806Pollution, Erosion and Sediment Control

806 POLLUTION, EROSION AND SEDIMENT CONTROL

806.1Description. This work shall consist of furnishing, installing, maintaining and removing temporary

pollution, erosion and sediment control measures; furnishing and placing permanent erosion control features; or a combination of both as shown on the plans or as directed by the engineer.

806.2Schedule of Work. Prior to the preconstruction conference and the start of construction, the contractor

shall submit schedules for the implementation of temporary pollution control and temporary and permanent erosion control work, as applicable, for construction operations. The contractor's schedule shall address specifically the pollution and erosion control measures planned at all streams or other bodies of water. No work shall start until the pollution and erosion control schedules and methods of operations have been approved by the engineer. Any delay of the work resulting from failure to submit acceptable pollution and erosion control schedules and methods of operations will be considered nonexcusable.

806.3Material. All material shall be in accordance with Division 1000, Material Details, and specifically as

herein.

806.4Construction Requirements. The engineer will limit the surface area of erodible earth material exposed

by clearing and grubbing or by excavation, borrow and fill operations in accordance with the following. The engineer may direct the contractor to provide immediate permanent or temporary pollution control measures to prevent contamination of adjacent streams or other bodies of water. Such work may involve the construction of temporary berms, dikes, dams, sediment basins and slope drains, and use of temporary mulches, seeding or other control devices or methods as necessary to control erosion and pollution. 806.4.1 If erosion and sediment control measures, as shown on the plans, are not suitable due to site conditions, a suitable system of Best Management Practices (BMP) as defined by the applicable Missouri State Operating Permit for land disturbance activities and the Stormwater Pollution Prevention Plan (SWPPP), shall be applied as approved by the engineer. 806.4.2 The contractor shall exercise effective management practices throughout the life of the project to control pollution. Pollutants such as chemicals, fuels, lubricants, bitumen, raw sewage or other harmful material shall not be discharged on or from the project. Temporary pollution control measures, such as storage and handling of petroleum products and other pollutants, shall be coordinated with temporary and permanent erosion and sediment control features specified in the contract to ensure economical, effective and continuous erosion and pollution control. These requirements will also apply to work within easements designated by the Commission. 806.4.3 The contractor shall incorporate all permanent erosion, sediment, and pollution control features into the project at the earliest practical time. Temporary measures shall be used to correct conditions that develop during construction which were not foreseen during the design stage, that are needed prior to installation of permanent pollution control features, or that are needed temporarily to control erosion and sediment that develops during normal construction practices, but are not associated with permanent control features on the project. 806.4.4 Installation of temporary control measures shall be scheduled to coincide with clearing and grubbing operations, but before grading operations begin. The project land area disturbance shall not exceed one acre without installation of erosion and sediment controls. The total project land disturbance area shall not exceed 20 acres without written approval from the engineer. 806.4.5 The engineer may allow additional land disturbance acreage if appropriate BMP's including temporary seeding and mulching, have been applied to previously disturbed areas and the contractor has the resources to apply the BMP's to the expanded area. 806.4.6 Unless otherwise provided or approved in writing by the engineer, construction operations in streams or other bodies of water shall be restricted to those areas that must be entered for the construction of temporary or permanent structures. Streams or other bodies of water shall be promptly cleared of all falsework, piling, debris or other obstructions placed therein or caused by construction operations. 806.4.7 Fording of streams or other bodies of water with construction equipment will not be permitted, except as allowed by the engineer. Temporary bridges or other structures shall be used when frequent crossing of streams 508 or other bodies of water is necessary. Unless otherwise approved in writing by the engineer, mechanized equipment shall not be operated in streams or other bodies of water except as may be required to construct channel changes and temporary or permanent structures. If a Corps of Engineer Section 404 or Department of Natural Resources Section 401 permit is applicable for a project, the permit requirements and conditions will prevail. 806.4.8 The contractor shall obtain all necessary permits for all project support activities located off the project site. Project support activities include, but are not limited to, borrow areas, waste areas, plant sites, and staging areas. All costs associated with the permits and pollution control shall be at the contractor’s expense, including providing, installing, maintaining, and removal of all erosion and sediment control devices, and final stabilization of disturbed areas. 806.4.9 In the event of conflict between these requirements and the pollution control laws, rules or regulations of other federal, state or local agencies, the more restrictive laws, rules or regulations will apply. 806.4.10 The contractor is encouraged to incorporate mulch from the clearing and grubbing operation into the BMP’s on the project. BMP’s may consist of compost filled socks, compost filter berms, soil protection cover or any other method as approved by the engineer. 806.4.11 Unless otherwise specified, or directed by the engineer, all temporary erosion and sediment control measures shall be removed by the contractor after permanent erosion and sediment control measures are established and the project has achieved final stabilization as defined in the SWPPP. Biodegradable erosion and sediment control materials may be allowed to be incorporated into the project in accordance with the SWPPP, as approved by the engineer. Rock from ditch checks and other temporary sediment devices may be repositioned to serve as ditch liner in accordance with the SWPPP, and as directed by the engineer. 806.4.12 Portland cement concrete residue and wash water and other operations that produce sediment laden runoff shall be managed by an appropriate control measure. 806.4.12.1 Portland cement concrete residue and wash water shall be discharged into a plastic lined pit, plastic lined straw bale enclosure, or other commercially available water tight enclosure suitable for containing concrete residue and wash water as approved by the Engineer. 806.4.12.2 Water from aggregate washing and other operations that produce sediment laden water shall be treated by filtration, settling basins, or other means sufficient to comply with the general water quality criteria established by MDNR. 806.4.12.3 No direct payment will be made for the design, installation, maintenance or removal of controls necessary to contain Portland cement concrete residue and wash water or other water from sediment producing operations.

