Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10)

Riprap, Quarry Spalls, Slope Protection, and Rock for Erosion and Scour Protection and Rock Walls

9-13

9-13.5(2) Poured Portland Cement or Blended Hydraulic Cement Concrete

Slope Protection

Cement concrete for poured concrete slope protection shall be commercial concrete in
conformance with

Section 6-02.3(2)B

9-13.5(3) Pneumatically Placed Portland Cement or Blended Hydraulic

Cement Concrete Slope Protection

Cement – This material shall be portland cement or blended hydraulic cement as specified
in

Section 9-01

Aggregate – This material shall meet the requirements for fine aggregate as specified in

Section 9-03.1

. The moisture content of the fine aggregate at the time of use shall be

between 3 and 6 percent by weight.

Reinforcement – Wire mesh reinforcement shall conform to the provisions of

Section 9-07.7

Water – Water shall conform to the provisions of

Section 9-25.1

9-13.6 Vacant
9-13.7

Rock for Rock Wall

9-13.7(1) Rock for Rock Walls and Chinking Material

Rock for rock walls and chinking material shall be hard, sound and durable material, free
from seams, cracks, and other defects tending to destroy its resistance to weather, and
shall meet the following test requirements:

Test

Test Method

Requirements

Specific Gravity, SSD

AASHTO T 85

2.55 min.

LA Wear

AASHTO T 96

50% max.

Degradation

WSDOT T 113

15 min.

Absorption

AASHTO T 85

3% max.

Rock for rock wall sizes are approximately as follows:

Rock Size

Rock Weight (lbs)

Average Dimension (in.)

One Man

50 to 200

12 to 18

Two Man

200 to 700

18 to 28

Three Man

700 to 2,000

28 to 36

Four Man

2,000 to 4,000

36 to 48

Five Man

4,000 to 6,000

48 to 54

Six Man

6,000 to 8,000

54 to 60

Chinking material shall be a minimum of 4 inches average dimension.

Erosion Control and Roadside Planting

9-14

Erosion Control and Roadside Planting

9-14.1

Materials Submittals and Acceptance

Standard

Specification

Section

Material

For each material used the Contractor shall submit

a materials certificate of compliance in accordance

with

Section 1-06.2

along with the following

information to the Engineer

9-14.2(1)

Topsoil Type A

Compliance with the applicable section.

9-14.2(2)

Topsoil Type B

9-14.2(3)

Topsoil Type C

Seed

Fertilizer

Mulch and Amendments

Straw

Hydraulically Applied

Erosion Control Products

Test results, dated within 3 years prior to the date of

application, from an independent, accredited laboratory,

as approved by the Engineer, that show the product

meets requirements of this section.

9-14.5(2)A

Long-Term Mulch in

Section

Test results reported on WSDOT Form 220-042

documenting that the mulch meets the requirements in

Section 9-14.5(2) Table 1 and this section.

9-14.5(2)B

Moderate-Term Mulch

Test results reported on WSDOT form 220-043

documenting that the mulch meets the requirements

in Section 9-14.5(2) Table 1 and the applicable

requirements of these sections.

9-14.5(2)C

Short-Term Mulch

9-14.5(3)

Bark and Wood Chip

Mulch

Compliance with the applicable section.

9-14.5(4)

Wood Strand Mulch

A satisfactory test report, performed in accordance with

WSDOT T 125 and compliance with this section.

9-14.5(6)

Agriculture Grade Gypsum Compliance with the applicable section.

9-14.5(7)

Tackifier

Test results that show the tackifier meets requirements

Section 9-14.5(2)

Table 1 and compliance with

this section.

Page 9-110

Erosion Control and Roadside Planting

Standard

Specification

Section

Material

For each material used the Contractor shall submit

a materials certificate of compliance in accordance

with

Section 1-06.2

along with the following

information to the Engineer

9-14.5(8)

Compost

Fourteen days prior to application.
a) A copy of the Solid Waste Handling Permit issued

to the manufacturer by the Jurisdictional Health

Department in accordance with https://apps.leg.wa.gov/

WAC/default.aspx?cite=173-350 (Minimum Functional

Standards for Solid Waste Handling).
b) Test results that show the compost complies with the

processes, testing, and standards specified in

WAC 173-

350

and this section. An independent Seal of Testing

Assurance (STA) Program certified laboratory shall

perform the testing.
c) A copy of the manufacturer’s Seal of Testing

Assurance STA certification as issued by the U.S.

