Technical_Specifications.pdf

TECHNICAL

SPECIFICATIONS

FOREBAY DREDGING AT

CENTER SPRINGS POND

BID 25/26-14

Town of Manchester, CT

MOBILIZATION AND PROJECT CLOSEOUT

TECHNICAL SPECIFICATIONS

MOBILIZATION AND PROJECT CLOSEOUT

DESCRIPTION

“Mobilization and Project Closeout” consist of all work necessary for moving project personnel and equipment to the project site; all work necessary for the establishment of the Contractors’ field offices, buildings and other facilities, if required, which are necessary for Contract performance; the preparation of work plans and other documents identified elsewhere in the

Contract that must be submitted by the Contractor prior to the start of physical construction;

demobilization of plant and equipment; completion of all physical work; and completion of administrative closeout items as required by the Contractor.

MEASUREMENT

“Mobilization and Project Closeout” will be measured for payment in accordance with Section

9.75.04 of the Form 818.

PAYMENT

The work under this item will be paid for at the Contract lump sum price for “Mobilization and

Project Closeout” which price shall include materials, equipment, tools, transportation, labor and all work incidental thereto. Payment for this item shall be made only once per project site as depicted on the Plans.

Pay Item Pay Unit

Mobilization and Project Closeout Lump Sum

EROSION AND SEDIMENTATION CONTROLS

“Erosion and Sedimentation Controls” includes the furnishing, placing, maintaining and removal of erosion and sedimentation control measures where shown on the Plans or where directed by the Engineer.

MATERIALS

Geotextile shall conform to Section M.08.01.19 of Form 818.

Silt Sack shall be Hi-Flow Siltsack® Type A (for Type “C-L” catch basin tops) and Type B with curb deflector (for Type “C” catch basin tops or other structure with curb inlets) as manufactured by ACF Environmental, Inc., Richmond, VA (800-448-3636) or approved equal. Silt sack shall be provided with internal overflows and meet the following criteria:

Properties Test Method Units

Grab Tensile Strength ASTM D-4632 265 lbs

Gran Tensile Elongation ASTM D-4632 20%

Puncture ASTM D-4833 135 lbs

Mullen Burst ASTM D-3786 420 psi

Trapezoid Tear ASTM D-4533 45 lbs

UV Resistance ASTM D-4355 90%

Apparent Opening Size ASTM D-4751 #20 U.S. Sieve

Flow Rate ASTM D-4491 200 gal/min/sq ft

Permittivity ASTM D-4491 1.5/sec

Crushed stone for Construction Entrances shall conform to “Grading A” of Section M.02.06 of

Form 818.

Straw wattles shall be AEC Premier Straw Wattle, as manufactured by American Excelsior

Company, Arlington, TX (1-866-9FIBERS), or approved equal.

Turbidity curtain shall be manufactured by ACF Environmental, Richmond, VA (800-448-3636) or approved equal.

RESPONSIBILITY

It is the Contractor’s sole responsibility to provide and continually inspect and maintain all erosion and sedimentation control measures on the site. Failure to do so may result in enforcement actions by the Town of Manchester or State of Connecticut. The erosion and sedimentation control measures shown on the Plans or in these Specifications are intended as a guideline to show the minimal control measures required based on the intended construction.

Additional control measures may be necessary depending upon the Contractor’s operations and scheduling of the project.

CONSTRUCTION DETAILS

Geotextile sedimentation control systems may consist of either a prefabricated geotextile fence or a geotextile fence assembled by the Contractor in the field. Geotextile sedimentation control systems shall be installed so that the bottom six (6) inches of the fabric is buried by either trenching or by laying the six (6) inch section horizontally on the ground and burying by ramping the soil up to the control fence. All geotextile fences shall be a least 42 inches in exposed height as installed, with not less than a two (2) degree and not more than a 20 degree inclination toward the potential silt source. Hardwood posts shall have a minimum cross-section size of at least 1.5 inches by 1.5 inches and a minimum length of 30 inches. Steel posts shall be at least 0.5 pound per linear foot with a minimum length of 48 inches. Spacing between posts shall not exceed ten

(10) feet, and all posts shall be driven a minimum of 12 inches into the ground. When joints between sections of geotextile sedimentation control systems are necessary, geotextile shall be spliced together only at a support post, with a minimum six (6) inch overlap, and securely sealed.

