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

Page 8-14

Erosion Control and Water Pollution Control

If trenching is not feasible due to rocky soils or not advisable due to proximity to a
downslope sensitive area, a different sediment control device that does not require
trenching shall be used in place of silt fence.

Backup support is needed for silt fence in areas where extra strength may be required,
such as the toe of steep cut or fill slopes or areas where equipment may push excessive
soils toward the fence. When backup support is used, wire shall have a maximum mesh
spacing of 2 inches, and the plastic mesh shall be as resistant to ultraviolet radiation as
the geotextile it supports. The strength of the wire or plastic mesh shall be equivalent to
or greater than as required in

Section 9-33.2(1)

, Table 6, for unsupported geotextile (i.e.,

180 lbs. grab tensile strength in the machine direction). Post spacing and attachments
shall be as shown in the Standard Plans.

8-01.3(9)A3 High Visibility Silt Fence

High visibility silt fence (HVSF) shall be orange in color and only be used for the dual
purpose of demarcating site preservation lines and a sediment control device in a location
where high visibility mesh fence and black silt fence would otherwise be used together
at same location. If use of HVSF is allowed the geotextile material shall meet the material
requirements of

Section 9-33.2(1)

, Table 6. Post spacing and attachments shall be as

shown in the Standard Plans.

Backup support is needed for high visibility silt fence (HVSF) in areas where extra strength
may be required, such as the toe of steep cut or fill slopes or areas where equipment may
push excessive soils toward the sensitive or protected areas. When backup support is
used, wire shall have a maximum mesh spacing of 2 inches, and the plastic mesh shall be
as resistant to ultraviolet radiation as the geotextile it supports. The strength of the wire
or plastic mesh shall be equivalent to or greater than as required in

Section 9-33.2(1)

Table 6, for unsupported geotextile (i.e., 180 lbs. grab tensile strength in the machine
direction). Post spacing shall be as shown in the Standard Plans.

When sediment deposits reach approximately ⅓ the height of the silt fence, or 8 inches
whichever is lower the deposits shall be removed and stabilized in accordance with

Section 8-01.3(15)

8-01.3(9)B

Gravel Filter, Wood Chip, or Compost Berm

Filter berms shall retain sediment and direct flows. The gravel filter berm shall be a
minimum of 1 foot in height and shall be maintained at this height for the entire time
they are in use. Rock material used for filter berms shall meet the grading requirements
in

Section 9-03.9(2)

, but shall not include any recycled materials as outlined in

Section 9-03.21

The wood chip berm shall be a minimum of 2 feet in height and shall be maintained at this
height for the entire time they are in use.

The Compost Berm shall be constructed in accordance with the detail in the Plans.
Compost shall be Medium Compost.

Erosion Control and Water Pollution Control

8-01

8-01.3(9)C Vacant
8-01.3(9)D

Inlet Protection

Inlet protection shall be installed below or above, or as a prefabricated cover at each inlet
grate, as shown in the Plans. Inlet protection devices shall be installed prior to beginning
clearing, grubbing, or earthwork activities.

Geotextile fabric in all prefabricated inlet protection devices shall meet or exceed the
requirements of

Section 9-33.2

, Table 1, for Moderate Survivability, and the minimum

filtration properties of Table 2.

When the depth of accumulated sediment and debris reaches approximately ½ the height
of an internal device or ⅓ the height of the external device (or less when so specified by
the manufacturers), or as designated by the Engineer, the deposits shall be removed and
stabilized on-site in accordance with

Section 8-01.3(16)

Below Inlet Grate

Below Inlet Grate devices shall be prefabricated units specifically designed for inlet
protection and shall remain securely attached to the drainage Structure when fully loaded
with sediment and debris, or at the maximum level of sediment and debris specified by
the manufacturer.

Above Inlet Grate

Above Inlet Grate devices may be silt fence, sandbags, or prefabricated units specifically
designed for inlet protection.

The device shall remain securely in place around the drainage Structure under all
conditions.

Inlet Grate Cover

Inlet Grate Cover devices shall be prefabricated units specifically designed for inlet
protection and have the following features:
1. Be a sewn geotextile fabric unit fitted to the individual grate and completely

enclosing the grate.

