S01. Atch 1 Specifications.pdf

Quencer-Wetland Restoration Jefferson County 850 - 1 May 2020

WETLAND RESTORATION

CONSTRUCTION SPECIFICATIONS

For

William Quencer Town of Brownville

Jefferson County, New York

Jefferson County 850 - 2 May 2020

NATURAL RESOURCES CONSERVATION SERVICE

CONSTRUCTION SPECIFICATION

850 – STRUCTURE FOR WETLAND RESTORATION

1. SCOPE

The work shall consist of constructing and/or installing structure(s) for wetland restoration at locations shown on the drawings.

Prior to commencing construction, public utilities shall be notified in accordance with N.Y.S. Industrial Code Part 753.

2. MATERIALS

The earth material used in constructing the ditch plugs shall be obtained from required excavations and designated borrow areas. It shall be free of frozen particles, brush, roots, sod, stones over 6 inches in diameter, organic material, topsoil or other objectionable materials.

The selection, blending, routing and disposition of materials in the various fills shall be subject to approval by the Engineer or designated representative.

3. FOUNDATION

The foundation area shall be cleared of all trees, logs, stumps, roots, brush, boulders, rubbish and debris. Topsoil and sod shall be stripped to the depth as shown on the drawings or as indicated in the field by the Engineer or designated representative. The stripped material shall be stockpiled for use on disturbed areas after construction. The foundation shall not be frozen, and its surface shall be thoroughly scarified before placement of fill material. Ruts left over from the tracks of construction equipment or made by the teeth of the excavator bucket shall be considered adequate scarification.

Compaction shall be as specified in Section 6.

4. BORROW AREA

Borrow areas within the impoundment area shall be as shown on the drawings or flagged in the field by the Engineer. If high permeability materials are exposed during excavation within the pool area, excavation shall be halted. Twelve (12) inches of suitable low permeability material shall be placed in lifts no thicker than 6 inches to cover the pervious layer and each lift shall be compacted as specified in Section 6. Suitability of the low permeability material shall be determined by the Engineer or designated representative.

Excavated side slopes shall be no steeper than 3H:1V unless specified in Section 8.

Jefferson County 850 - 3 May 2020

Excavation depth shall not exceed 2½ feet below the specified normal water elevation except in those areas shown on the drawings or flagged in the field by the Engineer or designated representative.

If additional borrows areas are needed, the locations and suitability of materials shall be determined by the Engineer or designated representative.

Borrow areas shall be finished as shown on the drawings or as specified in Section 8.

5. FILL PLACEMENT AND COMPACTION

The placing and spreading of fill material for ditch plugs shall be started at the lowest point of the foundation. The fill shall be placed in horizontal lifts not to exceed 6 inches unless specified in Section 8. No fill material shall be placed in standing or flowing water. The distribution and gradation of materials throughout the fill shall be such that there will be no lenses, pockets, streaks, or layers of material differing substantially in texture or gradation from the surrounding material.

Each lift of fill material shall be compacted with a minimum of four passes of the tracks of construction equipment such as a bulldozer, track mounted excavator, or by use of a non-vibratory roller compactor so that all parts of each lift are equally compacted. The actual number of passes required to achieve adequate compaction shall be determined in the field by the Engineer or designated representative.

Fill material shall have optimum moisture content for compaction. The Engineer or designated representative shall determine if the soil has sufficient water content. Material with a moisture content that is too high shall be dried prior to placement. Material with a moisture content that is too low shall be wetted.

Application of water by spraying the top of the in-place lift or another method approved by the Engineer or designated representative shall be used.

6. FINAL GRADING

Stockpiled topsoil shall be spread on all disturbed areas to a minimum depth of 4 inches. Topsoil on the ditch plugs and spoil piles shall be smoothed enough to be free draining and allow for seeding. Within the excavated impoundment and borrow area, the topsoil shall be left rough with clumps of vegetation and soil.

Undesirable vegetation shall be eliminated from this area. Desirability of vegetation shall be determined by the Engineer or designated representative. No topsoil shall be placed in excavated sump area.

7. MEASUREMENT AND PAYMENT

Payment for the Structure for Wetland Restoration will be made at the contract lump sum price. Such payment shall constitute full compensation for all labor, material, equipment, tools and all other appurtenances necessary and incidental to the completion of the work, including supplying, installing, and backfilling any associated structure.

Jefferson County 850 - 4 May 2020

Compensation for any item of work described in the contract but not listed in the bid schedule will be included in the payment for the work to which it is made subsidiary. Such items are identified in Section 8 of this specification.

Jefferson County 850 - 5 May 2020

8. ITEMS OF WORK AND ADDITIONAL CONDITIONS

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

A. Site Preparation

1. Mobilize equipment using approved legal ROW access.

2. Removal of water from the construction site, shall be accomplished so that erosion and the transporting of sediment and other pollutants are minimized.

(a) The contractor shall install, maintain, and operate all cofferdams, channels, flumes, sumps, and all other temporary diversion and protective works needed to divert streamflow and other surface water through or around the construction site. Control of surface water shall be continuous during the period that damage to construction work could occur. Unless otherwise specified and/or approved, the diversion outlet shall be into the same drainage way that the water would have reached before being diverted.

(b) Foundations, cutoff trenches, and all other parts of the construction site shall be dewatered and kept free of standing water and muddy conditions as necessary for the proper execution of the work. The contractor shall furnish, install, operate, and maintain all drains, sumps, pumps, casings, well points, and all other equipment required to properly dewater the site as specified. Dewatering systems that cause a loss of soil fines from the foundation areas will not be permitted.

(c) When temporary works are no longer needed, the contractor shall remove and return the area to a condition similar to that which existed before construction. Areas where temporary works were located shall be graded for slightly appearance with no obstruction to natural surface water flows or the proper functioning and access to the works of improvement installed.

