HEARTLAND CO-OP / IOWA SEED ASSOCIATION

BATCH & BUILD 2025-2026

CEDAR, MARSHALL, MUSCATINE, POWESHIEK + TAMA COUNTIES, IOWA

TECHNICAL PLANS AND SPECIFICATIONS

December 2025

PROJECT NO. 25-32609

TECHNICAL SPECIFICATIONS FOR:

HEARTLAND CO-OP / IOWA SEED ASSOCIATION BATCH & BUILD 2025-2026

CEDAR, MARSHALL, MUSCATINE, POWESHIEK, AND TAMA COUNTIES, IOWA

DECEMBER 2025

PROJECT NO. 25-32609

I hereby certify that this engineering document was prepared by me or under my direct personal supervision and that I am a duly licensed Professional Engineer under the laws of the State of Iowa.

12/29/2025 Spencer Dean Pech, P.E. Date

License No.: P28161

My License Renewal Date is December 31, 2026

Sections covered by this seal:

All sections Listed in Table of Contents

ISG

217 EAST 2ND ST

SUITE 110

DES MOINES, IA 50309

END OF CERTIFICATIONS PAGE

TECHNICAL PLANS AND SPECIFICATIONS FOR

HEARTLAND CO-OP / IOWA SEED ASSOCIATION

BATCH & BUILD 2025 - 2026

CEDAR, MARSHALL, MUSCATINE, POWESHIEK + TAMA COUNTIES, IOWA

TABLE OF CONTENTS

ITEMS OF WORK

CONSTRUCTION SPECIFICATIONS & STANDARDS

IA-1 Site Preparation CS-001 (2013) IA-3 Structure Removal CS-003 (2011) IA-5 Pollution Control CS-005 (2011) IA-6 Seeding and Mulching for Protective Cover CS-006 (2011) IA-342 Critical Area Planting IR-342 (2022)

NRCS-8 Mobilization and Demobilization CS-008 (2001) IA-9 Subsurface Drain Investigation, Removal, and Repair CS-009 (2014) IA-11 Removal of Water CS-011(2011) IA-21 Excavation CS-021 (2013) IA-23 Earthfill CS-023 (2015) IA-24 Drainfill CS-024 (2015) IA-26 Topsoiling CS-026 (2011)

IA-31 Concrete CS-031 (2013)

IA-45 Plastic (PVC, PE) Pipe CS-045 (2011) IA-46 Tile Drains for Land Drainage CS-046 (2013) IA-51 Corrugated Metal Pipe Conduits CS-051 (2011) IA-61 Loose Rock Riprap CS-061 (2015) IA-95 Geotextile CS-095 (2018)

IA-382 Fence PS-382 (2023) IA-604 Saturated Buffer PS-604 (2022) IA-605 Denitrifying Bioreactor PS-605 (2022) IA-620 Underground Outlet PS-620 (2024)

CONSTRUCTION INSPECTION PLAN

CONSTRUCTION SPECIFICATIONS & STANDARDS

Natural Resources Conservation Service

Construction Specification 000 IA CS-00-1 Site Preparation

NRCS, IA SPECIFICATION IA CS-001, Page 1 of 2 July 2013

1. SCOPE

Site preparation work shall consist of clearing, grubbing, stripping, refuse removal, bank sloping and structure removal on the site as necessary to rid the site of all undesirable materials on or near the surface and prepare the site for the structure. All woody growth within the construction area shall be cleared and all stumps and roots one inch in diameter or larger shall be grubbed from the site. In addition, all areas within 25 feet of the footprint of the structure shall be cleared and grubbed except as directed by NRCS. The work shall also consist of the removal and disposal of structures (including fences) that must be removed to perform other items of work.

For wetland restoration, enhancement, or creation projects, the wetland area shall be disturbed as little as possible and existing naturally vegetated spillway areas shall not be disturbed.

2. FOUNDATION PREPARATION

The construction areas shall be stripped a minimum of 6 inches to remove all unsuitable materials such as organic matter, grasses, weeds, sod, debris, and stones larger than 6 inches in diameter.

In an earth embankment foundation area, all channel banks and sharp breaks shall be sloped to no steeper than 1.5 horizontal to 1 vertical.

The foundation area shall be thoroughly scarified before placement of fill material. The surface shall have moisture added or shall be compacted if necessary so that the first layer of fill material can be compacted and bonded to the foundation.

3. STRIPPED MATERIAL DISPOSAL

Suitable soil material shall be stockpiled for use as topsoil. The other stripped materials shall be buried, removed from the site, or disposed of as directed by the owner or NRCS. Whenever possible, material shall not be disposed of in the pool area created by the structure.

Stockpiled materials around a construction site should be placed so as not to hinder subsequent construction operations.

4. DISPOSAL OF REFUSE MATERIALS

Waste materials from clearing and structure removal shall be burned or buried at locations approved by the owner. Buried materials shall be covered with a minimum of 2 feet of earthfill. Whenever possible, material shall not be disposed of in any pool area created by the structure.

All refuse shall be disposed of in a manner which complies with all local and state regulations.

5. SALVAGE

Items to be salvaged shall be as shown on the drawings. Structures and fencing materials that are designated to be salvaged shall be carefully removed and neatly placed in the specified storage areas.

NRCS, IA SPECIFICATION IA CS-001, Page 2 of 2 July 2013

6. SPECIFIC SITE REQUIREMENTS

A. Measurement and Payment

Compensation for any work item described in the contract documents but not listed in the bid schedule will be included in the payment for the item of work to which it is made subsidiary. Such items and bid items to which they are made subsidiary are identified in Items of Work and Construction Details section of this specification.

