Section 4169.  Erosion Control Materials

 

4169.01     DESCRIPTION.

All materials required to be furnished and described in this section.

 

4169.02     SEEDS.

 

A.     Furnish seeds approved for use according to requirements of this section, including specified purity and germination, as shown in Tables 4169.02-1 and 4169.02-2.

 

Table 4169.02-1: Seeds (Common Names, Scientific Names, Purity, and Germination)

Common Name

Scientific Name

Purity (%)

Germination (%)

DOMESTIC GRASSES

Bluegrass, Kentucky

Poa pratensis

85

80

Bluegrass, Ky. RAM-1

Poa pratensis-RAM-1

95

85

Bluegrass, Ky. PARK

Poa pratensis-PARK

95

85

Brome, smooth-LINCOLN

Bromus inermis

90

85

Fescue, tall, FAWN

Festuca arundinacea-FAWN

98

85

Fescue, chewings, red

Festuca rubra var. commutate

98

90

Fescue, creeping, red

Festuca rubra

98

85

Fescue, red-PENNLAWN

Festuca rubra PENNLAWN

98

85

Fescue, Tall, Olympic (Fineleaf)

Festuca arundinacea-Olympic

98

85

Fescue, Tall, Rebel (Fineleaf)

Festuca arundinacea

98

85

Fescue, Sheeps

Festuca ovina

98

85

Orchardgrass

Dactylis glomerata

90

90

Red top

Agrostis alba

92

85

Reed Canarygrass

Phalaris arundinacea

98

70

Wildrye, Canada

Elymus Canadensis

95

85

Wildrye, Russian

Elymus junceus

95

85

Ryegrass, Perennial

Lolium perenne

95

90

Timothy

Phleum pratense

99

85

LEGUMES

Alfalfa, RANGER/VERNAL

Medicago sativa

99

90(a)

Alfalfa, Travois

Medicoa spp.

99

90(a)

Birdsfoot Trefoil EMPIRE

Lotus corniculatus

98

85(a)

Crownvetch, Emerald

Coronilla varia

98

70(a)

Hairy Vetch

Vicia villosa

96

85(a)

Lespedeza, Korean

Lespedeza stipulacea

98

80(a)

Red Clover, medium

Trifolium pretense

99

90(a)

Alsike Clover

Trifolium hybridum

99

90(a)

White Clover

Trifolium repens

98

90(a)

NURSE CROP OR STABILIZING CROP

Oats

Avena sativa

97

90

Rye

Secale cereale

97

90


Sudangrass, PIPER

Sorghum vulgare var. sudanese

98

85

(a)     Includes hard seed.

 

Table 4169.02-2: Seeds (Common Names, Scientific Names, and PLS)

Common Names

Scientific Names

PLS (%)

*Furnish seed certified as Source Identified Class (Yellow Tag) Source G0-Iowa.

 

NATIVE GRASSES

 

 

