ATT_005_Plan_Set_A_Manston_Slough_Construction_Specs_rev_1.pdf

NATURAL RESOURCES

CONSERVATION SERVICE

MINNESOTA

CONSTRUCTION AND MATERIALS

SPECIFICATIONS

FOR

Manston Slough

WRP

WILKIN COUNTY

SOIL AND WATER

CONSERVATION DISTRICT

NRCS-Minnesota 7/21/2016 Index

Manson Slough

WRP

CONSTRUCTION SPECIFICATIONS

MN-2 Clearing and Grubbing ......................................................................................... 5/05 MN-5 Pollution Control .................................................................................................. 5/05 MN-6 Seeding, Sprigging, and Mulching ....................................................................... 5/05 MN-8 Mobilization and Demobilization ........................................................................ 5/01 MN-21 Excavation ............................................................................................................ 5/05 MN-23 Earthfill ................................................................................................................ 5/05 MN-26 Topsoiling ............................................................................................................ 5/05

NRCS-Minnesota (210-VI-NEH, May 2005) MN2-1

Minnesota Construction Specification 2—Clearing and Grubbing

1. Scope The work consists of clearing and grubbing and disposal of trees, snags, logs, brush, stumps, shrubs, and rubbish from the designated areas.

2. Protection of existing vegetation Trees and other vegetation designated to remain undisturbed shall be protected from damage throughout the duration of the construction period. Any damages resulting from the contractor's operations or neglect shall be repaired by the contractor.

Earthfill, stockpiling of materials, vehicular parking, and excessive foot or vehicular traffic shall not be allowed within the drip line of vegetation designated to remain in place. Vegetation damaged by any of these or similar actions shall be replaced with viable vegetation of the same species, similar condition, and like size unless otherwise approved by the engineer.

Any cuts, skins, scrapes, or bruises to the bark of the vegetation shall be carefully trimmed and local nursery accepted procedures used to seal damaged bark.

Any limbs or branches 0.5 inch or larger in diameter that are broken, severed, or otherwise seriously damaged during construction shall be cut off at the base of the damaged limb or branch flush with the adjacent limb or tree trunk. All roots 1-inch or larger in diameter that are cut, broken, or otherwise severed during construction operations shall have the end smoothly cut perpendicular to the root.

Roots exposed during excavation or other operations shall be covered with moist earth or backfilled as soon as possible to prevent the roots from drying out.

3. Marking The limits of the area(s) to be cleared and grubbed will be marked by stakes, flags, tree markings, or other suitable methods. Trees to be left standing and uninjured will be designated by special markings placed on the trunk about 6 feet above the ground surface.

4. Clearing and grubbing All trees must be cut, sheared, or mowed such that the stumps are flush with the surround ground. A brush pulverizer or machine which yield similar results shall be used to clear and grub.

5. Disposal All materials cleared and grubbed from the designated areas shall be disposed of in a manner specified in section 7. The contractor is responsible for complying with all local rules and regulations and the payment of any and all fees that may result from disposal at locations away from the project site.

6. Measurement and Payment Payment for clearing and grubbing is made at the contract lump sum price. Such payment shall constitute full compensation for all labor, equipment, tools, and all other items necessary and incidental to the completion of the work.

NRCS-Minnesota (210-VI-NEH, May 2005) MN2-2

7. Work and Construction Details Work to be performed in conformance with this specification and the construction details are:

a. BID ITEM 3, CLEARING AND GRUBBING

1) Payment shall be by Method 1, lump sum payment.

2) All areas within the construction limits will be cleared and grubbed.

3) All stumps, roots, and root clusters shall be grubbed such that the stumps are flush with the surround ground.

4) All cleared and grubbed material shall be pulverized into pieces no larger than 6” in diameter.

NRCS-Minnesota (210-VI-NEH, May 2005) MN5-1

Minnesota Construction Specification 5—Pollution Control

The work consists of installing measures or performing work to control erosion and minimize the production of sediment and other pollutants to water and air from construction activities.

2. Material specification All material furnished shall meet the requirements of the material specifications listed in section 7 of this specification.

3. Erosion and sediment control measures and works The measures and works shall include, but are not limited to, the following:

Staging of earthwork activities—The excavation and moving of soil materials shall be scheduled to minimize the size of areas disturbed and unprotected from erosion for the shortest reasonable time.

Seeding—Seeding to protect disturbed areas shall occur as soon as reasonably possible following completion of that earthwork activity.

Mulching—Mulching to provide temporary protection of the soil surface from erosion.

Diversions—Diversions to divert water from work areas and to collect water from work areas for treatment and safe disposition. They are temporary and shall be removed and the area restored to its near original condition when the diversions are no longer required or when permanent measures are installed.

Stream crossings—Culverts or bridges where equipment must cross streams. They are temporary and shall be removed and the area restored to its near original condition when the crossings are no longer required or when permanent measures are installed.

Sediment basins—Sediment basins collect, settle, and eliminate sediment from eroding areas from impacting properties and streams below the construction site(s). These basins are temporary and shall be removed and the area restored to its original condition when they are no longer required or when permanent measures are installed.