For items of work which lump sum prices are established in the contract, the quantity of work will not be measured for payment. Payment for each item will be made at the contract lump sum price and will constitute full compensation for completion of the work.

For items of work for which specific unit prices are established in the contract, the payment will be made based on the approved quantity measured by the engineer or weight tickets. Payment will constitute full compensation of the work completed as defined by each work item.

B. Items of Work and Construction Details

“Site Preparation”:

1. Bid Item No. 1

This item will consist of work to remove and dispose of existing material to remove vegetation on areas to be excavated or filled. Total depth of vegetative stripping and topsoil stripping shall equal a combined depth of 12", with the estimated cubic yards of topsoil removal as shown in the plans. The topsoil replacement quantity shall be paid separately.

This item will also include any tree and brush removal along with any fences. These shall be considered incidental to site stripping.

This item will be paid out as a lump sum.

NRCS, IA SPECIFICATION - Page 1 of 2 February 2011

000 IA-3 Structure Removal

The work shall consist of the removal, salvage and/or disposal of structures (including fences) from the designated areas and as indicated on the drawings.

2. MARKING

Each structure or item to be removed will be marked by means of stakes, flags, painted markers or other suitable methods.

3. REMOVAL

All structures designated for removal shall be removed to the specified extent and depth.

4. SALVAGE

Structures that are designated to be salvaged shall be carefully removed and neatly placed in the specified storage areas. Salvaged structures that are capable of being disassembled shall be dismantled into individual members or sections. Such structures shall be neatly match marked with paint prior to disassembly. All pins, nuts, bolts, washers, plates and other loose parts shall be marked or tagged to indicate their proper location in the structure and shall be fastened to the appropriate structural member or packed in suitable containers. Materials from fences designated to be salvaged shall be placed outside the work area on the property from which they are removed. Wire shall be rolled into uniform rolls of convenient size. Posts and rails shall be neatly piled.

5. DISPOSAL OF REFUSE MATERIALS

Refuse materials resulting from structure removal shall be burned or buried at locations shown on the drawings. Buried materials shall be covered with a minimum of 2 feet of earthfill. Whenever possible, material shall not be disposed of in the pool area created by the structure.

All refuse shall be disposed of in a manner which complies with all local and state regulations.

NRCS, IA February 2011SPECIFICATION - Page 2 of 2

Specific Site Requirements

000 IA CS-005 Pollution Control 2011

NRCS, IA SPECIFICATION IA CS-005, Page 1 of 3 February 2011

The work shall consist of installing measures or performing work to control erosion and minimize the production of sediment and other pollutants to water and air during construction operations.

2. MATERIALS

All materials furnished shall meet the requirements shown on the drawings or in the specifications.

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 so that areas unprotected from erosion will be minimized. These areas will be unprotected for the shortest time feasible.

Seeding: Structures and disturbed areas shall be seeded as soon as possible after construction is completed.

Temporary seedings may be used as an alternative to other stabilization measures as approved by

NRCS.

Mulching: Construction areas that have been disturbed but have no construction activity scheduled for 21 days or more shall have erosion protection measures applied by the 14th day. This erosion protection may be mulching or other approved temporary measures. Construction areas shall not be left open during a winter shutdown period and shall be protected by mulching.

All seeding and mulching shall be completed in accordance with the seeding plan and Iowa Construction Specification IA-6, Seeding and Mulching for Protective Cover.

The following works may be temporary. If they are installed as a temporary measure, they shall be removed and the area restored to its original state when they are no longer needed or when permanent measures are installed.

Diversions: Diversions may be required to divert clean runoff water away from work areas and to collect runoff from work areas for treatment and safe disposition.

Stream Crossings: Culverts or bridges may be required where construction equipment must cross streams.

Sediment Basins: Sediment basins may be required to settle and filter out sediment from eroding areas to protect properties and streams below the construction site.

Sediment Filters: Straw bale filters, geotextile sediment fences, or other equivalent methods may be used to trap sediment from areas of limited runoff. Sediment filters shall be properly anchored to prevent erosion under them.

Waterways: Waterways may be required for the safe removal of runoff from fields, diversions, and other structures or measures

NRCS, IA SPECIFICATION IA CS-005, Page 2 of 3 February 2011

4. CHEMICAL POLLUTION

The Contractor shall provide watertight tanks or barrels or construct a sump sealed with plastic sheets to be used to dispose of chemical pollutants, such as drained lubricating or transmission oils, greases, soaps, concrete mixer wash water, asphalt, etc., produced as a by-product of the construction work.

At the completion of the construction work, sumps shall be removed and the area restored without causing pollution.

Sanitary facilities such as chemical toilets or septic tanks shall not be placed adjacent to live streams, wells, or springs. They shall be located at a distance sufficient to prevent contamination of any water sources. At the completion of construction work, facilities shall be disposed of without causing pollution.

5. AIR POLLUTION

The burning of brush or trash or disposal of other materials shall adhere to local and state regulations.

Fire prevention measures shall be taken to prevent the start or the spreading of wild fires, which result from project work. Fire breaks or guards shall be constructed 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 insure safe operations at all times. If chemical dust suppressants are used, 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 five working days before use.

6. MAINTENANCE, REMOVAL, AND RESTORATION

All pollution control measures and works shall be adequately maintained in a functional condition as long as needed during the construction operation. All temporary measures shall be removed and the site restored to as near original conditions as practical.

7. SPECIFIC SITE REQUIREMENTS

items and bid items to which they are made subsidiary are identified in Items of Work and Construction Details section of this specification.