Composting Council dated within 90 calendar days of

the application.
d) Compost test data submitted on WSDOT Form

220-038.
e) A sample of the compost approved for use.
f) A list of feed stocks by volume for each compost type.
g) Physical contaminants shall not exceed 0.5 percent by

weight of total sampled compost.
h) Compliance with the applicable section.

9-14.5(9)

Horticultural Grade

Perlite

Test results reported on WSDOT Form 220-037

documenting that the horticultural grade perlite meets

the requirements of this section.

9-14.6(2)

Biodegradable Erosion

Control Blanket

Test results reported on WSDOT Form 220-039

documenting that the biodegradable erosion control

blanket meets the requirements of this section.

Independent laboratory test results from the National

Transportation Product Evaluation Program (NTPEP)

meeting the requirements of Section

9-14.5(2)A

9-14.5(2)B

9-14.5(2)C

9-14.6(5)

Wattles

Compliance with the applicable section.

9-14.6(6)

Compost Socks

9-14.7

Plant Materials

If cuttings are taken from private property the

contractor shall submit a copy of the written permission

to the Engineer prior to cuttings being collected.

Erosion Control and Roadside Planting

9-14

9-14.2 Topsoil

Topsoil shall not contain any recycled material, foreign materials, or any listed Noxious
and Nuisance weeds of any Class designated by authorized State or County officials.
Aggregate shall not comprise more than 10 percent by volume of Topsoil and shall not be
greater than two inches in diameter.

9-14.2(1) Topsoil Type A

Topsoil Type A shall be as specified in the Special Provisions.

9-14.2(2) Topsoil Type B

Topsoil Type B shall be native topsoil taken from within the project limits either from the
area where roadway excavation is to be performed or from strippings from borrow, pit,
or quarry sites, or from other designated sources. In the production of Topsoil Type B, all
vegetative matter, less than 4 feet in height, shall become a part of the topsoil.

9-14.2(3) Topsoil Type C

Topsoil Type C shall be native topsoil meeting the requirements of Topsoil Type B but
obtained from a source provided by the Contractor outside of the Contracting Agency
owned right of way.

9-14.3 Seed

Seed of the type specified shall be certified in accordance with

WAC 16-302

. Seed mixes

shall be commercially prepared and supplied in sealed containers. The labels shall show:
(1)  Common and botanical names of seed,
(2)  Lot number,
(3)  Net weight,
(4)  Pounds of Pure live seed (PLS) in the mix,
(5)  Origin of seed.

All seed vendors must have a business license issued by supplier’s state or provincial
Department of Licensing with a “seed dealer” endorsement.

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Erosion Control and Roadside Planting

9-14.4 Fertilizer

Fertilizer shall be a standard commercial grade of organic or inorganic fertilizer of the kind
and quality specified. It may be separate or in a mixture containing the percentage of total
nitrogen, available phosphoric acid, and water-soluble potash or sulfur in the amounts
specified. All fertilizers shall be furnished in standard unopened containers with weight,
name of plant nutrients, and manufacturer’s guaranteed statement of analysis clearly
marked, all in accordance with State and Federal laws.

Fertilizer shall be supplied in one of the following forms:
(1) A dry free-flowing granular fertilizer, suitable for application by agricultural fertilizer

spreader.

(2) A soluble form that will permit complete suspension of insoluble particles in water,

suitable for application by power sprayer.

(3) A homogeneous pellet, suitable for application through a ferti-blast gun.
(4) A tablet or other form of controlled release with a minimum of a 6 month release

period.

(5) A liquid suitable for application by a power sprayer or hydroseeder.

9-14.5

Mulch and Amendments

All amendments shall be delivered to the site in the original, unopened containers
bearing the manufacturer’s guaranteed chemical analysis and name. In lieu of containers,
amendments may be furnished in bulk. A Manufacturer’s Certificate of Compliance shall
accompany each delivery. Compost and other organic amendments shall be accompanied
with all applicable health certificates and permits.

9-14.5(1)

Straw

Straw shall be in an air-dried condition, free of noxious weeds, seeds, and other materials
detrimental to plant life. Hay is not acceptable.