The installations shall be maintained or replaced until they are no longer necessary for the purpose intended or are ordered removed by the Engineer. Cleanout of accumulated sediment shall be accomplished when one-half of the original height of the sedimentation control system, as installed, becomes filled with sediment or as ordered by the Engineer.

The geotextile fence systems will be completely removed from the project at the completion of the project, unless specifically authorized by the Engineer to be left in place.

Straw wattles shall be securely staked into the ground with minimum 1 1/8” x 1 1/8” wood stakes.

Unless a specific type of sedimentation control system is indicated on the plans or directed by the

Engineer, the type of system will be at the Contractor’s option.

Silt sacks shall be installed in accordance with manufacturer’s instructions and shall be emptied and legally disposed of when they have collected 6” to 12” of sediment and when directed by the

Engineer. Silt sacks shall be inspected every 1 to 2 weeks and after every major rainfall event.

Turbidity curtains shall be installed in accordance with manufacturer’s instructions.

Erosion and sedimentation control measures shall be installed and accepted by the Engineer prior to any excavation, grubbing or other operation that disturbs existing ground.

MEASUREMENT AND PAYMENT

“Erosion and Sedimentation Controls” will be measured for payment by the lump sum and shall include the furnishing, installation, maintaining and removal of all erosion and sedimentation control measures shown on the Plans or directed by the Engineer. It shall include all labor, equipment, materials, tools and incidentals required. Partial payment of 75% of the unit price will be paid at the time of installation. The remaining 25% of the unit price will be paid at the time of removal.

Erosion and Sedimentation Controls Lump Sum

HANDLING WATER

HANDLING WATER

“Handling Water” shall consist of:

1) Dewatering of the existing sediment forebay as necessary to complete the work;

2) The construction of temporary measures to bypass continuous flow of water around the construction area, or other such protective facilities and methods as are necessary for the conduction of water beyond the limits of construction;

Hay bales and silt fence shall conform to the requirements of “Erosion and Sedimentation

Controls” elsewhere in these Specifications.

The Contractor shall monitor the forecasted weather and schedule the work when there is a forecasted period of consecutive days of dry weather.

The Contractor shall furnish the Engineer with a plan that provides all details and methods for handling water and accomplishing the work to the satisfaction of the Engineer.

Dewatering pumping from within the areas of work shall be done in such a manner as to minimize turbidity within the pond. Pump systems shall be fitted with mesh screens necessary to minimize impacts to aquatic wildlife.

Prior to pumping, a pump settling basin as shown on the Plans shall be installed to control sediment from entering the main pond.

Unless otherwise provided, or directed, all such temporary protective work shall be removed and disposed of in an approved manner when no longer required.

“Handling Water” will be measured for payment by the lump sum, and shall include all tools, material, equipment, labor and work incidental to the dewatering and construction, maintaining and removal of temporary construction measures required to perform the work as shown on the

Plans.

Handling Water Lump Sum

SEDIMENT REMOVAL

SEDIMENT REMOVAL

“Sediment Removal” shall consist of:

1) The removal of existing sediment within the work area necessary to restore the forebay bottom to its original elevations;

2) The dewatering of the excavated sediment at the location shown on the Plan;

3) The hauling of dewatered excavated material from the work area to the Manchester

Landfill (311 Olcott Street Manchester);

All materials required for handling water shall conform with the applicable section of these

Specifications. If proposed materials are not specified, the Contractor shall provide material submittals to the Engineer for review and approval.

