557 SECTION 642 TEMPORARY POLLUTION CONTROL
The Contractor shall exercise every reasonable precaution throughout the life of the project to control water pollution. Construction of permanent drainage facilities as well as performance of other contract work which will contribute to the control of si ltation shall be accomplished at the earliest practicable time during the life of the Contract. Pollutants such as chemicals, fuels, lubricants, bitumens, raw sewage, and other harmful waste shall not be discharged into or alongside of rivers, streams, im poundments (lakes, reservoirs, etc.) or into natural or manmade water courses leading thereto. The Contractor shall also comply with the applicable regulations of the Department of Natural Resources and other statues relating to the prevention and abateme nt of pollution. The purpose of these Specifications is to set forth certain temporary water pollution control measures which shall be required by the Contract in addition to the above.
642.1 -DESCRIPTION : This work shall consist of temporary control measures performed during the life of the Contract to control water pollution through use of berms, rock check dam, sediment structures (traps or basins), mulches, fiber mats, seeding slope drains, and other erosion control devices or construction methods, in accordance with these Specifications and in reasonably close conformity with the lines, grades, thickness and typical cross sections shown on the Plans or established by the Engineer. The temporary pollution control provisions contained shall be coordinated with the permanent erosion control features specified elsewhere in the Contract to the extent practical to keep total erosion control costs to a mi nimum. These provisions shall also apply to work conducted outside the project right -of-way, such as operations in a borrow pit or waste site, where such work occurs as a result of the construction of the project. These temporary water pollution control measures shall be continued until; permanent controls have been established; the need has been eliminated as determined by the Engineer; or the project has been accepted.
642.2 -MATERIALS : Materials will be considered acceptable when they are capable of accomplishing the intended purpose, do not in themselves contribute to pollution and comply with the following:
mater ial acceptable to the Engineer. Mulch materials shall be reasonably free of noxious weeds. Chemical mulch binders shall conform to the requirements in subsection
715.27.1
ii. Slope drains may be constructed of pipe, fiber mats, rubble, Portland cement concrete, bituminous concrete, or other material that will adequately control erosion and is acceptable to the Engineer. iii. Temporary seed, such as annual ryegrass (Italian ryegrass), weeping lovegrass, cereal rye or wheat, barley or oats, and mi llet, used in temporary seed mixture or seed mixtures B or D, shall be of a commercial grade meeting requirements of the State Seed Law, Temporary seed labeled with the notation "germination below standard" will not be acceptable for use on projects. Temp orary seed shall not be used on the project after one year from the date of germination test shown on the label. Seed other than that specified above shall meet the requirements of subsection 715.28.
558 iv. Fertilizer shall be a commercial grade of 1 -2-1 ratio, meeting requirements of the governing state and federal laws.
Temporary Structures, etc.). vi. Ground agricultural limestone shall be of a commercial grade. vii. Engineering fabric for silt fence shall meet the requirements of subsection 715.11.5 and have a minimum width of three ( 3) feet. Wood, steel, or synthetic support posts having a minimum length of three ( 3) feet plus the burial depth shall be used. They shall be of sufficient strength to resist damage during installation and to the support applied loads due to material or wate r build up behind the silt fence. viii. Dewatering Device shall meet the requirements of subsection 715.11.10.
CONSTRUCTION METHODS
642.3-PRECONSTRUCTION CONFERENCE : At the pre -construction conference, the Contractor shall submit for approval their schedules and methods for accomplishing the required temporary and permanent pollution control work during the construction stages involving clearing and grubbing; grading and drainage; structures; bases and pavement; and others as applicable. The Contractor shall also submit for approval proposed schedules and method for pollution control on haul roads, borrow pits, waste sites, and other project related operations, as applicable, conducted outside the right -of-way. No work shall be started until the above pollution control schedules and methods have been approved by the Engineer.