Sediment filters—Straw bale filters or geotextile sediment fences trap sediment from areas of limited runoff. Sediment filters shall be properly anchored to prevent erosion under or around them. These filters are temporary and shall be removed and the area restored to its original condition when they are no longer required or when permanent measures are installed.

Waterways—Waterways for the safe disposal of runoff from fields, diversions, and other structures or measures. These works are temporary and shall be removed and the area restored to its original condition when they are no longer required or when permanent measures are installed.

Other—Additional protection measures as specified in section 7 of this specification or required by Federal, State, or local government.

NRCS-Minnesota (210-VI-NEH, May 2005) MN5-2

4. Chemical pollution The contractor shall provide watertight tanks or barrels or construct a sump sealed with plastic sheets to dispose of chemical pollutants, such as drained lubricating or transmission fluids, grease, soaps, concrete mixer washwater, or asphalt, produced as a by-product of the construction activities. At the completion of the construction work, sumps shall be removed and the area restored to its original condition as specified in section 7 of this specification. Sump removal shall be conducted without causing pollution.

Sanitary facilities, such as chemical toilets, or septic tanks shall not be located next to live streams, wells, or springs. They shall be located at a distance sufficient to prevent contamination of any water source. At the completion of construction activities, facilities shall be disposed of without causing pollution as specified in section 7 of this specification.

5. Air pollution The burning of brush or slash and the disposal of other materials shall adhere to state and local regulations.

Fire prevention measures shall be taken to prevent the start or spreading of wildfires that may result from project activities. Firebreaks or guards shall be constructed and maintained at locations shown on the drawings.

All public access or haul roads used by the contractor during construction of the project shall be sprinkled or otherwise treated to fully suppress dust. All dust control methods shall ensure safe construction operations at all times. If chemical dust suppressants are applied, the material shall be a commercially available product specifically designed for dust suppression and the application shall follow manufacturer's requirements and recommendations. A copy of the product data sheet and manufacturer's recommended application procedures shall be provided to the engineer 5 working days before the first application.

6. Maintenance, removal, and restoration All pollution control measures and temporary works shall be adequately maintained in a functional condition for the duration of the construction period. All temporary measures shall be removed and the site restored to near original condition.

7. NPDES Stormwater Pollution Prevention Plan (SWPPP) Additional Erosion and Sediment Control measures are outlined in the project NPDES SWPPP and on the Erosion and Sediment Control (ESC) plan sheet. Requirements noted in the MPCA Permit (MN R100001) are also a requirement of this project.

8. Measurment and Payment This item is considered incidental to the price of the project. No pay item is associated with this item.

NRCS-Minnesota (210-VI-NEH, May 2005) MN5-3

9. Construction Details:

POLLUTION CONTROL BEST MANAGEMENT PRACTICES, PERMIT FEES, AND

INSPECTIONS

1) The item shall consist of:

a) Contractor designated inspector to carry out required NPDES Permit inspections and record keeping.

b) Installing and maintaining erosion and sediment control (ESC) BMPs during project construction according to the SWPPP, ESC plan sheet, and permit requirements.

c) Managing emergency BMP installation, grading, and site maintenance as may be required due to rainfall runoff events or inspections.

d) Submitting and paying for application for MPCA “General Storm Water Permit for Construction Activity, MN R100001” (the Permit).

2) Contractor is responsible to designate an NPDES Construction Permit inspector and record keeper. This person shall be familiar with and follow the NPDES Permit requirements for inspections and record keeping.

3) A silt fence or floating silt fence shall be installed wherever storm water runoff downstream of construction activity will readily flow into moving water and as shown on the ESC plan sheet.

The silt fences shall be installed prior to the start of construction.

4) The implementation of ESC methods as presented in the SWPPP or as arise over the duration of construction shall be implemented by the contractor.

5) Contractor is responsible to have BMP corrective materials available within 24 hours of observation or notification of ESC issues that may develop during construction.

6) Contractor is responsible to correct and repair ESC breaches or runoff that occur during construction and until temporary seeding is established at 4 inches of growth.

NRCS-Minnesota (210-VI-NEH, May 2005) MN6-1

Minnesota Construction Specification 6—Seeding, Sprigging, and Mulching

1. Scope The work consists of preparing the area for treatment; furnishing and placing seed, sprigs, mulch, fertilizer, inoculants, lime, and other soil amendments; and anchoring mulch in designated areas as specified.

2. Material Seed—All seed shall conform to the current rules and regulations of the state where it is being used and shall be from the latest crop available. It shall meet or exceed the standard for purity and germination listed in section 6.

Seed shall be labeled in accordance with the state laws and the U.S. Department of Agriculture rules and regulations under the Federal Seed Act in effect on the date of invitations for bids. Bag tag figures are evidence of purity and germination. No seed will be accepted with a test date of more than 9 months before the delivery date to the site.

Seed that has become wet, moldy, or otherwise damaged in transit or storage will not be accepted. The percent of noxious weed seed allowable shall be as defined in the current State laws relating to agricultural seeds. Each type of seed shall be delivered in separate sealed containers and fully tagged unless exception is granted in writing by the engineer.

Fertilizer—Unless otherwise specified, the fertilizer shall be a commercial grade fertilizer. It shall meet the standard for grade and quality specified by State law. Where fertilizer is furnished from bulk storage, the contractor shall furnish a supplier's certification of analysis and weight.