All straw material shall be Certified Weed-Free Straw using North American Weed
Management Association (NAWMA) standards or the Washington Wilderness Hay and
Mulch (WWHAM) program run by the Washington State Noxious Weed Control Board.
Information can be found at

www.nwcb.wa.gov

In lieu of Certified Weed-Free Straw, the Contractor shall submit documentation that the
material is steam or heat treated to kill seeds, or shall submit U.S., Washington State, or
other states’ Department of Agriculture laboratory test reports, dated within 90 days prior
to the date of application, showing that there are no viable seeds in the straw.

Erosion Control and Roadside Planting

9-14

9-14.5(2) Hydraulically Applied Erosion Control Products (HECPs)

All HECPs shall be made of natural plant fibers unaltered by synthetic materials, and in a
dry condition, free of noxious weeds, seeds, chemical printing ink, germination inhibitors,
herbicide residue, chlorine bleach, rock, metal, plastic, and other materials detrimental to
plant life.

The HECP shall be suitable for spreading with a hydroseeder.

All HECPs shall be furnished premixed by the manufacturer with Organic or Synthetic
Tackifier as specified in

Section 9-14.5(7)

. The product shall be hydrated in accordance

with the manufacturer’s recommendations.

The Contractor shall submit test results, dated within 3 years prior to the date of
application, from an independent, accredited laboratory, as approved by the Engineer,
showing that the product meets the following requirements:

Table 1

HECP Requirements

These test requirements apply to the fully mixed product, including tackifiers, dyes, or other

additives that may be included in the HECP final product in its sprayable form.

Properties

Test Method

Requirements

Acute

Toxicity

EPA-821-R-02-012 Methods for

Measuring Acute Toxicity of Effluents.

Test leachate from recommended

application rate receiving 2 inches of

rainfall per hour using static test for No-

Observed-Adverse-Effect-Concentration

(NOEC).

Four replicates are required with no

statistically significant reduction in

survival in 100 percent leachate for a

Daphnid at 48 hours and Oncorhynchus

mykiss (rainbow trout) at 96 hours.

Solvents EPA 8260 (SW846)

Benzene –

< 0.03 mg/kg

Methylene chloride – < 0.02 mg/kg

Naphthalene –

< 5 mg/kg

Tetrachloroethylene – < 0.05 mg/kg

Toluene –

< 7 mg/kg

Trichloroethylene –

< 0.03 mg/kg

Xylenes –

< 9 mg/kg

Heavy

Metals

EPA 6010 or 6020 (SW856)

Antimony –

< 4 mg/kg

Arsenic –

< 6 mg/kg

Barium –

< 80 mg/kg

Boron –

< 160 mg/kg

Cadmium –

< 2 mg/kg

Total Chromium –

< 4 mg/kg

Copper –

< 10 mg/kg

Lead –

< 5 mg/kg

Nickel –

< 2 mg/kg

Selenium –

< 10 mg/kg

Strontium –

< 40 mg/kg

Zinc –

< 30 mg/kg

Heavy

Metals

EPA 6010 or 6020 (SW856) or EPA 7470

or 7471 (SW856)

Mercury –

< 2 mg/kg

Page 9-114

Erosion Control and Roadside Planting

If the HECP contains cotton or straw, the Contractor shall submit documentation that the
material has been steam or heat treated to kill seeds, or shall submit U.S., Washington
State, or other states’ Department of Agriculture laboratory test reports, dated within
90 days prior to the date of application, showing that there are no viable seeds in
the mulch.

The HECP shall be manufactured in such a manner that, when agitated in slurry tanks
with water, the fibers will become uniformly suspended, without clumping, to form
a homogeneous slurry. When hydraulically applied, the material shall form a strong
moisture-holding mat that allows the continuous absorption and infiltration of water.

If the HECP contains a dye to facilitate placement and inspection of the material, it
shall be nontoxic to plants, animals, and aquatic life and shall not stain concrete or
painted surfaces.

The HECP shall not be harmful to plants, animals, and aquatic life.

9-14.5(2)A

Long-Term Mulch

Long-Term Mulch shall adhere to the soil, create a blanket-like mass and bond with the
soil surface to create a continuous, porous, absorbent, and flexible erosion-resistant
blanket that allows for seed germination and plant growth. Long-Term Mulch shall meet
the requirements in

Table 2

, Long-Term Mulch Test Requirements. Products containing

cellulose fiber produced from paper or paper components will not be approved or
accepted. With the exception of seed and water, field mixing of additives or components
is not acceptagble.

