20061864 Ver 1_Drawing and Specifications_20061204

2 0 0 6 1 8 4
PROJECT TECHNICAL SPECIFICATIONS &
DRAWINGS
HINGS BLUFF RAW WATER INTAKE CANAL DREDGING
CITY OF WILMINGTON, NORTH CAROLINA
CONTRACT NO.511-0802.1
AMENDMENT N0.2
PREPARED BY:
HDR ENGINEERING, INC. OF THE CAROLINAS
9970-14 BEACH DRIVE
CALABASH, NORTH CAROLINA 28467
PROJECT NO. 12000-44908-018
NOVEMBER 2006
Exhibit A

Table of Contents
Component
Page Number
General Job Description .............................................................................................1
Section 01060 -Special Conditions ............................................................................................2
Section 02270 -Soil Erosion and Sediment Control ...................................................................5
Exhibit A

1
General Project Description
2 The City of Wilmington's Kings Bluff Raw Water Pump Station is located along
3 the Cape Fear River just upstream of the US Army Corps of Engineer's Lock Dam #1 in
4 Bladen County. A 600-foot manmade canal allows water from the Cape Fear to reach the
5 raw water intake. Over time, silt and sand accumulates in the canal. Maintenance
6 dredging is required periodically to remove this accumulation of sediment. This canal
7 has been dredged several times since the canal was originally constructed.
8 The Kings Bluff Raw Water Intake Canal Dredging project is intended to return
9 the canal to the original dimensions. The project is to remove approximately 2,100 cubic
to yards of accumulated sediment from the canal and edge of the Cape Fear River. The
11 spoil material will be placed on the banks of the intake canal and stabilized. Any
12 drainage of water will either drain. back into the intake canal or through adjacent
13 vegetation after passing through a silt fence.
Exhibit A

2
PART 1 - GENERAL
SECTION 01060
SPECIAL CONDITIONS
4 1.1 PRECONSTRUCTION CONFERENCE
5 A. A preconstruction conference shall be held at City of Wilmington Public Utilities Department,
6 City of Wilmington, Wilmington, North Carolina after award of Contract. City of Wilmington
7 will nofify the Contractor as to .the date and time of the conference two (2) weeks in advance of
8 the proposed date. Contractor's Project Manager and Project Superintendent and if appropriate,
9 Contractor's Subcontractor Representatives shall attend.
10 1.2 PROJECT SIGNS (NOT REQUIItED)
11 1.3 CONTRACTOR'S FIELD OFFICE (NOT REQUIRED).
12 1.4 DRAWINGS AND CONTRACT DOCUMENTS FOR CONTRACTOR USE.
13 A. Refer to General Conditions.
14 B. Contractor shall pick up three (3) copies of "no-chazge" documents within 10 days from date of
15 Notice to Proceed.
16 C. Additional documents after "no-charge" documents will be furnished to Contractor at cost.
17 1.5 TESTING (NOT REQUIItED)
18 1.6 ORDER OF CONSTRUCTION AND CONSTRUCTION SCHEDULE
19 A. Construction operations will be scheduled to allow the Owner uninterrupted operation of
20 existing adjacent facilities.
21 B. Notify City of Wilmington Public Utilities Department 10 days prior to work beginning.
22 Coordinate connections with existing work to ensure timely completion of interfaced items.
23 C. At no time shall Contractor or his employees modify operation of the existing facilties or start
24 construction modifications without approval of the Owner except in emergency to prevent or
25 minimise damage.
26 D. Within 10 days after award of Contract, submit for approval a critical path type schedule.
27 Account for schedule of Subcontracts. Include proper sequence of construction, various crafts,
28 purchasing time, shop drawing approval, material delivery, and similaz time consuming factors.
29 Show on schedule as a minimum, earliest starting, earliest completion, latest starting, and latest
30 finish for each task or item.
31 E. If Contractor does not take necessary action to accomplish work according to schedule, he may
32 be ordered by Owner in writing to take necessary and timely action to improve work progress.
33 Order may require increased work forces, extra equipment, extra shifts or other action as
34 necessary. Should Contractor refuse or neglect to take such action authorized, under provisions
35 of this contract, Owner may take necessary actions including, but not necessarily limited to,
36 withholding of payment and termination of contract.
37 Upon receipt of approved. "Work Schedule," within 10 days, submit to Owner an estimated
38 payment schedule by each month of project duration.
39 1.7 PROJECT MEETINGS
40 A. The Owner will conduct construction meetings involving:
41 1. Contractor's project manager.
42 2. Contractor's project superintendent.
L:xhibit A 2