When required by the contract, a representative sample of the fertilizer shall be furnished to the engineer for chemical analysis.

Inoculants—The inoculant for treating legume seeds shall be a pure culture of nitrogen-fixing bacteria prepared specifically for the species and shall not be used later than the date indicated on the container or as otherwise specified. A mixing medium, as recommended by the manufacturer, shall be used to bond the inoculant to the seed. Two times the amount of the inoculant recommended by the manufacturer shall be used except four times the amount shall be used when seed is applied using a hydraulic seeder. Seed shall be sown within 24 hours of treatment and shall not remain in the hydraulic seeder longer than 4 hours.

Lime and other soil amendments—Lime shall consist of standard ground agriculture limestone, or approved equivalent. Standard ground agriculture limestone is defined as ground limestone meeting current requirements of the State Department of Agriculture. Other soil amendments shall meet quality criteria and application requirements specified in section 6.

Mulch tackifiers—Asphalt emulsion tackifiers shall conform to the requirements of ASTM D 977, Specification for Emulsified Asphalt. The emulsified asphalt may be rapid setting, medium setting, or slow setting. Nonasphaltic tackifiers required because of environmental considerations shall be as specified in section 6.

Straw mulch material—Straw mulch shall consist of wheat, barley, oat or rye straw, hay, grass cut from native grasses, or other plants as specified in section 6. The mulch material shall be air-

NRCS-Minnesota (210-VI-NEH, May 2005) MN6-2 dry, reasonably light in color, and shall not be musty, moldy, caked, or otherwise of low quality.

The use of mulch that contains noxious weeds is not permitted. The contractor shall provide a method satisfactory to the engineer for determining weight of mulch furnished.

Other mulch materials—Mulching materials, such as wood cellulose fiber mulch, mulch tackifiers, synthetic fiber mulch, netting, and mesh, are other mulching materials that may be required for specialized locations and conditions. These materials, when specified, must be accompanied by the manufacturer's recommendations for methods of application.

3. Seeding mixtures, sod, sprigs, and dates of planting The application rate per acre for seed mixtures, sprigs, or sod and date of seeding or planting shall be as shown on the plans or as specified in section 6.

4. Seedbed preparation and treatment Areas to be treated shall be dressed to a smooth, firm surface. On sites where equipment can operate on slopes safely, the seedbed shall be adequately loosened (4 to 6 inches deep) and smoothed. Depending on soil and moisture conditions, disking or cultipacking, or both, may be necessary to properly prepare a seedbed. Where equipment cannot operate safely, the seedbed shall be prepared by hand methods by scarifying to provide a roughened soil surface so that broadcast seed will remain in place.

If seeding is to be accomplished immediately following construction operations, seedbed preparation may not be required except on a compacted, polished, or freshly cut soil surface.

Rocks larger than 6 inches in diameter, trash, weeds, and other debris that will interfere with seeding or maintenance operations shall be removed or disposed of as specified in section 6.

Seedbed preparation shall be discontinued when soil moisture conditions are not suitable for the preparation of a satisfactory seedbed as determined by the engineer.

5. Seeding, sprigging, fertilizing, mulching, and stabilizing All seeding or sprigging operations shall be performed in such a manner that the seed or sprigs are applied in the specified quantities uniformly in the designated areas. The method and rate of seed application shall be as specified in section 6. Unless otherwise specified, seeding or sprigging shall be accomplished within 2 days after final grading is completed and approved.

The rate, amount, and kind of mulching or mesh shall be as specified in section 6. Mulches shall be applied uniformly to the designated areas. They shall be applied to areas seeded not later than 2 working days after seeding has been performed. Straw mulch material shall be stabilized within 24 hours of application using a mulch crimper or equivalent anchoring tool or by a suitable tackifier. When the mulch crimper or equivalent anchoring tool is used, it shall have straight blades and be the type manufactured expressly for and capable of firmly punching the mulch into the soil. Where the equipment can be safely operated, it shall be operated on the contour. Hand methods shall be used where equipment cannot safely operate to perform the work required.

The tackifier shall be applied uniformly over the mulch material at the specified rate, or it shall be injected into the mulch material as it is being applied. Mesh or netting stabilizing materials shall be applied smoothly, but loosely on the designated areas. The edges of these materials shall be buried or securely anchored using spikes or staples as specified in section 6.

NRCS-Minnesota (210-VI-NEH, May 2005) MN6-3

The contractor shall maintain the mesh or netting areas until all work under the contract has been completed and accepted. Maintenance shall consist of the repair of areas damaged by water erosion, wind, fire, or other causes. Such areas shall be repaired to reestablish the intended condition and to the design lines and grades required by the contract. The areas shall be refertilized, reseeded, and remulched before the new application of the mesh or netting.

6. Construction details Seed and mulch the ditch plugs, disposal areas and ditch fill areas, as identified by NRCS technical representative.

The mesic seeding mixture shall consist of the following species, varieties and rates of Pure Live Seed per acre:

Nurse Crop—Seed Oats at a rate of 1 bushel per acre.

