Hampton River Supplemental Spec-Dredging.pdf

PART 1 - GENERAL

1.1 SCOPE

Supplemental

Specification:

DREDGING

1.1.1 The work covered by this Section includes the furn ish ing of a l l mater ia l and equipment and the performing of all labor to complete the mechanical dredging and disposal of the dredged material as herein specified or directed by the City of Hampton

(“Owner”). Dredging activities shall be in accordance to the most updated plan set named, “Hampton River Maintenance Dredging” (“Contract Drawings”). Hydraulic dredging is not permitted.

1.1.2 This work shall include, but is not limited to:

a. Mechanical dredging of soil, organics and minor debris to the lines and grades indicated on the Contract Drawings.

b. Transportation and disposal of dredged materials at the Contractor-specified disposal site.

c. Removal, separation and disposal in an approved off-site location of non-organic and organic woody debris encountered during dredging operations.

d. Adhering to all requirements of approved disposal sites.

1.1.3 The materials to be removed under this Contract primarily consist of maintenance dredge materials and are principally mud, silt, soft clay, sand, organic matter, debris, trash, and combinations thereof, but shall include any material found within the area to be dredged.

Minor variations in the subsurface materials are to be expected and, if encountered, will not be considered as being materially different and will be included in the dredged materials excavated and disposed as part of this contract.

1.2 NOTIFICATIONS AND SUBMITTALS

1.2.1 Miss Utility (VA 811.com) Notification - The Contractor shall comply with all requirements of the Virginia Underground Utility Damage Prevention Act § 56-265.14

(the Miss Utility Law). The Contractor must call the Miss Utility Notification Center at

811 OR 1-800-552-7001 a t l eas t 72 hours before commencing any excavation work, including dredging.

The Contractor shall provide to the City of Hampton, in writing, all Ticket numbers, Miss Utility system responses and other information upon completion of the Contractor's notification process to Miss Utility prior to dredging. Requirements of the law, procedures to be followed by the Contractor and other pertinent information for the

Contractor's use can be found at http://www.missutilityofvirginia.com (or http://va811.com/lawspolicies/).

Each “person" as defined in the Underground Utility Damage Prevention Act must http://www.missutilityofvirginia.com/ http://va811.com/lawspolicies/ provide their own notice of excavation. Subcontractors may not work under another company’s ticket unless they are under the direct supervision of the company that provided the notice of excavation. The Contractor shall allow a minimum of 72 hours after notifying the Miss Utility notification center and begin excavation only after checking the Positive Response System and confirm through the Ticket Information Exchange (TIE)

System, that all applicable utilities have either marked their underground line locations or reported that no lines are present in the work vicinity. The Contractor shall wait an additional 24 hours before commencing excavation work if any utility operators have failed to respond to the Ticket Information Exchange within the first 48 hours.

If the Contractor is delayed due to conflict with a Private Utility after construction begins, the Contractor shall not be compensated for delay for not performing due diligence with the Miss Utility Private Utility location issues.

1.2.2 Dredging Operations Plan - Prior to any dredging work or any land disturbance, the

Contractor s h a l l h o s t a p r e c o n s t r u c t i o n m e e t i n g . At least one week prior to the preconstruction meeting, the Contractor shall submit a dredging plan for approval by the

Owner. No work shall begin without approval of the plan by the Owner. The plan shall include the following:

a. Names and specifications for all dredging w o r k to be used for each specific work element.

b. Name and location of the permitted disposal site and all applicable permits including but not limited to those listed in “Part 2 – Permits.”

c. Method and equipment for transporting dredged material from the dredging site to the shore side re-handling site.

d. Method and equipment for re-handling dredged material to shore.

e. Sequence of construction.

f. Coordinates and elevations of all control points for electronic positioning and vertical control.

g. Quality Control procedures.

h. Pre-dredge survey per Paragraph 1.2.6 and Section 3.7.

i. Complete project team organization with duties, responsibilities, and authorities clearly defined.

j. Schedule.

k. Spill Containment Plan.

1.2.3 Pre- and Post-Dredging Site Inspection Reports - Submit pre- and post-dredging site inspection reports to document site conditions for the canal dredged.

a. Contractor shall notify the City of Hampton one week prior to the preconstruction conference, one week prior to the commencement of land disturbing/dredging operations, and one week prior to the final inspection. A joint inspection of Hampton

River Maintenance Dredging Project limits shall be conducted by the Contractor and the Owner prior to commencing dredging operations. Pre-dredge site inspections shall document the condition of existing landscaping, shoreline, storm drain outfalls, and other site amenities (pavement, sidewalks, curb and gutter, ramps, etc.).

b. The Contractor and Owner shall conduct a post-dredging site inspection no more than

30 and no less than 5 days following completion of dredging. This inspection shall document the post-dredge condition of landscaping, shoreline, storm drains and other amenities (pavement, sidewalks, curb and gutter, ramps etc.) to ascertain any damages or deficiencies. The Contractor shall repair any damage attributed to (or due to) the

Contractor’s operation in a timely manner and at his expense as identified during this post-dredge inspection.

c. Inspect the work, keep records of work performed. Furnish, at the request of the

Owner, boats, boatmen, laborers, and materials necessary for inspecting, and supervising the work. When required, provide transportation for the Owner and inspectors to and from adjacent points on shore and the dredging plant. All transportation efforts are incidental to the dredging activity.