1 3. Owner's designated representative(s).
2 4. Contractor's subcontractors as appropriate to the work in progress.
3 B. Meetings conducted maybe called by Owner at convenient times throughout the duration of the
4 Project.
5 C. The Owner will take meeting minutes and submit copies of meeting minutes to participants and
6 designated recipients identified at the Preconstruction Conference. Corrections, additions or
7 deletions to the minutes shall be noted and addressed at the following meeting.
8 D. The Owner will have available at each meeting full chronological file of all previous meeting
9 minutes.
10 E. The Contractor shall have available at each meeting up-to-date record drawings.
11 1.8 VIDEO RECORDING EQUIPMENT (NOT REQUIRED)
12 1.9 SPECIAL CONSIDERATIONS
13 A. Contractor shall be responsible for negotiations of any waivers or alternate ,arrangements
14 required to enable transportation of equipment to the site.
15 B. Maintain conditions of access road to site such that access is not hindered as the result of
16 construction related activities.
17 C. Maintain in good repair temporary structures, fences, barricades, and other related items.
18 D. Special Hazards. Each Contractor and his subcontractor's Public Liability and Property Damage
19 Insurance shall provide adequate protection against the following special hazards:
20 Excavation
21 Flooding
22 E. Safety. Each Contractor alone shall be solely and completely responsible for conditions of the
23 job site in connection with his work, including safety of all persons and property, preparatory to
24 and during performance of the Work. This requirement shall apply continuously and not be
25 limited to normal working hours.
26 1. The Construction Documents,, and the construction hereby contemplated are to be governed,
27 at all times, by applicable provisions of local and State laws, and regulations, and Federal
28 laws, including but not limited to, the latest amendments of the following: Department of
29 Labor, Bureau of Labor Standards Safety and Health Regulations for Construction, and
30 Williams and Steiger Occupational Safety and Health Act of 1970, including rules and
31 regulations pursuant thereto, applicable to the Work and performance of the Contract
32 (OSHA).
33 2. The duty of the Owner to conduct construction review of each Contractor's performance is
34 not intended to include review of the adequacy of the Contractor's safety measures in, on, or
35 near the construction site.
36 All explosives shall be stored in a secure manner and all storage places shall be marked
37 clearly "DANGEROUS EXPLOSIVES", and shall be in the care of competent watchmen at
38 -all times.
39 F. Inspections by Federal and State Agencies. Authorized representatives and agents of the State
40 and Federal Government shall be permitted to inspect all work, materials, payrolls, records of
41 personnel, invoices of materials, and other relevant data and records.
42 G. Post-Construction Survey. Submit a survey to the City of Wilmington prepared by a Registered
43 Licensed Surveyor showing the post-construction conditions of the project site.
44 1. Use benchmark provided by the City of Wilmington.
45 2. Scale shall be 1 inch equals 40 feet horizontal and 1 inch equals 4 feet vertical.
46 3. Submit one hard copy of survey on at least two sheets of 24 inch by 36 inch paper.
47 a. Sheet one shall reflect post-construction plan view.
Exhibit :~