Oz Per Total OZ Total LBS

Scientific Name Common Name Acre Required Required Aster ericoides Heath aster 0.3 17 1.1 Amorpha canescens Leadplant 0.5 28 1.8 Liatris aspera Rough blazing star 1.3 73 4.6 Aster laevis Smooth aster 0.3 17 1.1 Desmodiam canadense Canada tick trefoil 1.0 56 3.5 Heliopsis helianthoides Common Ox-ey 3.0 168 10.5 Phlox pilosa Prairie phlox 1.0 56 3.5 Monarda fistulosa Wild bergamot 1.5 84 5.3 Verbena hastata Blue Vervain 0.6 34 2.1 Rudbeckia hirta Black-eyed Susan 1.5 84 5.3 Asclepias syriaca Common Milkweed 2.0 112 7.0 Petalostemum purpurum Purple prairie clover 1.5 84 5.3 Heliopsis maximiliani Maximillian sunflower 2.0 112 7.0 Solidago rigida Stiff goldenrod 1.2 67 4.2 Petalostemum candidum White prairie clover 2.0 112 7.0 Achellea millefolium Yarrow 0.5 28 1.8 Andropogon gerardii Big Bluestem 17.6 986 61.6 Bouteloua curtipendula Side-oats grama 19.2 1,075 67.2 Bromus kalmii Kalms brome 8.0 448 28.0 Elymus canadensis Canada Wild Rye 17.6 986 61.6 Panicum virgatum Switchgrass 3.2 179 11.2 Elymus trachycaulus Slender wheatgrass 11.2 627 39.2 Bouteloua gracilla Blue grama 4.8 269 16.8 Schizachyrium scoparium Little Bluestem 16.0 896 56.0 Sorghastrum nutans Indianagrass 17.6 986 61.6 Spartina pectinata Prairie cordgrass 8.0 448 28.0

NRCS-Minnesota (210-VI-NEH, May 2005) MN6-4

Seed scrape side slopes, and bottom areas with the following wet area seed mix.

Oz Per Total OZ Total LBS

Scientific Name Common Name Acre Required Required Asclepia incarnata Swamp milkweed 1.0 36 2.3 Desmodium canadense Canada tick trefoil 2.0 72 4.5 Eupatorium maculatum Joe-pye weed 1.0 36 2.3 Eupatorium perfoliatum Boneset 0.5 18 1.1 Helenium autumnale Sneezeweed 1.0 36 2.3 Lobelia siphilitica Great blue lobelia 0.5 18 1.1 Pedicularis lanceolata Swamp lousewort 2.0 72 4.5 Penthorum sedoides Ditch stonecrop 0.2 7 0.5 Rudbeckia hirta Black-eyed Susan 1.0 36 2.3 Solidago riddellii Riddell's goldenrod 0.5 18 1.1 Verbena hastata Blue vervain 1.0 36 2.3 Vernonia fasciculata Ironweed 1.0 36 2.3 Zizea aurea Golden alexanders 2.0 72 4.5 Panicum miaceum Proso Millet 60.0 2,160 135.0 Beckmannia syzigachne American slough grass 9.0 324 20.3 Spartina pectinata prairie cord grass 5.0 180 11.3 Scolachlog festucacea White top Grass 4.0 144 9.0 Glyceria grandis American manna grass 8.0 288 18.0 Scirpus validus Softstem bulrush 4.0 144 9.0 Sparganium eurycapum Giant bur reed 4.0 144 9.0 Scarex stipata Field oval sedge 2.0 72 4.5 Scirpus fluviatillis River bulrush 3.0 108 6.8 Scirpus cyperinus Woolgrass 0.1 4 0.2

NRCS-Minnesota (210-VI-NEH, May 2005) MN6-5

Seeding Dates Dormant After Nov 1st

If construction is complete outside of the permenant seeding window. A temporary seeding of

Scientific Name Common Name Oz/Ac Total oz Required

Total lbs Required

Lolium multiflorum Annual Rye 64 5856 366 Elymus virginicus Virginia Wild Rye 64 5856 366 shall be seeded upon construction completion of each site with the permanent seeding to be completed at the next available permanent seeding window. Dormant seeding can occur with up to 3” of snow cover.

Seeding Method—Apply seed uniformly at the specified rate by broadcasting or drilling. Harrow lightly following the seeding operation to cover the seed unless the cultipacker seeder equipment cannot operate. Cover the seed by hand using a rake or similar tool.

Fertilizer—Fertilizer is not needed.

Mulching—Straw mulch shall be applied uniformly at a rate of 3,000 lbs. minimum, to 4,000 lbs.

maximum per acre. Straw mulch material shall be stabilized by the use of a disk type anchoring tool.

through up to 3" snow depth May 15th-June 30th.

NRCS (2010-VI-NEH, May 2001 MN8-1

Construction Specification 8—Mobilization and Demobilization

1. SCOPE

The work consists of the mobilization and demobilization of the contractor's forces and equipment necessary for performing the work required under the contract. It does not include mobilization and demobilization for specific items of work for which payment is provided elsewhere in the contract.

Mobilization will not be considered as work in fulfilling the contract requirements for commencement of work.