1.2.4 Dredging Daily Reports - During the performance of all dredging operations, equipment operators shall fill out a Daily Dredging Report for each calendar day's activity on each dredge being operated. Forms to be used shall be developed by the Contractor and approved by the Owner prior to starting of work. Forms shall be filled out completely and legibly; including signatures, using black ink. The original forms shall be held by the Contractor and given to the Owner upon request. The Daily Report shall be filled out for each calendar day even when the equipment is not working. Progress payments for dredging will not be made until a complete set of reports over the payment period are in the

Owner's possession along the supporting material explained in Paragraph 1.2.6 and Section

3.7.

1.2.5 Dredging Progress Plan - The Contractor shall prepare and maintain a daily progress plan of the dredging work. The plan shall have the same scale as that of the Project Drawings for the area being dredged and shall be marked to indicate the progress of the dredging work daily. These records shall be turned over to the Owner at the end of work.

1.2.6 Monthly Pay Applications – The Contractor shall prepare and submit monthly pay applications to the Owner with all applicable dredging surveys (pre-dredge survey and monthly post-dredge surveys per Section 3.7). The surveys shall be the basis of volume calculations to be included with each pay application to verify the quantity requested for payment by the Owner. Deviations from the quantity presented in the design plans and the quantity billed monthly shall have been explained and justified in writing to the Owner per

Section 3.7.

1.3 PERMITS

1.3.1 The Contractor shall comply with conditions and requirements of the following permits:

a. U.S. Army Corps of Engineers (USACE), Virginia Marine Resources Commission

(VMRC), and Department of Environmental Quality (DEQ) Permits for work occurring within the river and the associated canals and ancillaries.

b. U.S. Army Corps of Engineers (USACE) and Department of Environmental Quality

(DEQ) Permits for the designated Owner approved disposal site.

1.3.2 The Contractor shall comply with the requirements of all permits including the Virginia

Department of Environmental Quality (DEQ) General VPDES Permit for Discharges of

Stormwater from Construction Activities (if applicable) and the project Stormwater

Pollution Prevention Plan (SWPPP) prepared by the Contractor. The Contractor shall be responsible for any Notice of Violations (NOV) associated with non-compliance of any permits, laws or regulations.

PART 2 – MATERIALS – Not Used

PART 3 - EXECUTION

3.1 CONDUCT OF DREDGING WORK

3.1.1 Limits of Dredging - The limits of dredging are shown on the Project Drawings provided. The

Contractor shall dredge within the limits to the lines and grades shown following the directions in the General Notes and notes on the plans.

3.1.2 Mechanical Dredging - Material excavated by mechanical dredges (bucket, backhoe or dipper) shall be placed in hopper barges and transported to shoreline, where the barges (or dredged materials) shall be directly loaded into sealed dump trucks or dumpsters for transport to the disposal area. Excavated material may not be re-placed or stored in the water (misplaced) or stockpiled onsite. All hopper barges shall be kept in good condition and the coamings kept in good repair. Failure to repair leaks or change methods of operations that cause overflow or spillage will result in suspension of dredging and/or re-handling operations and require prompt repair or change of operation to prevent leakage, overflow or spillage. Dredging from the shoreline will be permitted in designated areas (dredging from the shoreline is not anticipated for this project).

3.1.3 Furnish, set and maintain buoys or PVC pipe markers at no more than 100-foot intervals along the limits to define the work and to facilitate inspection. Markers may be offset a uniform distance from the dredging toes. Establish and maintain gages in locations observable from each part of the work so that the depth may be determined. Suspend dredging when the gages or ranges cannot be seen or followed. All buoys and PVC pipe markers are incidental to the dredging activity.

3.1.4 Trash, debris, and other miscellaneous man-made and natural objects should be expected during dredging. The materials may be encountered at any location but are expected to be primarily limited to the surface and near surface areas. Material to be expected may include, but is not limited to, plastics, lumber, and tree branches. Such materials shall be handled in accordance with the following:

a. Material shall be placed in a separate barge or other conveyance.

b. Material shall be disposed of outside the limits of work on a land disposal area in accordance with local, state, and Federal laws and regulations.

c. The Contractor shall coordinate any tree trimming or vegetation removal required with the Owner prior to work.

3.2 REQUIRED DREDGING PRISM, OVERDEPTH AND SIDE SLOPES

3.2.1 Required Dredging Prism - Within the specific areas indicated to be dredged or areas approved by the Owner, the required dredging prism is defined by the required depths and applicable side slopes as indicated and specified. The actual quantity within the required dredging prism will be computed from the volume differences between the pre and post-dredge survey.