Table 2

Long-Term Mulch Test Requirements

The Contractor shall supply independent test results from the National Transportation Product

Evaluation Program (NTPEP) on 5-year intervals generated on or after November 1, 2015

showing that the product meets the Cover-Factor (C Factor) in accordance with ASTM D6459.

Properties

Test Method

Requirements

Performance in

Protecting Slopes

from Rainfall-

Induced Erosion

ASTM D6459. Test in one soil type.

Soil tested shall be sandy loam as

defined by the NRCS Soil Texture

Triangle.

C Factor = 0.01 maximum using

Revised Universal Soil Loss Equation

(RUSLE)

The Contractor shall submit test results from an independent, accredited laboratory, on 5-year

intervals generated on or after July 15 of 2017 showing that the product meets the follow-ing

requirements.

Properties

Test Method

Requirements

Water Holding

Capacity

ASTM D7367

800 percent minimum

Organic Matter

Content

AASHTO T 267

90 percent minimum

Seed Germination

Enhancement

ASTM D7322

Long Term
420 percent minimum

Erosion Control and Roadside Planting

9-14

9-14.5(2)B

Moderate-Term Mulch

Within 48 hours of application, the Moderate-Term Mulch shall bond with the soil surface
to create a continuous, absorbent, flexible, erosion-resistant blanket. Moderate-Term
Mulch shall effectively perform the intended erosion control function in accordance with
Section 8-01.3(1) for a minimum of 3 months, or until temporary vegetation has been
established, whichever comes first.

9-14.5(2)C

Short-Term Mulch

Short-Term Mulch shall effectively perform the intended erosion control function in
accordance with Section 8-01.3(1) for a minimum of 2 months, or until temporary
vegetation has been established, whichever comes first. Short-Term Mulch shall not be
used in conjunction with permanent seeding.

9-14.5(3) Bark or Wood Chip Mulch

Bark or wood chip mulch shall be derived from fir, pine, or hemlock species. It shall not
contain resin, tannin, or other compounds in quantities that would be detrimental to plant
life. Sawdust shall not be used as mulch. Mulch produced from finished wood products or
construction debris will not be allowed.

Bark or wood chips when tested shall be in accordance with WSDOT

T 123

and shall

meet the following loose volume gradation:

Sieve Size

Percent Passing

Minimum

Maximum

2″

100

No. 4

9-14.5(4) Wood Strand Mulch

Wood strand mulch shall be a blend of angular, loose, long, thin wood pieces that are
frayed, with a high length-to-width ratio, and it shall be derived from native conifer or
deciduous trees. A minimum of 95 percent of the wood strand shall have lengths between
2 and 10 inches. At least 50 percent of the length of each strand shall have a width and
thickness between 1/16 and ½ inch. No single strand shall have a width or thickness greater
than ½ inch.

The mulch shall not contain salt, preservatives, glue, resin, tannin, or other compounds in
quantities that would be detrimental to plant life. Sawdust or wood chips or shavings will
not be acceptable.

This product shall not be harmful to plants, animals, and aquatic life.

Page 9-116

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9-14.5(5) Agricultural Grade Dolomite Lime

Agricultural grade dolomite lime shall be in a pelletized or granular form, meeting the
grading requirements of ASTM C602 for Class E.

9-14.5(6) Agricultural Grade Gypsum

Agricultural grade gypsum shall consist of Calcium Sulfate (CaSO

∙2H

O) in a pelletized or

granular form and shall meet the following grading requirements;

Sieve Size

Percent Passing

¼”

99 – 100

No. 20

20 max

All percentages are by weight.

9-14.5(7) Tackifier

Tackifiers are used as a tie-down for soil, compost, seed, and/or mulch. Tackifiers shall
contain no growth or germination-inhibiting materials and shall not reduce infiltration
rates. Tackifiers shall hydrate in water and readily blend with other slurry materials.
Tackifiers shall include a mulch tracer added to visible aid uniform application, and shall
not be harmful to plans, animals, or aquatic life.

9-14.5(7)A

Organic Tackifier

Organic tackifiers shall be derived from natural plant sources and shall not be harmful to
plants, animals, and aquatic life.

9-14.5(7)B

Synthetic Tackifier

Synthetic tackifiers shall not be harmful to plants, animals, and aquatic life.