Access to the forebay shall be via the northern shoreline only (in the vicinity of the proposed pre-forebay). A minimum 5’ wide buffer shall be maintained along the remaining pond edges to minimize impacts to wetlands vegetation.

All erosion and sedimentation control measures shall be installed prior to starting the dredging operation.

Forebay dewatering shall conform to the requirements of the “Handling Water” specification elsewhere in this contract. The Contractor shall stage the dredging operation such that small pools of water remain within the work area for aquatic habitat to take refuge. Effort shall be taken to relocate and/or protect aquatic wildlife during the sediment removal as needed.

It is anticipated that traditional excavation methods will be used for the dredging operation. The

Contractor may submit alternate methods for approval.

The exact quantity of material to be excavated is not known, but is estimated at between 750 and

1,000 cubic yards. It is the intent to remove soft sediment and restore the forebay bottom as close to the original elevations (shown on the Plan) as possible. The Town will provide two benchmark elevations close to the work area to assist with determining excavation depths.

Excavated material shall be transported to the proposed area for dewatering.

The sediment will be sampled by the Town in accordance with the Town of Manchester’s

Special Waste Disposal program. Sediment shall remain in the dewatering area until the results of the testing are received. Once the sediment has sufficiently dewatered and test results are received, it shall be transported to the Manchester Landfill for disposal. Tipping fees will be waived.

“Sediment Removal” will be measured for payment by the actual number of cubic yards of dewatered dredged material, and shall include all tools, material, equipment, labor and work incidental to complete the work as specified.

Sediment Removal Cubic Yards

RIPRAP PRE-FOREBAY

TECHNCIAL SPECIFICATIONS

RIPRAP PRE-FOREBAY

DESCRIPTION

“Install Riprap Preforebay” includes the furnishing and installation of angular shaped crushed stone slope protection on a prepared base at the locations shown on the Plans or as directed by the Engineer in accordance with these Specifications.

A. Stone: Stone shall consist of sound, tough, durable and angular rock, free from decomposed stones or other defects impairing its durability. The size of a stone as hereinafter specified shall be its least dimension. Broken concrete or rounded stones are not acceptable. The type of material to be used shall be as noted on the plans, in the special provisions or as may be ordered by the Engineer.

Grading for the various types of riprap shall conform to the requirements of Section

M.12.02.03 “Modified Riprap” of Form 818.

B. Geotextile shall conform to Section M.08.01.19 of Form 818 and shall be submitted to the Engineer for approval.

C. Granular fill shall conform to the requirements of Section M.02.01 of Form 818.

The contractor shall excavate and key into the existing slope as shown in the plans. Bedding material shall be placed on the prepared area and compacted to the depth, lines and grades indicated on the plan. The riprap shall be placed to its full course thickness in one operation in such a manner as to produce a reasonably well-graded mass of rock without causing displacement of the underlying material. The finished surface shall be free from pockets of small stones and clusters of large stones. Placing this material by methods likely to cause segregation of the various sizes of stone will not be permitted. Rearranging of individual stones by mechanical or hand methods will be required to the extent necessary to obtain a reasonably well-graded distribution of the specified stone sizes. The completed course shall be of the specified thickness and to the lines and grades as shown on the plans or as ordered by the Engineer.

“Install Riprap Pre-Forebay” will be measured for payment by the lump sum, completed and accepted, and shall include all excavation, geotextile, bedding material, riprap, equipment, tools, and labor incidental thereto.

Install Riprap Pre-Forebay Lump Sum

RESTORATION OF LAWN AND WETLAND AREAS

AND EROSION CONTROL BLANKET

RESTORATION OF LAWN AND WETLAND AREAS AND EROSION CONTROL BLANKET

“Restoration of Lawn Areas” includes all work required to establish turf, including the furnishing and installation of screened topsoil and of a specified slurry mixture of seed, fiber, fertilizer and stabilizer emulsion with hydro-mulch equipment, where shown on the Plans or where directed by the Engineer.