1 1) Show elevation contours at one foot intervals.
2 2) .Show excavation area and spoil pile placement area.
3 b. Sheet two shall reflect post-construction cross-sections.
4 1) Include post construction cross sections at stations indicated on project drawing.
5 2) Cross-sections shall span from disturbed area boundary on either side of intake
6 canal.
7 3) Indicate top of spoil pile elevation at each cross section.
8 4) Indicate toe of spoil pile elevation at each cross section.
9 4. Submit an electronic version of the drawings in Autocad 2005 format.
1o PART 2 - PRODUCTS - (NOT APPLICABLE TO THIS SECTION)
l1 PART 3 - EXECUTION - (NOT APPLICABLE TO THIS SECTION)
12
END OF SECTION
Exhibit A

1 SECTION 02270
2 SOIL EROSION AND SEDIMENT CONTROL
3 PART 1 - GENERAL
4 1.1 SUMMARY
5 A. Section Includes:
6 1. Soil erosion and sediment control.
7 1.2 QUALITY ASSURANCE
8 A. Referenced Standards:
9 1. Erosion control standards: Most recent version of the "Erosion and Sediment Control
10 Planning and Design Manual" by NC DENR Division of Land Resources.
11 1.3 DEFINITIONS
12 A. Temporary Diversions: A temporary ridge or excavated channel or combination ridge and
13 channel constructed across sloping land on a predetermined grade.
14 B. Excavated Drop Inlet Protection (Temporary): An excavated area in the approach to a storm
15 drain drop inlet or curb inlet.
16 C. Fabric Drop Inlet Protection (Temporary): A temporary fabric barrier placed around a drop inlet.
17 D. Temporary Sediment Trap: A small, temporary ponding basin formed by an embankment or
18 excavation to capture sediment.
19 E. Sediment Fence (Silt Fence): A temporary sediment barrier consisting of filter fabric buried at
20 the bottom, stretched, and supported by posts.
21 F. Rock Dam: A rock embankment located to capture sediment.
22 G. Check Dam: Small temporary stone dams constructed across a drainageway.
23 H. Seeding: Preparation of topsoil and planting of vegetation to prevent soil erosion.
24 I. Temporary Gravel Construction Entrances/Exit: A graveled area or pad located at points where
25 vehicles enter and leave a construction site.
26 J. Rock Pipe Inlet Protection: Rock embanlanent located to prevent a drainage pipe inlet from
27 becoming blocked by sediment.
28 K. d50: A mixture of stones in which 50% of the stone by weight would be smaller than the
29 diameter specified.
30 1.4 BORROW AREAS, SPOIL AREAS AND OTHER AREAS DISTURBED BY
31 CONSTRUCTION
32 A. Design, install and maintain erosion control measures in accordance with referenced standards
33 and these specifications.
34 1.5 NONCOMPLIANCE
35 A. Implement any corrective actions when directed by OWNER.
36 B. Failure to comply with this Section is grounds for temporary suspension of the Work.
37 1. Temporary suspension, when invoked, will be effective until satisfactory installation of
38 erosion control measures.
39
F.-,xhibit .4 $