Big Bluestem*

Andropogon gerardii

30

Little Bluestem*

Andropogon scoparius

30

Switchgrass*

Panicum virgatum

63

Indiangrass*

Sorghastrum nutans

30

Sorghastrum nutans

Bouteloua curtipendula

30

Western Wheatgrass*

Agropyron smithii

56

Buffalograss*

Buchloe dactyloides

60

Sand Bluestem*

Andropogon gerardii, var. paucipilus

30

Blue Grama

Bouteloua gracilis

30

Intermediate Wheatgrass

Agropyron intermedium

70

Slender Wheatgrass

Agropyron trachycaulum, var. unilaterale

70

Prairie Dropseed

Sporobolus heterolepis

65

Sand Dropseed

Sporobolus cryptandrus

65

Sand Lovegrass

Eragrostis trichodes

65

Weeping Lovegrass

Eragrostis curvula

65

Hairy Wood Chess

Bromus purgans

60

Blue-joint grass

Calamagrostis Canadensis

47

Bottlebrush sedge

Carex comosa

62

Tussock sedge

Carex stricta

78

Fox sedge

Carex vulpinoidea

64

Virginia wild-rye

Elymus virginicus

60

Reed manna grass

Glyceria grandis

50

Fowl manna grass

Glyceria striata

72

Common rush

Juncus effuses

80

Rice Cut Grass

Leesia oryzoides

62

Rye grass, annual

Lolium italicum

89

Fowl bluegrass

Poa palustris

72

Green bulrush

Scirpus atrovirens

45

Wool grass

Scirpus cyperinus

78

Soft-stem bulrush

Scirpus vallidus

78

Indian grass

Sorghastrum nutans

60

Spike Rush

Eleocharis palustris

71

FORBS

Canada anemone

Anemone Canadensis

72

Marsh milkweed

Asclepias incarnate

25

New England aster

Aster novae-angliae

25

Swamp aster

Aster puniceus

25

Showy tic-trefoil

Desmodium canadense

25

Joe-pye weed

Eupatorium maculatum

66

Boneset

Eupatorium perfoliatum

41

Ox Eye sunflower

Heliopsis helianthoides

38

Blue-flag iris

Iris virginica-shrevii

19

Meadow blazingstar

Liatris ligulistylis

24

Tall blazingstar

Liatris pycnostachya

24

Great blue lobelia

Lobelia siphilitica

13

Reed manna grass

Glyceria grandis

50

Fowl manna grass

Glyceria striata

72


Common Rush

Juncus effuses

80

Rice Cut Grass

Leesia oryzoides

62

 

B.    Furnish all seeds, including grass, legume, forbs, and cereal crop seeds, from an established seed dealer or certified seed grower. Ensure they meet requirements of the Iowa Department of Agriculture regulations (Iowa Seed Law) and are labeled accordingly. Ensure the test date to determine the percentage of germination requirement was completed within a 9 month period exclusive of the calendar month in which the test was completed. Ensure the seed analysis on the label is mechanically printed.

 

C.    Approval of all seed for use will be based on the accumulative total of PLS specified for each phase of the work, so that the PLS is not less than the accumulative total of the PLS specified. PLS is obtained by multiplying purity times germination.

 

D.    If the seed does not comply with minimum requirements for purity and germination and such seed cannot be obtained, the Engineer may approve use of the seed on a basis of PLS or may authorize a suitable substitution for the seed specified.

 

E.    The accumulative total of Pure Live Seed (PLS) is the product obtained by multiplying the pounds (kilograms) of each seed by the purity and germination percentages expressed as decimals. Calculations will be based on test results of samples taken by the Contracting Authority. If the seeds were not sampled or if these test results are not available, the PLS will be calculated from information shown on the label.

 

4169.03     FERTILIZER.

Furnish fertilizer of the grade, type, and form specified and that complies with Iowa Department of Agriculture rules and the following requirements:

 

A.    Fertilizer grade will be identified according to the percent nitrogen (N), percent available phosphoric acid, (P2O5), and percent water soluble potassium, (K2O), in that order. Approval will be based on that identification.

 

B.    Furnish all fertilizer from an established fertilizer dealer. Ensure guaranteed analysis is provided either through mechanically printed commercial fertilizer bags or through a manufacturer's (not a distributor's) bill of lading.

 

C.    Fertilizer inspection and acceptance will be according to Materials I.M. 469.03.

 

D.    Furnish fertilizer of a type that can be uniformly distributed by the application equipment. Fertilizer may be chemically combined or may be furnished as separate ingredients. If supplying chemically combined fertilizer, have each unit of fertilizer chemically combined. Ensure the manufacturer’s guarantee indicates compliance with this agreement. If supplying fertilizer as separate ingredients, comply with the following:

·         Each of the separate ingredients of uniform size,

·         Analysis guaranteed by the manufacturer.

·         Mixed using a drum mixer, grinder mixer, or other mechanical mixers.

·         Mixed only by the fertilizer dealer.

 

E.    When 6-24-24 chemically combined commercial fertilizer has been specified, a combination of ammoniated phosphate (either monoammonium phosphate (11-52-0) or diammonium phosphate (18-46-0)), muriate of potash (granular form), and urea (granular form) may be used.

 

F.     When 13-13-13 chemically combined commercial fertilizer has been specified, a combination of ammoniated phosphate (either monoammonium phosphate (11-52-0) or diammonium phosphate (18-46-0)), muriate of potash (granular form), and urea (granular form) may be used.