9-14.5(8) Compost

Compost products shall be the result of the biological degradation and transformation
of organic materials under controlled conditions designed to promote aerobic
decomposition. Compost shall be stable with regard to oxygen consumption and carbon
dioxide generation. Compost shall be mature with regard to its suitability for serving as
a soil amendment or an erosion control BMP as defined below. The compost shall have
a moisture content that has no visible free water or dust produced when handling the
material.

Compost production and quality shall comply with

WAC 173-350

Compost products shall meet the following physical criteria:
1. Compost material shall be tested in accordance with U.S. Composting Council

Testing Methods for the Examination of Compost and Composting (TMECC) 02.02-
B, “Sample Sieving for Aggregate Size Classification”.

Erosion Control and Roadside Planting

9-14

Fine compost shall meet the following gradation:

Sieve Size

Percent Passing

Minimum

Maximum

1″

100

⅝″

100

¼″

100

Note: Maximum particle length of 4 inches.

Medium compost shall meet the following gradation:

Sieve Size

Percent Passing

Minimum

Maximum

1″

100

⅝″

100

¼″

Note: Maximum particle length of 4 inches. Medium compost shall have a carbon to nitrogen
ratio (C:N) between 18:1 and 35:1. The carbon to nitrogen ratio shall be calculated using the dry
weight of “Organic Carbon” using TMECC 04.01A divided by the dry weight of “Total N” using
TMECC 04.02D.

Coarse compost shall meet the following gradation:

Sieve Size

Percent Passing

Minimum

Maximum

2″

100

1″

100

¾″

100

¼″

Note: Maximum particle length of 6 inches. Coarse compost shall have a carbon to nitrogen
ratio (C:N) between 25:1 and 35:1. The carbon to nitrogen ratio shall be calculated using the dry
weight of “Organic Carbon” using TMECC 04.01A divided by the dry weight of “Total N” using
TMECC 04.02D.

2. The pH shall be between 6.0 and 8.5 when tested in accordance with U.S.

Composting Council TMECC 04.11-A, “1:5 Slurry pH”.

3. Physical contaminants, defined in

WAC 173-350

(plastic, concrete, ceramics, metal,

etc.) shall be less than 0.5 percent by weight as determined by U.S. Composting
Council TMECC 03.08-A “Classification of Inerts by Sieve Size”.

4. Minimum organic matter shall be 40 percent by dry weight basis as determined

by U.S. Composting Council TMECC 05.07A “Loss-On-Ignition Organic Matter
Method (LOI)”.

5. Soluble salt contents shall be less than 4.0 mmhos/cm when tested in accordance

with U.S. Composting Council TMECC 04.10 “Electrical Conductivity”.

6. Maturity shall be greater than 80 percent in accordance with U.S. Composting

Council TMECC 05.05-A, “Germination and Root Elongation”.

Page 9-118

Erosion Control and Roadside Planting

7. Stability shall be 7-mg CO2–C/g OM/day or below in accordance with U.S.

Composting Council TMECC 05.08-B “Carbon Dioxide Evolution Rate”.

8. The compost product shall originate from organic feedstocks as defined in

WAC

173-350

as “Wood waste”, “Yard debris”, “Post-consumer food waste”, “Preconsumer

animal-based wastes”, and/or “Preconsumer vegetative waste”. The Contractor shall
provide a list of feedstock sources by percentage in the final compost product.

9. The Engineer may also evaluate compost for maturity using U.S. Composting Council

TMECC 05.08-E “Solvita® Maturity Index”. Fine compost shall score a number 6 or
above on the Solvita® Compost Maturity Test. Medium and Coarse compost shall
score a 5 or above on the Solvita® Compost Maturity Test.

9-14.5(9) Horticultural Grade Perlite

Horticultural grade perlite shall be in a pelletized or granular form.

Horticultural grade perlite shall meet the following requirements for quality and grading:

Quality Requirements

Property

Test Method

Requirement

pH (of water slurry)

PI 202

6.5 – 8.0

Bulk Density, lb/ft

PI 200

2 – 10

PI, abbreviation for the Perlite Institute

Gradation Requirements

Sieve Size

Percent Passing

No. 4

99 – 100

No. 18

30 max

No. 30

10 max

All percentages are by weight.

