CAVE_ElectricLine_Reveg_Reqt_0001.docx

CAVE Electrical Line Revegetation Requirements

Weed Free Material Sources: Do not import into the project limits rock, sand, gravel, earth, subsoil, or other natural materials from a Contractor-selected non-commercial materials source, that have not been certified free of non-native, invasive plant species. Materials imported into the project limits which do not include a noxious weed free certification may be rejected and ordered by the CO to be removed from the project limits. The CO has the discretion of requesting inspection of certified materials by a third party, and rejecting the use of the source if non-native plants or seeds thereof are found to be present.

REVEGETATION CONTRACTOR QUALIFICATIONS

The Contractor/Subcontractor shall have a minimum of three years of experience performing post-disturbance site preparation activities (e.g. slope recontouring, soil decompaction, soil scarification, erosion control material installation) and hydroseeding utilizing the two-step method with native plant seed within the Chihuahuan Desert region. The Contractor/Sub must also provide a listing of relevant project experience, as well as three references available for contact.

SITE SOIL PREPARATION-

Recontouring and Decompaction: Shape/recontour the slopes and areas with disturbed soil by adjusting slopes in the horizontal and vertical planes to blend into existing, adjacent natural ground. Decompact slopes 1V:3H, or flatter, to a depth of 6-10" perpendicular to the natural flow of water, as determined by the CO. Scarification/de-compaction equipment (e.g. subsoiler, deep spader, ripping tines) will be used in such a manner that scarification furrows are no further than 6-9 inches apart and, where possible, equipment will travel across the site in 2 passes in perpendicular directions (cross-hatched pattern). When decompacting minimize water usage to only the amount needed to abate dust. Leave the soil surface roughened such that obvious furrows are eliminated. In addition, the maximum dirt clod size should be 4–6 inches in order to obtain a roughened surface that will maximum soil/seed contact. Take care to not re-compact the topsoil (e.g. do not repeatedly move heavy equipment over the site). Only conduct scarification/decompaction activities within one week prior to seeding. If there is a potential for erosion to occur, implementation of erosion control measures such as wattles are required. Coordinate at least 2 weeks prior to preparing areas with CO and NPS DSC representative to ensure their on-site presence at the initiation of site preparation activities.

SEEDING

Seed Source: The seed mix shall be locally appropriate, native species. All seed shall be government furnished. The seeding rate shall be 15-20 PLS (pure live seed) pounds per acre. Prior to seeding seed shall be pre-mixed at quantities provided by NPS.

Time of Seeding: Perform all seeding between June 15 and July 15 as the first preference. Seeding October 15 through January 15 may also be allowed per CO approval. Hydroseeding shall not be permitted over snow or during freezing temperatures. Any changes to the seeding window shall be directed by the CO and approved by the NPS representative in advance. Notify the CO three weeks before the seed is needed to ensure timely delivery.

Amendments: No fertilizers, mycorrhizae, or other amendments shall be added to the project areas.

Hydroseeding Implementation: Seed shall be applied utilizing the two-stage hydroseeding method described below:

First Application (Seed):

Preferred Method: Seed shall be applied by hand or with hand seeders. Mix seed with sand at a 1:1 ratio to aid in seed dispersal if working in extremely windy conditions. Seed will be distributed in such a way as to assure all species in the seed mix are evenly distributed across the area, regardless of seed size. Lightly rake the seed into the soil to a depth of ¼”. Do not smooth with the backside of the rake, light furrows in the soil are desired.

Secondary Method if Approved by CO: Seed shall be applied using hydroseeding equipment capable of providing a uniform application using water as the carrying agent. Add 500 lbs/acre of tracer material consisting of virgin wood fiber mulch to the water/seed to provide visible evidence of uniform application.

Second Application (Mulch):

2,000 lbs/acre of long strand virgin wood fiber and;

Non-toxic, and natural and biodegradable plant-based psyllium/alpha plantago tackifier. Depending on product apply at a rate of 80 lbs per acre on slopes less than 3H:1V and apply at a rate of 100 lbs/acre on slopes greater than 3H:1V.

Non-toxic, 100% environmentally safe tracer dye material at a rate of around 200-300 pounds per acre to provide visible evidence of uniform application.

All hydromulch mixing shall be performed in a clean tank. The tank and all hoses must be rinsed a minimum of three times, to remove any seed prior to arriving at the project site. The CO or authorized representative shall inspect the hydroseed equipment prior to operations and the contractor should assume a demonstration of clean water running through the tank/hoses will be required. The hydroseeder must be equipped with a built-in continuous agitation and recirculation system of sufficient operating capacity to produce homogeneous slurry and a discharge system that will apply slurry to the designated areas at a continuous and uniform rate.

The Contractor shall spray designated areas with the slurry in a sweeping motion and in an arched stream until a uniform coat is achieved, with no slumping or shadowing, as the material is spread at the required rate. The hydroseed slurry should float down from the arched stream, as opposed to being shot directly at the ground. During hydroseeding the existing native vegetation must be protected from damage (including, but not limited to, coating with mulch, damage by direct spray, and dragging hose). Notify the CO three weeks before hydroseeding to ensure that NPS oversight of seeding operations can be coordinated.

Warranty / Seeding Success Criteria: Seeded areas shall reach an average minimum of 20% cover of native plant species by the end of the first growing season following seeding implementation. Any areas greater than 15x15ft that do not meet the 20% cover shall be re-seeded following the hydroseed specifications above.