 

G.    Fertilizer may be furnished in a dry or liquid form.

 

H.    Furnish a list of the number of containers and a corresponding scale ticket from an approved scale for the fertilizer to be used in the work.

 

I.      Official samples taken by the Contracting Authority may be tested. A tolerance of minus 1.0% from the guaranteed analysis for each nutrient will be considered substantial compliance.

 

J.     Ground limestone is to be of the type known as No. 1 fine (70% passing No. 200 sieve) with an analysis of elemental calcium of no less than 37% or no more than 40%.

 

4169.04     INOCULANT FOR LEGUMES.

An inoculant is a culture of bacteria specifically formulated for legume seeds (alfalfa, clovers, lespedeza, birdsfoot trefoil, hairy vetch, and crownvetch). Ensure the manufacturer's container indicates the specific legume seed to be inoculated and the expiration date. Use inoculant that meets the requirements of the Iowa Seed Law. Follow the safety precautions specified on the product label.

 

4169.05     STICKING AGENT.

A sticking agent is a commercial material recommended by the manufacturer to improve adhesion of inoculant to the seed. For quantities less than 50 pounds, the sticking agent need not be a commercial agent; however, the Engineer’s approval is required. Apply separately prior to application of inoculant. Follow safety precautions specified on the product label. A sticking agent is not required if a liquid formulation of inoculant is used.

 

4169.06     SOD.

 

A.    Use sod consisting of approximately 1 inch of well established turf consisting of live Kentucky bluegrass, unless otherwise specified. Ensure sod is free from roots of trees or brush, stones, and other objectionable materials. Ensure sod is free from all noxious weeds and reasonably free of all other weeds.

 

B.    Ensure sod is cut in strips of uniform width and thickness with ends square. The Engineer may order the thickness adjusted to meet the sod conditions. Cut sod to the length specified for the use intended. If not specified, cut to a minimum length of 3 feet. Mow sod areas to a height of approximately 1 1/2 inches to 2 inches prior to cutting.

 

C.    Ensure sod was regularly maintained prior to cutting. Apply pre-emergence weed control chemicals and weed control chemicals for broadleaf weeds.

 

D.    Roll or stack sod within 1 hour after being cut. The Engineer may approve other methods of handling sod. Take precautions to prevent drying or heating. Do not use sod damaged by heat or dry conditions, or sod cut more than 18 hours before being incorporated into the work.

 

E.    Sod will be subject to inspection by the Engineer at the job site, and approval of the work constitutes approval of the material.

 

4169.07     MULCH.

 

A.    Straw Mulch.

Material used as mulch may consist of dry cereal straw or native grass straw. Use Certified Noxious Weed Seed Free Mulch certified by the Iowa Crop Improvement Association or other state’s Crop Improvement Associations. Bail cereal or native grass straw the same growing season as the grain was harvested from the plant.

 

B.    Hydraulic Mulches.

 

1.     Wood Cellulose Fiber.

a.     Natural or cooked cellulose fiber processed from whole wood chips, or a combination of (50%-50%) cellulose fiber produced from whole wood chips and recycled fiber from sawdust, recycled paper, chipboard, or corrugated cardboard.

b.     Contains a colloidal polysaccharide tackifier adhered to the fiber to prevent separation during shipment and avoid chemical coagglomeration during mixing.

c.     Forms a homogeneous slurry of fibers, tackifier, and water that can be applied with standard hydraulic mulching equipment and be dyed green to facilitate visual metering during application.

d.     Contains no growth or germination inhibiting factors, and has a minimum pH of 4.8.

 

2.     Bonded Fiber Matrix.

a.     Long-strand wood fibers held together by organic tackifiers and bonding agents that, when dry, become insoluble and non-dispersible.

b.     Upon curing (24 to 48 hours) forms a continuous, 100% coverage, flexible, absorbent, erosion-resistant blanket that encourages seed germination.

c.     Manufactured to be applied with standard hydraulic mulching equipment and dyed green to facilitate visual metering during application.

d.     Contains no growth or germination inhibiting factors.

e.     Physical Properties:

1)    Fibers: Virgin wood, greater than 88% by volume.

