Appendix_R.pdf

APPENDIX R

REVEGETATION AND EROSION CONTROL

REVEGETATION AND EROSION CONTROL

1. APPLICABLE PUBLICATIONS. Are listed below and form a part of this specification to the extent referenced. The publications are referred to in the text by the basic designation only.

Association of Official Analytical Chemists (AOAC) Publication:

Official Methods of Analysis (13th Edition 1980 and Supplements 1 & 2).

2. GENERAL. The seeding work will be accomplished only when satisfactory results can be expected. When conditions such as drought, excessive moisture, high winds or other factors prevail to such an extent that satisfactory results are not anticipated, the Contracting Officer may, at his discretion, stop any phase of the work. Work will resume only when, at the discretion of the Contracting Officer, the desired results are likely to be obtained. All seeding will be conducted across the slope. Seeding measures will be accomplished as specified herein.

3. FERTILIZING, SEEDING, AND MULCHING. Are required under this contract and will be accomplished on the areas specified in the contract plans and described in these specifications. Outcroppings of rock, rock cuts, rock fills, concrete structures, and areas of rock protection will be avoided.

4. PLANTING SEASON. Seeding will be performed from the middle of June until the first week in July. Seeding will be accomplished on those project features that are complete as of this time unless otherwise approved by the Contracting Officer. If the Contracting Officer determines that work under this contract has not progressed sufficiently on an area to allow efficient performance or in any way prevent satisfactory results, seeding may be delayed until the next appropriate planting season.

5. MATERIALS.

5.1 Fertilizer. Will be applied to all areas at a rate of 40 pounds of available nitrogen (ammonium sulfate with a urea formaldehyde base) and 50 pounds of available phosphorous (usually expressed as phosphorus pentoxide) per acre. Fertilizer will be granular and uniform in composition, free flowing, and suitable for application with approved equipment. The fertilizer will be delivered to the site in plastic bags or other suitable containers, each fully labeled, conforming to the applicable State fertilizer laws, and bearing the name, trade name or trade mark, and warranty of the producer.

5.2 Seed Mixtures. Must be certified, locally-adapted strains or varieties as shown in Table 1. Seed with the higher Pure Live Seed (PLS*) will be purchased. All seeding rates and pounds of seed needed in mixture per acre will be adjusted to the PLS purchased.

* Pure Live Seed (PLS) is determined by multiplying the germination of a lot of seed by the purity. For example, a 100-pound bag of seed with a germination of 50 percent and purity of 80 percent would be computed as follows: 50% X 80% = 40% PLS. Therefore, a 100-pound sack of seed contains only 40-pounds of Pure Live Seed. To obtain a satisfactory revegetation and erosion control from seed mixtures, one would need to plant 2.5 times the PLS number to achieve 100-percent plant coverage. Except as noted, all seeding recommendations are based on PLS.

TABLE 1

Pounds of PLS* Number of Seeds Applied Needed in Mixture Plant Name Variety Per Square Foot of Soil Per Acre

Grasses Sand dropseed Vaughn 12.0 0.10 Indian ricegrass** Nezpar 12.8 3.0 Galleta Viva 7.4 2.0 Alkali sacaton Salado 9.2 0.25 Blue grama Hachita 8.0 0.75 Subtotals 48.6 6.1

Shrubs Fourwing saltbush closest source 1.0 Apache plume closest source 1.0 Subtotal 2.0

Total Poundage 8.1

** Seed will be 2-years old

5.3 Hay Mulch. Must be bailed, bright, native prairie hay, broom sedge, bluestem hay, King Ranch bluestem hay, or hay of other grasses and sedges having the equivalent in leafiness, structure, and fiber strength. Hay material which has passed through a seed-harvesting combine or a thresher will not be acceptable. A minimum of 65 percent of weight of the herbage making up the material will be 10 inches or longer. Mulch materials which contains mature seed of noxious weeds or other species, including crops which would be detrimental to the grasses planted on the mulched areas or provide a menace to surrounding farmlands, will not be acceptable. Discolored, weathered, rotted, molded, brittle hay or any hay harvested during dormant season will not be acceptable. Hay will be applied at the rate of 1.5 to 2 tons per acre.

5.4 Topsoil. Must have sufficient texture, organic content, etc., to germinate planted seeds and support long-term growth. Top soil shall not be excessively sodic or saline. The Exchangeable Sodium Percentage (ESP) or Sodium Absorption Ratio (SAR) will be less than 13 and salinity will be less than 6 mmhos/cm or decicemans/m. Topsoil shall not contain noxious weeds that would prevent or impair establishment and long-term growth of planted species.

6. INSPECTION AND TESTS.

6.1 Fertilizer. Six signed copies of fertilizer invoices will be provided.

Invoices shall show quantities and grade of each fertilizer furnished.