9-14.6

Erosion Control Devices

9-14.6(1) Polyacrylamide (PAM)

PAM is used as a tie-down for soil, compost, or seed, and is also used as a flocculent. PAM
products shall meet ANSI/NSF Standard 60 for drinking water treatment with an AMD
content not to exceed 0.05 percent. PAM shall be anionic and shall be linear, and not
cross-linked. The minimum average molecular weight shall be greater than 5-mg/mole.
The charge density shall be no less than 15 percent and no greater than 30 percent. The
product shall contain at least 80 percent active ingredients and have a moisture content
not exceeding 10 percent by weight. PAM shall be delivered in a dry granular or powder
form.

Erosion Control and Roadside Planting

9-14

9-14.6(2) Biodegradable Erosion Control Blanket

Biodegradable erosion control blankets, including netting if present, shall be made of
natural plant fibers unaltered by synthetic materials. All blanket material shall effectively
perform the intended erosion control function until permanent vegetation has been
established, or for a minimum of 6 months, whichever comes first.

9-14.6(2)A

Biodegradable Erosion Control Blanket for Slopes Steeper than

3:1 (H:V)

Table 6

Properties

ASTM Test Method

Requirements for Slopes Steeper

than 3:1

Protecting Slopes

from Rainfall-Induced

Erosion

ASTM D6459
Soil tested shall be sandy loam as

defined by the NRCS**
Soil Texture Triangle

C factor = 0.04 maximum for

cumulative R-Factor<231

Mass Per Unit Area

ASTM D6475

7.6 oz./sq. yd. minimum

Light Penetration

ASTM D6567

44% maximum

Tensile Strength MD

× XD*

ASTM D6818

10.0 × 6.0 pounds/inch minimum

Tensile Elongation MD

× XD*

ASTM D6818

38% × 33% maximum

*MD is Machine Design and XD is Cross Direction
**Natural Resource Conservation Services

9-14.6(2)B

Biodegradable Erosion Control Blanket for Slopes Flatter than

3:1 (H:V)

Table 7

Properties

ASTM Test Method

Slope Flatter than 3:1 Requirements

Protecting Slopes

from Rainfall-Induced

Erosion

ASTM D6459
Soil tested shall be sandy loam as

defined by the NRCS**
Soil Texture Triangle

C factor = 0.15 maximum for

cumulative R-Factor<231

Mass Per Unit Area

ASTM D6475

7.6 oz./sq. yd. minimum

Light Penetration

ASTM D6567

40% maximum

Tensile Strength MD

× XD*

ASTM D6818

6.5 × 2.3 pounds/inch minimum

Tensile Elongation MD

× XD*

ASTM D6818

38% × 33% maximum

*MD is Machine Design and XD is Cross Direction
**Natural Resource Conservation Services

Page 9-120

Erosion Control and Roadside Planting

9-14.6(2)C

Biodegradable Erosion Control Blanket for Ditches

Table 8

Properties

Test Method

Requirements

Performance in

Protecting Earthen

Channels from

Stormwater-Induced

Erosion

ASTM D6460
Soil tested shall be sandy loam as

defined by the NRCS**
Soil Texture Triangle

Limiting Shear (T

Limit

) = 2.0 psf

minimum.
Limiting Velocity (V

Limit

) = 7.5 ft/

sec flow minimum.

Mass per Unit Area

ASTM D6475

7.4 oz./ sq. yd. minimum

Light Penetration

ASTM D6567

65% maximum

Tensile Strength MD

× XD*

ASTM D6818

9.6 × 3.2 lbs/inch minimum

Tensile Elongation MD

× XD*

ASTM D6818

38% × 33% maximum

*MD is Machine Design and XD is Cross Direction
**Natural Resource Conservation Services

9-14.6(3) Plastic Covering

Plastic covering shall meet the requirements of ASTM D4397 for polyethylene sheeting.

9-14.6(4) Check Dams

All materials used for check dams shall be non-toxic and not pose a threat to wildlife
when installed.

9-14.6(4)A

Biodegradable Check Dams

Biodegradable check dams shall meet the following requirements:

Wattle

Section 9-14.6(5)

Compost Sock

Section 9-14.6(6)

Coir Log

Section 9-14.6(7)

The Contractor may substitute a different biodegradable check dam as long as it complies
with the following and is accepted by the Engineer:
1. Made of natural plant fiber unaltered by synthetic material.
2. Netting if present shall be made of natural plant fibers unaltered by synthetic

materials. Materials shall effectively perform the intended erosion control function
until permanent vegetation has been established or for a minimum of 6 months,
whichever comes first.