1 C. Pay any cost of fines or penalties levied from NC Department of Environment and Natural
2 Resources.
PART 2 - PRODUCTS
2.1 MATERIALS
5 A. Temporary Diversion: Use soil available at site; apply seed, lime, and fertilizer.
6 B. Excavation Drop Inlet Protection: Use well graded rock and gravel (NC DOT 57).
7 C. Fabric Drop Inlet Protection:
8 1. Synthetic Fabric. Nylon polyester, or ethylene yarn with tensile strength of SO lb/in
9 minimum. The cloth should contain ultraviolet ray inhibitors and stabilizers.
10 2. Ensure that posts are 1.331b/linear ft. steel with a minimum length of 4 ft. Make sure that
11 steel posts have projections to facilitate fastening the fabric.
12 D. Temporary Sediment Trap: Class B stone with d50 of 9 inches and a maximum size of 14 inches.
13 E. Sediment Fence (Silt Fence):
14 1. Using a synthetic filter fabric or a pervious sheet of polypropylene, nylon, polyester, or
15 polyethylene yam, which is certified by the manufacturer or supplier as conforming to the
16 requirements shown in Table 1. Synthetic filter fabric should contain ultraviolet ray
17 inhibitors and stabilizers to provide a minimum of 6 months of expected usable construction
18 life at a temperature range of 0 to 120 degrees F.
19 2. Ensure that posts for sediment fences are 1.33 lb/linear ft. steel with a minimum length of 4
20 ft. Make sure that steel posts have projections to facilitate fastening the fabric.
21 3. For reinforcement of standard strength filter fabric, use wire fence with a minimum 14
22 gauge and a maximum mesh spacing of 6 inches.
23 4. No. 9 wire staples at least 1-1/2" in length.
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Table 1
Physical Property Requirements
Filtering Efficiency
Tensile Strength at
20% (max.) Elongation
Slurry Flow Rate
85% (min.)
Standard Strength:
301b/lin. in. (min.)
Extra Strength:
SO lb/lin.in. (min.)
0.3 gaUsq.ft./min. (min.)
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F. Rock Dam:
1. Well graded rock and gravel (NCDOT - 57).
2. Extra strength filter fabric of the following specifications:
15% minimum elongation
400 psi minimum burst strength
801b. minimum punctures strength
30/130 apparent opening size -max./min.
1401b. minimum ultraviolet exposure strength retention
"No growth" rating for Fungus Resistance Testing
G. Check Dam: NCDOT Class A or B erosion control stone.
H. Temporary Gravel Construction Entrance/Exit: 2-3" coarse aggregate.
I. Rock Pipe Inlet Protection: No. 5 or No. 57 Class A sediment control stone.
{:xh,~~i, ;a

PART 3 - EXECUTION
2 3.1 PREPARATION
3 A. Prior to Dredging Activities:
4 1. Install perimeter dikes and swales and sediment fencing.
5 2. Excavate and shape sediment basins and traps.
6 3. Construct pipe spillways and install stone filter where required.
7 4. Machine compact all berms, dikes and embankments for basins and traps.
8 5. Install straw bales where indicated.
9 a. Provide two stakes per bale.
10 b. First stake angled toward previously installed bale to keep ends tight against each other.
11 B. Construct sediment traps where indicated on Drawings during rough grading as grading
12 progresses.
13 C. Temporarily seed basin slopes and topsoil stockpiles:
14 1. Rate: 1/2 LB/1000 SF.
15 2. Reseed as required until good stand of grass is achieved.
16 3. Establish temporary vegetation of critical areas immediately after any land disturbing
17 activity.
18 D. Pitch Lines: Restabilize all disturbed or relocated ditch lines by installing a temporary ditch
19 liner of jute or geotextile fabric on the ditch bottom and side slopes.
20 E. Protect existing trees and other vegetation to remain against damage.
21 1. Do not smother trees by stockpiling spoil or construction materials within drip line.
22 3.2 INSTALLATION
23 A. Temporary Diversions:
24 1. Remove and dispose of vegetation or other objectionable material.
25 2. Excavate parabolic, trapezoidal, or V-shaped channel with a side slope of 2:1 or flatter, 3:1
26 where vehicles cross.
27 3. A permanent vegetative cover is required for diversion channels with grades between 0.2
28 and 3%.
29 4. Ensure that the minimum cross-section meets all design requirements and that the top of the
30 dike is not lower at any point than the design elevation plus the specified settlement.
31 5. Provide sufficient room around diversions to permit regrading and clean-out.
32 6. Vegetate the ridge immediately after construction, unless it will remain in place less than 30
33 ~ working days.
34 B. Fabric Drop Inlet Protection (Temporary):
35 1. Space stakes evenly around the perimeter of the inlet a maximum of 3 feet apart, and
36 securely drive them into the ground, approximately 18 inches deep. They should be driven
37 close to the drop inlet so that overflow will fall directly into the structure.
38 2. To provide stability, frame with 2 x 4 inch wood strips around the crest of the overflow area
39 at a maximum of 1.5 feet above the drop inlet crest.
40 3. Fasten fabric securely to the stakes and frames. Joints must be overlapped to the next stake.
41 The bottom 12 inches of the fabric should be entrenched with at least 4 inches of crushed
42 stone or 12 inches of compacted soil as backfill.
43 4. Ensure that both fabric and supporting stakes are sufficiently strong to hold a 1.5 ft. head of
44 water without failures.
45 5. The top of the frames and fabric must be well below the ground elevation downslopes from
46 the drop inlet to keep runoff from bypassing the inlet.
47 6. It maybe necessary to build a temporary site on the down slope side of the structures to
48 prevent bypass flow. Improved performance and sediment storage volume can be obtained
49 by excavating the area.
lxhibit .A