806.10.1 Description. This work shall consist of constructing and maintaining temporary berms at the top of

slopes or transverse to the centerline of fills as shown on the plans.

.2 Material. Type B berms shall consist of graded material from within the project limits, rock, or other

suitable material approved by the engineer. Type C berms shall consist of rock with a predominant size between 4 inches and 12 inches.

.3 Construction Requirements. Temporary berms shall be constructed and maintained to the

approximate dimensions shown on the plans.

.3.1 Type B Berms. Type B berms shall be machine compacted with a minimum of three passes over the

entire width of the berm. Material removed from Type B berms shall be incorporated in the embankment when possible. The contractor shall remove and dispose of any excess or unsuitable material to a location approved by the engineer. 509

.3.1 Type B berms shall drain to a compacted outlet at slope drain. On transverse berms, the top width of

the berms may be wider and the side slopes flatter to allow equipment to pass over these berms with minimal disruption.

.3.2 Type C Berms. Vegetative mulch, erosion control blanket or geotextile fabric, if required by the

engineer, shall be placed on the upslope of the Type C berm. The vegetative mulch shall be placed in such a manner that the final compacted thickness is 2 inches. The material for the vegetative mulch shall be in accordance with Sec 802. The vegetative mulch erosion control blanket or geotextile fabric shall be removed and replaced as directed by the engineer.

.4 Method of Measurement. Measurement of Type B and C berms will be made to the nearest linear

foot.

.5 Basis of Payment. The accepted quantities of Type B and C berms will be paid for at the contract unit

price and will be considered full compensation for material, installation, maintenance, removal and any other hand work necessary to construct the berms. No payment will be made for the straw layer, erosion control blanket or geotextile fabric on the Type C berm. No payment will be made for any seeding and mulching needed after removal. SECTION 806.20 TEMPORARY SLOPE DRAINS.

806.20.1 Description. This work shall consist of furnishing, constructing maintaining and removing temporary

slope drains to carry water down slopes and to reduce erosion. The method selected shall be approved by the engineer prior to construction.