2)    Organic Material: Greater than 96% by volume.

3)    Tackifier: 8 to 10%.

4)    pH:  4.8 minimum.

5)    Moisture Content: 12% ±3%.

6)    Minimum Water Holding Capacity: 1.2 gallons per pound.

f.      All components pre-packaged by manufacturer to ensure material performance and compliance. Field mixing of additives or any components will not be allowed.

g.     Other products not meeting requirements of Article 4169.07, B, 2, e, may be approved if they meet the following requirements:

1)    Contain non-toxic tackifiers that upon drying become insoluble and non-dispersible to eliminate direct raindrop impact on soil according to ASTM D 7101 and EPA 2021.0-1.

2)    Contain no germination or growth inhibiting factors and do not form a water-resistant crust that can inhibit plant growth.

3)    Hydraulic mulch that is completely photo-degradable or biodegradable.

4)    Contain a minimum 90% organic material according to ASTM D 2974.

5)    Have a rainfall event (R-factor) of 140 < R according to ASTM D 6459.

6)    Have a cover factor of C ≤ 0.03 according to ASTM D 6459.

7)    Vegetation Establishment of 400% minimum according to ASTM D 7322.

8)    Water Holding Capacity 600% minimum according to ASTM D 7367.

 

3. Mechanically-Bonded Fiber Matrix.

a.     Long-strand wood fibers and crimped, interlocking synthetic fibers.

b.     Upon curing (2 hours) forms a continuous, 100% coverage, flexible, absorbent, porous, erosion-resistant blanket that encourages seed germination.

c.     Manufactured to be applied with standard hydraulic mulching equipment and dyed green to facilitate visual metering during application.

d.     Contains no growth or germination inhibiting factors.

e.     Physical Properties:

1)    Virgin Wood Fibers: 73% minimum.

2)    Crimped, Interlocking Synthetic Fibers: 5% ±1%.

3)    Tackifier: 10% ±1%.

4)    Moisture Content: 12% ±3%.

5)    Minimum Water-Holding Capacity: 1.2 gallons per pound.

6)    pH: 4.8 minimum.

f.      All components pre-packaged by manufacturer to ensure material performance and compliance. Field mixing of additives or any components will not be allowed.

g.     Other products not meeting requirements in Article 4169.07, B, 3, e, may be approved if they meet the following requirements:

1)    Contain non-toxic tackifiers that upon drying become insoluble and non-dispersible to eliminate direct raindrop impact on soil according to ASTM D 7101 and EPA 2021.0-1.

2)    Contain no germination or growth inhibiting factors and do not form a water-resistant crust that can inhibit plant growth.

3)    Hydraulic mulch that is completely photo-degradable or biodegradable.

4)    Contain a minimum 90% organic material according to ASTM D 2974.

5)    Have a rainfall event (R-factor) of 175 < R according to ASTM D 6459.

6)    Have a cover factor of C ≤ 0.01 according to ASTM D 6459.

7)    Vegetation Establishment of 500% minimum according to ASTM D 7322.

8)    Water Holding Capacity of 700% minimum according to ASTM D 7367.

 

4169.08. Compost.

 

A.    Use an organic substance produced by the biological and biochemical decomposition of source-separated compostable materials separated at the point of waste generation. Organic substances may include, but are not limited to:

·         Leaf and yard trimmings,

·         Food scraps,

·         Food processing residues,

·         Manure and/or other agricultural residuals,

·         Forest residues and bark, and

·         Soiled and/or unrecyclable paper and biosolids.

 

B.    Compost is to contain no visible admixture of refuse or other physical contaminants nor any material toxic to plant growth. Compost is to meet the additional requirements below. All physical requirements are to comply with the United States Composting Council, “Testing Methods for the Examination of Composting and Compost” (TMECC).

 

1.     Minimum organic material: 30% (dry weight basis) as determined by loss on ignition.

 

2.     Moisture content: 30% to 60%. Organic material shall be loose and friable and not dusty.

 

3.     Soluble salts: less than 5.0 ds/m.

 

4.     Stability: Carbon dioxide evolution rate less than 8 according to TMECC 5.08-B. Growth screening: Emergence a minimum of 80% for all compost to be vegetated.