2. EQUIPMENT AND MATERIAL

Mobilization shall include all activities and associated costs for transportation of contractor's personnel, equipment, and operating supplies to the site; establishment of offices, buildings, and other necessary general facilities for the contractor's operations at the site; premiums paid for performance and payment bonds including coinsurance and reinsurance agreements as applicable; and other items specified in section 4 of this specification.

Demobilization shall include all activities and costs for transportation of personnel, equipment, and supplies not required or included in the contract from the site; including the disassembly, removal, and site cleanup of offices, buildings, and other facilities assembled on the site specifically for this contract.

This work includes mobilization and demobilization required by the contract at the time of award. If additional mobilization and demobilization activities and costs are required during the performance of the contract as a result of changed, deleted, or added items of work for which the contractor is entitled to an adjustment in contract price, compensation for such costs will be included in the price adjustment for the item or items of work changed or added.

3. MEASUREMENT AND PAYMENT

Payment will be made as the work proceeds, after presentation of paid invoices or documentation of direct costs by the contractor showing specific mobilization and demobilization costs and supporting evidence of the charges of suppliers, subcontractors, and others. When the total of such payments is less than the lump sum contract price, the balance remaining will be included in the final contract payment.

Payment of the lump sum contract price for mobilization and demobilization will constitute full compensation for completion of the work.

Payment will not be made under this item for the purchase costs of materials having a residual value, the purchase costs of materials to be incorporated in the project, or the purchase costs of operating supplies.

4. ITEMS OF WORK AND CONSTRUCTION DETAILS

Items of work to be performed in conformance with this specification and the construction details are:

a. BID ITEM 1, MOBILIZATION AND DEMOBILIZATION

1) The item shall consist of mobilization and demobilization of the contractor’s forces and equipment necessary for performing the work required under the contract as specified above.

2) Payment shall be by Method 1, lump sum.

NRCS-Minnesota (210-VI-NEH, May 2005) MN21-1

Minnesota Construction Specification 21—Excavation

1. Scope The work shall consist of the excavation required by the drawings and specifications and disposal of the excavated materials.

2. Classification Excavation will be classified as common excavation or rock excavation in accordance with the following definitions or will be designated as unclassified.

Common excavation shall be defined as the excavation of all materials that can be excavated, transported, and unloaded by the use of heavy ripping equipment and wheel tractor-scrapers with pusher tractors or that can be excavated and dumped into place or loaded onto hauling equipment by means of excavators having a rated capacity of one cubic yard and equipped with attachments (such as shovel, bucket, backhoe, dragline or clam shell) appropriate to the character of the materials and the site conditions.

Rock excavation shall be defined as the excavation of all hard, compacted or cemented materials the accomplishment of which requires blasting or the use of excavators larger than defined for common excavation. The excavation and removal of isolated boulders or rock fragments larger than one cubic yard in volume encountered in materials otherwise conforming to the definition of common excavation shall be classified as rock excavation.

Excavation will be classified according to the above definitions by the Engineer, based on his judgment of the character of the materials and the site conditions.

The presence of isolated boulders or rock fragments larger than one cubic yard in size will not in itself be sufficient cause to change the classification of the surrounding material.

For the purpose of this classification, the following definitions shall apply:

Heavy ripping equipment shall be defined as a rear-mounted, heavy duty, single-tooth, ripping attachment mounted on a tractor having a power rating of 200-300 net horsepower (at the flywheel).

Wheel tractor-scraper shall be defined as a self-loading (not elevating) and unloading scraper having a struck bowl capacity of l2-20 yards.

Pusher tractor shall be defined as a track type tractor having a power rating of 200-300 net horsepower (at the flywheel) equipped with appropriate attachments.

Unclassified Excavation. Items designated as "Unclassified Excavation" shall include all materials encountered regardless of their nature or the manner in which they are removed. When excavation is unclassified, none of the definitions or classifications stated in Section 2 of this specification shall apply.

3. Blasting The transportation, handling, storage, and use of dynamite and other explosives shall be directed and supervised by a person of proven experience and ability in blasting operations.

NRCS-Minnesota (210-VI-NEH, May 2005) MN21-2

Blasting shall be done in such a way as to prevent damage to the work or unnecessary fracturing of the foundation and shall conform to any special requirements in Section 10 of this specification.

4. Use of excavated materials To the extent they are needed, all suitable materials from the specified excavations shall be used in the construction of required permanent earthfill or rockfill. The suitability of materials for specific purposes will be determined by the Engineer. The Contractor shall not waste or otherwise dispose of suitable excavated materials.

5. Disposal of waste materials All surplus or unsuitable excavated materials will be designated as waste and shall be disposed of at the locations shown on the drawings or shall be disposed of by the Contractor at sites of his own choosing away from the site of the work.

6. Bracing and shoring Excavated surfaces too steep to be safe and stable if unsupported shall be supported as necessary to safeguard the work and workmen, to prevent sliding or settling of the adjacent ground, and to avoid damaging existing improvements. The width of the excavation shall be increased if necessary to provide space for sheeting, bracing, shoring, and other supporting installations. The Contractor shall furnish, place and subsequently remove such supporting installations.

7. Structure and trench excavation Structure or trench excavation shall be completed to the specified elevations and to sufficient length and width to include allowance for forms, bracing and supports, as necessary, before any concrete or earthfill is placed or any piles are driven within the limits of the excavation.