.2 Construction Requirements. The contractor shall provide temporary, impermeable slope drains to

carry water or water with suspended solids down fill slopes until permanent erosion control measures are established. The contractor shall provide temporary slope drains on fillslopes at approximately 500-foot intervals or as directed by the engineer. All temporary slope drains shall be adequately anchored to the slope to prevent disruption of flow. The inlet ends shall include a ditch check and be constructed to channel water into the temporary slope drain. Outlet ends shall have some means of dissipating the energy of the water to reduce erosion downstream and have the ability to capture sediment. After removal, the contractor shall restore the site of the slope drains to the satisfaction of the engineer.

.3 Method of Measurement. Measurement of temporary slope drains will be made to the nearest linear

foot.

.4 Basis of Payment. The accepted quantities of temporary slope drains will be paid for at the contract

unit price. Payment shall include furnishing, constructing, maintaining and removing temporary slope drains, and restoration of the slope drain sites. No payment will be made for any seeding and mulching needed after removal. SECTION 806.30 TEMPORARY DITCH AND INLET CHECKS.

806.30.1 Description. This work shall consist of furnishing, constructing, maintaining, removing and disposing

of temporary ditch and inlet checks.

.2 Construction Requirements

.2.1 Rock Ditch Checks. Rock ditch checks shall be constructed in accordance with the plans, or as

directed by the engineer, and shall have a minimum effective height of 18 inches. The predominant size of the rock used shall range between 4 inches and 12 inches.

.2.2 Alternate Ditch Checks. Alternate ditch checks shall be constructed in accordance with the

manufacturer's specifications,, and as shown on the plans, or as directed by the engineer. Alternate ditch checks shall have a minimum effective height of 9 inches, shall follow guidance provided in the SWPPP, and shall perform to the level that meets or exceeds the requirement of the current Missouri Operating Permit. 510

.2.2.1 Compost filter socks used for alternate ditch checks shall meet the requirements of AASHTO R51

Other proprietary devices may be used, as approved by the engineer. Acceptance of the material will be based on the manufacturer's certification and upon acceptable performance in the field, as determined by the engineer.

.2.2.2 Unless otherwise disallowed, the contractor has the option to construct rock ditch checks in lieu of

alternate ditch checks. Rock ditch checks constructed in lieu of alternate checks shall have a minimum effective height of 18 inches. Spacing shall be increased, as determined by the engineer, to account for the additional height of rock ditch check. The toe-to-top capacity requirements shown on the plans will be used to determine the spacing.

.2.3 Inlet Checks. Inlet checks shall be installed in accordance with the plans or as directed by the

engineer to prevent sediment from entering drop inlets, manholes, and other openings to culverts and closed drainage systems.

.2.3.1 Inlet checks shall be constructed in accordance with Sec 806.30.2.1, rock ditch checks, and shall

completely surround the inlet or other structure, as indicated on the plans. Other allowable methods of protecting inlets will be listed in the SWPPP.

.2.4 Curb Inlet Checks. Curb inlet checks shall consist of socks filled with rock, or other fillers of

sufficient weight to keep the device in place. Compost filter socks used for curb inlet checks shall meet the requirements of AASHTO R51. Curb inlet checks shall be installed in the gutter or as shown on the plans. Other proprietary devices may be used, as approved by the engineer.

.3 Maintenance. The contractor shall monitor the condition of all temporary checks and repair or replace

checks that are not functional. The contractor shall remove sediment in accordance with Sec 806.110. Alternate ditch checks shall be maintained in accordance with this provision and the manufacturer's specifications or as directed by the engineer.

.4 Removal. All types of temporary checks shall remain in service until removal has been approved by

the engineer. Removal shall be in accordance with Sec 806.4.11 and as stated herein. The contractor shall remove any sediment from the check, remove the check, and restore the area to match existing ground condition. When necessary, seeding and mulching shall be in accordance with Secs 802 and 805 respectively, and shall be considered incidental.

.5 Method of Measurement

.5.1 Measurement of rock ditch checks will be made to the nearest linear foot as measured along the top

of the check. Rock ditch checks constructed in lieu of alternate checks will be included in this measurement for payment. Inlet checks, except for curb inlet checks, will be included in this measurement for payment.