Samples of each lot of fertilizer will be tested upon request of the Contracting Officer. Sampling and testing will be done in accordance with official methods of analysis of the Association of Official Analytical Chemists at the discretion of the Contracting Officer. The empty fertilizer bags or containers will be retained, and on completion of the project, a final check of total quantities of fertilizer used will be made against the total area treated. If minimum rates of application have not been met, additional quantities of these materials, to make up minimum application specified, will be distributed as directed.

6.2 Seed. The Contracting Officer will be furnished six signed copies of statement from the vendor, certifying that each container of seed delivered is labeled in accordance with the Federal Seed Act and is, at least, equal to requirements previously specified. This certification and copies of the official seed analysis, or official seed tags, will be obtained from the vendor and will be furnished on, and with, all copies of seed invoices.

Invoices, certifications, and seed analysis will be furnished prior to commencement of planting operations. Each lot of seed may be re-sampled and re-tested, in accordance with latest rules and regulations under the Federal Seed Act, at the discretion of the Contracting Officer. Such re-sampling and re-testing will be made by, or under, the supervision of the Government. If these tests reveal the seed to be below the specified pure live seed content, the Contractor will be required to plant additional seed to compensate for the deficiency at no additional cost to the Government. The seed re-test will be conducted by the State Seed Laboratory.

6.3 Mulch. Not less than five days prior to commencement of seeding operations, the Contracting Officer will be notified of sources from which mulch materials (hay, straw, and gravel) are available and the quantities thereof. Representative samples of the material proposed for use will be submitted for approval. A weight certificate, signed by a public weigher, will be furnished prior to applying for the hay and straw mulch. The Mulch material will be unloaded and stacked in an orderly manner.

6.4 Soil for Repairs (if required). Not less than five days prior to the commencement of seeding operations, the Contracting Officer will be notified of the source from which soil for repairs is to be furnished. The material will be inspected to determine whether or not it meets the necessary requirements for repair material. The soil will be subject to approval prior to use.

7. GENERAL CONSTRUCTION REQUIREMENTS. Equipment must be in good condition and will be provided for accomplishing the work. Equipment will be subject to approval before work is started.

7.1 Clearing. Areas to be seeded will be cleared of any materials that might impede work progress and proper restoration techniques. These shall include stumps, roots, cables, wire, garbage or other debris. The collected material will be burned or removed from the site. Rocks up to cobble size may be left to foster water harvesting and to help establish seeds.

7.2 Seedbed Preparation.

7.2.1 Grading. Previously established grades will be maintained on areas to be treated in a true and even condition and necessary repairs will be made to previously graded areas. Areas having significant inadequate drainage, as indicated by ponding of water in low lying areas or on other areas, will be filled or graded to drain as directed by the Contracting Officer. Slight depressions and furrows, perpendicular to the flow of water, may be left or created to foster water harvesting.

7.2.2 Scarifying/Tilling. Immediately prior to seeding, the soil will be tilled and/or scarified, depending on the soil hardness, to a depth of 4-6 inches to prepare an acceptable seed bed. Areas with some established grass cover need not be scarified. The minimum acceptable depth will be 4 inches and will be confirmed by the Contracting Officer by random and frequent inspections. This work will be accomplished by ripping, disking, or harrowing on the contour, and care will be taken to maintain the contour. The Contractor shall utilize tractors with adequate horsepower and heavy-duty tillage equipment in accomplishing the specified tillage operations. Areas severely compacted will be tilled with a heavy-duty disc or chisel-type breaking plow, followed by disking with a harrow and smoothed with a weighted spike tooth harrow, railroad irons, or bridge timber float drag. When a chisel plow is used, the chisel will be set not to exceed 10 inches apart and the areas will be cross or double tilled. Tilled areas will be left smooth, i.e., free of large clods and clumps not greater than egg size. A range of soil particle size, up to egg size, is desirable. As stated, slight depressions and furrows perpendicular to water flow will be permitted. If the soil is in a loosened and friable state (up to a minimum of 4 inches) as a consequence of construction activities, this operation need not be performed (as determined by the Contracting Officer).

7.2.3 Mechanical Application of Fertilizer. Will be applied following scarification of the soil, and prior to commencing seeding operations. No more than 24 hours shall elapse between fertilization and seeding operations.

The fertilizer distributor box will be equipped with baffle plates to prevent downward movement of fertilizer when operating on a slope. Application of fertilizer by use of a fertilizer attachment for the rangeland drill, as hereinafter specified, will be permissible for simultaneous dispersal of fertilizer and seed. Fertilizer shall not be dispensed through a seed hopper.

Fertilizer will be uniformly distributed with a fertilizer distributor (Eke Flow) or comparable substitute, at the rate previously specified.