3. Straw bales shall not be used as check dams.

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9-14

9-14.6(4)B

Non-biodegradable Check Dams

Non-biodegradable check dams shall meet the following requirements:
1. Geotextile materials shall conform to

Section 9-33

for silt fence.

2. Other such devices that meet the requirements of

Section 9-14.6(4)

and shall be

approved by the Engineer prior to installation.

9-14.6(5) Wattles

Wattles shall consist of cylinders of plant material such as weed-free straw, coir, wood
chips, excelsior, or wood fiber or shavings encased within netting made of natural
plant fibers unaltered by synthetic materials. Wattles shall be a minimum of 8 inches in
diameter. Netting material shall be clean, evenly woven, and free of encrusted concrete
or other contaminating materials such as preservatives. Netting material shall be free
from cuts, tears, or weak places and shall effectively perform the intended erosion control
function until permanent vegetation has been established or for a minimum of 6 months,
whichever comes first.

If wood chip filler is used, it shall meet the material requirements as specified in

Section

9-14.5(3)

. If straw filler is used, it shall meet the material requirements as specified

in Section 9-14.4(1). If wood shavings are used, 80 percent of the fibers shall have a
minimum length of 6 inches between 0.030 and 0.50 inches wide and between 0.017 and
0.13 inches thick.

Stakes for wattles shall be made of wood from untreated Douglas fir, hemlock, or pine
species.

9-14.6(6) Compost Socks

Compost socks shall consist of fabric made of natural plant fibers unaltered by synthetic
materials. The compost sock shall be filled with Medium Compost as specified in Section
9-14.5(8). Compost socks shall be at least 8 inches in diameter. The sock shall be clean,
evenly woven; free of encrusted concrete or other contaminating materials; free from
cuts, tears, broken or missing yarns; free of thin, open, or weak areas; and free of any
type of preservative. Sock fabric shall effectively perform the intended erosion control
function until permanent vegetation has been established or for a minimum of 6 months,
whichever comes first.

Stakes for compost socks shall be made of wood from untreated Douglas fir, hemlock, or
pine species.

Page 9-122

Erosion Control and Roadside Planting

9-14.6(7) Coir Log

Coir logs shall be made of 100 percent durable coconut (coir) fiber uniformly compacted
within woven netting made of bristle coir twine with a minimum tensile strength of 80 lbs.
The netting shall have nominal 2 by 2-inch openings. Log segments shall have a maximum
length of 20 feet, with a minimum diameter as shown in the Plans. Logs shall have a
minimum density of 7 lbs/cf.

Stakes shall be untreated Douglas fir, hemlock, or pine species. Wood stakes shall have a
notch to secure the rope ties. Rope ties shall be made of ¼-inch diameter commercially
available hemp rope.

9-14.6(8) High Visibility Fencing

High visibility fence shall be UV stabilized, orange, high-density polyethylene or
polypropylene mesh.

Support posts shall be wood or steel in accordance with

Standard Plan

I-10.10. The posts

shall have sufficient strength and durability to support the fence through the life of the
project.

9-14.6(9) High Visibility Silt Fence

High visibility silt fence shall be a minimum of 5 feet in height, high visibility orange, UV
stabilized and shall meet the geotextile requirements in

Section 9-33

Table 6. Support

posts shall be in accordance with the

Standard Plans

. The posts shall have sufficient

strength and durability to support the fence through the life of the project.

9-14.7

Plant Materials

9-14.7(1) Description

Bareroot plants are grown in the ground and harvested without soil or growing medium
around their roots.

Container plants are grown in pots or flats that prevent root growth beyond the sides and
bottom of the container.

Balled and burlapped plants are grown in the ground and harvested with soil around a
core of undisturbed roots. This rootball is wrapped in burlap and tied or placed in a wire
basket or other supportive structure.

Cuttings are live plant material without a previously developed root system. Source plants
for cuttings shall be dormant when cuttings are taken and all cuts shall be made with a
sharp instrument. Cuttings may be collected. If cuttings are collected, the requirement
to be nursery grown or held in nursery conditions does not apply. Written permission
shall be obtained from property owners and provided to the Engineer before cuttings are
collected. The Contractor shall collect cuttings in accordance with applicable sensitive
area ordinances. Cuttings shall meet the following requirements:

Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10) - page 83