3.2.2 Overdepth - To cover inaccuracies of the dredging process, material actually removed from within the specific areas to be dredged to a depth of not more than 0.5 foot (6 inches) below the required depth will be quantified and paid for at the contract unit price.

3.2.3 Side Slopes and End Slopes – Material excavated in the area contained within the 4:1 (horizontal-to-vertical) side slopes will be paid for. Material actually removed, within limits approved by the

Owner, to provide for final side and end slopes not flatter than shown on the Project Drawings, but not in excess of the amount originally lying above this limiting slope, will be quantified and paid for, whether dredged in original position or by dredging space below the pay slope plane at the bottom of the slope for up-slope material capable of falling into the cut.

3.3 EXCESSIVE DREDGING

3.3.1 Material taken from beyond the limits as extended in subparagraphs 3.2.2 and 3.2.3 above will be deducted from the total amount dredged as excessive overdepth and/or side slope dredging. Nothing herein should be construed to prevent payment for the removal of shoals performed in accordance with Paragraph 3.5.2. The Contractor should be aware that dredging of material below or beyond depths or widths authorized in the Permits will expose him or her to potential legal action and fines from Federal and State Regulatory Agencies.

3.4 EXECUTION OF THE WORK

3.4.1 The execution of work shall ensure the stability of pipes, culverts, docks, revetments, and other structures lying on or adjacent to the site of the work, insofar as structures may be jeopardized by dredging operations.

Repair damage resulting from dredging operations, insofar as such damage may be caused by variation in locations or depth of dredging, or both, from that indicated or permitted under the contract.

3.4.2 Provide a system of communication between the Owner and the dredge crew

3.5 FINAL EXAMINATION AND ACCEPTANCE

3.5.1 Upon completion of dredging operations, a final post-dredge survey shall be conducted that includes the entire project dredging limits for review by the Owner. Should any shoals, humps, or other deviations from contract depth be disclosed that were not present in the monthly post-dredge surveys, the Contractor shall remove these features by dredging at the contract Unit Price for dredging.

3.5.2 Shoaling - If shoaling occurs in any section previously accepted, including shoaling in the finished lake/canal, because of the natural lowering of the side slopes, the Owner may direct the Contractor to re-dredge the shoaled areas at the contract Unit Price.

3.5.3 Final acceptance of the whole or a part of the work and the deductions or corrections of deductions made thereon will not be reopened after having once been made, except on evidence of collusion, fraud or obvious error, and the acceptance of a completed section shall not change the time of payment of the retained percentages of the whole or any part of the work.

3.5.4 Upon final acceptance of the work, promptly remove equipment and perform site cleanup. This includes barges, ranges, buoys, piles, and other markers or obstructions. All shall be removed within 10 calendar days of the final acceptance; otherwise, the project will be considered uncomplete and the Liquidated Damages may apply.

3.6 SITE RESTORATION

Upon completion of dredging and removal of dredging plant, the Contractor shall restore the construction area, staging area, and any streets to preconstruction conditions. Work shall include, but is not limited to, grading, seeding, bank restoration and repair of damaged site amenities. The Contractor shall meet all the final site stabilization requirements of the applicable Stormwater Pollution Prevention Plan (SWPPP).

3.7 MEASUREMENT AND PAYMENT

3.7.1 Dredging will be measured in cubic yards and payment will be at the contract unit price per cubic yard.

3.7.2 Pre-dredge surveys shall be conducted by the Contractor. Contractor shall notify the Owner of deviations between the pre-dredge survey and the existing condition survey provided in the

Contract Drawings.

3.7.3 Consistent with 1.2.6, the Contractor shall prepare and submit monthly pay applications to the

Owner with all applicable dredging surveys (pre-dredge survey and monthly post-dredge surveys). These surveys shall be prepared by a licensed professional land surveyor in the

Commonwealth of Virginia. The surveys shall be the basis of volume calculations to be included with each pay application to verify the quantity request for payment by the Owner.

Volumes shall be measured per cubic yard and shall be calculated by the Contractor by computing the total between the bottom surface shown by the pre-dredge survey and the bottom surface shown by the monthly post-dredge survey. Volumes shall include materials removed within the over-depth and side slopes described on the Contract Drawings, less any deductions that may be required for misplaced material and material removed outside the pay template. The volume of material removed and paid for shall be computed electronically using the 3D DTM surfaces prepared from the pre-dredge and post-dredge surveys.

3.7.4 Deviations between the quantity billed and the proposed dredged quantity shown for the respective sections of the dredging project area specified in the Contract Drawings shall be explained and justified in writing to the Owner.

3.7.5 The total quantity of “Dredging”, measured as provided above, will be paid for at the contract unit price per cubic yard. The above process and payments will be full compensation for all submittals, meetings, inspections, regulatory requirements, and dredging work to include all other labor, equipment, and incidentals necessary to complete the requirements of this section.

Payment will be made under:

a. Pay Item: Dredging

b. Pay Unit: Cubic Yard