7.2.4 Planting seed.

7.2.4.1 Standardization. Prior to the initiation of the seeding process, a typical area to be seeded will be selected. The Contractor shall conduct seeding equipment calibration tests in the presence of the Contracting Officer, to determine the appropriate equipment setting for planting seed at the specified rates. The entire seeding operation will be performed in this area according to project specifications and agreed upon by the Contracting Officer and the Contractor. This area shall serve as a trial run for the seeding work that will follow and the quality of work expected. If unplanted skips are noted after germination and growth of grass, the Contractor will be required to seed unplanted areas with specified grass or grass mixtures, at no additional cost to the Government. Seeding boxes will be kept at least half full during seeding operations to ensure even distribution of seed over all areas. Seeding equipment operation on slopes will be anchored, as required, to prevent downward movement of equipment and formation of deep ridges or ruts.

7.2.4.2 Planting. Seed will be planted with a rangeland drill to a minimum depth of 0.25 inch and not deeper then 0.5 inch. Direction of planting will be across the slope, i.e., parallel to the contour. Seeding operations will be accomplished as permissible, weather conditions permitting, and during the specified field dates. Seeding rates, types, and quantities provided as specified in subparagraph, Seed Mixtures. The seed will be mixed thoroughly in the presence of the Contracting Officer and planted through the chaffy seed box. The seed will be planted after tilling and prior to mulching. Disks and spouts on the seed drill will be adjusted to 10 inches apart. The disks will be equipped with depth-control bands. The prescribed mix and rate will be uniformly applied over the area to be seeded. Bulk poundage for each species of seed will be determined by the PLS content of the seed purchased. The PLS poundage given in subparagraph, Seed Mixtures, will not be misinterpreted to mean the bulk poundage of seed to be used. The Contracting Officer will verify the Contractor's seed rate computations. Seed boxes will be kept at least half full during seeding operations to insure even distribution of seed over all the areas seeded. Bulk may be increased by the use of fertilizer, cornmeal, sawdust, rice hulls, sand, or other acceptable medium. Seeding equipment operating on slopes will be anchored, as required, to prevent downslope movement and formation of deep ridges or ruts. For small areas inaccessible to a seed drill, seeding may be accomplished by broadcasting with a "cyclone" hand-held seeder or comparable broadcast seeder. If seed is broadcast, it will be covered by lightly raking by hand. If unplanted skips and areas are observed after germination of the grass, the Contractor will be required to seed the these areas with specified grass or grass mixtures, at no additional cost to the Government.

7.2.4.3 Protection. Seeded areas must be protected against foot traffic or other use by erecting barricades immediately after seeding is completed and by placing warning signs of a type approved by the Contracting Officer on the various areas. Such protective devices will be maintained until completion of all work under this contract.

7.2.5 Mulching.

7.2.5.1 Applying Mulch. The grass hay mulch will be spread uniformly in a continuous blanket, using 1.5-to-2.0 tons of mulch per acre. Mulch will be spread by hand or by an approved blower-type mulch spreader, and applied so as to prevent excessive breakage of the mulch material. If this cannot be accomplished, the mulch will be spread by hand. Care will be exercised to insure that all wire from baled hay is collected as it is removed from the bale and then removed from the site. Mulching will be started at the windward side of relatively flat areas, or at the upper part of a steep slope, and continued, uniformly, until the area is covered. The mulch will not be bunched and the thickness of the mulch will be limited so that some sunlight and all precipitation will reach the ground and so that the mulch can be anchored.

7.2.5.2 Anchoring Mulch. Immediately following the spreading, the mulch will be anchored in the soil to a depth of 2-3 inches. An approved machine, comparable to a disk harrow with cupped disks removed and replaced with straight rolling coulters adjusted to 8 inches apart and having edges approximately 1/8-inch wide, will be used to anchor the mulch. The machine(s) will be weighted and operated in such a manner to secure the hay firmly in the ground to form a soil-binding mulch and prevent loss, or bunching, of the hay by wind. Suitably anchored mulch will be firmly embedded in the soil with an anchored "tent" formed by the hay strands between crimp lines. The mulch anchoring machine will be anchored as required to prevent downslope movement and the formation of ridges and ruts. Suitable anchoring equipment will be on hand, ready for use, prior to applying the mulch. The coulters will be at least 10 inches in diameter. Mulch will be secured within 24 hours after seeding. The number of passes needed, not to exceed three, will be determined by the Contracting Officer.

7.2.5.3 Maintenance. Mulched areas will be maintained until all work, or designated portions thereof, have been completed and accepted. Maintenance will consist of providing protection against traffic by erecting barricades and placing warning signs as specified in paragraph, Protection. Any damage will be repaired and mulch material that has been damaged by wind, or other causes, will be replaced and secured.

8. QUALITY CONTROL.

8.1 General. The Contractor will establish and maintain quality control for the work covered in this section of the Technical Provisions to assure compliance with contract requirements and maintain quality control records for all construction operations including, but not limited to the following:

(1) Field Inspection of materials.

(2) Seeding.

(3) Maintenance.

8.2 Two legible copies of these records and tests, as well as the records of corrective measures taken, will be furnished to the Government, as directed by the Contracting Officer.