1 C. Temporary Sediment Trap:
2 1. Clean, grub and strip the area under the embankment of all vegetation and root mat before
3 construction begins: Remove all surface soil containing high amounts of organic matter.
4 2. Ensure that fill material for the embanlanent is free of roots, woody vegetation, organic
5 matter, and objectionable material. Place the fill in lifts not to exceed 9 inches and machine
6 compact it. Over fill the embankment 6 inches to allow for settlement.
7 3. Construct the outlet section in the embankment. Protect the connection between the riprap
8 and the soil from piping by using filter fabric or a keyway cutoff trench between the riprap
9 structure and the soil.
10 a. Place the filter fabric between the riprap and soil. Extend the fabric across the spillway
11 foundation and sides to the top of the dam; or
12 b. Excavate a keyway trench along the centerline of the spillway foundation extending up
13 the sides to the height of the dam The trench should be at least 2 ft. deep and 2 ft. wide
14 with 1:1 side slopes.
15 4. .Clear the pond area below the elevation of the crest of the spillway to facilitate sediment
16 cleanout.
17 5. All cut and fill slopes should be 2:1 or flatter.
18 6. Ensure that the stone (drainage) section of the embanlaiient has a minimum bottom width of
19 3 ft. and maximum side slopes of 1:1 that extend to the bottom of the spillway section.
20 7. Construct the minimum finished stone spillway bottom width with 2:1 side slopes extending
21 to the top of the overfilled embankment. Keep the thickness of the sides of the spillway
22 outlet structure at a minimum of 21 inches. The weir must be level and constructed to grade
23 to assure design capacity.
24 8. Material used in the stone section should be awell-graded mixture of stone with a d50 size
25 of 9 inches (class B erosion control stone is recommended) and a maximum stone size of 14
26 inches. The stone may be machine placed and the smaller stones worked into the voids of
27 the larger stones. The stone should be hard, angular, and highly weather-resistant.
28 9. Ensure that the stone spillway outlet section extends downstream past the toe of the
29 embankment until stable conditions are reached and outlet velocity is acceptable for the
30 receiving stream. Keep the edges of the stone outlet section flush with the surrounding
31 ground and shape the center to confine the outflow stream (References: Outlet Protection).
32 10. Direct emergency bypass to natural, stable areas. Locate bypass outlets so that flow will not
33 damage the embankment.
34 11. Stabilize the embankment and all disturbed areas above the sediment pool and downstream
35 from the trap immediately after construction (References: Surface Stabilization).
36 12. Ensure that the spillway crest is level and 1.5 feet below the top of the dam at all points.
37 13. Remove sediment and restore capacity to original trap dimensions when sediment has
38 accumulated to 'h design depth.
39 D. Sediment Fence (Silt Fence):
40 1. Construct the sediment bamer of the specified synthetic filter fabrics.
41 2. Ensure that the height of the sediment fence does not exceed 18 inches above the ground
42 surface. (Higher fences may impound volumes of water sufficient to cause failure of the
43 structure.)
44 3. Construct the filter fabric from a continuous roll cut to the length of the barrier to avoid
45 joints. When joints are necessary, securely fasten the filter cloth only at a support post with
46 overlap to the next post.
47 4. Support standard strength filter fabric by wire mesh fastened securely to the upslope side of
48 the posts using heavy duty wire staples at least 1 inch long, or the wires. Extend the wire
49 mesh support to the bottom of the trench.
50 5. When a wire mesh support fence is used, space posts a maximum of 8 ft. apart. Support
51 posts should be driven securely into the ground to a minimum of 18 inches.
52 6. Extra strength filter fabric with 6-foot post spacing does not require wire mesh support
53 fence. Staple or wire the filter fabric directly to posts.
54 7. Excavate a trench approximately 4 inches wide and 8 inches deep along the proposed line of
55 posts and upslope from the barrier.
Exhibit :\