The contractor shall exercise extreme care during the removal stages to minimize the loss of soil sediment and debris that was trapped during construction.

Stripping of topsoil shall be accomplished as specified in Section 3 of this Specification. The stripped topsoil shall be salvaged and re-used.

B. Grading Existing Topsoil piles

1. Grade existing topsoil to match adjacent land, no higher than 3 feet and 6:1 side slopes. All areas will be seeded and mulched according to the attached seed specification.

C. Pothole Excavation

1. Areas to be excavated shall be stripped of all topsoil and sod and kept separate from subsoil to be respreads on spoils mounds.

2. All potholes will be irregular in shape with no islands or peninsulas.

Jefferson County 850 - 6 May 2020

3. Potholes will have varying depths with excavated depths not to exceed 5 feet and no less than 1 foot.

4. Potholes side slopes will be 6H to 1V or flatter.

5. 4-6” layer of topsoil will be sporadically spread within the finished pothole.

6. Excess spoil material will be spread adjacent to pothole and not exceed 3 foot high.

7. Topsoil will be respreads on spoil mounds prior to seeding and mulching.

D. P4-Pothole Rework

1. Dewater pothole prior to starting excavation work.

2. Remove peninsula, strip off any topsoil and stockpile. Excavate clay parent material northwest as indicated on plan view.

3. Expand the pothole footprint and excavate some deeper depths within the pool area.

4. Northwest location for excess excavated material must be stripped of topsoil and sod prior to placement measuring 20 feet wide and running the length of the pothole, see detail on plan view. This will ensure water does not seep out of pothole’s lower end. Excess excavated material will be piled no higher than 2 feet and material will be covered with topsoil and/or sod prior to seed and mulch.

E. Ditch Plug Excavation

1. Remove all existing vegetation and topsoil from the footprint of each ditch plug.

Topsoil shall be stockpiled for re-spreading on the plug.

2. Borrow material for ditch plug will be located at least 10 feet from the upstream toe of the plug. Borrow excavations will not exceed 3 feet depth and side slopes will be no steeper than 6 to 1.

3. Fill material will not contain vegetation, sod, frozen material, brush and roots, or stones larger than 6 inches in diameter.

4. Ditch plug horizontal lifts will not exceed 9 inches. No fill material will be placed in standing or flowing water.

5. Each lift of fill material will be compacted with 3 passes of a track-mounted construction equipment.

6. All side slopes will be no steeper than 5H: 1V.

7. A minimum of 4 inches of topsoil will be spread on each completed ditch plug prior to seed and mulch.

Jefferson County 850 - 7 May 2020

F. Seeding and Demobilization

1. All disturbed areas will be broadcast seeded if site is accessible within 24 hours of completion or alternative timeline approved by NRCS representative The seed will be a uniform mixture at the following rates:

a. Ensylva Creeping Red Fescue 20 lbs/ac

b. Common Redtop 3 lbs/ac

c. Empire Birdsfoot Trefoil 8 lbs/ac

G. Straw mulch will be applied at a rate of 2 tons/acre (100-120 bales per acre).

Seeding must be completed before September 15th. Any seeding completed after September 15th must include 30 lbs/ac of winter rye.

H. Silt fence will be removed from site and will be disposed of according to manufacturer recommendations.

I. Repair/refurbish access or any other property damage during construction. All debris, excess construction, material and all small metal debris must be removed from the site prior to demobilizing equipment.

Design Narrative William Quencer

Wetland Restoration

LOCATION:

Wetland Restoration project is located off Star School Road in the Town of Brownville situated in Jefferson County, New York. GPS coordinates 44°02'24.9"N, 76°01'00.2"W.

PROJECT:

The main objectives of the William Quencer wetland restoration project align with the objectives of Agricultural Conservation Easement Program- Wetland Reserve Easements (ACEP- WRE) formerly known as the Wetland Reserve Program and Conservation Practice Standard 657 to protect, restore, and enhance the functions and values of wetland ecosystems to attain:

1. Habitat for migratory birds and other wetland-dependent wildlife.

2. To re-establish the original hydrology and vegetative plant community that existed prior to agricultural manipulation.

3. Improve water quality by filtering sediments and chemicals, reduce flooding, recharge groundwater, protect biological diversity and provide opportunities for educational, scientific and limited recreational activities.

The wetland restoration project is on a permanent easement that is 100% cost- share by NRCS

DESIGN SUMMARY:

Construction of this wetland project had commenced in 2015. Due to unexpected situations, construction was halted and has not recommenced. This federal contract will be to commence construction under existing site conditions in accordance with the design drawings and specifications provided in Attachment C.

This project does not require permits.

The design calls for installation of five ditch plugs to restore the wetland hydrology of site by plugging an existing draining ditch which drains north from Star School road towards the Perch River. The ditch plugs will prevent the surface ditch from draining the site and also create small open water regimes upstream of each ditch plug. The ditch plugs vary in length, but all have a top width of 20 feet, 5 to 1 side slopes and average 2.3 feet in height. The fill material may be obtained from the material excavated for the pothole construction.

The design also includes five potholes that will be excavated at various locations in accordance with the design drawings. Each pothole will have varying depths. The potholes will be excavated within clearings located in a scrub shrub area dominated by willows and within the abandoned hayfield. Each pothole will vary in area from 0.1-1.0 acres to encompass approximately 6 acres total for all five. Excavated material will be graded and blended into adjacent areas in low mounds not to exceed 3 feet in height and located a minimum of 20 feet apart or graded into adjacent upland areas where practical. Excavated material will be covered with topsoil to promote natural vegetation.

PERFORMANCE PERIOD:

The estimated performance period to complete the construction is twenty business days (four weeks).