“Restoration of Wetland Areas” includes all work required to establish vegetation, including the furnishing and installation of screened topsoil, and of a specified slurry mixture of seed, fiber, fertilizer and stabilizer emulsion with hydro-mulch equipment, within the wetlands areas identified on the Plan or where directed by the Engineer.

“Erosion Control Blanket” includes the furnishing and installation of a manufactured straw/fiber blanket at the locations shown on the Plans or where directed by the Engineer.

Fertilizer: Fertilizer shall conform to the requirements of Section M.13.03 of Form 818 or an approved equal. Soil testing and analysis may be performed by the Contractor at the

Contractor’s expense to determine fertilizer rate. Submit Manufacturer’s product specifications and guaranteed purity analysis for fertilizer. Apply at a minimum rate of 25 lbs/ 1,000 SF or as per recommended by results of soil testing.

Mulch: Cellulose fiber mulch shall conform to the requirements of Section M.13.05.3 of Form

818. Apply at a minimum rate of 40 lbs/ 1,000 SF.

Tackifier: Organic tackifier shall be applied at rate of 70 lbs./acre

Topsoil: The term topsoil used herein shall mean a soil meeting the soil textural classes established by the United States Department of Agriculture Classification System based upon the proportion of sand, silt, and clay size particles after passing a two (2) millimeter (mm) sieve and subjected to a particle size analysis. The topsoil shall not contain less than 6% nor more than

20% organic matter as determined by loss-on-ignition of oven dried samples dried at 105 degrees centigrade.

The following textural classes shall be acceptable:

Loamy sand, including coarse, loamy fine, and loamy very fine sand

Sandy loam, including coarse, fine and very fine sandy loam

Loam

Silt loam, with not more than sixty (60) percent silt

The topsoil to be furnished by the Contractor shall be loose, friable, reasonably free of admixtures of subsoil, free from refuse, stumps, roots, brush, weeds, rocks, and stones ½ inch and over in all dimensions. The topsoil shall also be free from any material that will prevent the formation of a suitable seedbed or prevent seed germination and plant growth.

Seed: Shall meet the requirements of Section M.13.04 of Form 818 and be fresh and clean and new crop seed composed of an evenly graded mixture by proportion and testing minimum percentages of purity and germination indicated, or as approved by the Engineer.

The grass seed mixture, for lawns with <=3:1 slope with mowing required, shall have no noxious weeds in mix and shall conform to the following CTDOT mixture:

Species

Proportion by Weight

(Pounds)

Minimum

Purity

(Percent)

Minimum

Germination

(Percent)

VELVET

BENTGRASS

(ARGOSTIS

CANINA)

Certified Variety

25 96 85

RED FESCUE

(FESTUCA RUBRA

L. SSP. RUBRA)

Certified Variety

35 97 80

PARTRIDGE PEA

(CHAMAECRISTA

FASCICULATA)

Certified Variety

10 95 90

INDIAN GRASS

(SORGHASTRUM

NUTANS)

Certified Variety

15 95 90

CANADA

WILDRYE

(ELYMUS

CANADENSIS)

Certified Variety

5 95 90

KENTUCKY BLUE

GRASS (POA

PRATENSIS)

Certified Variety

10 95 90

Under no circumstances shall annual Ryegrass, Italian Rye, or any other seed be added to the seed mixture.

The seed mixture for channel embankments and lawns >3:1 slope with mowing not required shall have no noxious weeds in mix and shall generally conform to the following requirements:

Proportion by

Weight

(Percent)

Minimum

Germination

(Percent)

Creeping Red Fescue 54.0 85

Redtop 5.0 85

Crown Vetch 40.0 90

Other Ingredients 1.0 -

The seed mixture for wetlands areas shall be submitted to the Engineer for review and approval.

The seed mixture for wildflower mix shall be submitted to the Engineer for review and approval.

“Temporary” grass seed shall be annual ryegrass, or an approved equal. The temporary grass shall be used for topsoil and similar material stockpiles that are not to be used within 30 days or used for other applications as directed by the Engineer or submitted to the Engineer for review and approval.