For items of work which lump sum prices are established in the contract, the quantity of work will

For items of work for which specific unit prices are established in the contract, the payment will be

1. Subsidiary Item - Pollution Control

NRCS, IA SPECIFICATION IA CS-005, Page 3 of 3 February 2011

This item shall consist of applying and performing all construction activities in a manner that will minimize water pollution, air pollution and soil erosion.

No separate payment will be made for Pollution Control. Compensation for this item will be other items as appropriate.

000 IA-6 Seeding and Mulching for Protective Cover

NRCS, IA SPECIFICATION IA CS-006, Page 1 of 6 February 2011

The work shall consist of seeding, mulching, and fertilizing all disturbed areas and other areas as indicated on the drawings or otherwise designated.

2. SEEDBED PREPARATION AND APPLICATION

The entire area to be seeded shall be reasonably smooth and all washes and gullies shall be filled to conform to the desired cross-section before actual seedbed preparation is begun. At this stage of the operation, the required fertilizer and lime shall be applied uniformly and incorporated into the top 3 inches of the soil with suitable tillage equipment. The seedbed preparation operation shall be suspended when the soil is too wet or too dry. The seedbed shall be loosened to a depth of at least three inches.

On side slopes steeper than 2-1/2 horizontal to1 vertical, the 3 inch minimum depth of seedbed preparation is not required, but the soil shall be worked enough to insure sufficient loose soil to provide adequate seed cover.

Unless otherwise specified, the seeding operation shall be performed immediately after preparation of the seedbed. The seed shall be drilled or broadcast by equipment that will insure uniform distribution of the seed.

3. MATERIALS

The seeding, fertilizing, and mulching requirements are as specified in Section 5 of this specification.

Straw from cereal grains or hay will be used as mulching material. It shall be relatively free of weeds.

4. MULCH APPLICATION

The required mulching shall be performed as soon as possible after seeding unless otherwise specified.

The mulch shall be applied uniformly over the area. The type and rate shall be as specified. When mulching is required, all areas seeded during any one day shall be mulched within 24 hours. The mulch may be spread by any means that results in a uniform cover.

The mulch shall be anchored. Anchoring of the mulch may be performed by a mulch anchoring tool or regular farm disk weighted and set nearly straight, by installation of mulch netting, or by other methods approved by NRCS.

NRCS, IA SPECIFICATION IA CS-006, Page 2 of 6 February 2011

5. SPECIFIC SITE REQUIREMENTS

5.1 Site-Specific Seed Mix List

County Site Seed Mix

Marshall

15a. Craig & Mary Pfantz IA CP25 30-10 Standard

15b. Sandra Pfantz IA CP25 30-10 Standard

18 HEA LLC IA CP25 30-10 Standard

Tama

2. KRK Farms IA CP25 30-10 Standard

4. Schroder Trust IA CP25 30-10 Standard

Poweshiek

1. Beverly Squiers SUDAS 9010 Native Grass and Forbs (Wildflower) Mix

9. ARD Farms SUDAS 9010 Native Grass and Forbs (Wildflower) Mix

10. MTD Farms SUDAS 9010 Native Grass and Forbs (Wildflower) Mix

Muscatine

19. Larry Streets Site 1 IA CP25 30-10 Standard

22. SUDAS 9010 Native Grass and Forbs (Wildflower) Mix

24. SUDAS 9010 Type 2 (Permanent Cool Season Mixture for Slopes and Ditches)

25. IA CP25 30-10 Standard

26. SUDAS 9010 Native Grass and Forbs (Wildflower) Mix

28. IA CP25 30-10 Standard

Cedar

20. Larry Streets Site 2 IA CP25 30-10 Standard

31. Pasture Mix: Smooth Bromegrass, Birdsfoot Trefoil & Chicory*

*DOES NOT INCLUDE: Alfalfa and/or Clover

32. IA CP25 30-10 Standard

34. IA CP25 30-10 Standard (See Plan Sheet D.10 for Area)

Pasture Mix: Smooth Bromegrass, Birdsfoot Trefoil & Chicory*

(See Plan Sheet D.10 for Area)

NRCS, IA SPECIFICATION IA CS-006, Page 3 of 6 February 2011

5.2 IA CP25 30-10 Standard Requirements

NRCS, IA SPECIFICATION IA CS-006, Page 4 of 6 February 2011

5.2 SUDAS 9010 Native Grass and Forbs (Wildflower) Requirements

NRCS, IA SPECIFICATION IA CS-006, Page 5 of 6 February 2011

5.3 SUDAS 9010 Type 2 (Permanent Cool Season Mixture for Slopes and Ditches) Requirements

5.4 Pasture Mix: Smooth Bromegrass, Birdsfoot Trefoil & Chicory*

Refer to Iowa Conservation Practice 342 Critical Area Planting for seeding rate for Smooth Bromegrass and Birdsfoot Trefoil. Mix should include Chicory. Mix shall not include any Alfalfa or Clover. Submit proposed seed mix to landowner, Watershed Coordinator and Engineer for approval.

5.5 Measure and Payment; Items of Work

Measure and payment shall be to the nearest hundredth of an acre of seeded area. Item includes all labor, equipment, and fertilizer required to complete the work. Refer to the plans for further details.

“Seeding”:

1. Bid Item No. 2

This item will consist of seeding the areas as shown on the plans.

Some areas of the sites may have existing CRP vegetation or steep slopes with existing vegetation. Local NRCS personnel will determine if these areas will be included as part of the seeding areas for this project or will be left as is. Site-specific seed mixes are subject to change based on input from local NRCS personnel. This may affect the bid quantity and Contractor will verify with Engineer the seed mix and number of acres that will require seeding.