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8. Backfill the trench with compacted soil or gravel placed over the filter fabric.
9. Do not attach filter fabric to existing trees.
E. Rock Dam:
1. Clear the areas under the embankment and strip it of its roots and other objectionable
material. Clear the reservoir area to facilitate sediment removal.
2. Excavate a cutoff trench a minimum of 2 feet deep and 2 feet wide with 1:1 side slopes
under the total length of the dam at its centerline. Line the trench with extra-strength at its
centerline. Line the trench with extra-strength filter fabric before backfilling with rock.
Apply filter fabric under the rock fill embankment, from the upstream edge of the keyway to
the downstream edge of the apron. Overlap the material a minimum of 1 foot at all joints,
with the upstream strip laid over the downstream strip.
3. Construct the embankment with well-graded rock and gravel. It is important that rock
abutments be at least 2 foot higher than the spillway crest and at least 1 foot higher than the
downstream face of the dam, all the way to the toe, to prevent scour and erosion at the
abutments.
4. Sediment-laden water from the construction site should be diverted into the basin reservoir
at the furthest area from the dam.
5. Construct the rock dam before the basin area is cleared to minimize sediment yield from
construction of the basin. Stabilize immediately all areas disturbed during the construction
of the dam except the sediment pool (References: Surface Stabilization).
6. Safety. Sediment basins should be considered dangerous because they attract children.
Steep side slopes should be avoided. Fences with warning signs maybe needed if the
trespassing is likely. All state and local requirements must be followed.
F. Check Dams:
1. Place stone to the lines and dimensions shown in the plan on a filter fabric foundation.
2. Keep the center stone section at least 9 inches below natural ground level where the dam
abuts the channel banks.
3. Extend stone at least 1.5 feet beyond the ditch banks to keep overflow water from
undercutting the dam as it re-enters the channel
4. Set spacing between dams to assure that the elevation at the top of the lower dam is the
same as the toe elevation of the upper dam
5. Protect the channel downstream from the lowest check dam, considering that water will
flow over and around the dam.
6. Make sure that the channel reach above the most upstream dam is stable.
7. Ensure that channel appurtenances, such as culvert entrances below check dams,.are not
subject to damage or blockage from displaced stones.
G. Temporary Gravel Construction Entrance/Exit:
1. Clear the entrance and exit area of all vegetation, roots, and other objectionable material and
properly grade it.
2. Place the gravel to the required grade and dimensions and level.
3. Provide drainage to carry water to a sediment trap or other suitable outlet.
4. Use geotextile fabrics because they improve stability of the foundation in locations subject o
seepage or high water.
H.' Rock Pipe Inlet Protection:
1. Clear the pipe inlet area of all.vegetation, roots, and other objectionable material.
2. Place Stone to full height of pipe.
3.3 MAINTENANCE
A. Temporary Diversions:
1. Inspect weekly and, after every rainfall, remove sediment from the flow area and repair the
diversion ridges. Also check and maintain outlets.
2. When the protected area is permanently stabilized, remove the ridges and the channel to
blend with the natural ground level and appropriately stabilize site.
Fxhibii :\