 

5.     pH: 6.0 - 8.0.

 

6.     Fecal Coliform: Comply with TMECC 07.01-B.

 

7.     Heavy Metals: Comply with TMECC 04.06 and TMECC 04.13-B.

 

8.     Comply with the following for particle size:

·         Pneumatic Seeding (Urban): 100% passing the 1/2 inch screen.

·         Pneumatic or Mechanical Seeding (Rural): 100% passing the 1 inch screen, 80% to 90% passing the 3/4 inch screen, and 70% to 80% passing the 1/2 inch screen.

·         Filter Sock, Filter Berm, and Filter Blanket: 100% passing the 2 inch screen, 70% to 90% passing the 1 inch screen, and 50% to 70% passing the 1/2 inch screen.

 

4169.09     STAKES FOR HOLDING SOD.

Use either wood or metal wire stakes for holding sod. Use wood stakes in sandy soils or when the Engineer requires.

 

A.    Wood Stakes.

·         1 to 1 1/2 inches wide, 1/4 to 1/2 inch thick, and 12 inches long.

·         Where this length of stake does not provide firm bearing, the Engineer may require stakes of sufficient length to secure firm bearing.

 

B.    Wire Stakes.

·         Staples made from No. 11 wire or heavier and with a minimum 2 inch flat spread on the top of the sod.

·         Legs at least 6 inches long. The Engineer may require wire legs longer than 6 inches.

 

4169.10     SPECIAL DITCH CONTROL, turf reinforcement mat, SLOPE PROTECTION, and Outlet or channel scour protection (transition mat).

Comply with the following and meet the requirements of Materials I.M. 469.10.

 

A.    Wire Staples.

Meet the following requirements for wire staples for holding special ditch control wood excelsior mat and special ditch control jute mesh over sod:

 

1.     U-shaped wire staples.

 

2.     Each leg a minimum of 6 inches long. In sandy soil conditions the Engineer may require the length of each leg to be a minimum of 12 inches.

 

3.     No. 11 diameter wire.

 

4.     Staples of sufficient hardness to facilitate installation without bending.

 

B.    Special Ditch Control.

 

1.     Wood Excelsior Mat.

                        A mat of interlocking wood fibers. Meet the following requirements:

·         Plastic netting applied to both sides for holding the excelsior in place.

·         Nontoxic to growth of plants and germination of seeds.  

·         Minimum dry weight of 0.68 pounds per square yard according to ASTM D 6475.

·         Furnished in rolls with a uniform width of 48 inches, with a tolerance of minus 1 inch and a minimum length of 80 feet.

·         Furnished in plastic bags or otherwise protected to prevent damage from weather and handling.

 

2.     Coconut Fiber Mat.

At the Contractor's option, coconut fiber mat may be substituted for wood excelsior mat for special ditch control. Meet the following requirements:

·         Uniform thickness with the coconut fiber evenly distributed over the entire area of the mat.

·         Both sides of the mat covered with polypropylene netting attached with cotton thread.

·         Minimum dry weight of 0.40 pounds per square yard according to ASTM D 6475.

·         Furnished in rolls with a uniform width of 48 inches with a tolerance of minus 1 inch and a minimum length of 80 feet. 

·         Furnished in plastic bags or otherwise protected to prevent damage from weather and handling.

 

C.    Slope Protection.

Wood excelsior mat, coconut fiber mat, straw mat, or straw coconut mat may be used for slope protection.

 

1.     Wood Excelsior Mats.

A mat of interlocking wood fibers meeting the requirements of Article 4169.10, B, 1. with the following exceptions:

·         Plastic netting applied to one or both sides for holding the excelsior in place. Mats without netting where the excelsior is mechanically stitched together to hold it in place may be allowed.

·         Minimum dry weight of 0.50 pounds per square yard according to ASTM D 6475.