All seed must be clean and weed free. Seeding rates are expressed in pounds of pure live seed per acre. All native seed must be yellow-tagged Iowa ecotype unless approved otherwise by IDALS-DSCWQ.

Seeding mixture for each site shall be as specified in Section 5.1. Where seeding rate is not specified, number of seeds will be based on Iowa Conservation Practice 342 Critical

Area Planting. Refer to Iowa Conservation Practice 342 Critical Area Planting

NRCS, IA SPECIFICATION IA CS-006, Page 6 of 6 February 2011

Implementation Requirements for seedbed preparation, fertilizer, mulching, and seeding date requirements. Contractor’s proposed seed mix shall be submitted to Engineer and local NRCS office for approval at least 2 weeks before seed is to be applied.

Measurement and Payment will be based on the area successfully seeded and measured to the nearest 0.1 acre.

2. Weed Control (Not a Bid item)

Weed control may be needed depending upon the start date of the contract, the initiation of construction activities, and the seeding date requirements.

Weed control will be added to the contract with a change order to be negotiated between

Contractor and Division based on conditions observed and the type of weed control used and will be paid only once. If delays require additional weed control, this will be paid for at Contractor’s own expense.

Weed control may include placement of a cover crop such as oats or rye, spraying with appropriate chemicals, or disking. If thistles are present, only spraying is allowed for weed control and shall include appropriate chemicals designed to control thistles.

United States Department of Agriculture

USDA is an equal opportunity provider, employer and lender. www.ia.nrcs.usda.gov

Natural Resources Conservation Service Des Moines, Iowa

Iowa Conservation Practice 342 June 2017 revised October 2022

Critical Area Planting Iowa Implementation Requirements

Definition Establishing permanent vegetation on sites that have or are expected to have high erosion rates, and on sites that have physical, chemical or biological conditions that prevent the establishment of vegetation with normal practices.

Purpose Stabilize areas with existing or expected high rates of soil erosion by water and wind.

Stabilize areas, such as sand dunes and other riparian areas.

Stabilize stream and channel banks, ponds and other shorelines, and earthen features of structural conservation practices.

Condition Where Practice Applies This practice applies to highly disturbed areas, such as: active or abandoned mined lands; urban restoration sites;

construction areas; conservation practice construction sites; eroded banks of natural and constructed channels and lake shorelines; areas needing stabilization before or after natural disasters, such as floods, hurricanes, tornadoes and wildfires; and other areas degraded by human activities or natural events.

Criteria for Conservation Cover

A. Seeding Periods Permanent, perennial vegetative cover and/or trees will be established during the first recommended seeding or planting period for the selected species or mixture. Planting dates are outlined on Table 1 of this implementation requirement. Planting immediately after construction of earthen structures such as terraces, grade stabilization, or ponds may be completed at the discretion of the Conservation Planner with Job Approval Authority.

B. Fertilizer and Lime Requirements No fertilizer requirement for seedings that are predominantly native. Apply 50 lbs per acre of Nitrogen and follow Iowa State University PM-1688 to apply phosphorus, potassium and lime (lime to a minimum target pH of 6.0 at a 3 inch depth) based on a soil test.

When a current soil test is not available, apply 50 lbs P2O5 per acre, 50 lbs K2O per acre and 1000 pounds per acre ECCE lime. Fertilizer requirements may be waived at the discretion of the Conservation Planner with Job Approval Authority on sites:

• Less than 1 acre in size.

• Where application equipment cannot access the site (i.e. steep sides of terraces, grade stabilization, ponds).

• Field practices, such as waterways, when soil tests for adjacent cropland is at optimum or higher.

Critical Area Planting (342) Natural Resources Conservation Service

C. Companion Crop All critical area plantings will contain a companion crop of spring cereal rye or will be mulched. Mulching is recommended on slopes steeper than 4:1 where mowing of a companion crop may be difficult or dangerous.

Mulch of small grain straw shall be used at the rate of 2 tons/ac.

For spring seedings of introduced species, oats or a spring cereal grain shall be seeded at a rate of 1 1/2 bushels/acre to reduce soil erosion and help control weed competition. The oats shall be clipped at the time of seed head emergence to promote growth of the new permanent cover. The use of the companion crop is not required when interseeding.

D. Seedbed preparation and Seeding

1. Conventional seeding for spring and late summer seeding periods where site conditions allow for safe operation of equipment.

• The seedbed shall be worked to a depth of 3”, smooth, friable and firm before seeding.

• All tillage operations shall be performed across the general slope of the land.

• Grass and legume seed shall be drilled uniformly over the area at a 1/4-1/2 inch depth or broadcast uniformly over the area and rolled into the seedbed.

• Where erosion is a concern prepare a seedbed with tillage tool that will leave enough residue or provide mulch to provide adequate protection.

2. No-till seeding for spring, late summer and dormant seeding periods where site conditions allow for safe operation of equipment.

• Approved herbicides shall be applied to kill or suppress existing weed competition, as necessary. Herbicides will not be used in waterways or filter strips adjacent to wetlands or other waterbody.

• A drill designed for no-till planting shall be used to plant the seed at a depth of 1/4 - 1/2 inch.

3. Frost Seeding

• Broadcast seed for only those species approved for frost seeding as shown in table 2 and table 3.

4. Hydro-seeding

• Hydro-seeding can be used on all sites but especially on sites that are too steep for regular seeding equipment to operate. The prescribed procedure will be to apply the seed and fertilizer in a water slurry uniformly over the surface. A second trip will be needed to apply an asphalt emulsion to long fiber mulch as it is blown on.