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B. Fabric Drop Inlet Protection (Temporary):
1. Inspect the fabric barrier after each rain and make repairs as needed.
2. Remove sediment from the pool area as necessary to provide adequate storage area for the
next rain.
3. When the contributing drainage area has been adequately stabilized, remove all materials
and any unstable sediment and dispose of them properly. Bring the disturbed area to the
grades of the drop inlet and smooth and compact it. Appropriately stabilize all bare areas
around the inlet.
C. Temporary Sediment Trap:
1. Inspect temporary sediment traps after each period of significant rainfall. Remove sediment
and restore the trap to its original dimensions when the sediment has accumulated to one-
half the design depth of the trap. Place the sediment that is removed in the designated
disposal area and replace the contaminated part of the gravel facing.
2. Check the structure for damage from erosion or piping. Periodically check the depth of the
spillway to ensure it is a minimum of 1.5 feet below the low point of the embankment.
Immediately fill any settlement of the embankment to slightly above design grade. Any
riprap displaced from the spillway must be replaced immediately.
3. After all sediment-producing areas have been permanently stabilized, remove the structure
and all unstable sediment. Smooth the area to blend with the adjoining areas and stabilize
properly.
D. Sediment Fence (Silt Fence):
1. Inspect sediment fences at least once a week and after each rainfall. Make any required
repairs immediately.
2. Should the fabric of a sediment fence collapse, tear, decompose, or become ineffective,
replace it promptly. Replace burlap every 60 days.
3. Remove sediment deposits as necessary to provide adequate storage volume for the next
rain and to reduce pressure on the fence. Take care to avoid undermining the fence during
cleanout.
4. Remove all fencing materials and unstable sediment deposits and bring the area to grade.
Stabilize it after the contributing drainage area has been properly stabilized.
E. Rock Dam:
1. Check sediment basins after each rainfall. Remove sediment and restore original volume
when sediment accumulates to about one-half the design volume.
2. Check the structure for erosion, piping, and rock displacement after each significant
rainstorm and repair immediately.
3. Remove the structure and any unstable sediment immediately after the construction site has
been permanently stabilized. All water and sediment should be removed from the basin
prior to dam removal. Sediment should be placed in designated disposal areas and not
allowed to flow into streams or drainageways during structure removal.
4. Smooth the basin site to blend with the surrounding area and stabilize.
F. Check Dam:
1. Inspect check dams and channels for damage after each runoff event.
2. Anticipate submergence and deposition above the check dam and erosion from high flows
around the edges of the dam. Correct all damage immediately. If significant erosion occurs
between dams, install a protective riprap liner in that portion of the channel.
3. Remove sediment accumulated behind the dams as needed to prevent damage to channel
vegetation, allow the channel to drain through the stone check dam and prevent large flows
from cairying sediment over the dam. Add stones to dams as needed to maintain design
height and cross section.
I~xhibit :\
10

G. Temporary Gravel Construction Entrance/Exit: Maintain the gravel pad in a condition to
prevent mud or sediment from leaving the construction site. This may require periodic
topdressing with 2-inch stone. After each rainfall, inspect any structure used to trap sediment
and clean it out as necessary. Immediately remove all objectionable materials spilled, washed,
or tracked onto public roadways.
6 H. Rock Pipe Inlet Protection:
7 1. Inspect stone arrangement weekly and after every rainfall event.
8 2. Maintain specified dimensions and remove sediment buildup when the sediment level is '/z
9 the height of the rocks.
10 3.4 NEAR COMPLETION OF CONSTRUCTION
11 A. Eliminate basins, dikes, traps, etc.
12 B. Grade to finished or existing grades.
13 C. Fine grade all remaining earth areas, then seed and mulch.
14 D. Seeding:
15 1. Materials.
16 a. Use 25 percent annual rye and 75 percent fescue mix.
17 2. Preparation.
18 a. Loosen surface to minimum depth of 4 IN.
19 b. Correct surface irregularities in order to prevent low areas.
20 3. Installation.
21 a. Employ satisfactory methods of sowing using mechanical power driven drills or
22 seeders, or mechanical hand seeders, or other approved equipment.
23 b. Distribute seed evenly over entire area at rate of application not less than 4 LBS of seed
24 per 1000 SF.
25 c. Immediately protect seeded areas against erosion by mulching.
26 1) Spread mulch in a continuous blanket using 1-1/2 tons per acre to a depth of 4 or 5
27 straws.
28 END OF SECTION
Exhibit A 11