectives• Pure wood material• Bale, truck, and handle like straw mulch
• 50 lb and 600 lb bales• Apply by straw blowers, hand, helimulch• Store and apply wet or dry• Naturally weed-free• Palletize for easy handling
Design objectives for wood-strand mulch
forestconcepts™
Material Design Experiments• Blends (152 experiments at USFS Moscow, ID)
– Lengths, widths, application rates– Two slopes, two soil types
• Effect of material thickness– 1mm, 2mm, 4mm thickness– Three slopes, one blend
• Spreading methods – uniformity– Machine blowing, hand spreading, helicopter drop
• Wind mobility– Washington Technology Center / WSU– Results in July 2006
WoodStraw® Technical Erosion Control Material
forestconcepts™
USFS RMRS Lab Results
Sediment from Rain + 1st Flow
0.0
200.0
400.0
600.0
800.0
1000.0
1200.0
1400.0
1600.0
0 10 20 30 40 50 60 70 80
Cover (%)
Sedi
men
t Los
s (g
).
LM 15%LM 30%LS 15%LS 30%
WoodStraw® Technical Erosion Control Material
Sediment / Erosion Control
Percent Cover
83% reduction
94% reduction
forestconcepts™
USFS RMRS Lab Results
Runoff from Rain Only
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
0 10 20 30 40 50 60 70 80
Cover (%)
Runo
ff (L
). LM 15%LM 30%LS 15%LS 30%
Runoff / Infiltration
Percent Cover
forestconcepts™
WoodStraw® - Application Rates
40% coverage 50% coverage 70% coverage
80 Regular Bales/Acre7 Large Bales/Acre
Slopes < 5%
150 Regular Bales/Acre13 Large Bales/Acre
Slopes <33%
276 Regular Bales/Acre24 Large Bales/Acre
Slopes >33%
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forestconcepts™
Chambers Creek QuarryTacoma, WA
~ 35” Rainfall Per Year
Site 1 – 14% slopeWoodStraw – 50% coverAg Straw – 90% cover
Site 2 – 58% slopeWoodStraw – 50% coverAg Straw – 75% cover
forestconcepts™
UW - Pack ForestEatonville, WA
~ 50 in. annual rainfall
forestconcepts™
Ernst RanchPaso Robles, CA
~ 8 in. annual rainfall
forestconcepts™
Ernst Ranch
Ernst Site Intensity
0.000.300.600.901.201.501.802.10
26-Dec 29-Dec 1-Jan 4-Jan 7-Jan 10-Jan
Date
Inte
nsity
(in/
hr)
Sediment - Event (Ernst)
63.0
95.1
48.6
3.50.3
0
20
40
60
80
100
Date
Sedi
men
t (kg
)
Control Wood Barley
forestconcepts™
Straw Decomposition Curve
Straw Mulch - Ernst Site
y = -0.004x2 - 0.0073x + 0.9139R2 = 0.921
0.000.100.200.300.400.500.600.700.800.901.00
0 2 4 6 8 10 12
Months since application
Perc
ent o
f ini
tial c
over
forestconcepts™
Field Trial Conclusions
• Wood-strand mulch performed in the field the same as in the lab
• Initial sediment reduction for wood strands applied at 70% cover is equal to straw at 90%
• Wood-strand mulch does not decay or move in first year after application while barley straw cover reduced to less than 30%
forestconcepts™
Manufacturing
forestconcepts™ 17
Wind Resistance Research Data
15
17
19
21
35 41
44
45 47
51
0
1
2
3
4
0 10 20 30 40 50 60
Mob
ility
Sca
le
Wind Speed (mph)
Wind Mobility: Agrcultural Straw vs WoodStraw™ Wood Strand Material
Ag Straw WoodStraw
4 = Blown Away
3 = Mass Movement
2006 Washington State University - N. Copeland
2 = Leading Edge Movement
1 = Few Strands Blow
0 = No Movement
forestconcepts™ 18
Wind Erosion & Dust Control Capability
0 20 40 60
0
100
200
300
PM10
Con
cent
ratio
n (m
g/m
3 )
0 20 40 60Tim e (seconds)
0 20 40 60
0.5 cm1.0 cm2.0 cm4.0 cm
Bare Soil Agricultura l S traw W ood S trands
PM10 concentration over time for a free stream velocity of 18 m/s.2007 Washington State University - N. Copeland
05/04/10
forestconcepts™
Mines, Pipelines, & PowerlinesRuby Pipeline
Crandall Canyon Mine
Rio Puerco Mine
Miami Globe Mine
Sugarite Mine
forestconcepts™
Survey of Users – Dec. 2012• Survey Monkey – 20 invitations/6 respondents
• 3 Project Managers & 3 Contractors• 4 Federal & 2 State• All <100 acres with most 1-10 acre• 3 Mines, 1 Pipeline & 2 Watershed Protection Projects• Site Conditions:
• 3 were mixed slopes, 1 moderate & 2 steep slopes (~70%)• Soils moderately to highly erosive• 4 used hand crews to apply, 2 straw blower & 1 helicopter• 50% application coverage for 5 & 70% coverage for 1
• Had Considered Using Alternative Solutions:• Ag Straw (3)• Hydroseed (1)• Rolled Erosion Blankets (1)• Wood Chips (1)
forestconcepts™
Survey of Users – Dec. 2012 (Cont.)
• Primary Reasons for Use of Wood-strand Mulch– Erosion Control Performance – Resistant to High Winds – Long Life & Durability – No Invasive Species
• Ease of Application for Wood-strand Mulch– Easy - 1– Moderate - 2– Somewhat Difficult - 3– Difficult - 0
forestconcepts™
Survey of Users – Dec. 2012 (Cont.)
• Overall Performance of Wood-strand Mulch– Excellent - 3– Good - 1– Moderate - 1– Poor - 0– To recent to evaluate - 1
• Was Wood-strand Mulch Worth the Cost?– Yes - 5– No - 1
• Would They Consider/Recommend Wood-strand Mulch?– Yes - 6– No - 0
forestconcepts™
Thank You!