5. Sodding

• All sod used shall be free of noxious weeds as listed in Iowa State Laws and shall be cut from stands giving not less than 90 percent ground cover.

• Only moist, fresh sod shall be used. Lay sod as soon as possible after delivery to the site. Wet soil to a depth of 2 inches or more prior to laying the sod. Lay the sod from the lower end of the slope. Sod strips shall be laid at right angles to the flow of water, stagger joints. Fill any open joints with loose soil. Tamp or roll laid sod to insure a solid contact of root mass to soil surface.

• On severely steep sites or when anticipating overland flow, sod shall be held in place by woven wire, wooden pegs, wire staples, or similar material. Pegs or staples will be a minimum of 10 inches long.

E. Seeding Stand Improvement This includes any stand modification that maintains some vegetative component of the original stand.

1. Incorporation of grasses and/or legumes with light tillage.

• Weaken the existing stand in the fall or early winter by use of herbicides, grazing, mowing or a combination of these methods.

• Use a disk, cultivator, or similar tool to disturb 40- 50% of the existing stand.

• Grass and legumes shall be drilled uniformly over the area at 1/4-1/2 inch depth, or broadcast uniformly over the area and rolled into the seedbed.

• Remove early spring regrowth by mowing to reduce competition and allow the new seedlings to become established.

2. Incorporation of grasses and/or legumes with no- tillage (interseeding) for spring, late summer and dormant seeding periods.

• When interseeding into existing sod, graze, burn, mow or apply herbicides to kill strips or suppress existing vegetation and to control weed competition. Herbicides will not be used in waterways or filter strips adjacent to wetlands or other waterbody.

• Control broadleaf weeds by applying herbicide at least two weeks prior to applying contact herbicides and prior to seeding.

• Grass and legumes shall be drilled uniformly over the area at 1/4-1/2 inch depth.

• Remove early spring regrowth by mowing to reduce competition and allow the new seedlings to become established.

3. Incorporation of grasses and/or legumes with frost seeding.

• Broadcast seed only species approved for frost seeding as shown in table 2 and table 3. Small smooth

(shiny) seeded species are best for incorporation into the soil during freezing and thawing.

• Frost seeding is likely to be more successful if existing stand is weak and less than 50 percent of the ground is covered with live vegetation.

F. Inoculation

1. Legume seed shall be inoculated and the inoculant shall be specific to the legume seeded.

2. When more than one legume species is used, each species shall be inoculated separately.

G. Seed Quality

1. All seed shall be of high quality and comply with Iowa Seed and Weed Laws.

2. Cool season (introduced) grass and legume seeding rates are expressed in bulk pounds/acre. Seed quality shall not drop below 80% Pure Live Seed (PLS) where PLS = (% germination + dormant seed) X % purity).

3. Native grass species seeding rates are expressed in PLS pounds/acre.

H. Management during the Establishment Year Plant species and cultivars shall be selected based upon:

1. Climatic conditions such as annual rainfall, seasonal rainfall, growing season length, humidity levels, temperature extremes and the USDA Plant Hardiness Zones.

2. Soil condition and position attributes such as pH, percent slope, available water holding capacity, aspect, drainage class, inherent fertility, flooding and ponding, and levels of salinity and alkalinity.

3. Plant characteristics such as season of growth, vigor, ease of establishment, longevity of the species, growth habit, adaptation to soil conditions, and conservation value.

4. Resistance to diseases and insects common to the site or location.

5. Compatibility with other plant species and their selected cultivars in rate of establishment and growth habit when seeded together as a mixture.

6. Seeding Rates

The pure stand rates in table 2 of this standard are the minimum rates for planting a single species stand into well-prepared seedbed at the proper placement. The pure stand rates are decreased to a percentage of the desired stand when used to calculate a mixture of two or more species. Select combinations of plant species and cultivars best adapted to site conditions.

7. When frost seeding is used, the seeding rate shown in table 2 and table 3 shall be multiplied by 1.5.

8. Introduced Species

• Approved introduced plant species, allowable mixture composition and the pure stand seeding rate are shown in Table 2.

• A designed seeding mixture shall meet criteria specified in table 2 as to species composition and seeding rate.

• For critical area seeding used for erosion control, at least 50% of mixture shall be composed of grasses.

• Tall Fescue shall not compose more than 10% of the mixture if the secondary purpose is for wildlife.

• Mixtures may include up to 20% native grasses. Use the criteria for the predominant species in the mixture for stand establishment.

• Approved native plant species, allowable mixture composition and a pure stand seeding rate are shown in Table 3.

• A designed seeding mixture shall meet criteria specified in table 3 as to species composition and seeding rate. At least 50% of the mixture shall be composed of grasses. For seeding mixtures with the secondary purpose of wildlife not more than 20% of the mixture will be composed of switchgrass.

• When developing seeding mixtures, except eastern gamma grass, use 60 seeds/sq. ft. for grass stands.

• Mixtures may include up to 20% introduced legumes. Use the criteria for the predominant species in the mixture for stand establishment.

I. Weed Control During the Establishment Year Weed control during the establishment year shall be provided to ensure survival of the new permanent seeding.

1. To manage severe weed competition, native species may be mowed no closer than 8 inches and introduced species no closer than 4 inches.

2. Approved herbicides may be used on both introduced and native plantings to control weed species.

J. Establishment of Temporary Cover Temporary cover may be required to reduce potential weed and erosion problems where one of the following conditions exists.