 

2.     Straw Mat, Straw-Coconut Fiber Mat, or Coconut Fiber Mat.

At the Contractor's option straw mat, straw-coconut fiber mat, or coconut fiber mat may be substituted for wood excelsior mat for slope protection. Meet the following requirements:

·         Consistent thickness with the straw, straw-coconut fiber, or coconut fiber evenly distributed over the entire area of the mat.

·         The top side of the mat covered with polypropylene netting attached with cotton thread.

·         Minimum dry weight (mass) of 0.40 pounds per square yard according to ASTM D 6475.

·         Furnished in rolls with a uniform width of 48 inches, with a tolerance of minus 1 inch and a minimum length of 80 feet.

·         Furnished in plastic bags or otherwise protected to prevent damage from weather or handling.

 

D.    Netting.

 

1.     Comply with the following mesh netting sizes. A tolerance of plus or minus 0.10 inch applies to netting size.

·         Netting applied on wood excelsior mats: no more than 1 inch by 2 inches.

·         Netting applied on coconut fiber only mats for channel and slope: no more than 3/4 inch by 3/4 inch.

·         Netting applied on the top side of straw and straw-coconut fiber mats for slopes only: no more than 1/2 inch by 1/2 inch.

 

2.     A minimum weight of 9 pounds per 1000 square yards is required for netting for special ditch control or slope protection.

 

E.    Turf Reinforcement Mat (TRM).

 

1.     Type 1 TRM: constructed of a web of mechanically or melt-bonded polymer netting, or monofilaments fibers entangled to form a strong and dimensionally stable mat. Bonding methods include polymer welding, thermal or polymer fusion, or the placement of synthetic fibers between two high-strength, biaxially-oriented nets, mechanically bound by parallel stitching with polyolefin thread. Products may contain a degradable component.

 

2.     Type 2 and 3 TRM: constructed of a web of mechanically or melt-bonded polymer netting, or monofilaments, or fibers that are entangled to form a strong and dimensionally stable mat. Non-woven bonding methods include polymer welding, thermal or polymer fusion, or the placement of fibers between two high-strength, biaxially oriented nets, mechanically bound by parallel stitching with polyolefin thread. Components are to be 100% synthetic and resistant to biological, chemical, and ultraviolet degradation.

 

3.     Type 4 TRM: a high performance/survivability TRM composed of monofilament yarns woven into a resilient uniform configuration. Use mats consisting of a matrix exhibiting very high interlock and reinforcement capacities with both soil and root systems and demonstrating a high tensile modulus. TRMs manufactured from discontinuous or loosely held together by stitched or glued, netting, or composites will not be allowed in this category. Components are to be 100% synthetic and resistant to biological, chemical, and ultraviolet degradation. Use this category when field conditions exist with high loading and/or high survivability requirements.

 

4.     Comply with Table 4169.10-1 for minimum material property and performance requirements:

 

               Table 4169.10-1: Minimum Material Property and Performance Requirements

Property

Property

Test Method

Type 1

Type 2

Type 3

Type 4

Material

Thickness

ASTM

D 6525

0.25 in

0.25 in

0.25 in

0.25 in

Material

Tensile Strength(a, b)

ASTM

D 6818

125 lb/ft

240 lb/ft

750 lb/ft

3000 lb/ft

Material

UV Resistance

ASTM

D 4355

80% @

500 hrs

80% @

1000 hrs

80% @

1000 hrs

90% @

3000 hrs

Performance

Maximum Shear Stress (Channel Applications)c

ASTM

D 6460

7-9 lb/ft2

10-11 lb/ft2

12-14 lb/ft2

15-16 lb/ft2

Performance

Maximum Slope Gradient

(Slope Applications)

N/A

1:1 (H:V) or flatter

1:1 (H:V) or flatter

1:1 (H:V) or greater

1:1 (H:V) or greater

a.     Minimum Average Roll Values, machine direction only.

b.     Tensile Strength of structural components retained after exposure.

c.     Maximum shear stress that fully-vegetated TRM can sustain without physical damage or excess erosion (1/2 inch soil loss) during a 30 minute flow event in large scale testing. Acceptable large scale testing protocol includes ASTM D 6460 or independent testing conducted by the Texas Transportation Institute, Colorado State University, Utah State University, or other approved testing facility. Bench scale testing is not acceptable.