.5.2 Measurement of alternate ditch checks will be made to the nearest linear foot as measured along the

top of the check.

.5.3 No measurement will be made for any portion of a check that exceeds the length necessary to

adequately span the ditch as shown on the plans or as directed by the engineer.

.5.4 Measurement of curb inlet checks will be made per each check

.6 Basis of Payment

.6.1 The accepted quantities of rock ditch checks, alternate ditch checks, inlet checks, and curb inlet

checks will be paid for at the contract unit price for each pay item included in the contract. If the engineer determines unusual conditions warrant complete replacement of a check, payment will be made for the replacement check at the contract unit price.

.6.2 Payment for sediment removal shall be in accordance with Sec 806.110

SECTION 806.40 SEDIMENT BASINS. 511

806.40.1 Description. This work shall consist of constructing and maintaining temporary or permanent

sediment basins as shown on the plans or as directed by the engineer. This work shall include clearing and excavation to construct the basin, disposal of excavated material, and providing and installing rock or other stabilizing material as approved by the engineer. For temporary basins, removal, backfilling, and site restoration is also included in the work.

.2 Construction Requirements. The sediment basin shall be an excavated or dammed storage area with

defined side slopes. Inlet and outlet areas shall be lined with rock of sufficient size to withstand the water flow. In lieu of rock, other allowable liners may be used as described in the SWPPP. Outlets may be constructed with a riser pipe, surface skimmers, or stabilized spillway, or a combination of one or more of these features.

.2.1 The inlet of a sediment basin shall be constructed with a wide cross-section and a minimum grade to

prevent turbulence and to allow deposition of soil particles.

.2.2 Sediment shall be removed and disposed in accordance with Sec 806.110, and before the depth

reaches approximately one-half the original depth of the sediment basin in any part of the pool.

.2.3 Temporary sediment basins shall remain in service until removal has been approved by the engineer

Removal shall be in accordance with Sec 806.4.11 and as stated herein. The contractor shall remove any sediment from the basin, backfill, compact all excavations, restore the area to match existing ground conditions, and seeding and mulching in accordance with Secs 802 and 805 respectively.

.3 Method of Measurement

.3.1 Measurement of excavation to construct sediment basin will be made to the nearest tenth of a cubic

yard.

.3.2 Measurement of rock placed to construct sediment basins will be made to the nearest tenth of a cubic

yard.

.4 Basis of Payment

.4.1 The accepted quantities for excavation to construct sediment basins will be paid for at the contract

unit price. Payment includes clearing, excavation, removal, backfilling and final grading.

.4.2 The accepted quantity for rock used to construct sediment basins will be paid for at the contract unit

price. Payment shall include furnishing, placing, and removal of rock.

.4.3 No direct payment will be made for seeding and mulching necessary to restore the area after

removal.

.4.4 Payment for sediment removal shall be in accordance with Sec 806.110

SECTION 806.50 TEMPORARY SEEDING.

806.50.1 Description. This work shall consist of furnishing and applying fertilizer and seed in disturbed areas

authorized by the engineer. Mulch shall be applied following temporary seeding in accordance with Sec 802. Temporary seeding and mulching is utilized to provide interim stabilization of disturbed areas where staging requires the area to be disturbed again at a later date, and for areas to be seeded with warm season grasses that are finish-graded, but application of permanent seeding is disallowed per Sec 805.3.1.2. Finish grading will not be required except for areas that will not receive further grading prior to permanent seeding. Hydraulic seeding and fertilizing in accordance with Sec 805 will be permitted.

.2 Construction Requirements. Seeding and mulching shall be a continuous operation on all cut and

fillslopes, excess material sites and borrow pits during the construction process. All disturbed areas shall be seeded and mulched as necessary to control erosion in accordance with the Missouri State Operating Permit. Seed bed shall be prepared in accordance with Sec 801. When the engineer allows the contractor to disturb additional ground beyond the restrictions in Sec 806.4.4 solely to enhance the contractor’s operation, the 512 contractor shall not receive compensation for temporary seed or mulch, as required by the engineer, for ground cover for areas exceeding the restrictions in Sec 806.4.4.