Erosion control blanket: shall be a machine produced mat consisting of 100% coconut fiber.

The blanket shall be of consistent thickness with the coconut fiber evenly distributed over the entire area of the mat. The blanket shall be covered on the top side with heavyweight photodegradable polypropylene netting having ultraviolet additives to delay breakdown and an approximate 5/8 inch x 5/8 inch mesh, and on the bottom side with a lightweight photodegradable polypropylene netting with an approximate ½ inch x ½ inch mesh. The blanket shall be sewn together on 1 ½ inch centers with degradable thread.

Coconut fiber erosion control blanket shall be C125 as manufactured by North American Green, or approved equal. The C125 erosion control blanket shall have the following properties:

Material content

Coconut Fiber 100%

Netting Both sides, heavyweight UV stabilized

(3 lb/1000 sq ft approx wt)

Thread 100% Black Polypropylene

Physical Specifications

Width 6.67 feet

Length 108 feet

Weight 44 lbs +/- 10%

Area 80 sq yds

Stitch spacing 1.5 inches

Wire staples are to be produced from 11 gauge .118 to .120 bright basic industrial quality

1008/1010 wire, minimum cast, light oil protection. The staples shall be produced in a 6” x 1” x 6” U-shaped configuration.

Construction methods shall be those established as agronomically acceptable and feasible and which are approved by the Engineer.

The existing ground shall be graded to a reasonably true surface.

Topsoil shall be spread and shaped to meet existing elevation, after settlement and compaction has occurred, and have a minimum depth of four (4) inches with all stone larger than ½" removed.

In wetland areas, 8” of native topsoil/organic matter shall be stripped, stockpiled and reused for wetlands plantings.

It shall be the Contractor's responsibility to restore to the line, grade and surface all eroded areas with approved material and to keep topsoiled areas in acceptable condition until the completion of the construction work.

Examine work area before proceeding with any work and notify the Engineer in writing on conditions which may prevent the proper execution of this work. Failure to report unsuitable conditions will require the contractor to rectify unacceptable work at no additional cost to the

Town.

Allow the planting area soil surface to dry out for one day only prior to the hydroseeding application. Exercise care not to allow the soil surface to be overly saturated with water prior to the hydroseeding installation. At the same time the soil surface should not become too dry during this period. There should be some residual moisture within the first 1/4 inch of the soil surface.

Notify the Engineer at least 48 hours prior to starting the hydroseeding operation. The Engineer shall be present during the hydroseeding operation and has final determination if conditions are acceptable for hydroseed application.

Application rates for hydroseed shall be as defined by the manufacturer.

Apply the hydroseed in the form of a slurry consisting of organic soil amendments, commercial fertilizer, and any other chemicals that are called out. When hydraulically sprayed onto the soil, the mulch shall form a blotter-like material. Direct the spray operation so that this procedure will drill and mix the slurry components into the soil, the slurry spray will also penetrate the soil surface, thus ensuring maximum impregnation and coverage. The impregnation and mixing of the components will help in retaining moisture while stabilizing soil surface from superficial erosion.

Do not leave the hydroseeding slurry components in the hydroseeding machine for more than two (2) hours because of possible seed destruction. If slurry components are left idle for more than two hours in the machine, add 50% more of the originally specified seed mix to any slurry mixture which has not been applied within the two hours after mixing. Add 75% more of the original seed mix to any slurry mixture which has not been applied eight (8) hours after mixing.

All mixtures more than eight (8) hours old, must be disposed, offsite, at the contractor's expense.

Spray the area with a uniform visible coat, using the dark color of the cellulose fiber as a visual guide. The slurry shall be applied in a downward drilling motion via a fan stream nozzle. Insure that all of the slurry components enter and mix with the soil. Insure the uniformity of the hydroseed application.