1. Fields with herbicide carry over.

2. Where planting is delayed due to unavailability of seed.

3. The normal planting period has passed.

4. Temporary cover or mulching will be established on sites where construction delays or shutdowns occur if the delay or shutdown will last more than 30 days.

5. The temporary cover shall be seeded as specified in Table 4.

K. Site Protection and Access Control Grazing animal access to planted areas will be controlled for a minimum of two growing seasons during the establishment period.

All areas to be grazed will have a grazing plan that meets the criteria in the Iowa Field Office Technical Guide.

Grazing shall be permanently excluded on high hazard areas, such as cut banks, areas of seepage, or other potentially unstable areas.

9. Native Species

L. Re-vegetate Degraded Sites that Cannot Be Stabilized Through Normal Farming Practices

If gullies or deep rills are present, they will be filled and leveled as necessary to allow equipment operation and ensure proper site and seedbed preparation.

Based on a soil test and other appropriate site evaluations, soil amendments will be added as necessary to improve or eliminate physical or chemical conditions that inhibit plant establishment and growth.

Table 1. Seeding dates for introduced and native species

Type of Seeding Introduced Species2

(Grasses and Legumes) Native Species3

Spring March 1 - May 15 April 1 - July 1

Late Summer August 1 - September 15 Not Recommended

Dormant1 November 15 - Freeze November 15 - Freeze

Frost1 February 1 - March 15 February 1 - March 15

1. Refer to Table 2 and 3 for applicable plant species.

2. Includes all species generally considered introduced.

3. Includes all warm and cool season natives planted in mixture.

Table 2. Seeding chart for introduced plant species

% of Mixture (Range Allowed)

Plant Species Critical Areas Grassland3/

Trees, Shrubs & Wildlife

Seeding Rate PLS/acre

Smooth bromegrass1 0-100 0-25 25

Kentucky bluegrass1 0-80 0-10 25

Orchardgrass2 0-25 0-100 10

Timothy2 0-25 0-100 10

Alfalfa2 0-50 0-50 20

Red clover2 0-50 0-50 16

Birdsfoot trefoil2 0-50 0-25 16

Reed Canarygrass5 0-25 0 16

Perennial rye 0-50 0-50 25

Ladino clover2 0-50 0-50 8

Red top 0-50 0-80 10

Alsike clover2 0-50 0-50 8

Tall Fescue1,7 0-50 0-10 16

Table 2. Seeding chart for introduced plant species cont…

% of Mixture (Range Allowed)

Plant Species Critical Areas Grassland3/

Trees, Shrubs & Wildlife

Seeding Rate PLS/acre

Sweetclover2,4 0-20 0-20 10 Intermediate Wheatgrass1,6 0-75 0-75 30

Meadow Bromegrass 0-100 0-25 30

Meadow Fescue 0-75 0-25 16

1. For critical area seeding used for erosion control, at least 50% from the grassland or wildlife seeding mixture shall be composed of sod forming grasses.

2. Species suitable for frost seeding, increase seeding rate by a factor of 1.5.

3. Mixtures may include up to 20% native grasses. See Table 3 for seeding rates. Use the criteria for the predominate species in the mixture for establishment.

4. Sweet clover is to be used in mixtures only.

5. Reed Canary grass is to be used only for very wet sites with high nutrient load only if Reed Canary grass is already present downstream of the practice.

6. Suitable for well drained sites.

7. Tall Fescue will not consist of more than 10% of the mix if primary or secondary purpose is for wildlife.

Table 3. Seeding chart for native plant species

Grasses1

% of Mixture (Range Allowed)

Pure Stand Seeding Rate PLS lbs./acre

Seeds/

sq. ft.

Approx.

Seeds/ lb.

Big bluestem, Andropogon gerardi 0-100 16 60 165,000

Blue grama, Bouteleloua gracilis 0-20 4 75 825,000

Buffalograss, Buchloe dactyloides 0-20 65 60 40,000

Canada wildrye, Elymus canadensis 0-20 22 61 121,000

Eastern gamagrass, Tripsacum dactyloides 0-100 20 4 7,500

Indiangrass, Sorghastrum nutans 0-100 15 60 175,000

Little bluestem, Schizachyrium scoparium 0-20 11 60 240,000

Sideoats gramma, Bouteloua curtipendula 0-20 14 61 191,000

Switchgrass, Panicum virgatum2 0-100 7 62 389,000

Virgina Wildrye, Elymus virginicus 0-20 27 60 96,000

Western wheatgrass, Agropyroni smithi 0-20 24 61 110,000

1. When developing seed mixtures, except eastern gamagrass, use 60 seeds/sq. ft. for grass stands. Grass and forb/legume mixtures are 40 seeds/sq. ft. for the grass component and minimum of 20 seeds/sq. ft. for forb/legume component.