.2.1 The contractor shall provide permanent seeding and mulching following temporary seeding in

accordance with Sec 805. Any preparation of the seed bed that might be necessary prior to permanent seeding to ensure germination shall be considered incidental to temporary seeding. All washouts and rills shall be repaired at the contractor's expense prior to permanent seeding.

.2.2 Temporary seeding mixtures of cereal grains shall be applied at a minimum rate of 100 pounds per

acre. All erodible seeded areas shall provide a minimum of 20 plants of the species planted per square foot on at least two random counts per acre in representative areas of the field. For areas with a large percentage of rock, the number of living plants shall be proportional to the percentage of erodible surface, as determined by the engineer. The counts will be conducted 60 days after the species is planted.

.2.3 Fertilizer shall be applied at a rate of 40 pounds nitrogen (N) per acre

.2.4 Lime will not be required for temporary seeding of unfinished areas. In finished areas, where

temporary seeding is placed due to warm season grass planting time restrictions, 100 percent of the lime specified for warm season grasses shall be applied at the time of temporary seeding.

.3 Method of Measurement. Measurement of temporary seeding areas will be made to the nearest tenth

of an acre.

.4 Basis of Payment. The accepted quantities of temporary seeding will be paid for at the contract unit

price per acre. Payment for fertilizer shall be included in the cost of temporary seeding. When lime is applied in accordance with Sec 806.50.2.4 upon request from the contractor, payment for the lime application will be made as a partial payment for Seeding - Warm Season Grasses. The remaining payment for Seeding - Warm Season Grasses will be made after permanent seeding is complete. SECTION 806.60 SEDIMENT TRAP.

806.60.1 Description. This work shall consist of constructing, maintaining and removing sediment traps as

shown on the plans or as directed by the engineer.

.2 Construction Requirements

.2.1 Sediment traps shall be constructed as shown on the plans or as directed by the engineer. Traps may

require excavation, or placement of rock of sufficient size to impound water, or a combination of excavation and placement of rock.

.2.2 Sediment traps shall be installed with clearing and grubbing operations or as directed by the

engineer. The contractor shall monitor sediment levels and remove sediment in accordance with Sec 806.110.

.2.3 Sediment traps shall remain in service until removal has been approved by the engineer. Removal

shall be in accordance with Sec 806.4.11 and as stated herein. The contractor shall remove any sediment from the trap, backfill, compact all excavations, restore the area to match existing ground condition, and seeding and mulching in accordance with Secs 802 and 805 respectively.

.3 Method of Measurement

.3.1 Measurement of excavation to construct sediment traps will be made to the nearest tenth of a cubic

yard.

.3.2 Measurement of rock placed to construct sediment traps will be made to the nearest tenth of a cubic

yard.

.4 Basis of Payment

513

.4.1 The accepted quantity for excavation to construct sediment traps will be paid for at the contract unit

price. Payment includes clearing, excavation, removal, backfilling, and final grading.

.4.2 The accepted quantity for rock used to construct sediment traps will be paid for at the contract unit

price. Payment shall include furnishing, placing, and removal of rock.

.4.3 No direct payment will be made for seeding and mulching necessary to restore the area after

removal.

.4.4 Payment for sediment removal will be in accordance with Sec 806.110

SECTION 806.70 SILT FENCE.

806.70.1 Description. This work shall consist of furnishing, installing, maintaining, and removing of a silt fence

to control sediment along slopes and other designated areas. The quantity of silt fence shown on the plans may be increased or decreased, as directed by the engineer. The engineer may also modify the location as necessary to improve the effectiveness of the silt fence. Variations in quantity and location will not be considered as a change in work.

.2 Material. When geotextile fabric is used, material shall be in accordance with Sec 1011. All other

material shall be as specified in the SWPPP.