2. Have built-in lifting devices to allow manual access of the stormwater system.
3. Utilize an orange monofilament geotextile fabric.

Check dams or functionally equivalent devices may be used as inlet protection devices
with the approval of the Engineer.

Page 8-16

Erosion Control and Water Pollution Control

8-01.3(10) Wattles

Wattles are used as a flow control and sediment control device. Wattles shall be installed
as soon as construction will allow or when designated by the Engineer. Wattle installation
and trenching shall begin from the base of the slope and work uphill prior to any topsoil
or compost placement. Excavated material from trenching shall be spread evenly along
the uphill slope and be compacted using hand tamping or other method approved by the
Engineer. On gradually sloped or clay-type soils trenches shall be 2 to 3 inches deep. On
loose soils, in high rainfall areas, or on steep slopes, trenches shall be 3 to 5 inches deep,
or half the thickness of the wattle, whichever is greater.

Wattles shall be laid out, spaced, and staked in accordance with the Standard Plans.
Live stakes can be used in addition to, but not as a replacement for, wooden stakes. If
trenching and staking is not possible due to rocky soils, compost socks shall be used
instead of wattles.

The Contractor shall exercise care when installing wattles to ensure the method of
installation minimizes the disturbance of waterways and prevents sediment or pollutant
discharge into water bodies.

8-01.3(11) Outlet Protection

Outlet protection shall prevent scour at the outlets of ponds, pipes, ditches or other
conveyances. All quarry spall material used for outlet protection shall be free of
extraneous material and meet the gradation requirements in

Section 9-13.1(5)

8-01.3(12) Compost Sock

Compost socks are used to disperse flow and sediment. Compost socks shall be installed
as soon as construction will allow but before flow conditions create erosive flows or
discharges from the site. Compost socks shall be installed prior to any mulching or
compost placement. Compost socks shall be laced together end-to-end with coir rope
or ends shall be securely overlapped to create a continuous length. Terminal ends of
the continuous length shall be curved 2 to 4 feet upward into the slope to prevent
concentrated flows from going around the terminal ends. Finished grades shall be of
a natural appearance with smooth transitions. Compost for compost socks shall be
Medium Compost.

Compost socks shall be laid out, spaced and staked in accordance with the Standard Plans.
Live stakes can be used in addition to, but not as a replacement for, wooden stakes. If
staking is not possible or if the compost sock is being used on concrete, heavy blocks or
an equivalent item shall be used to weigh down and secure the sock.

The Contractor shall exercise care when installing compost socks to ensure that the
method of installation minimizes disturbance of waterways and prevents sediment
or pollutant discharge into water bodies. Stakes shall be removed to minimize soil
disturbance.

Erosion Control and Water Pollution Control

8-01

8-01.3(13) Temporary Curb

Temporary curbs shall divert or redirect water around erodible soils.

Temporary curbs shall be installed along pavement edges to prevent runoff from flowing
onto erodible slopes. Water shall be directed to areas where erosion can be controlled.
Temporary curbs shall be a minimum of 4 inches in height. Temporary curb shall be
installed so that ponding does not occur in the adjacent roadway.

8-01.3(14) Temporary Pipe Slope Drain

Temporary pipe slope drain shall be Corrugated Polyethylene Drain Pipe and shall be
constructed in accordance with the Plans.

Water interceptor dikes or temporary curbs shall be used to direct water into pipe slope
drain. The entrance to the drain may consist of a prefabricated funnel device specifically
designed for application, rock, sand bags, or as approved by the Engineer.

The pipe fittings shall be water tight and the pipe secured to the slope with metal posts,
wood stakes, or sand bags.

The water shall be discharged to a stabilized conveyance, sediment trap, stormwater
pond, rock splash pad, or vegetated strip, in a manner to prevent erosion and maintain
water quality compliance.

8-01.3(15) Maintenance

Erosion and sediment control BMPs shall be maintained or adaptively managed as
required by the CSWGP until the Engineer determines they are no longer needed. When
deficiencies in functional performance are identified, the deficiencies shall be rectified
immediately.