2. Species suitable for frost seeding, multiply seeding rate by factor of 1.5.

Table 4. Temporary Seeding Recommendations

Fields with atrazine1 carryover, lack of suitable seed or late planting date

Sudangrass 20 lbs./acre

Sorghum-Sudangrass hybrid 20 lbs./acre

Corn 2 bushels/acre

Fields where planting is delayed, due to lack of suitable seeding or late planting date

Oats 3 bushels/acre

Winter rye 2 bushels/acre

Spring or winter wheat 2 bushels/acre

1. For other herbicide carryover problems, check with the area office.

Table 5. Critical Area Seedbed Mixtures for Specific Site Conditions

Site Conditions Seeding Mixture Rate lbs./acre

Moderately to well drained, limed or non-acid, fertile soils

Alfalfa Red clover Smooth bromegrass

Alfalfa Timothy Smooth bromegrass Or Orchardgrass

Or 8

Imperfectly drained soils

Red clover Ladino clover Orchardgrass

Birdsfoot trefoil Smooth bromegrass Timothy

Big bluestem Switchgrass

Poorly drained soils

Birdsfoot trefoil Timothy Or Orchardgrass

Or 12

Alsike clover Ladino clover Tall fescue Or Timothy

Or 5

Table 5. Critical Area Seedbed Mixtures for Specific Site Conditions cont…

Site Conditions Seeding Mixture Rate lbs./acre

Very wet sites with high nutrient loading (i.e. animal waste filter strips)

Reed canary grass 16

Tall fescue 16

Switchgrass 7

Medium acid to strongly acid (6.0-5.1) with well drained to poorly drained soil that has a high clay content

Birdsfoot trefoil Tall fescue Bromegrass

Medium to strongly acid (pH 6.0-5.1) shallow (20 in.) with poorly drained soils with low fertility and low level management

Birdsfoot trefoil Tall Fescue Red top Switchgrass

Deep or coarse sands, droughty, usually acid (pH 6.0) Sand lovegrass Switchgrass Prairie sandreed grass

Reclaimed acid mine spoil (pH 4.0) Birdsfoot trefoil Red clover Crown vetch Tall fescue

Reclaimed acid mine spoil, deep coarse sands, droughty, low fertility (pH 4.0)

Switchgrass Big bluestem Indiangrass Little bluestem

Alkaline mine spoil (pH 7.4)

Bromegrass Alfalfa

Bromegrass Timothy

Specific Site Requirements

Refer to IA-CS-006 Seeding and Mulching for Protective Cover for site-specific seed mix.

210-VI-NEH SPECIFICATION CS-008, Page 1 of 2 May 2001

NATURAL RESOURCES CONSERVATION SERVICE

CONSTRUCTION SPECIFICATION

Construction Specification 8—Mobilization and Demobilization

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. 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

210-VI-NEH SPECIFICATION CS-008, Page 2 of 2 May 2001 price and will constitute full compensation for completion of the work.

For items of work for which specific unit prices are established in the contract, the payment will be

“Mobilization”:

1. Bid Item No. 3

This item shall consist of mobilizing and demobilizing personnel and equipment in preparation to perform the work within the scope of this contract.

Any work that is necessary to provide access to the site including, but not limited to, grading, temporary culverts, and clearing will be included in this item. When construction is completed access areas will be restored, as close as practical, to its original condition.

Any fence removed for access and /or to provide work area shall be replaced with same or like materials as approved by the engineer.

The Contractor shall exercise caution to minimize the amount of damage caused by the grading and clearing operations.

Portable toilets shall be provided at the construction site and used for the sanitary facilities.

This item shall not include transportation of personnel, equipment and operating supplies within the work limits areas of this contract.

Payment will constitute full compensation for related subsidiary item, Pollution Control.

Payment will be made as the work proceeds and will paid out on the percent of the project complete as the work progresses. Payment of the lump sum contract price for mobilization and demobilization will constitute full compensation for the completion of the work.

Contractor is to contact “Iowa One Call” for utility locations a minimum of two (2) days prior to any excavation/construction. The ticket number must be provided to Engineer.

NRCS, IA SPECIFICATION IA CS-009, Page 1 of 4 December 2014

NATURAL RESOURCES CONSERVATION SERVICE

CONSTRUCTION SPECIFICATION

IA-9 SUBSURFACE DRAIN INVESTIGATION,

REMOVAL, AND REPAIR

The work shall consist of investigation, location, repair, and/or removal of subsurface drains (tile) near new or existing animal waste storage facilities or in wetland restoration, enhancement, or creation project areas, or other situations where subsurface drains may be present.

2. INVESTIGATION AND LOCATION

An inspection trench at least 10 inches wide shall be dug at the location shown on the drawings or as directed by the engineer or his representative. The trench shall be at least 6 feet deep measured from the original ground line, unless otherwise shown on the plans. The Engineer or his representative shall examine the trench and excavated material to identify tile lines.

Size, material, operating condition and direction of flow of each conduit shall be documented. Location and flow line elevation of each conduit shall be surveyed with horizontal and vertical control based on benchmarks shown on the plans.

The inspection trench shall be documented by surveying the natural ground and trench bottom location and elevations at the beginning, end, and every 50 feet for trenches longer than 50 feet.

Backfilling shall not be started without approval of the Engineer. See Section 5 for backfill specifications.

Trench shields, shoring and bracing, or other methods necessary to safeguard the workers and work, and to prevent damage to the existing improvements shall be furnished, placed, and subsequently removed by the contractor.

3. TILE REPAIR

Unless designated for removal, replace damaged conduit with new conduit having equal or greater capacity using material specified in Section 6 or 7. When replacing short sections of clay or concrete tile with single-wall corrugated polyethylene pipe, use the next larger nominal size.

Make connections with manufactured fittings and tight joints. Where joints have gaps that would allow soil to enter, cover the joint with a permanent type material such as coal tar pitch treated roofing paper, fiber glass sheet or mat, or plastic sheet.

If the investigation trench has been excavated below the existing drain grade, backfill the trench with gravel or well-pulverized soil in layers not over four (4) inches thick and tamp by hand or manually directed power tamper to provide a firm foundation for the conduit at the existing grade. Do not backfill with any soil containing broken tile fragments.