8. Borrow Excavation When the quantities of suitable materials obtained from specified excavations are insufficient to construct the specified fills, additional materials shall be obtained from the designated borrow areas.

The extent and depth of borrow pits within the limits of the designated borrow areas shall be as directed by the Engineer.

Borrow pits shall be excavated and finally dressed in a manner to eliminate steep or unstable side slopes or other hazardous or unsightly conditions.

9. Overexcavation Excavation in rock beyond the specified lines and grades shall be corrected by filling the resulting voids with portland cement concrete made of materials and mix proportions approved by the Engineer. Concrete that will be exposed to the atmosphere when construction is completed shall contain not less than 6 sacks of cement per cubic yard of concrete. Concrete that will be permanently covered shall contain not less than 4-1/2 sacks of cement per cubic yard. The concrete shall be placed and cured as specified by the Engineer.

Excavation in earth beyond the specified lines and grades shall be corrected by filling the resulting voids with approved compacted earthfill, except that, if the earth is to become the subgrade for riprap, rockfill, sand or gravel bedding, or drainfill, the voids may be filled with material conforming to the specifications for the riprap, rockfill, bedding or drainfill.

NRCS-Minnesota (210-VI-NEH, May 2005) MN21-3

The cost of unauthorized excavation and the backfill required to replace unauthorized excavation shall be borne by the Contractor.

10. Construction details

Excavation is classified as common excavation.

Excavation shall consist of all common excavation labeled (CE) on the drawings. This shall include all necessary excavation required, but not limited to, foundation excavation, borrow excavation & scrape excavation.

Suitable materials from the excavations may be placed directly as Class C earthfill in accordance with Construction Specification 23, Earthfill, as approved by the inspector.

Unsuitable materials from the excavations shall be designated as waste and shall be disposed of in areas approved by the NRCS technical representative.

Buried material shall have a minimum of 2 feet of cover and shall be left in a condition to provide a free draining surface.

Borrow material required shall be obtained from areas approved by the NRCS technical representative.

The borrow areas shall be a maximum depth of 3.5’. Finished slopes shall match 10 feet horizontal to 1 foot vertical as in drawing.

Scrape disposal shall be as shown on plan or as directed by NRCS representative.

Rock found under the embankment foundation will be remove and buried outside of the pool boundary or as directed by the NRCS technical representative.

Excavations shall meet the current OSHA publication 1926, SubPart P, EXCAVATIONS.

Ingress and egress to the site shall be as directed by the NRCS technical representative.

No blasting shall be allowed.

NRCS-Minnesota (210-VI-NEH, May 2005) MN23-1

Minnesota Construction Specification 23—Earthfill

The work consists of the construction of earth embankments, other earthfills, and earth backfills required by the drawings and specifications.

Earthfill is composed of natural earth materials that can be placed and compacted by construction equipment operated in a conventional manner.

Earth backfill is composed of natural earth material placed and compacted in confined spaces or adjacent to structures (including pipes) by hand tamping, manually directed power tampers or vibrating plates, or their equivalent.

2. Material specifications All fill material shall be obtained from required excavations and designated borrow areas. The selection, blending, routing, and disposition of material in the various fills shall be subject to approval by the engineer.

Fill materials shall contain no frozen soil, sod, brush, roots, or other perishable material. Rock particles larger than the maximum size specified for each type of fill shall be removed prior to compaction of the fill.

The types of material used in the various fills shall be as listed and described in the specifications and drawings.

3. Foundation preparation Foundations for earthfill shall be stripped to remove vegetation and other unsuitable material or shall be excavated as specified.

Except as otherwise specified, earth foundation surfaces shall be graded to remove surface irregularities and shall be scarified parallel to the axis of the fill or otherwise acceptably scored and loosened to a minimum depth of 2 inches. The moisture content of the loosened material shall be controlled as specified for the earthfill, and the surface material of the foundation shall be compacted and bonded with the first layer of earthfill as specified for subsequent layers of earthfill.

Earth abutment surfaces shall be free of loose, uncompacted earth in excess of 2 inches in depth normal to the slope and shall be at such a moisture content that the earthfill can be compacted against them to produce a good bond between the fill and the abutments.

Rock foundation and abutment surfaces shall be cleared of all loose material by hand or other effective means and shall be free of standing water when fill is placed upon them. Occasional rock outcrops in earth foundations for earthfill, except in dams and other structures designed to restrain the movement of water, shall not require special treatment if they do not interfere with compaction of the foundation and initial layers of the fill or the bond between the foundation and the fill.

Foundation and abutment surfaces shall be no steeper than one horizontal to one vertical unless otherwise specified. Test pits or other cavities shall be filled with compacted earthfill conforming to the specifications for the earthfill to be placed upon the foundation.

NRCS-Minnesota (210-VI-NEH, May 2005) MN23-2

4. Placement Earthfill shall not be placed until the required excavation and foundation preparation have been completed and the foundation has been inspected and approved by the engineer. Earthfill shall not be placed upon a frozen surface nor shall snow, ice, or frozen material be incorporated in the earthfill matrix.