Exercise special care to prevent any of the slurry from being sprayed onto any hardscape areas including concrete walks, fences, walls, buildings, etc. Remove all slurry sprayed onto these surfaces at the contractor's expense.

Contractor shall save all seed and fertilizer tags and fiber mulch bags for the Engineer to verify compliance with the drawings and specifications.

The Contractor shall maintain the area until sufficient seed growth has occurred to stabilize the soil. This includes the restoration of all eroded areas, and the placing and maintaining of erosion control measures as required to prevent further erosion.

Normal seeding season shall be:

For Grass:

Spring seeding - March 15 to June 30

Fall seeding - August 15 through October 31

For Wildflower:

Spring seeding - March 1 to May 15

Fall seeding - November 15 to December 15

Seeding at other times will be allowed only with permission of the Engineer.

The Contractor may be required to top dress and reseed certain areas to achieve sufficient, uniform turf establishment.

MAINTENANCE

Upon completion of hydroseeding operations, maintain all hydroseeded areas for a period of 90 calendar days as follows:

1. Germination stage irrigation: Approximately 24 hours after hydroseeding the planting areas, initiate the watering sequence. Leave the water on long enough to moisten the soil thoroughly to the depth of the slurry mulch taking care not to super saturate or wash away the slurry and seed. Perform frequent, light irrigation until the seed has germinated. Repair all seed washings and erosion.

2. Establishment stage irrigation: After germination, reduce each watering. The specific watering program shall be approved by the Engineer.

Fertilize all hydroseeded areas with an approved commercial fertilizer approximately thirty (30) calendar days from the start of the maintenance period.

ACCEPTANCE

Final approval and acceptance will be given in writing by the Engineer following a final acceptance inspection. The Engineer reserves the option to extend the maintenance period to achieve complete germination of all turf or other plant materials with a uniform height, color and density throughout all hydroseeded areas. Final acceptance may be given at the end of the 90 calendar day maintenance period if an acceptable germination of turf and adequate plant establishment has been obtained, as determined by the Engineer.

GUARANTEE AND REPLACEMENT

Provide a guarantee for a period of one (1) year after final acceptance, that the installed grass areas be at least the quality and condition as at the time of acceptance. Rehydroseed unacceptable areas during the guarantee period. The guarantee shall not include damage or loss of turf due to acts of God, acts of vandalism or negligence on the part of the Town.

“Restoration of Lawn Areas” and “Restoration of Wetland Areas” will be measured for payment by the actual number of square yards of topsoil and turf establishment performed in accordance with the Plans and Specifications.

The following items will not be measured separately for payment, but shall be considered as included in the unit price bid for “Restoration of Lawn Areas” or “Restoration of Wetland

Areas”:

1. Excavation

2. Fertilizer, seed or mulch

3. Topdressing and reseeding

4. Water

5. Lawn areas outside the grading limits disturbed by the Contractor

“Erosion Control Blanket” will be measured for payment by the actual number of square yards of erosion control matting installed and accepted. Turf establishment under the erosion control blanket will be measured for payment under the “Restoration of Lawn Areas” item.

PAYMENT

This work will be paid for at the contract unit price bid for "Restoration of Lawn Areas" or

“Restoration of Wetlands Areas”, which price shall include all the furnishing and fine grading of slope and lawns areas, topsoil, fertilizer, seed, replacement of lawn structures, labor, tools and equipment incidental thereto.

Any disturbance of lawns beyond the grading limits shown on the Plans shall be restored to its original condition by the Contractor at no expense to the Town of Manchester.

Final payment for this item will not be issued until grass is established to the approval of the

Engineer. Partial payments may be made, but in no case will more than 50% of the item be paid until the grass is established to the approval of the Engineer.

“Erosion Control Blanket” will be paid for at the contract unit price bid for “Erosion Control

Blanket”, which price shall include all materials, labor, tools and equipment necessary to install the erosion control blanket in accordance with the Plans and Specifications.

Restoration of Lawn Areas Square Yard