The BMPs shall be inspected on the schedule outlined in

Section 8-01.3(1)B

for

damage and sediment deposits. Damage to or undercutting of BMPs shall be repaired
immediately.

In areas where the Contractor’s activities have compromised the erosion control functions
of the existing grasses, the Contractor shall overseed at no additional cost to the
Contracting Agency.

The quarry spalls of construction entrances shall be refreshed, replaced, or screened to
maintain voids between the spalls for collecting mud and dirt.

Unless otherwise specified, when the depth of accumulated sediment and debris
reaches approximately ⅓ the height of the BMP the deposits shall be removed. Debris or
contaminated sediment shall be disposed of in accordance with

Section 2-03.3(7)C

. Clean

sediments may be stabilized on-site using BMPs as allowed by the Engineer.

Page 8-18

Erosion Control and Water Pollution Control

8-01.3(16) Removal

The Contractor shall remove all temporary BMPs, all associated hardware and associated
accumulated sediment deposition from the project limits prior to Physical Completion
unless otherwise allowed by the Engineer. When the temporary BMP materials are made
of natural plant fibers unaltered by synthetic materials the Engineer may allow leaving the
BMP in place.

The Contractor shall remove BMPs and associated hardware in a way that minimizes soil
disturbance. The Contractor shall permanently stabilize all bare and disturbed soil after
removal of BMPs. If the installation and use of the erosion control BMPs have compacted
or otherwise rendered the soil inhospitable to plant growth, such as construction
entrances, the Contractor shall take measures to rehabilitate the soil to facilitate
plant growth. This may include, but is not limited to, ripping the soil, incorporating soil
amendments, or seeding with the specified seed.

At the request of the Contractor and at the sole discretion of the Engineer the CSWGP
may be transferred back to the Contracting Agency. Approval of the Transfer of Coverage
request will require the following:
1. All other Work required for Contract Completion has been completed.
2. All Work required for compliance with the CSWGP has been completed to the

maximum extent possible. This includes removal of BMPs that are no longer needed
and the site has undergone all Stabilization identified for meeting the requirements
of Final Stabilization in the CSWGP.

3. An Equitable Adjustment change order for the cost of Work that has not been

completed by the Contractor.

4. Submittal of the Washington State Department of Ecology Transfer of Coverage form

(Ecology Form ECY 020-87a) to the Engineer.

If the Engineer approves the transfer of coverage back to the Contracting Agency
the requirement in

Section 1-07.5(3)

for the Contractor’s submittal of the Notice of

Termination form to Ecology will not apply.

8-01.4 Measurement

8-01.4(1) Lump Sum Bid for Project (No Unit Items)

When the Bid Proposal contains the item “Erosion Control and Water Pollution
Prevention” there will be no measurement of unit or force account items for Work defined
in

Section 8-01

except as described in Sections

8-01.4(3)

and

8-01.4(4)

. Also, except as

described in

, all of Sections

are deleted.

Erosion Control and Water Pollution Control

8-01

8-01.4(2) Item Bids

When the Proposal does not contain the items “Erosion Control and Water Pollution
Prevention”, Sections

8-01.4(1)

and

8-01.5(1)

are deleted and the Bid Proposal will

contain some or all of the following items measured as noted.

ESC lead will be measured per day for each day that an inspection is made and a report is
filed.

Erosion control blanket and plastic covering will be measured by the square yard along the
ground slope line of surface area covered and accepted.

Turbidity curtains will be measured by the linear foot along the ground line of the
installed curtain.

Check dams will be measured per linear foot one time only along the ground line of the
completed check dam. No additional measurement will be made for check dams that are
required to be rehabilitated or replaced due to wear.

Stabilized construction entrances will be measured by the square yard by ground slope
measurement for each entrance constructed.

Tire wash facilities will be measured per each for each tire wash installed.

Street cleaning will be measured by the hour for the actual time spent cleaning pavement,
refilling with water, dumping and transport to and from cleaning locations within the
project limits, as authorized by the Engineer. Time to mobilize the equipment to or from
the project limits on which street cleaning is required will not be measured.

Inlet protections will be measured per each for each initial installation at a drainage
structure.

Silt fence, gravel filter, compost berms, and wood chip berms will be measured by the
linear foot along the ground line of the completed barrier.