642.4 -GENERAL REQUIREMENTS : The Engineer has the authority to limit the surface area of erodible earth material exposed by clearing and grubbing, to limit the surface area of erodible earth material exposed by excavation, borrow and fill operations and to direct the Contractor to provide immediate permanent or temporary pollution control measures as necessary to prevent contamination of adjacent streams or other watercourses, lakes, ponds, or other areas of water i mpoundment. Such work may involve the construction of temporary berms, rock check dam, sediment structures (traps, ponds or dams), slope drains, and use of temporary mulches, mats, seeding or other control devices or methods as necessary to control erosio n. The Contractor shall incorporate all permanent erosion control features into the project at the earliest practicable time as outlined in their acceptable schedule. Temporary pollution control measures shall be used to correct conditions that develop du ring construction that 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 that develops during normal construction practices, but are n ot associated with permanent control features on the project. Where erosion is likely to be a problem, clearing and grubbing operations shall be so scheduled and performed that grading operations and permanent erosion control features can follow immediately if the project conditions permit; otherwise temporary erosion control measures may be required between successive construction stages. The Engineer will limit the area of excavation, borrow and embankment operations in progress commensurate with the Co ntractor's capability and progress in keeping the finish grading, mulching, seeding, and other such permanent pollution control measures current in accordance with the accepted schedule. Should seasonal limitations make such coordination unrealistic, temp orary erosion control measures shall be taken immediately to the extent feasible and justified.
559 Unless otherwise approved in writing by the Engineer, construction operations in rivers, streams, and impoundments shall be restricted to those areas where cha nnel changes are shown on the Plans and to those areas which must be entered for the construction of temporary or permanent structures. Rivers, streams, and impoundments shall be promptly cleared of all falsework, piling, debris or other obstructions placed or caused by the construction operations. Excavation from any source shall not be deposited in or near rivers, streams, or impoundments or otherwise located in such a manner which might be susceptible to erosion due to high water, flooding, or runoff. Frequent fording of live streams with construction equipment will not be permitted; therefore, temporary bridges or other structures shall be used wherever an appreciable number of stream crossings are necessary. Unless otherwise approved in writing by t he Engineer, mechanized equipment shall not be operated in live streams except as may be required to construct channel changes and temporary or permanent structures. The location of all local material pits other than commercially operated sources, and all waste areas will be subject to the approval of the Engineer, and construction operations shall be conducted and pollution control measures implemented so that, both during and after completion of the work, erosion will not result in water pollution. The Contractor shall, in accordance with the guidance contained in subsection 642.3, submit schedules and methods in complete consonance with the intent of this Specification to prevent water pollution to the maximum extent possible. To provide a positive gui de in this area, no more than 750,000 square feet each of erodible soil shall be exposed as a result of (1) clearing and grubbing and (2) excavation, embankment, borrow or waste for a maximum cumulative total of 1,500,000 square feet without the approval of the Engineer. Approval to proceed beyond this point will be contingent upon (1) the Engineer's satisfaction, based on performance, as to the Contractor's ability to proceed with their operation and still maintain pollution control at the level contemplated by this Specification, and (2) seeding and mulching of disturbed areas at the Contractor's expense. It is further understood that regardless of an approval such as the above or compliance with an approved schedule as set forth in subsection 642.3, the Engineer may impose whatever limitations deemed necessary to assure an operation providing for pollution control consistent with the intent of this Specification. Reimbursement for such necessary temporary control measures required to eliminate the need for such limitation will be in accordance with the pertinent sections of this Specification. There will be no additional reimbursement to the Contractor due to losses from delays, production decreases or other causes resulting from the imposition of such a limitation. In the event of conflict between these requirements and pollution control laws, rules, or regulations of other Federal, State, or local agencies, the more restrictive shall apply. A Dewatering Device shall be installed on a slights lope so incoming water flows downhill through the Device without creating more erosion. The neck of the Dewatering Device shall be tightly strapped to the discharge hose. The contractor may place the bag on an aggregate or hay bale bed to maximize water fl ow through the surface area of the bag. The Dewatering Device is full when it no longer can efficiently filter sediment or pass water at a reasonable rate. Flow rates will vary depending on the size of the Dewatering Device, amount of sediment discharged into the Dewatering Device, the type of ground, rock, or other substance under the bag and the degree of the slope on which the bag lies. The Dewatering Device will normally accommodate flow rates of 1000 gallons per minute. Use of excessive flo w rates or overfilling the Dewatering Device with sediment will cause ruptures of the bag or failure of the hose attachment straps.