 

F.    Outlet or Channel Scour Protection (Transition Mat)

 

1.     Mat.

a.     Constructed of 85% minimum UV resistant material with a maximum ground cover of 80%.

b.     Meet the requirements of Table 4169.10-2:

 

Table 4196.10-2: Material Property and Performance Requirements

Property

Test Method

Value

Mass/Unit Area (max)

ASTM D 6566

3 lbs/ft2

Thickness (min)

ASTM D 6525

0.4 in

Thickness (max)

ASTM D 6525

1.1 in

Tensile Strength (TD)

ASTM D 6818

550 lbs/ft

Percent Open Area (min)

ASTM D 6567

20%

UV Stability

ASTM D 4355

85%

 

2.     Anchoring Devices.

a.     Furnish bullet tip style anchors made of a metal alloy attached to a wire rope.

b.     Anchors capable of withstanding a minimum 300 pounds of pull out resistance in cohesive soils.

c.     Wire rope a minimum of 30 inches in length with a minimum breaking strength of at least 300 pounds.

d.     The top washer a minimum of 3 inches in diameter and constructed of a UV resistant plastic.

e.     Each anchor equipped to allow the retightening of the anchor when deemed necessary by the Engineer.

 

4169.11     Filter Fabric.

Furnish nonwoven polypropylene, UV stabilized filter fabric complying with Table 4169.11-1.

 

Table 4169.11-1: Filter Fabric Properties

Property

Typical

Minimum

Tensile Strength, lbs

130

115

Grab Elongation, %

70

50

Trapezoidal Tear Strength, lbs

60

50

 

4169.12     Perimeter and Slope Sediment Control Device.

 

A.    General.

 

1.     Provide wattles, sediment logs, and filter socks consisting of wood products (including wood mulch), cereal grain straw, or native grass straw the following materials contained in a tube of photo degradable fabric or synthetic netting.:

a.     Wattles: Cereal straw or native grass straw certified by the Iowa Crop Improvement Association or other state’s Crop Improvement Associations as Certified Noxious Weed Seed Free Mulch. Wattles with observed seed heads will not be accepted.

b.     Sediment logs: Wood excelsior fibers.

c.     Filter socks: Compost (from an approved source meeting Article 4169.08) wood chips, or mulch.

 

2.     Fill wattles, sediment logs, and filter socks using a mechanical device. Hand filling of wattles, sediment logs, and filter socks will not be allowed.

 

3.     Ensure wattles, sediment logs, and filter socks do not contain:

•       A visible admixture of refuse or other physical contaminants,

•       Germination or growth inhibiting factors, or

•       Material toxic to plant growth.

 

4.     Ensure wattles, sediment logs, and filter socks have waterproof identification tags printed using permanent ink and containing manufacturer’s name and address. For wattles and sediment logs, tags shall be attached to the inside of the netting of each wattle or sediment log. For filter socks, tags shall be attached to the outside of each sock.

 

5.     Approved perimeter and slope sediment control devices are listed in Materials I.M. 469.10, Appendix E.

 

B.    Wattles and Sediment Logs.

 

1.     Ensure cereal grain straw for wattles or sediment logs is Certified Noxious Weed Seed Free Mulch certified by the Iowa Crop Improvement Association or other state’s Crop Improvement Associations.

 

2.     Wattles or sediment logs with observed unharvested seed heads will not be accepted.

 

3.     For wood excelsior sediment logs and straw wattles, mMeet the following minimum weight requirements:

•       20 inch sediment logs and straw wattles: 3 pounds per foot with tolerance of 0.25 pounds per foot.

•       12 inch sediment logs and straw wattles: 2 pounds per foot with tolerance of 0.25 pounds per foot.

•       9 inch sediment logs and straw wattles: 1 pound per foot with a tolerance of 0.1 pounds per foot.

•       6 inch sediment logs and straw wattles: 0.5 pounds per foot with a tolerance of 0.1 pounds per foot.

 

C.    Filter Socks.

Provide filter socks with a maximum 3/8 inch opening and filled with a compost/wood blend filter material consisting of compost from an approved source meeting Article 4169.08.