Wattles and compost socks will be measured by the linear foot.

Temporary curbs will be measured by the linear foot along the ground line of the
completed installation.

Temporary pipe slope drains will be measured by the linear foot along the flow line of the
pipe.

Coir logs will be measured by the linear foot along the ground line of the completed
installation.

Outlet protections will be measured per each initial installation at an outlet location.

Temporary seeding, temporary mulching, and tackifiers will be measured by the acre by
ground slope measurement.

Compost blanket will be measured by the square yard by ground slope surface area
covered and accepted.

Page 8-20

Erosion Control and Water Pollution Control

8-01.4(3) Reinstating Unit Items with Lump Sum Erosion Control and

Water Pollution Prevention

The Contract Provisions may establish the project as lump sum, in accordance with

Section 8-01.4(1)

and also include one or more of the items included above in

Section

8-01.4(2)

. When that occurs, the corresponding measurement provision in

Section

8-01.4(2)

is not deleted and the Work under that item will be measured as specified.

8-01.4(4)

Items not included with Lump Sum Erosion Control and Water

Pollution Prevention

Compost blanket will be measured by the square yard by ground slope surface area
covered and accepted.

Temporary mulch will be measured by the acre by ground slope surface area covered and
accepted.

High visibility fence will be measured by the linear foot along the ground line of the
completed fence.

8-01.5 Payment

8-01.5(1) Lump Sum Bid for Project (No Unit Items)

Payment will be made for the following Bid item when it is included in the Proposal:

“Erosion Control and Water Pollution Prevention”, lump sum.

The lump sum Contract price for “Erosion Control and Water Pollution Prevention”
shall be full pay to perform the Work as described in

Section 8-01

except for costs

compensated by Bid Proposal items inserted through Contract Provisions as described in

Section 8-01.4(2)

. Progress payments for the lump sum item “Erosion Control and Water

Pollution Prevention” will be made as follows:
1. The Contracting Agency will pay 15 percent of the bid amount for the initial set up

for the item. Initial set up includes the following:
a. Acceptance of the TESC Plan provided by the Contracting Agency or submittal

of a new TESC Plan,

b. Submittal of a schedule for the installation of the BMPs,
c. Identifying water quality sampling locations, and

2. Seventy percent of the bid amount will be paid in accordance with

Section 1-09.9

3. Once the project is physically complete and copies of the all reports submitted to

Ecology have been submitted to the Engineer, and, if applicable, transference of the
CSWGP back to the Contracting Agency is complete, the remaining 15 percent of
the bid amount shall be paid in accordance with

Section 1-09.9

Erosion Control and Water Pollution Control

8-01

8-01.5(2) Item Bids

“ESC Lead”, per day.

“Turbidity Curtain”, per linear foot.

“Erosion Control Blanket”, per square yard.

“Plastic Covering”, per square yard.

“Check Dam”, per linear foot.

“Inlet Protection”, per each.

“Gravel Filter Berm”, per linear foot.

“Stabilized Construction Entrance”, per square yard.

“Street Cleaning”, per hour.

“Silt Fence”, per linear foot.

“Wood Chip Berm”, per linear foot.

“Compost Berm”, per linear foot.

“Wattle”, per linear foot.

“Compost Sock”, per linear foot.

“Coir Log”, per linear foot.

“Temporary Curb”, per linear foot.

“Temporary Pipe Slope Drain”, per linear foot.

“Temporary Seeding”, per acre.

“Temporary Mulching”, per acre.

“Compost Blanket”, per square yard.

“Outlet Protection”, per each.

“Tackifier”, per acre.

“Erosion/Water Pollution Control”, by force account as provided in Section 1-09.6.

Maintenance and removal of erosion and water pollution control devices including
removal and disposal of sediment, stabilization and rehabilitation of soil disturbed
by these activities, and any additional Work deemed necessary by the Engineer to
control erosion and water pollution will be paid by force account in accordance with
Section 1-09.6.

To provide a common Proposal for all Bidders, the Contracting Agency has entered an
amount in the Proposal to become a part of the Contractor’s total Bid.

