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

2

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.

4

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.

5

• 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%

9

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!