Earthfill shall be placed in approximately horizontal layers. The thickness of each layer before compaction shall not exceed the maximum thickness specified in section 9 or shown on the drawings.

Materials placed by dumping in piles or windrows shall be spread uniformly to not more than the specified thickness before being compacted.

Hand compacted earth backfill shall be placed in layers whose thickness before compaction does not exceed the maximum thickness specified for layers of earth backfill compacted by manually directed power tampers.

Earth backfill shall be placed in a manner that prevents damage to the structures and allows the structures to assume the loads from the earth backfill gradually and uniformly. The height of the earth backfill adjacent to a structure shall be increased at approximately the same rate on all sides of the structure.

Earthfill and earth backfill in dams, levees, and other structures designed to restrain the movement of water shall be placed to meet the following additional requirements:

(a) The distribution of materials throughout each zone shall be essentially uniform, and the earthfill shall be free from lenses, pockets, streaks, or layers of material differing substantially in texture, moisture content, or gradation from the surrounding material. Zone earthfills shall be constructed concurrently unless otherwise specified.

(b) If the surface of any layer becomes too hard and smooth for proper bond with the succeeding layer, it shall be scarified parallel to the axis of the fill to a depth of not less than 2 inches before the next layer is placed.

(c) The top surface of embankments shall be maintained approximately level during construction with two exceptions: A crown or cross-slope of about 2 percent shall be maintained to ensure effective drainage, or as otherwise specified for drainfill or sectional zones.

(d) Dam embankments shall be constructed in continuous layers from abutment to abutment except where openings to facilitate construction or to allow the passage of streamflow during construction are specifically authorized in the contract.

(e) Embankments built at different levels as described under (c) or (d) above shall be constructed so that the slope of the bonding surfaces between embankment in place and embankment to be placed is not steeper than 3 feet horizontal to 1 foot vertical. The bonding surface of the embankment in place shall be stripped of all material not meeting the requirements of this specification and shall be scarified, moistened, and recompacted when the new earthfill is placed against it. This ensures a good bond with the new earthfill and obtains the specified moisture content and density at the contact of the inplace and new earthfills.

5. Control of moisture content During placement and compaction of earthfill and earth backfill, the moisture content of the material being placed shall be maintained within the specified range.

The application of water to the earthfill material shall be accomplished at the borrow areas insofar as

NRCS-Minnesota (210-VI-NEH, May 2005) MN23-3 practicable. Water may be applied by sprinkling the material after placement on the earthfill, if necessary. Uniform moisture distribution shall be obtained by disking.

Material that is too wet when deposited on the earthfill shall either be removed or be dried to the specified moisture content prior to compaction.

If the top surface of the preceding layer of compacted earthfill or a foundation or abutment surface in the zone of contact with the earthfill becomes too dry to permit suitable bond, it shall either be removed or scarified and moistened by sprinkling to an acceptable moisture content before placement of the next layer of earthfill.

6. Compaction Earthfill—Earthfill shall be compacted according to the following requirements for the class of compaction specified:

Class A compaction—Each layer of earthfill shall be compacted as necessary to provide the density of the earthfill matrix not less than the minimum density specified in Section 9 or identified on the drawings. The earthfill matrix is defined as the portion of the earthfill material finer than the maximum particle size used in the compaction test method specified.

Class B compaction—Each layer of earthfill shall be compacted to a mass density not less than the minimum density specified.

Class C compaction—Each layer of earthfill shall be compacted by the specified number of passes of the type and weight of roller or other equipment specified or by an approved equivalent method. Each pass shall consist of at least one passage of the roller wheel or drum over the entire surface of the layer.

Class D compaction—Each layer of ditchfill shall be compacted by the specified number of passes with the placement or hauling equipment over the entire area.

Earth backfill—Earth backfill adjacent to structures shall be compacted to a density equivalent to that of the surrounding inplace earth material or adjacent required earthfill or earth backfill.

Compaction shall be accomplished by hand tamping or manually directed power tampers, plate vibrators, walk-behind, miniature, or self-propelled rollers. Unless otherwise specified heavy equipment including backhoe mounted power tampers or vibrating compactors and manually directed vibrating rollers shall not be operated within 2 feet of any structure. Towed or self-propelled vibrating rollers shall not be operated within 5 feet of any structure. Compaction by means of drop weights operating from a crane or hoist is not permitted.

The passage of heavy equipment will not be allowed:

• Over cast-in-place conduits within 14-days after placement of the concrete

• Over cradled or bedded precast conduits within 7 days after placement of the concrete cradle or bedding

• Over any type of conduit until the backfill has been placed above the top surface of the structure to a height equal to one-half the clear span width of the structure or pipe or 2 feet, whichever is greater, except as may be specified in section 9.

Compacting of earth backfill adjacent to structures shall not be started until the concrete has attained the strength specified in section 9 for this purpose. The strength is determined by compression testing of test cylinders cast by the engineer for this purpose and cured at the work site in the manner specified in ASTM C 31 for determining when a structure may be put into service.

NRCS-Minnesota (210-VI-NEH, May 2005) MN23-4

When the required strength of the concrete is not specified as described above, compaction of earth backfill adjacent to structures shall not be started until the following time intervals have elapsed after placement of the concrete.