.2.1 Posts. Wood, steel or synthetic posts may be used. Posts shall be of sufficient length, but no less than

4 feet, to ensure adequate embedment while fully supporting the fence and shall have sufficient strength to resist damage during installation and to support applied loads while in service.

.2.2 Prefabricated Fence. Prefabricated fence systems may be used if the systems meet all of the above

material requirements.

.3 Construction and Maintenance Requirements

.3.1 Fabric Fence. The contractor shall install silt fence as shown on the plans and at other locations

directed by the engineer. Fence construction shall be adequate to handle the stress from hydraulic and sediment loading. Fabric at the bottom of the fence shall be buried a minimum of 6 inches to prevent flow under the barrier. The trench shall be backfilled, and the soil compacted over the fabric. Fabric splices with a minimum 2- foot overlay shall be located only at a support post. Any installation method acceptable to the engineer will be allowed as long as the effectiveness and intent of the silt fence is achieved.

.3.1.1 Post spacing shall not exceed 5 feet. Posts shall be driven a sufficient depth into the ground or

placed on closer spacing as necessary to ensure adequate resistance to applied loads.

.3.1.2 The silt fence shall be fastened securely to the upslope side of the post. When wire support fence is

used, the wire shall extend into the trench a minimum of 2 inches.

.3.2 Alternate Fence Types. Alternate fence types shall have a minimum effective height of 9 inches,

shall follow guidance provided in the SWPPP, and shall perform to the level that meets or exceeds the requirement of the current Missouri Operating Permit. Compost filter socks meeting the requirements of AASHTO R51 may be used as an alternate to fabric silt fence. Additional alternate silt fence types shall be in accordance with the SWPPP or as approved by the engineer. Acceptance of the material will be based on the manufacturer's certification and upon acceptable performance in the field, as determined by the engineer.

.3.3 Maintenance. The contractor shall monitor the condition of all fences and repair or replace fences

that are not functional as long as the fences are necessary to contain sediment runoff. Any deficiencies shall be corrected by the contractor in accordance with the SWPPP. In addition, the contractor shall review the effectiveness of silt fences in areas where construction activities have changed the natural contour and drainage runoff. Where deficiencies exist, additional silt fences shall be installed as approved or directed by the engineer.

.3.4 Sediment. The contractor shall remove and dispose of sediment in accordance with Sec 806.110

Segments of silt fence that receive heavy sediment loading may require a secondary silt fence or installation of 514 other controls to adequately contain sediment.

.3.5 Removal. Silt fence shall be removed in accordance with Sec 806.4.11 and as specified herein. The

contractor shall remove and dispose of any excess silt accumulation along the fence, shall restore the area to match existing ground condition, and seeding and mulching in accordance with Secs 802 and 805 respectively.

.4 Method of Measurement. Silt fence will be measured to the nearest linear foot from end to end of

each separate installation.

.5 Basis of Payment

.5.1 The accepted quantities of silt fence will be paid for at the contract unit price

.5.2 No direct payment will be made for seeding and mulching necessary to restore the area after

removal.

.5.3 Payment for sediment removal will be in accordance with Sec 806.110

SECTION 806.80 TEMPORARY PIPE.

806.80.1 Description. This work shall consist of installing and removing temporary pipe utilized to carry water

under temporary roadways, silt fences, berms or other locations determined by the engineer.

.2 Material. Any pipe approved by the engineer may be used

.3 Construction Requirements. Installation of temporary pipe shall be in accordance with the

specifications for permanent pipe and shall prevent water from causing erosion around the pipe. All backfill material for pipes shall be placed in 6-inch lifts and mechanically compacted. Compaction tests will not be required. Temporary pipe placed in intermittent or active streams for the convenience of the contractor shall be installed in accordance with Sec 806.100 and any applicable permits.

.4 Method of Measurement. Measurement of temporary pipe will be made to the nearest linear foot for

those pipes specified on the plans.

.5 Basis of Payment. The accepted quantities of temporary pipe will be paid for at the contract unit price

for temporary pipes specified on the plans. No payment will be made for temporary pipes that the contractor chooses to install to facilitate construction. Unless provided as a pay item in the contract documents, no direct payment will be made for the placement and removal of the backfill material or rock. SECTION 806.90 EROSION CONTROL BLANKETS AND TURF REINFORCEMENT MATS.

806.90.1 Description. This work shall consist of furnishing and placing erosion control blankets (ECBs) and

turf reinforcement mats (TRMs) on slopes or ditches for short-term or long-term protection of seeded areas at locations shown on the plans or as directed by the engineer.

.2 Material. ECBs and TRMs shall be used as designated in the contract or as approved by the engineer

The contractor shall provide ECBs and TRMs of the type specified in the contract and shall provide a manufacturer's certification stating that they are in accordance with Sec 1011.

.3 Construction Requirements. ECBs and TRMs shall be installed and maintained according to the

manufacturer's recommendations.

.4 Method of Measurement. Measurement of ECBs and TRMs will be made to the nearest square yard

of surface area covered.

.5 Basis of Payment. The accepted quantity of ECBs and TRMs will be paid for at the contract unit price

for each of the pay items included in the contract. If ECBs and TRMs are used in lieu of other erosion control measures, payment will be made at the contract unit price for the pay items in the contract for the respective items that the blanket replaces. 515 SECTION 806.100 TEMPORARY STREAM CROSSING.

0.1 Description. This work shall consist of constructing a temporary stream crossing to facilitate the

movement of equipment across a stream.

0.2 Construction Requirements. The contractor shall be responsible for the design, installation,

maintenance and removal of the temporary stream crossing and any structures installed for the construction of the temporary stream crossing. Appropriate measures shall be taken to maintain near normal downstream flows and to minimize flooding upstream. The temporary stream crossing shall be constructed to permit the free movement of the stream’s aquatic life. Fill material shall be clean rock of sufficient size to withstand expected high flows. Only graded rock and/or quarry-run rock shall be used. The rock must be reasonably well graded, with no particle dimension greater than approximately 12 inches, and no particle dimension less than approximately 9 inches. Gravel and dirt should not exceed 15% of the total fill volume.

0.2.1 Prior to construction of the temporary stream crossing, all information shall be submitted to the

engineer to ensure that it meets the terms and conditions of the Corps of Engineer permit. The contractor shall not begin construction on any temporary stream crossing without written permission from the engineer.

0.2.2 All approaches to the temporary stream crossing shall be maintained such that all storm water

runoff is diverted to retention devices.

0.2.3 When the temporary stream crossing is no longer needed, the crossing shall be removed as soon as

possible and the area shall be restored to pre-project conditions or to the satisfaction of the engineer.

0.3 Basis of Payment. No direct payment will be made for the design, installation, maintenance or

removal of temporary stream crossings. The contractor shall be responsible for all costs, including damage and penalties. SECTION 806.110 SEDIMENT REMOVAL.

806.110.1 Description. This work shall consist of removing and disposing of sediment from sediment control

devices, such as ditch and inlet checks, sediment basins, sediment traps, silt fence, and other devices that accumulate sediment.

0.2 Construction Requirements. The contractor shall monitor sediment levels in all sediment control

devices and remove sediment prior to the level reaching approximately one-half the design heights for checks and fences, and one-half the storage capacities for basins and traps. The engineer may require sediment removal from devices prior to levels reaching the specified limits.

0.2.1 The contractor shall dispose of the sediment in a location that does not allow the sediment to erode

back into the sediment devices or to pollute streams or other bodies of water.

0.3 Method of Measurement. Measurement of sediment removal will be made to the nearest tenth of a

cubic yard.

0.3.1 No measurement will be made for sediment removal that accumulates due to the contractor's failure

to complete erosion control measures in accordance with the SWPPP or as directed by the engineer. The engineer shall determine the volume of sediment that will be excluded from payment due to a lack of required erosion control measures.

0.3.2 No measurement will be made for removing any remaining sediment during final removal of the

sediment control devices.

0.4 Basis of Payment. The accepted quantity of sediment removal will be paid for at the contract unit

price.