Page 8-22

Erosion Control and Water Pollution Control

8-01.5(3) Reinstating Unit Items with Lump Sum Erosion Control and

Water Pollution Prevention

The Contract may establish the project as lump sum, in accordance with

Section 8-01.4(1)

and also reinstate the measurement of one or more of the items described in

Section

8-01.4(2)

, except for Erosion/Water Pollution Control, by force account. When that

occurs, the corresponding payment provision in

Section 8-01.5(2)

is not deleted and the

Work under that item will be paid as specified.

8-01.5(4) Items not included with Lump Sum Erosion Control and

Water Pollution Prevention

Payment will be made for the following Bid item when it is included in the Proposal:

“High Visibility Fence”, per linear foot.

Roadside Restoration

8-02

Roadside Restoration

8-02.1 Description

This Work consists of preserving, maintaining, establishing and augmenting vegetation
on the roadsides and within mitigation or sundry site areas. It includes vegetation
preservation, weed and pest control, furnishing and placing topsoil, compost, and soil
amendments, and furnishing and planting seed, sod and plants of all forms and container
types. It includes performing plant establishment activities and soil bioengineering. Work
shall be performed in accordance with these Specifications and as shown in the Plans or
as designated by the Engineer.

Trees, whips, shrubs, ground covers, cuttings, live stakes, live poles, live branches,
rhizomes, tubers, rootstock, and seedlings will hereinafter be referred to collectively as
“plants” or “plant material”. Grass, wildflowers, and other plant materials installed in seed
form will hereinafter be referred to collectively as “seed”.

8-02.2 Materials

Materials shall meet the requirements of the following sections:

Topsoil

9-14.2

Fertilizer

9-14.4

Mulch and Amendments

9-14.5

Erosion Control Devices

9-14.6

Plant Materials

9-14.7

Stakes, Guys, and Wrapping

9-14.8

Water

9-25.2

Botanical identification and nomenclature of plant materials shall be based on
descriptions by Hitchcock and Cronquist in “Flora of the Pacific Northwest”. Botanical
identification and nomenclature of plant material not found in "Flora" shall be based on
Bailey in “Hortus Third” or superseding editions and amendments or as referenced in the
Plans.

8-02.3

Construction Requirements

8-02.3(1) Responsibility During Construction

The Contractor shall prepare, install, and ensure adequate and proper care of all roadside
seeded, planted, and lawn areas on the project until all plant establishment periods
required by the Contract are complete or until Physical Completion of the project,
whichever is last.

Adequate and proper care shall include, but is not limited to, keeping all plant material in a
healthy, growing condition by watering, pruning, and other actions deemed necessary for
plant health. This Work shall include keeping the project area free from insect infestation,
weeds or unwanted vegetation, litter, and other debris along with retaining the finished
grades and mulch in a neat uniform condition.

Page 8-24

Roadside Restoration

Existing desirable vegetation shall be saved and protected unless removal is required by
the Contract or allowed by the Engineer.

The Contractor shall have sole responsibility for the maintenance and appearance of the
roadside restoration.

8-02.3(2) Work Plans

Three Work Plan submittals exist under this Section:
1. Roadside Work Plan: This plan is required when Work will disturb the roadside

beyond 20 feet from the pavement or where trees or native vegetation will be
removed, the Contractor shall submit a Type 2 Working Drawing.

2. Weed and Pest Control Plan: This plan is required when the proposal contains the

item “Weed and Pest Control,” and prior to application of any chemicals or weed
control activities, the Contractor shall submit a Type 2 Working Drawing.

3. Plant Establishment Plan: This plan is required when the proposal contains the item

“PSIPE__”, and prior to completion of Initial Planting, the Contractor shall submit a
Type 2 Working Drawing.

8-02.3(2)A

Roadside Work Plan

The Roadside Work Plan shall define the expected impacts to the roadside and
restoration resulting from Work necessary to meet all Contract requirements. The
Contractor shall define how the roadside restoration Work included in the Contract
will be phased and coordinated with project Work such as earthwork, staging, access,
erosion and water pollution control, irrigation, etc. The Roadside Work Plan shall include
the following:
1. Limiting impacts to roadsides:

a. Limits of Work including locations of staging or parking.
b. Means and methods for vegetation protection (in accordance with

Section 1-07.16(2)).

c. Locations outside of clearing limits where vegetation shall be removed to

provide access routes or other needs to accomplish the Work.

d. Plans for removal, preservation and stockpile of topsoil or other native

materials, if outside of clearing and grubbing limits and within the project limits.