Time interval Structure (days)

Vertical or near-vertical walls with earth loading on one side only 14 Walls backfilled on both sides simultaneously 7 Conduits and spillway risers, cast-in-place (with inside forms in place) 7 Conduits and spillway risers, cast-in-place (inside forms removed) 14 Conduits, pre-cast, cradled 2 Conduits, pre-cast, bedded 1 Cantilever outlet bents (backfilled both sides simultaneously) 3

7. Reworking or removal and replacement of defective earthfill Earthfill placed at densities lower than the specified minimum density or at moisture contents outside the specified acceptable range of moisture content or otherwise not conforming to the requirements of the specifications shall be reworked to meet the requirements or removed and replaced by acceptable earthfill. The replacement earthfill and the foundation, abutment, and earthfill surfaces upon which it is placed shall conform to all requirements of this specification for foundation preparation, approval, placement, moisture control, and compaction.

8. Testing During the course of the work, the engineer will perform quality assurance tests required to identify material; determine compaction characteristics; determine moisture content; and determine density of earthfill in place. Tests performed by the engineer will be used to verify that the earthfills conform to contract requirements of the specifications. Such tests are not intended to provide the Contractor with the information required by him for the proper execution of the work and their performance shall not relieve the Contractor of the necessity to perform tests for that purpose.

Densities of earthfill requiring Class A compaction will be determined in accordance with ASTM D 1556, D 2167, D 2922, or D 2937 except that the volume and moist weight of included rock particles larger than those used in the compaction test method specified for the type of fill will be determined and deducted from the volume and moist weight of the total sample before computation of density or, if using the nuclear gauge, added to the specified density to bring it to the measure of equivalent composition for comparison (See ASTM D 4718). The density so computed is used to determine the percent compaction of the earthfill matrix. Unless otherwise specified, moisture content is determined by one of the following methods: ASTM D 2216, D 3017, D 4643, D 4944, or D 4959.

9. Construction details Earthfill shall include all earthfill required to construct the embankments.

All areas beneath the embankments shall be stripped to a depth of 6 inches minimum or as directed by the NRCS technical representative prior to placing the earthfill.

The minimum moisture content of the earthfill material shall be such that when it is kneaded in the hand, the earthfill will form a firm ball that does not readily separate. The moisture content of the earthfill material shall be maintained within the limits required to ensure the crushing and blending of the soil clods and aggregations into a reasonable homogeneous mass. The maximum moisture

NRCS-Minnesota (210-VI-NEH, May 2005) MN23-5 content of the earthfill material shall be maintained within the limits required to prevent bulking or dilatance of the earthfill under the action of the hauling or compacting equipment and prevent adherence of the earthfill to the tread and tracks of the compacting equipment.

The earthfill shall be Class C compaction. Each layer of earthfill shall be compacted with 3 passes of a 200 pounds per square inch tamping roller.

The ditchfill shall be Class D compaction. Each layer of ditchfill shall be compacted with at least 1 pass of the placement or hauling equipment.

The maximum thickness of a layer of fill before compaction shall be 3 inches greater than the cleaned length of the feet on the sheepsfoot roller, with a maximum of 9 inches. Add 10% to fill height to account for settlement. The maximum size of rock fragments incorporated in the earthfill shall be 6 inches.

NRCS-Minnesota (210-VI-NEH, May 2005) MN26-1

Minnesota Construction Specification 26—Topsoiling

The work consists of furnishing and spreading topsoil to specified depths at locations shown on the drawings.

2. Quality of topsoil Topsoil shall consist of friable surface soil reasonably free of grass, roots, weeds, sticks, rocks, or other unsuitable material. Additional quality requirements, if any, are in section 6 of this specification.

3. Furnishing Topsoil shall be salvaged from designated earth surfaces that will be disturbed by construction activities. After designated sites have been cleared and grubbed, the topsoil shall be removed from the designated areas and stockpiled at locations shown on the drawings or acceptable to the engineer. Unsuitable material encountered during removal of topsoil shall be disposed of at locations shown on the drawings or approved by the engineer, or it will be otherwise hauled and disposed of at locations removed from the construction site. The contractor is responsible for complying with all local rules and regulations and the payment of any and all fees that may result from the disposal at locations outside the construction work limits.

4. Stockpiling Stockpiles of topsoil shall not conflict with the requirements of Construction Specification 5, Pollution Control, when made a part of this contract.

5. Spreading Spreading shall not be performed when the ground or topsoil is frozen, excessively wet, or otherwise in a condition detrimental to uniform spreading operations. Surfaces designated to receive a topsoil application shall be lightly scarified just before the spreading operation. Where compacted earthfills are designated to be topsoiled, the topsoil shall be placed concurrently with the earthfill and shall be bonded to the compacted fill with the compacting equipment.

Following the spreading operation, the topsoil surface shall be left reasonably smooth and without ruts or surface irregularities that could contribute to concentrated waterflow downslope.

6. Construction details

The topsoil shall be salvaged from within the work limits or as shown on the drawings. All areas beneath embankments will be stripped to a depth of 6 inches minimum or as directed by the technician. The topsoil shall be spread to a minimum depth of 4 inches on the earth fill and other areas as directed by the technician.

The maximum size of rock fragments shall be 3 inches