560 The Dewatering Device shall be disposed of as directed by the engineer.
642.5 -SEEDING AND MULCHING : 642.5.1 -General: Seeding paid for under this section will include seed mixtures as defined in subsection 642.5.3. The mixtures to be used will be determined by the Engineer. Seeding and mulching shall be performed on a continual basis starting when earth moving begins in the spring and stopping when the work stops in the winter or weather becomes too cold to operate seeding or mulching equipment. Embankments and cuts constructed during the winter season shall be treated as specified under subsection 642.5.4 , bullet iii. Seeding or mulching, or both, shall be performed on all cut and fill slopes, including waste sites and borrow pits, during the construction process. All disturbed areas such as diversion ditches, sediment basins, areas around sediment structures, haul road slopes, cleared and grubbed areas to remain exposed during a period of critical erosion, storage areas, location of batch plants, etc. shall be seeded when and where necessary to eliminate erosi on. Any areas failing to establish a satisfactory stand of grass due to weather conditions, adverse soil conditions, or due to erosion, shall be reseeded, refertilized and remulched as directed by the Engineer. Final seeding, or second and third step see ding following the original seeding shall be performed in accordance with Section 652.
642.5.2 -Schedule of Seeding Operations: Fill slopes, embankments, and waste sites shall be seeded and mulched in ten (10) foot lifts or once every two weeks, whichever occurs first. Cut slopes and borrow pits shall be seeded and mulched each fifteen ( 15) foot depth of excavation or once every two weeks, whichever occurs first. However, benched areas shall be seeded after completion of each bench, regardless of height.
642.5.3 -Seed Mixtures and Planting Seasons: Temporary seed mixtures shall be used on any embankment or area which will be s ubject to further construction work before the project is completed. Seed mixtures B or D shall be used on cut slopes and fill or other areas not likely to be destroyed by further construction activities. It is the intent of the specifications that fill slopes be constructed to template and seeded with Type B or D mixtures, in successive stages, without fill slopes being fine graded or dressed. The type of seed mixture to be used on any area will be determined by the Engineer in accordance with Tables 642.5.3.1 and 642.5.3.2.
561 TABLE 642.5.3.1 Temporary Seeding Mixtures Varity of Seed Spring Mar. 1 -May 15 Summer May 15 -Aug. 15 Fall & Winter Aug. 15 -Mar. 1 * lb per acre lb per acre lb per acre Annual ryegrass 10 10 Barley or Oats (local seeds) 50 Millet (Hungarian, German or Japanese) 50 Cereal rye or Cereal wheat 50 TOTAL 60 50 60
* See Paragraph 642.5.4. iii.
TABLE 642.5.3.2 Seed Mixtures B, D, & L Variety of Seed Seed Mixtures Type B * Type D ** Type L Median, Shoulders (Ditch Slope), Waterways, and Mowable Areas of Interchanges Cut and Fill Slopes (Including Benches) All Areas lb per acre lb per acre lb per acre Kentucky 31 F escue 65 20 Red Fescue
Crown Vetch 20 White Dutch Clover 3 Hard Fescue Mixture *** 63 Annual Ryegrass Aug 1 to May 15 7 7 12 or Weeping Lovegrass May 15 to Aug. 1 3 3 5
* Areas shall be considered mowable when slopes are 3 to 1 or flatter. ** 30 lb. of cereal rye or cereal wheat shall be added to Type D mixture when wood cellulose fiber is used as a mulch for fall seeding, after October 1, at no additional cost to the Division. *** A combination of approved certified varieties with no one variety exceeding 50% of the total hard fescue component .