2. Roadside Restoration:

a. Plan for propagation and procurement of plants, ground preparation for

planting, and installation of plants.

b. Means and methods to limit soil compaction where seeding and planting are to

occur, such as steel plates, hog fuel access roads, wood mats for sensitive areas
(including removal) and decompaction for unavoidable impacts.

c. Plan and timing to incorporate or remove erosion control items.

Roadside Restoration

8-02

3. Lawn Installation:

a. Schedule for lawn installation work.
b. Establishment and maintenance of lawns.

8-02.3(2)B

Weed and Pest Control Plan

The Weed and Pest Control Plan shall describe all weed and pest control needs for the
project.

The plan shall be prepared and signed by a licensed Commercial Pest Control Operator or
Consultant. The plan for control of weeds and pests on the Contract in accordance with
Section 8-02.3(3) shall include the following:
1. Names of plan preparer and pesticide operators, including contact information. The

Contractor shall furnish the Engineer evidence that all operators are licensed with
appropriate endorsements, and that the pesticide used is registered for use by the
Washington State Department of Agriculture.

2. Means and methods of weed control, including mechanical and/or chemical.
3. Schedule for weed control including re-entry times for pesticide application by

pesticide type.

4. Proposed pesticide use in accordance with Section 8-02.3(3)A: name, application

rate, and Safety Data Sheets of all proposed pesticides. Include a copy of the current
product label for each pesticide to be used.

5. Plan to ensure worker safety until pesticide re-entry periods are met.

8-02.3(2)C

Plant Establishment Plan

The Plant Establishment Plan shall describe activities necessary to ensure continued
health and vigor of planted and seeded areas in accordance with the requirements of
Sections 8-02.3(12) and 8-02.3(13). Should the plan become unworkable at any time
during the first-year plant establishment, the Contractor shall submit a revised plan prior
to proceeding with further Work. The Plant Establishment Plan shall include:
1. Proposed scheduling of joint inspection meetings, activities, materials, equipment to

be utilized for the first-year plant establishment.

2. Proposed adaptive management activities to ensure successful establishment of

seeded, sodded, and planted areas.

3. A contact person.
4. Management of the irrigation system, when applicable.

Page 8-26

Roadside Restoration

8-02.3(3) Weed and Pest Control

The Contractor shall control weed and pest species within the project area using
integrated pest management principles consisting of mechanical, biological, and
chemical controls that are outlined in the Weed and Pest Control Plan or as designated
by the Engineer. Controlling weeds consists of killing and removing weeds by chemical,
mechanical, and hand methods.

8-02.3(3)A

Chemical Pesticides

Chemical pesticides include, but are not restricted to, any substance or mixture of
substances intended for preventing, destroying, repelling or mitigating any pest, including
but not limited to, insecticides, herbicides, fungicides, adjuvants, and additives, including
plant regulators, defoliants and desiccants. The Contractor shall apply chemical pesticides
in accordance with the label recommendations, the Washington State Department of
Ecology, local sensitive area ordinances, and Washington State Department of Agriculture
laws and regulations. Only those pesticides listed in the table Herbicides Approved
for Use on WSDOT Rights of Way and accepted as part of the Weed and Pest Control
Plan or by written authorization from the Engineer may be used (www.wsdot.wa.gov/
maintenance/roadside/herbicide_use.htm).

The applicator shall be licensed by the State of Washington as a Commercial Applicator or
Commercial Operator, with additional endorsements as required by the Special Provisions
or the proposed weed control plan. All chemical pesticides shall be delivered to the job
site in the original containers, or if pre-mixed off-site, a certification of the components
and formulation from the supplier is required. The licensed applicator or operator shall
complete WSDOT Form 540-509, Commercial Pesticide Application Record, each day the
pesticide is applied and furnish a copy to the Engineer by the following business day.