Using selected soil free of hard clods, rocks, or frozen soil, hand tamp the backfill material around the haunch of the pipe in layers not over four (4) inches thick to provide support. Hold the conduit in place

NRCS, IA SPECIFICATION IA CS-009, Page 2 of 4 December 2014 mechanically while placing excavated material around and over the conduit to ensure proper alignment and grade is maintained. Complete the backfill operation according to Section 5.

4. TILE REMOVAL

Remove conduits as shown on the plans or directed by the Engineer or his representative, including envelope filter material or other flow enhancing material when present.

Cap or plug the open ends of the disconnected conduit to prevent soil entry when the conduit will continue to function downstream, or otherwise shown on the plans. For a minimum distance of two feet around each sealed conduit end, backfill in layers not over four (4) inches thick and tamp by hand or manually directed power tamper to a density equal to or greater than the surrounding undisturbed soil. Do not backfill with any soil containing broken tile fragments, large stones, frozen material, or large dry clods.

Where tile are located beneath an existing animal waste facility, remove the tile or fill the entire length of tile with concrete or Portland cement grout as shown on the plans. When tile removal is specified, the owner shall contact the Iowa Department of Natural Resources (IDNR) for permission to remove the drainage tile under the structure. The structure shall be emptied of waste or lowered to a point below the tile prior to its removal. The structure must be retested for percolation and the results submitted to IDNR and approval received prior to reusing the structure.

If shown on the plans or directed by the engineer, reroute upstream drain lines so the capacity of the upstream drainage system is maintained. Install conduit in accordance with Iowa Construction Specification IA-46, Tile Drains for Land Drainage.

5. BACKFILL

Compact soil around disturbed tile as specified in Section 3 (Tile Repair) and Section 4 (Tile Removal).

Keep the backfill within 5 feet of the conduit free from large stones, frozen material, and large dry clods.

Unless otherwise shown on the plans, backfill the remainder of the trench as follows:

For trenches located under or near structures, backfill in 12-inch layers and compact each layer to a density equal to or greater than the surrounding undisturbed soil.

For other locations, backfill the remainder of each trench with the excavated soil material which shall extend above the ground surface and be well rounded over the trench.

6. MATERIALS

Unless otherwise shown on the plans, conduit and fittings used for repair shall conform to the specifications listed in Table 1. Perforated pipe shall have a water inlet area of at least 1 square inch per foot, provided by perforations spaced uniformly along the long axis of the pipe. The perforations shall be circular or slots. Circular perforations shall not exceed 3/16 inch in diameter. Slots shall not be more than 1/8 inch wide.

NRCS, IA SPECIFICATION IA CS-009, Page 3 of 4 December 2014

Table 1. Acceptable pipe for subsurface drain repair

Kind of Pipe# Specification

Corrugated Polyethylene (PE) Pipe and Fittings, 3 to 6 inch ASTM F 405

Corrugated Polyethylene (PE) Pipe and Fittings, 3 to 24 inch ASTM F 667

Corrugated Profile Wall (Dual Wall) Polyethylene (PE) pipe, 2 to 60 inch ASTM F 2648$

Corrugated Profile Wall (Dual Wall) Polyethylene (PE) pipe, 12 to 60 inch ASTM F 2306$

Polyvinyl Chloride (PVC) Plastic Pipe, Schedules 40, 80 and 120 ASTM D 1785

PVC Pressure-Rated Pipe (SDR Series) ASTM D 2241

Clay drain tile ASTM C 4

Concrete drain tile ASTM C 412

#Pipe sizes are nominal and the ranges are inclusive $Pipe conforming to AASHTO M 252 (3 to 10 inch), or AASHTO M 294 (12 to 60 inch) is acceptable.

For items of work for which specific unit prices are established in the contract, the payment will be

“Tile Investigation”:

1. Bid Item No. 9

This item will consist of the excavation necessary to locate and verify the connection locations and elevations for the existing tiles as shown on the plans. This item shall also include backfilling of the trenches.

The Contractor shall locate and verify existing tile location(s) and elevations prior to construction and shall notify the Engineer of any discrepancies.

NRCS, IA SPECIFICATION IA CS-009, Page 4 of 4 December 2014

If extra work is required to locate additional tile not shown on the drawings, the Contractor can request additional compensation, but it must first be approved by the division.

Measurement for this item shall be measured in hours to the nearest half hour. Payment for Drainage Tile Investigation shall be made as noted in the plans.

000 IA-11 Removal of Water

NRCS, IA SPECIFICATION IA CS-011, Page 1 of 2 February 2011

The work shall consist of the removal of surface water and ground water as needed to perform the required construction in accordance with the plans and specifications.

2. DIVERTING SURFACE WATER

The Contractor shall build, maintain and operate all cofferdams, channels, diversions, flumes, sumps, and other temporary protective works needed to divert surface water away from the construction site while construction is in progress.

3. DEWATERING THE CONSTRUCTION SITE

Foundations, cutoff trenches, borrow areas and other parts of the construction site shall be dewatered as needed for proper execution of the construction work. The Contractor shall furnish, install, operate and maintain all works and equipment needed to perform the dewatering.

4. EROSION AND POLLUTION CONTROL

Removal of water from the construction site, including the borrow areas shall be accomplished in such a manner that erosion and the transmission of sediment and other pollutants are minimized.

5. REMOVAL OF TEMPORARY WORKS

After temporary works have served their purposes and before the Contractor leaves the site, they shall be removed.

For items of work for which specific unit prices are established in the contract, the payment will be

1. Subsidiary Item - Dewatering

NRCS, IA SPECIFICATION IA CS-011, Page 2 of 2 February 2011

This item shall include all costs to divert, pump, dam…