562 642.5.4 -Mulch, Fertilizer and Lime: Mulching, fertilizing and liming shall be in accordance with the following requirements:
Other types of chemical mulch binders may be used; these mulch binders shall be applied according to the manufacturer's specifications. Wood cellulose fiber mulch shall be applied on slopes steeper than 1½ to 1 at the rate of 1,500 lb. per acre. Fertilizer shall be applied at the rate of 800 lb. per acre of 10 -20-10 fertilizer or equivalent. Lime application rate will be de termined by the Engineer based upon pH test conducted in accordance with MP 700.04.10. ii. Wood chips, recovered from clearing and grubbing operations, or bark will be acceptable as a mulch for seeding and shall be used at a rate of 35 cubic yard per acre in lieu of straw or hay. iii. Mulch Alone - For embankments or cuts 1½ to 1 or flatter, susceptible to critical erosion during periods of cold weather, the Engineer may require a two ton per acre application of straw or hay mulch for temporary erosion co ntrol and later seeding. The straw or hay may be rolled immediately with a sheep foot roller to anchor the mulch. A chemical mulch binder may be used for anchoring mulch in accordance with the provisions in paragraph i. above. When the weather becomes fa vorable in the spring, these areas shall be seeded using the normal application rates of seed, fertilizer and lime. If additional mulch is needed, wood cellulose fiber, hay or straw shall be used; the rate of application and areas to be mulched with wood cellulose fiber, hay or straw shall be as determined by the Engineer.
642.6 -TEMPORARY PIPE, CONTOUR DITCHES, BERMS, SLOPE DRAINS, ROCK CHECK DAM, SILT FENCE, AND SUPER SILT FENCE :
642.61-Temporary Pipe: Temporary pipe and contour ditching shall be provided as
necessary to control erosion.
642.6.2 -Contour Ditches and Berms: Prior to suspension of construction operations for any appreciable length of time due to seasonal or other conditions, the Contractor shall shape the top of earthwork in such a manner as to permit and facilitate the runoff of rain water and shall construct earth berms along the top edges of embankments to intercept runoff water. The berm construction shall not be permitted to decrease the stability of the embankment section. In addition, the Contractor shall construct a berm at the end of each day's operation at the top edges of the embankment.
642.6.3 -Slope Drains: Temporary slope drains shall be provided to accommodate the runoff water intercepted above. These drains shall be located as needed and at no greater than 500 f eet intervals.
642.6.4 -Rock Check Dam (Ditch Checks): A barrier constructed of clean, non -erodible rock or other manufactured devices (i.e. – triangular silt dikes, coir logs, etc.) across a cut or median ditch. Rock Check Dams shall be constructed to control velocities, reduce erosion, and aid in sediment control.
563 642.6.5 -Silt Fence: The minimum height above ground for the silt fence shall be two (2) feet. Minimum embedment depth shall be eight ( 8) inches. The maximum post spacing shall be based on elongation of the geotextile as measu red in accordance with Test Method D 4632. Silt fence geotextile with elongation 50 % shall have a maximum post spacing of four (4) feet. Silt fence geotextile with elongation < 50 % shall have a maximum post spacing of 6.5 feet. When silt fence is installed in valleys where water can pond behind the fence then the post spacing shall be half of the maximum post spacing for the geotextile used. When silt fence is installed by the trenching method the geotextile at the bottom of the fence shall be buried in a "J" configuration to a minimum depth of eight ( 8) inches in a trench so that no flow can pass under the silt fence. Backfill the trench and compact the soil over the geotextile. When silt fence is installed by the soil slicing method the geotextiles hall be installed in a slit in the soil eight ( 8) to twelve ( 12) inches deep so that no flow can pass under the silt fence. Create the slit such that a horizontal chisel point (approx. 3 inches wide) at the base of a soil slicing blade (approx. ¾ inches wide) that slightly disrupts soil upward as the blade slices throu gh the soil. This upward disruption minimizes horizontal compaction and creates an optimal soil condition for mechanical compaction against the geotextile. Overturning of the soil shall not be permitted. The geotextile shall be mechanically inserted directly behind the soil slicing blade in a simultaneous operation, achieving consistent placement and depth. The silt fence geotextile shall be spliced together with a sewn seam only at a support post, or two sections of fence may be overlapped. Silt fence posts shall be driven to a minimum of twenty ( 20) inches into the ground. This depth shall be increased to two ( 2) feet if the fence is placed on a slope of 3:1 or greater. Where the minimum depth is impossible to attain, the posts shall be adequately secu red to prevent overturning of the fence due to loading. The