The Contractor shall ensure confinement of the chemicals within the designated areas.
The use of spray chemical pesticides shall require the use of anti-drift and activating
agents and a spray pattern indicator unless otherwise allowed by the Engineer.

The Contractor shall assume all responsibility for rendering any area unsatisfactory for
planting by reason of chemical application. Damage to adjacent areas, either on or off
the Highway Right of Way, shall be repaired to the satisfaction of the Engineer or the
property owner at no additional cost to the Contracting Agency.

8-02.3(3)B

Planting and Lawn Area Weed Control

Planting and lawn area weed control consists of controlling weeds and pests in planted
and lawn areas shown in the Plans. This Work is included in the bid items for planting and
lawn installation.

All planting and lawn areas shall be prepared so that they are weed and debris free at the
time of planting and until completion of the project. The planting areas shall include the
entire ground surface, regardless of cover, areas around plants, and those areas shown in
the Plans.

Roadside Restoration

8-02

Within planting or lawn areas, all species that are not shown in the Plans are unwanted
and shall be controlled unless specifically allowed by the Engineer to remain.

Grass growing within the mulch ring of a plant, including grass applied in accordance with
Sections 8-01.3(2)A1, 8-02.3(9) or 8-02.3(10), shall be considered a weed and shall be
controlled on the project in accordance with the weed and pest control plan.

All applications of post-emergent herbicides shall be made while green and growing tissue
is present. Residual herbicides shall not be used where rhizomatous species or perennial
species are indicated.

Should unwanted vegetation reach the flowering and seed stage in violation of these
Specifications, the Contractor shall physically remove and bag the seed heads prior to
seed dispersion. All physically removed vegetation and seed heads shall be disposed of
off-site at no cost to the Contracting Agency.

8-02.3(3)C

Project Area Weed and Pest Control

The Contractor shall control weeds not otherwise covered in accordance with Section
8-02.3(3)B, in all areas within the project limits, including erosion control seeding areas
and vegetation preservation areas, as designated by the Engineer.

When the Bid Item “Project Area Weed and Pest Control” is included in the Contract,
the Contractor shall also control all weeds specified as noxious by the Washington State
Department of Agriculture, the local Weed District, or the County Noxious Weed Control
Board outside of planting areas within the project limits.

8-02.3(4) Topsoil

Topsoil shall not be worked or placed when the ground or topsoil is frozen, or
excessively wet.

The Contractor shall protect topsoil stockpiled for project use to prevent erosion and
weed growth. Weed growth on topsoil stockpile sites shall be immediately eliminated in
accordance with the accepted Weed and Pest Control Plan and Section 8-02.3(3)C.

The subsoil where topsoil is to be placed shall be tilled to a depth of 1 foot or as specified
in the Special Provisions or the Plans. Topsoil of the type specified shall be evenly spread
over the specified areas to the depth shown in the Plans or as otherwise ordered by
the Engineer. Topsoil depths greater than 6 inches shall be placed in lifts no more than
6 inches in depth. The first lift of topsoil shall be incorporated with sub-soil to a depth of
8 inches and subsequent lifts placed and lightly tamped between lifts. After the topsoil
has been spread, all large clods, hard lumps, and rocks 2 inches in diameter and larger, and
litter shall be raked up, removed, and disposed.

8-02.3(4)A

Topsoil Type A

Topsoil Type A shall be as specified in the Special Provisions. The Contractor shall submit
a certification by the supplier that the contents of the Topsoil meet the requirements in
the Special Provisions.

Page 8-28

Roadside Restoration

8-02.3(4)B

Topsoil Type B

Topsoil Type B shall be taken from within the project limits. Topsoil Type B shall be taken
from areas shown in the Plans to the designated depth and stockpiled at locations that
will not interfere with the construction of the project, and outside of sensitive areas, as
allowed by the Engineer. The general limits of the material to be utilized for topsoil will
be indicated in the Plans or in the Special Provisions. The Engineer will make the final
determination of the areas where the most suitable material exists within these general
limits. Material for Topsoil Type B shall not be taken from a depth greater than 1 foot
from the existing ground unless otherwise designated by the Engineer. Prior to topsoil
removal, the Contractor shall reduce the native vegetation to a height not exceeding
1 foot. A minimum of two weeks prior to excavation of Topsoil Type B, the Contractor
shall pre-treat the vegetation on the designated Topsoil Type B areas according to the
Weed and Pest Control Plan. Areas beyond the slope stakes shall be disturbed as little
as possible in the above operations and under no circumstances shall Topsoil Type B be
stockpiled within 10 feet of any existing tree or vegetation area designated to be saved
and protected. The Contractor shall protect topsoil stockpile from weed infestation.

The Contractor shall set aside sufficient material to satisfy the needs of the project.

Upon completion of topsoil placement, the Contractor shall dispose of remaining
stockpiled Topsoil Type B not required for use on the project at no additional expense to
the Contracting Agency in accordance with Section 2-03.3(7)C.

Should a shortage of Topsoil Type B occur, and the Contractor has wasted or otherwise
disposed of topsoil material, the Contractor shall furnish Topsoil Type A or C at no
additional expense to the Contracting Agency.

8-02.3(4)C

Topsoil Type C

Topsoil Type C shall be naturally occurring topsoil obtained from a source provided by
the Contractor outside of the Contracting Agency-owned Right of Way. Topsoil Type C
shall meet the requirements of Sections 8-02.3(4) and 8-02.3(4)B. The Contractor shall
not begin removal of Topsoil Type C from the proposed source until the material has been
allowed for use by the Engineer.

8-02.3(5) Roadside Seeding, Lawn and Planting Area Preparation

This Work includes preparing worked areas for the installation of all types of permanent
erosion control planting. Work shall be conducted so the flow lines in drainage channels
are maintained. Material displaced by the Contractor’s operations that interferes with
drainage shall be removed from the channel and disposed of as allowed by the Engineer.

8-02.3(5)A

Seeding Area Preparation

The Contractor shall prepare roadside seeding areas as follows:
1. Remove all excess material, debris, stumps, and rocks greater than 3 inches in

diameter from areas to be seeded. Dispose of removed materials offsite.

2. Prepare roadside seeding area to a weed free and bare condition.

Roadside Restoration

8-02

3. Bring area to uniform grade and install topsoil, soil amendments, or compost

as specified. Any slopes 3(H) to 1(V) or steeper shall not be tilled unless
otherwise specified.

4. Compact to provide a reasonably firm but friable seedbed; tractor walk to uniformly

cover the surface with longitudinal depressions at least 2 inches deep formed
perpendicular to the natural flow of water on the slope. Condition the soil with
sufficient water so the longitudinal depressions remain in the soil surface until
completion of the seeding.

5. Seed and mulch within 2 days of preparation.

8-02.3(5)B

Lawn Area Preparation

The Contractor shall prepare lawn areas as follows:
1. Prepare lawn area to a weed free and bare condition in accordance with

Section 8-02.3(3)B.

2. Remove excess material, stumps, wood or rocks over 3 inches in diameter and

remove from site.

3. Bring area to uniform grade and install topsoil or soil amendments in accordance

with Section 8-02.3(4) and 8-02.3(6).

4. Till to an 8-inch depth, rake to a smooth even grade without low areas that trap

water, and compact with a 50-pound roller. The finished grade of the soil shall be
1 inch below the top of all curbs, junction and valve boxes, walks, driveways, and
other Structures.

5. Seed or sod the area within two days of preparation.

8-02.3(5)C

Planting Area Preparation

The Contractor shall prepare planting areas as follows:
1. Prepare planting area to a weed free and bare condition in accordance with

Section 8-02.3(3)B.

2. Decompact soil to a depth of 18 inches where construction activities have taken

place or where native soils are compacted.

3. Return soil to uniform grade even with surrounding areas, leaving no holes or

mounds over 3 inches in depth or height.

4. Remove excess material, stumps, wood or rocks over 3 inches in diameter and

remove from site.

5. Apply compost or other amendments as indicated in the plans and in accordance

with Section 8-02.3(6).

6. Cultivate amendments to a depth of 12 inches to provide a reasonably firm but

friable planting area. Do not till any slopes 3(H) to 1(V) or steeper.

Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10) - page 43