geotextile shall be properly fastened to the upslope side of the fence posts. Silt fences shall be continuous and transverse to the flow. The silt fence shall follow the contours of the site as closely as possible. Place the fence such that the water cannot runoff around the end of the fence. The silt fence trench shall be compacted on the upstream side first, and then the downstream side. The silt fence trench shall be compacted to a minimu m of 90% of the original ground density and the posts must be installed after compaction of the trench. The trench compaction will be based on visual inspection and the engineer may require compaction testing to verify the visual inspection. The contract or shall inspect all silt fences immediately after each rainfall and at least daily during prolonged rainfall. The contractor shall immediately correct any deficiencies. The contractor shall also make a daily review of the location of silt fences in areas where construction activities have altered the natural contour and drainage runoff to ensure that the silt fences are properly located for effectiveness. Where deficiencies exist as determined by the engineer, additional silt fence shall be installed as di rected by the engineer. When the sediment deposits reaches half the height of the fence the sediment shall be removed or a second silt fence shall be installed as directed by the engineer. The cost of this work shall be paid as “Sediment Removal” or “Silt Fence”. The silt fence shall remain in place until the engineer directs it be removed. Upon removal the contractor shall remove and dispose of any excess sediment accumulations, dress the area to give it a pleasing appearance, and vegetate all bare areas. Removed silt fence may be used at other locations provided the geotextile and other material requirements con tinue to be met to the satisfaction of the engineer.
564 642.6.6 -Super Silt Fence: Fence shall be in accordance with the latest specifications for standards detail book: Standard Detail F4 (Sheet 1 of 2) except as noted below: Once sedimentation has reached half of the Super Silt Fence height, all accum ulated sediment shall be removed and disposed of as directed by the Engineer. The Contractor shall inspect all super silt fences after each rainfall event of at least 0.5 inches or greater. Any deficiencies or damage shall be repaired by the Contractor. If the Super Silt Fence is damaged or inadvertently moved during the sedimentation removal process, the contractor shall immediately replace and/or repair any Super Silt Fence after the damage occurs. The Contractor shall be responsible for all details, d evices, accessories and special construction necessary to properly furnish, install, adjust and place in continuous satisfactory service and complete the work in an acceptable manner.
642.7 -METHOD OF MEASUREMENT : The work will be measured for payment at the unit bid prices for the items specified in 642.9. Berms constructed prior to suspension of construction operations and slope drains will be measured in linear feet; sediment traps, sediment basins, and sediment removal will be measured by the cubic yard; for sediment basins, risers will be measured by the unit and conduit for principal spillway under the dam will be measured in linear feet and included under Item 642008 -*; seed will be measured by the pound; straw, hay and wood cellulose fiber mulch will be measured by the ton; fertilizer and agricultural limestone will be measured by the ton; matting will be measured by the square yard; contour ditching will be measured by the linear foot. Measurements will be made on the surface of the work done when applicable. Anchoring for mulch or other chemical binde rs will not be measured separately, but their cost shall be included in the unit price bid for mulch. Temporary pipe will be measured by the linear foot complete and in place. If the Contractor elects to utilize a series of small pipes in lieu of one lar ge pipe, measurement for payment will be made only for a length necessary to extend one conduit under the haul road or sediment basin. Berms constructed at the end of each day's operation will not be measured for payment but their cost shall be included in the unit bid price for Item 207001 -*, "Unclassified Excavation." Rock check dams will be measured by the unit. Inlet Protection and Dewatering Device will be paid per each device used. Wood chips or bark will be measured by the cubic yard. It is assumed that 17.5 cubic yards of chips or bark are equal to one ton of straw for seeding. Wood chips or bark mulch will be measured by the truck load or other loose volume measurement, and payment will be made on a one ton equivalent of straw for ea ch 17.5 cubic yards of wood chips or bark mulch. Quantities reseeded, refertilized, or remulched will be measured and included for payment. The bid price for fertilizer shall be based on 10 -20-10 ratio. When other ratios of fertilizer are used, pay quan tities will be determined using the following table: