AMD 02 31 23 00.00 22.pdf

SECTION 31 23 00.00 22 (PWD ME)

EXCAVATION AND FILL

04/2023

PART 1 GENERAL

1.1 REFERENCES

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

AMERICAN WATER WORKS ASSOCIATION (AWWA)

AWWA C600 (2010) Installation of Ductile-Iron Water Mains and Their Appurtenances

ASTM INTERNATIONAL (ASTM)

ASTM C 136 (2014) Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates

ASTM C 33 (2016) Standard Specification for Concrete Aggregates

ASTM D 1140 (2014) Amount of Material in Soils Finer than the No. 200 (75-micrometer) Sieve

ASTM D 1556 (2015; E 2016) Density and Unit Weight of Soil in Place by the Sand-Cone Method

ASTM D 1557 (2012; E 2015) Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft3) (2700 kN-m/m3)

ASTM D 1883 (2016) CBR (California Bearing Ratio) of Laboratory-Compacted Soils

ASTM D 2216 (2010) Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass

ASTM D 2321 (2014; E 2014) Standard Practice for Underground Installation of Thermoplastic Pipe for Sewers and Other Gravity-Flow Applications

ASTM D 2434 (1968; R 2006) Permeability of Granular Soils (Constant Head)

ASTM D 2487 (2011) Soils for Engineering Purposes (Unified Soil Classification System)

DEMOLISH BULK FUEL FACILITY CUTLER 1694050

ASTM D 3786 (2013) Hydraulic Bursting Strength of Textile Fabrics-Diaphragm Bursting Strength Tester Method

ASTM D 422 (1963; R 2007; E 2014; E 2014)

Particle-Size Analysis of Soils

ASTM D 4318 (2010; E 2014) Liquid Limit, Plastic Limit, and Plasticity Index of Soils

ASTM D 4355 (2014) Deterioration of Geotextiles from Exposure to Light, Moisture and Heat in a Xenon-Arc Type Apparatus

ASTM D 4491 (2015) Water Permeability of Geotextiles by Permittivity

ASTM D 4533 (2015) Trapezoid Tearing Strength of Geotextiles

ASTM D 4632 (2015a) Grab Breaking Load and Elongation of Geotextiles

ASTM D 4751 (2016) Determining Apparent Opening Size of a Geotextile

ASTM D 4759 (2011) Determining the Specification Conformance of Geosynthetics

ASTM D 4833 (2007; E 2013; R 2013) Index Puncture Resistance of Geotextiles, Geomembranes, and Related Products

ASTM D 698 (2012; E 2014; E 2015) Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/cu. ft.

(600 kN-m/cu. m.))

U.S. ARMY CORPS OF ENGINEERS (USACE)

EM 385-1-1 (2014) Safety and Health Requirements Manual

U.S. ENVIRONMENTAL PROTECTION AGENCY (EPA)

EPA 530/F-93/004 (1993; Rev O; Updates I-IIV) Test Methods for Evaluating Solid Waste (Vol IA, IB, IC, and II) (SW-846.3-3)

EPA 600/4-79/020 (1983) Methods for Chemical Analysis of Water and Wastes. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/4-79/020 (NTIS PB84128677)

U.S. GENERAL SERVICES ADMINISTRATION (GSA)

CID A-A-1909 (Basic Notice 1; Canc. Notice 2) Fertilizer

FS A-A-203 (Rev C; Notice 2) Paper, Kraft, Untreated

STATE OF MAINE (SHS)

SHS MEDOT (2014) State of Maine Department of Transportation Standard Specifications, including revisions through award of this contract (See http://www.maine.gov/mdot/publications/)

38 MRSA §§ 420-C State of Maine Erosion and Sedimentation Control

38 MRSA §§420-D State of Maine Stormwater Management

38 MRSA §§481-490 State of Maine Site Location of Development

35-A MRSA §3452 State of Maine Natural Resources Protection Act

1.2 DEFINITIONS

1.2.1 Underdrain Backfill

A layer of clean, poorly graded crushed rock, stone, or natural sand or gravel having a high porosity which is placed beneath a building slab with or without a vapor barrier to cut off the capillary flow of pore water to the area immediately below a slab.

1.2.2 Degree of Compaction

Degree of compaction is expressed as a percentage of the maximum density obtained by the test procedure presented in ASTM D 1557, for general soil types, abbreviated as percent laboratory maximum density.

1.2.3 Hard Materials

Weathered rock, dense consolidated deposits, or conglomerate materials which are not included in the definition of "rock" but which usually require the use of heavy excavation equipment, ripper teeth, or jack hammers for removal.

1.2.4 Rock

Solid homogeneous interlocking crystalline material with firmly cemented, laminated, or foliated masses or conglomerate deposits, neither of which can be removed without systematic drilling and blasting, drilling and the use of expansion jacks or feather wedges, or the use of backhoe-mounted pneumatic hole punchers or rock breakers; also large boulders, buried masonry, or concrete other than pavement exceeding 1 cubic yard in volume.

Removal of hard material will not be considered rock excavation because of intermittent drilling that is performed merely to increase production.

SPECIAL NOTE: BLASTING IS NOT PERMITTED.

1.2.5 Non-Hazardous Soils

Non-hazardous soils shall include all soils which, upon generation, do not meet the definition of a hazardous waste as defined by the EPA Hazardous Waste Regulations 40 CFR 260 through 40 CFR 268, 40 CFR 273, and 40 CFR 279 and the State of Maine DEP Hazardous Waste Regulations Chapter 850-855.

1.2.6 Hazardous Soils

Hazardous soils shall include all soils which, upon generation, do meet the definition of a hazardous waste as defined by the EPA Hazardous Waste Regulations 40 CFR 260, 40 CFR 268, 40 CFR 273, and 40 CFR 279 and the State of Maine DEP Hazardous Waste Regulations Chapter 850-855.

1.3 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for Contractor Quality Control approval. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government. The following shall be submitted in accordance with Section 01 33 00 SUBMITTAL

PROCEDURES:

SD-01 Preconstruction Submittals

Shoring and Sheeting Plan; G

Dewatering Work Plan; G

Excavation and Trenching Plan; G

Excess Soil Disposal & Soil Sampling Plan; G

Submit 15 days prior to starting work.

SD-06 Test Reports

Waste Disposal characterization testing results; G

Dewatering testing results; G

Contractor sampling field log book entry; G

Pervious Granular Fill test; G

Borrow Materials; G

Fill and backfill test; G

Select material test; G

Density tests; G

Moisture Content Tests; G

Submit copies of all laboratory and field test reports within 24 hours of the completion of the test. If applicable, submit unit price item rock quantity surveys at least 24 hours in advance of removal.

1.4 DELIVERY, STORAGE, AND HANDLING

Perform in a manner to prevent contamination or segregation of materials.

1.5 CRITERIA FOR BIDDING

Base bids on the following criteria:

1.5.1 General Criteria

a. Surface elevations shown on drawings are approximate. Contractor shall confirm grades and inverts prior to start of work and ordering of materials.

b. Ground water elevation is estimated to be at approximately 4.5' to 9' below ground surface in the vicinity of the bulk tanks. The Contractor shall include all costs associated with all dewatering efforts. Failure by the Contractor to plan for groundwater conditions shall not be the basis for any claim nor equitable price or contract time adjustments. Historical sampling in the vicinity of the Tank Farm has documented the presence of PFAS constituents in soil and groundwater. Please see summary of 2020 and 2021 PFAS results at the end of this specification.

c. Removal of soils and rock beyond the lines and grades indicated will not be grounds for claims for additional payment.

d. Blasting will not be permitted on the site. Contractors means and methods may include hoe ramming or other approved methods.

Provide protection of adjacent facilities as necessary during prosecution of work.

1.5.2 Soil Management Criteria

a. The Contractor is responsible for all aspects of soil management from generation to disposal; including, excavation, stockpiling, onsite management, testing, loading, transport, and disposal.

b. Contractor must submit an Excess Soil Disposal & Sampling Plan to PWD ME EV for review and approval.

c. A site specific HASP describing proper HAZWOPER site controls for working with soil and groundwater potentially cotaining PFAS must be implemented for worker protection. Please see summary of 2020 and 2021 PFAS results at the end of this specification.

d. Reuse of excavated soil is prohibited.

e. Soil stockpiles must follow MEDEP Erosion and Sediment Control Best Management Practices. Soil stockpiles must be placed on and covered with 6 mil poly sheeting and surrounded with erosion and sediment controls to prevent runoff. Soil stockpiles must remain with limits of existing site.

Soil stockpiles must remain covered unless actively worked.

f. Contractor must use an experienced environmental professional for the collection of soil samples for disposal characterization.

g. Contractor must use a laboratory that has Maine state certification and NELAP/NELAC accreditation for all test methods required for soil analysis (see requirements in 1.5.4).

h. Soil stockpiles must not be added to once Contractor sample collection is complete.

j. Contractor must provide PWD ME EV with all documentation pertaining to the sampling event and results. Documentation includes but is not limited to: analytical results, maps and diagrams, copy of chain of custody and field log entries.

k. Contractor must clearly placard stockpiles with "Pending Characterization" while awaiting Contractor soil characterization test results and either "Non-Hazardous" or "Hazardous" based on those results.

Signs must be clearly legible and designed to withstand weathering for the duration of the project.

l. Contractor must not ship any soil without the written approval of the PWD ME CM and PWD ME EV.

m. Soil transported off the site must be disposed of at a licensed disposal facility, preapproved by PWD ME EV.

n. The Contractor must provide documentation to the PWD ME CM and PWD ME EV that soil removed from the site was disposed of at the approved landfill disposal facility.

1.6 GENERAL SOIL MANAGEMENT REQUIREMENTS

1.6.1 Soil Transported Off Base

Any soil transported off base from the site must be disposed of at a licensed non-municipal landfill disposal facility, which has been preapproved by PWD ME EV.

1.6.1 Bulk Materials in Contact With Soil

Bulk materials which are in contact with soil (e.g. - undisturbed bedrock, asphalt, concrete) may be transported off base for disposal or recycling, given there are no suspected hazardous constituents associated with the materials (e.g., PCB paint)and soil is completely removed prior to being loaded for transport(field determination by PWD ME Construction Manager (CM) or Engineering Tech (ET)). Information regarding the destination of these materials must be submitted to the PWD ME CM.

1.7 SOIL SAMPLING FOR WASTE CHARACTERIZATION

Testing parameters must meet the requirements of the selected landfill disposal facility including the type, number, and frequency of tests.

Chemical analysis of the samples must be performed by a laboratory that has Maine state certification and National Environmental Laboratory Accreditation Program (NELAP) accreditation for all test methods required for soil analysis (including PFAS constituents) and a Quality Systems Manual that conforms to the standards of ISO 17025.

1.8 SITE WASTE REMOVAL (SWR) MEETING

A SWR meeting must be held with the PWD ME CM and PWD ME EV prior to the removal of excavated soil from a project site to ensure all pertinent requirements of this contract have been met.

No transport of soil will be allowed until full concurrence is provided by the PWD ME CM.

1.9 REQUIREMENTS FOR TRANSPORTING BACKFILL ON BASE

Aggregates containing less than 10% fines (material passing the number 4 sieve) transported to the Shipyard from off base to be used as backfill do not require testing.

All other backfill materials which do not meet the above conditions must be tested for the following contaminants:

- Total Petroleum Hydrocarbons (TPH) (GC/FID)

- Total 8 RCRA Metals (7060, 7740, etc.)

- Total Volatiles (8260)

- Total Semi-Volatiles (8270)

- Total Pesticides (8081)

- Total Herbicides (8151)

- Total PCB's (8082)

- Ignitability/flash (1010-liquids, 1030-solids)

- Corrosivity/pH (9045)

- Reactive Sulfide (7.3.4.1)

Off base soil must not contain any contaminant concentration which exceeds the most current "Residential Scenario" values listed in Appendix 1 of the MEDEP Remedial Action Guidelines found at https://www.maine.gov/dep/spills/publications/guidance/. TPH concentrations must not exceed 100 mg/kg. If the total concentration of any Toxicity Characteristic Leaching Procedure (TCLP) regulated contaminant listed in 40 CFR 261.24 is greater than or equal to twenty times its regulatory threshold, TCLP analysis will be required. The off base soil must not contain any TCLP concentration which exceeds the current EPA values listed in 40 CFR 261.24, Table 1 Maximum Concentration of Contaminants for Toxicity Characteristic EPA limits.

Representative sampling and testing of the backfill must be conducted at a rate of 1 sample for every 1,000 tons, with a minimum of 1 sample per borrow source. Contractor must use a licensed, Maine state-certified and NELAP accredited laboratory for the chemical analysis. Backfill must not be transported on base until all laboratory test results have been approved by PWD ME EV.

Borrow pits must meet all appropriate state certification guidelines.

Written confirmation that the purchased backfill material did not come from a chemically impacted area must be provided by borrow pit supplier. Proof of certification and written confirmation must be provided to the PWD ME EV prior to backfill being brought on base.

NOTE: Should any clean backfill be removed for excess soil disposal, testing is required even if the project profile amount covers the amount being disposed of.

1.10 EXCESS SOIL DISPOSAL & SOIL SAMPLING PLAN

The Contractor shall submit an Excess Soil Disposal & Soil Sampling Plan indicating the licensed facility that will be used for off site disposal of excess hazardous and/or non-hazardous soil material. The Excess Soil Disposal & Soil Sampling Plan shall include the following:

1. Introduction - Provide a location and description of the excavation work required to complete the work under the contract. A site plan showing the limits of excavation and planned stockpile locations for soils to be reused and unsuitable or excess soils requiring disposal.

2. Excavation - Provide quantities of excavated materials.

3. Pre-Excavation Soil Characterization - To classify the soils that will require disposal, the Contractor shall collect representative soil samples to confirm the material meets the requirements of the contractors selected licensed disposal facility. The soil samples shall be sent to a laboratory that has Maine state certification and National Environmental Laboratory Accreditation Program (NELAP) accreditation for all test methods required for soil analysis (including PFAS constituents) and Quality Systems Manual that conforms to the standards of ISO 17025. The quantity & location of soil samples and laboratory tests shall be based on the disposal facility requirements.

4. Soil Sampling - The Contractor shall provide the analytical sampling requirements based on the licensed facility that will be accepting the soils for disposal. The soil shall be tested using a laboratory that has Maine state certification and National Environmental Laboratory Accreditation Program (NELAP) accreditation for all test methods required for soil analysis (including PFAS constituents) and Quality Systems Manual that conforms to the standards of ISO 17025.

5. Stockpiling - Provide description on how the soils shall be stockpiled within the limits of work and in accordance with the requirements provided in the plans & contract documents. The location of the proposed stockpile areas shall be shown on a site plan.

6. Transportation off base - Provide a description of how the soils will be transported to the approved disposal facility. The Contractor shall provide documentation to the Contracting Officer that soil removed from the site was disposed of at the approved disposal facility.

1.11 QUALITY ASSURANCE

1.11.1 Excavation and Trenching Plan

Provide Manufacturers Tabulated Data for trench boxes and other support systems to be used on the project. See EM 385-1-1, Section 25, Excavation and Trenching for requirements.

1.11.2 Dewatering Work Plan

The Contractor shall submit procedures for accomplishing dewatering work to the Contracting Officer for approval. The requirements of the plan is specified in Paragraph entitled DEWATERING herein.

1.11.3 Utilities

Movement of construction machinery and equipment over pipes and utilities, including groundwater monitoring wells, during construction shall be at the Contractor's risk. Perform work adjacent to non-Government utilities as indicated in accordance with procedures outlined by utility company.

Excavation made with power-driven equipment is not permitted within three (3 ) feet of known Government-owned utility or subsurface construction. For work immediately adjacent to or for excavations exposing a utility or other buried obstruction, excavate by hand. Start hand excavation on each side of the indicated obstruction and continue until the obstruction is uncovered or until clearance for the new grade is assured. Support uncovered lines or other existing work affected by the contract excavation until approval for backfill is granted by the Contracting Officer. Report damage to utility lines or subsurface construction immediately to the Contracting Officer.

PART 2 PRODUCTS

2.1 SOIL MATERIALS

2.1.1 Satisfactory Materials

Any materials classified by ASTM D 2487 as GW, GP, GM, GP-GM, GW-GM, GC, GP-GC, GM-GC, SW, SP free of debris, roots, wood, scrap material, vegetation, refuse, soft unsound particles, and frozen, deleterious, or objectionable materials. Unless specified otherwise, the maximum particle diameter shall be one-half the lift thickness at the intended location.

2.1.2 Unsatisfactory Materials

Materials which do not comply with the requirements for satisfactory materials. Unsatisfactory materials also include man-made fills, trash, refuse, or backfills from previous construction. Rock, boulders or stones with a particle diameter greater than one-half the lift thickness at the intended location, asphalt, or concrete materials shall be separated from any excess soils requiring disposal and shall be transported & disposed of by the Contractor. Unsatisfactory material also includes material classified as satisfactory which contains root and other organic matter, frozen material, and stones larger than 3 mminches. The Contracting Officer shall be notified of any contaminated materials.

2.1.3 Cohesionless and Cohesive Materials

Cohesionless materials include materials classified in ASTM D 2487 as GW, GP, SW, and SP. Cohesive materials include materials classified as GC, SC, ML, CL, MH, and CH. Materials classified as GM, GP-GM, GW-GM, SW-SM, SP-SM, and SM shall be identified as cohesionless only when the fines are nonplastic (plasticity index equals zero). Materials classified as GM and SM will be identified as cohesive only when the fines have a plasticity index greater than zero.

2.1.4 Expansive Soils

Soils that have a plasticity index equal to or greater than 20 when tested in accordance with ASTM D 4318.

2.1.5 Backfill and Fill Material

ASTM D 2487, classification GW, GP, GM, SW, SP, SM, with a maximum ASTM D 4318 liquid limit of 35, maximum ASTM D 4318 plasticity index of 12, and a maximum of 25 percent by weight passing ASTM D 1140,No. 200 sieve or meet the SHS MEDOT, Section 703.19 Granular Borrow specification.

2.1.6 Structural Fill Material

Structural fill should be a well-graded sand and gravel mixture free of roots, topsoil, loam, where indicated, organic material, and any other deleterious materials, as well as clods of silt or clay, and meet the following gradation requirements or meet the SHS MEDOT, Section 703.20 Gravel Borrow specification:

Screen or Sieve Size Percent Passing

6 inches 100 3 inches 70 - 100 No. 4 35 - 70 No. 40 5 - 35 No. 200 0 - 5

2.2 UTILITY BEDDING MATERIAL

Except as specified otherwise in the individual piping section, provide bedding for buried piping in accordance with AWWA C600, Type 4, except as specified herein. Backfill to top of pipe shall be compacted to 95 percent of ASTM D 698 maximum density. Plastic piping shall have bedding to spring line of pipe. Provide ASTM D 2321 materials as follows:

a. Class I: Angular,0.25 to 1.5 inches, graded stone, including a number of fill materials that have regional significance such as coral, slag, cinders, crushed stone, and crushed shells.

b. Class II: Coarse sands and gravels with maximum particle size of

1.5 inches, including various graded sands and gravels containing small percentages of fines, generally granular and noncohesive, either wet or dry. Soil Types GW, GP, SW, and SP are included in this class as specified in ASTM D 2487.

2.3 GRAVEL

Provide as specified in Section 32 11 16 BASE AND SUBBASE COURSES FOR RIGID

AND FLEXIBLE PAVING.

2.4 BORROW

Obtain borrow materials required in excess of those furnished from excavations from sources outside of Government property. Borrow materials shall meet SHS MEDOT 703.18

2.5 Topsoil

Natural, friable soil representative of productive, well-drained soils in the area, free of subsoil, stumps, rocks larger than 1 inch diameter, brush, weeds, toxic substances, and other material detrimental to plant growth. Amend topsoil pH range to obtain a pH of 5.5 to 7.

2.6 BURIED WARNING AND IDENTIFICATION TAPE

Polyethylene plastic and metallic core or metallic-faced, acid- and alkali-resistant, polyethylene plastic warning tape manufactured specifically for warning and identification of buried utility lines.

Provide tape on rolls,3 inch minimum width, color coded as specified below for the intended utility with warning and identification imprinted in bold black letters continuously over the entire tape length. Warning and identification to read, "CAUTION, BURIED (intended service) LINE BELOW" or similar wording. Color and printing shall be permanent, unaffected by moisture or soil.

Warning Tape Color Codes

Red: Electric Yellow: Gas,Oil;Steam,Air,Other Dangerous Materials Orange: CCTV, Telephone and Other Communications Purple: Reclaimed Water Blue: Water Systems Green: Sewer Systems White: Proposed Excavation Pink: Temporary Survey Markings

2.6.1 Warning Tape for Metallic Piping

Acid and alkali-resistant polyethylene plastic tape conforming to the width, color, and printing requirements specified above. Minimum thickness of tape shall be 0.003 inch. Tape shall have a minimum strength of 1500 psi lengthwise, and 1250 psi crosswise, with a maximum 350 percent elongation.

2.6.2 Detectable Warning Tape for Non-Metallic Piping

Polyethylene plastic tape conforming to the width, color, and printing requirements specified above. Minimum thickness of the tape shall be 0.004 inch. Tape shall have a minimum strength of 1500 psi lengthwise and 1250 psi crosswise. Tape shall be manufactured with integral wires, foil backing, or other means of enabling detection by a metal detector when tape is buried up to3 feet deep. Encase metallic element of the tape in a protective jacket or provide with other means of corrosion protection.

2.7 DETECTION WIRE FOR NON-METALLIC PIPING

Detection wire shall be insulated single strand, solid copper with a minimum of 12 AWG.

PART 3 EXECUTION

3.1 PROTECTION

3.1.1 Shoring and Sheeting

Provide shoring bracing, cribbing, trench boxes, underpinning, and sheeting where indicated. In addition to Section 25 A and B of EM 385-1-1, the Contractor shall include provisions in the shoring and sheeting plan that will accomplish the following:

a. Prevent undermining of pavements, foundations, utility pipelines, structures, and slabs.

b. Prevent slippage or movement in banks or slopes adjacent to the excavation.

3.1.2 Drainage and Dewatering

Provide for the collection and disposal of surface and subsurface water encountered during construction. Prepare a Dewatering plan that complies with State and Federal regulations, and the requirements specified herein.

3.1.2.1 Drainage

So that construction operations progress successfully, completely drain construction site during periods of construction to keep soil materials sufficiently dry. The Contractor shall establish/construct storm drainage features (ponds/basins) at the earliest stages of site development, and throughout construction grade the construction area to provide positive surface water runoff away from the construction activity and/or provide temporary ditches, berms swales, and other drainage features and equipment as required to maintain dry soils, prevent erosion and undermining of foundations. When unsuitable working platforms for equipment operation and unsuitable soil support for subsequent construction features develop, remove unsuitable material and provide new soil material as specified herein. It is the responsibility of the Contractor to assess the soil and ground water conditions presented by the plans and specifications and to employ necessary measures to permit construction to proceed. Excavated slopes and backfill surfaces shall be protected to prevent erosion and sloughing. Excavation shall be performed so that the site, the area immediately surrounding the site, and the area affecting operations at the site shall be continually and effectively drained.

3.1.2.2 Dewatering

a. The majority of the site may experience areas of shallow groundwater. Groundwater in the project area may contain detectable concentrations of PFAS constituents. Dewatering work and other aspects of the project must be planned under the assumption that PFAS constituent-impacted groundwater may be encountered up to the elevation listed in bidding criteria. Any groundwater elevations shown on drawings accompanying the specifications are elevations which existed at the time of subsurface investigations, and are for reference only. Historical sampling in the vicinity of the Tank Farm has documented the presence of PFAS constituents in soil and groundwater. Please see attached summary of 2020 and 2021 PFAS results.

b. The Contractor shall prepare a project specific dewatering plan.

The dewatering plan shall at a minimum address anticipated dewatering discharge volumes, pumping rates required to maintain construction in the dry, demonstrate adequate capacity to treat and dispose the discharge volume, and illustrate on a site plan the location proposed for dewatering discharge treatment systems and disposal locations. The plan must detail sampling detail and frequency and recharege area design. The plan shall describe implementation of construction dewatering practices in accordance with Maine Erosion and Sediment Control Best Management Practices (Maine DEPLW0588, latest edition). At no point shall construction dewatering be discharged to storm sewers.

The contractor shall be responsible for performing pre-construction site inspections and periodic site visits throughout construction to assess site conditions. The contractor shall update the excavation, sheeting and dewatering plans as construction progresses to reflect changing conditions and shall submit an updated plan to the Contracting Officer. The contractor shall submit a written report to the Contractor's Quality Control Manager and Contracting Officer, at least weekly, addressing the performance of the dewatering efforts, the Contractor's adherence to the plan and addressing any present or potential problems and recommendations.

The contractor shall be available to meet with the Contracting Officer at any time throughout the contract duration to review the performance of the dewatering system.

c. The Contractor's dewatering efforts shall control groundwater flowing toward or into excavations to prevent sloughing of excavation slopes and walls, boils, uplift and heave in the excavation and to eliminate interference with orderly progress of the construction. Dewatering Pits, french drains, sumps, ditches or trenches shall not be permitted within three (3) feet of the foundation of any structure. Control measures shall be taken by the time the excavation reaches the water level in order to maintain the integrity of the in situ material. The water level shall be maintained continuously 18" below the working level.

d. The dewaterng system shall include the following:

d1. Water must initially be pumped to Appropriately-sized storage container(s) (frac tanks or similar) d2. The water must then be pumped through a silt filter and two-stage treatment system with appropriate filter media to reduce the concentration of PFAS constituents to below 20 ng/L prior to recharge. The contractor must sample the water before and after the treatment system with sufficient frequency to demonstrate achievement of the discharge threshold and to determine when the filter media must be changed out (as appropriate). The treated water must be stored until analytical results are received confirming achievement of the discharge threshold.

d3. The water must subsequently be discharged to an appropriately-located, -sized, and -designed recharge area within the bermed area. The location of the recharge area must be selected in conjunction with the Government.

e. All waste associated with the dewatering (sediment from the tank, silt and filters from the silt filters, spent filter material, etc.) must be characterized and properly disposed of.

f. The Contractor shall prepare all appropriate submittals (Dewatering Plan, including sampling detail and frequency, and recharge area design) for Government review and approval.

g. A HASP must be prepared for working with soil and groundwater potentially containing PFAS.

3.1.3 Underground Utilities

The location of the existing utilities shown on the plans are approximate.

The Contractor shall physically field verify the location and elevation of the existing utilities indicated prior to starting construction. The Contractor shall submit a PWD Maine Dig Safe Utility Request Form and contact Dig Safe (1-888-344-7233). The Contractor shall confirm the location of all existing underground utilities prior to commencing any excavation work.

3.1.4 Machinery and Equipment

Movement of construction machinery and equipment over pipes during construction shall be at the Contractor's risk. Repair, or remove and provide new pipe for existing or newly installed pipe that has been displaced or damaged.

3.2 SURFACE PREPARATION

3.2.1 Clearing and Grubbing

Unless indicated otherwise, remove trees, stumps, logs, shrubs, brush and vegetation and other items that would interfere with construction operations within lines 5 feet outside of each building and structure line. Remove stumps entirely. Grub out matted roots and roots over 50 mm 2 inches in diameter to at least 18 inches below existing surface.

3.2.2 Stripping

Strip suitable soil from the site where excavation or grading is indicated and stockpile separately from other excavated material. Material unsuitable for use as topsoil shall be wasted, except that material meeting the requirements for backfill may be used for backfilling. Locate topsoil so that the material can be used readily for the finished grading. Where sufficient existing topsoil conforming to the material requirements is not available on site, provide borrow materials suitable for use as topsoil.

Protect topsoil and keep in segregated piles until needed.

3.2.3 Unsuitable Material

Remove vegetation, debris, decayed vegetable matter, sod, mulch, and rubbish underneath paved areas or concrete slabs.

3.3 EXCAVATION

3.3.1 General

Excavate to contours, elevations to complete the work indicated on the plans.

Keep excavations free from water. Excavate soil disturbed or weakened by Contractor's operations, soils softened or made unsuitable for subsequent construction due to exposure to weather. Excavations below indicated depths and/or limits identified in SHS Section 203, Excavation and Embankment and SHS Section 206, Structural Excavation will not be permitted except to remove unsatisfactory material. Unsatisfactory material encountered below the grades shown shall be classified by Contracting Officer and removed as directed. Refill with backfill or structural fill material, depending on location with respect to structures and compact as required in herein.

Unless specified otherwise, refill excavations cut below indicated depth with backfill and compact to minimum 95 percent of ASTM D 1557 maximum density. Satisfactory material removed below the depths indicated, without specific direction of the Contracting Officer, shall be replaced with satisfactory materials to the indicated excavation grade; except as specified for spread footings. Determination of elevations and measurements of approved over depth excavation of unsatisfactory material below grades indicated shall be done under the direction of the Contracting Officer. No extra payment will be made for removal of unsuitable soils and replacement with satisfactory material or select fills as may be directed by the Contracting Officer.

3.3.2 Pipe Trenches

Excavate to the dimension indicated. Grade and shape bottom of trenches to provide uniform support for each section of pipe after pipe bedding placement. Tamp if necessary to provide a firm pipe bed. Recesses shall be excavated to accommodate bells and joints so that pipe will be uniformly supported for the entire length. Rock, where encountered, shall be excavated to a depth of at least 6 inches below the bottom of the pipe.

Blasting is not allowed.

3.3.3 Hard Material and Rock Excavation

Remove hard material and rock to elevations indicated in a manner that will leave foundation material in an unshattered and solid condition. Blasting is not allowed. Roughen level surfaces and cut sloped surfaces into benches for bond with concrete. Protect shale from conditions causing decomposition along joints or cleavage planes and other types of erosion.

3.3.4 Excavated Materials

Satisfactory excavated material required for fill or backfill shall be placed in the proper section of the permanent work required or shall be separately stockpiled if it cannot be readily placed. Satisfactory material in excess of that required for the permanent work and all unsatisfactory material shall be disposed of as specified in herein in "DISPOSITION OF

SURPLUS MATERIAL."

3.4 CONTROL OF EXCAVATIONS AND EXCAVATED MATERIALS

All Excavation work shall conform with all applicable OSHA and EM385-1-1 requirements. All excavation activities shall conform with Shipyard requirements. All excavations shall be closed as soon as work within the excavation is complete. Excavated materials shall not be allowed to spread in an uncontrolled manner nor become contaminated with other debris. All excavations shall be properly barricaded with barricades and suitable warning devices in a good state of repair. The Government will not provide barricades for Contractor use. The following controls also apply:

3.4.1 Unnatural Fill Materials/Industrial Debris

Unnatural fill materials/industrial debris is soil containing buried debris from industrial operations. Materials include, but are not limited to, metal, plastic, brick, concrete, wood, containers, glass, and materials with unusual color or odor. Upon discovery of such materials, notify the Contracting Officer, who will arrange for the PWD ME Environmental Division to inspect the materials.

3.4.3 Excavated Materials to be Reused as Backfill

a. Excavated non-hazardous soil materials from excavations which will remain open for LESS THAN TWO WEEKS may remain at the site of excavation.

3.5 SUBGRADE PREPARATION

Unsatisfactory material in surfaces to receive fill or in excavated areas shall be removed and replaced with satisfactory materials as directed by the Contracting Officer. The surface shall be scarified to a depth of 6 inches before the fill is started. Sloped surfaces steeper than 1 vertical to 4 horizontal shall be plowed, stepped, benched, or broken up so that the fill material will bond with the existing material. When subgrades are less than the specified density, the ground surface shall be broken up to a minimum depth of 6 inches, pulverized, and compacted to the specified density. When the subgrade is part fill and part excavation or natural ground, the excavated or natural ground portion shall be scarified to a depth of 12 inches and compacted as specified for the adjacent fill.

Material shall not be placed on surfaces that are muddy, frozen, or contain frost. Compaction shall be accomplished by sheepsfoot rollers, pneumatic-tired rollers, steel-wheeled rollers, or other approved equipment well suited to the soil being compacted. Material shall be moistened or aerated as necessary to provide the moisture content that will readily facilitate obtaining the specified compaction with the equipment used.

Minimum subgrade density shall be as specified herein.

3.5.1 Proof Rolling

Proof rolling shall be done on an exposed subgrade free of surface water (wet conditions resulting from rainfall) which would promote degradation of an otherwise acceptable subgrade. After stripping, proof roll the existing subgrade of the developable site with six passes of a loaded 10 yard dump truck or a 15 ton, pneumatic-tired roller. Operate the truck or roller in a systematic manner to ensure the number of passes over all areas, and at speeds between2 1/2 to 3 1/2 miles per hour. Notify the Contracting Officer a minimum of 3 days prior to proof rolling. Proof rolling shall be performed in the presence of the Contracting Officer. Rutting or pumping of material shall be undercut as directed by the Contracting Officer and replaced with fill and backfill material.

3.6 FILLING AND BACKFILLING

Fill and backfill to contours, elevations required to complete the work.

Compact each lift before placing overlaying lift as specified below.

3.6.2 Backfill and Fill Material Placement

Provide for paved areas and under concrete slabs and tunnels, except where structural fill is provided. Place in 6 inch lifts. Do not place over wet or frozen areas. Place backfill material adjacent to structures as the structural elements are completed and accepted. Place and compact material to avoid loading upon or against adjacent structures.

3.6.3 Structural Fill Placement

Provide under structures not pile supported. Place in 6 inch lifts. Do not place over wet or frozen areas. Backfill adjacent to structures shall be placed as structural elements are completed and accepted. Place and compact material to avoid loading upon or against adjacent structures.

3.6.4 Backfill and Fill Material Placement Over Pipes and at Walls

Backfilling shall not begin until underground utilities systems have been inspected, tested and approved, and the excavation cleaned of trash and debris. Backfill shall be brought to indicated finish grade. Where pipe is coated or wrapped for protection against corrosion, the backfill material up to an elevation 2 feet above sewer lines and 1 foot above other utility lines shall be free from stones larger than 1 inch in any dimension. Heavy equipment for spreading and compacting backfill shall not be operated closer to foundation or retaining walls than a distance equal to the height of backfill above the top of footing; the area remaining shall be compacted in layers not more than 4 inches in compacted thickness with power-driven hand tampers suitable for the material being compacted.

Backfill shall be placed carefully around pipes or tanks to avoid damage to coatings, wrappings, or tanks.

3.6.6 Trench Backfilling

Backfill as rapidly as construction, testing, and acceptance of work permits. Place and compact trench backfill in6 inch lifts to top of trench and in 6 inch lifts toone foot over pipe outside structures and paved areas.

3.7 BORROW

Where satisfactory materials are not available in sufficient quantity from required excavations, approved borrow materials shall be obtained as specified herein.

3.8 BURIED WARNING AND IDENTIFICATION TAPE

Provide buried utility lines with utility identification tape. Bury tape12 inches below finished grade; under pavements and slabs, bury tape 6 inches below top of subgrade.

3.9 BURIED DETECTION WIRE

Bury detection wire directly above non-metallic piping at a distance not to exceed 12 inches above the top of pipe. The wire shall extend continuously and unbroken, from manhole to manhole. The ends of the wire shall terminate inside the manholes at each end of the pipe, with a minimum of 3 feet of wire, coiled, remaining accessible in each manhole. The wire shall remain insulated over it's entire length. The wire shall enter manholes between the top of the corbel and the frame, and extend up through the chimney seal between the frame and the chimney seal. For force mains, the wire shall terminate in the valve pit at the pump station end of the pipe.

3.10 COMPACTION

Determine in-place density of existing subgrade; if required density exists, no compaction of existing subgrade will be required. Density requirements specified herein are for cohesionless materials. When cohesive materials are encountered or used, density requirements may be reduced by 5 percent.

3.10.1 General Site

Compact underneath areas designated for vegetation and areas outside the 5 foot line of the paved area or structure to 90 percent of ASTM D 1557.

3.10.2 Utility Trenches

Compact top 12 inches of subgrades to 95 percent of ASTM D 1557. Compact common fill, fill and backfill material, structural fill material to 95 percent of ASTM D 1557.

3.10.3 Adjacent Area

Compact areas within 5 feet of structures to 95 percent of ASTM D 1557.

3.10.4 Paved Areas

Compact top 12 inches of subgrades to 95 percent of ASTM D 1557. Compact fill and backfill materials to 95 percent of ASTM D 1557.

3.11 FINISH OPERATIONS

3.11.1 Grading

Finish grades as indicated within one-tenth of one foot. Grade areas to drain water away from structures. Maintain areas free of trash and debris. For existing grades that will remain but which were disturbed by Contractor's operations, grade as directed.

3.11.2 Topsoil and Seed

Scarify existing subgrade. Provide 6 inches of topsoil for newly graded finish earth surfaces and areas disturbed by the Contractor. Topsoil shall not be placed when the subgrade is frozen, excessively wet, extremely dry, or in a condition otherwise detrimental to seeding, planting, or proper grading. If there is insufficient on-site topsoil meeting specified requirements for topsoil, provide topsoil required in excess of that available. Seed shall match existing vegetation. Provide seed at 5 pounds per 1000 square feet. Provide granular controlled release fertilizer containing the following minimum percentages, by weight, of plant food nutrients:

10 percent available nitrogen 5 percent available phosphorus

Provide mulch and water to establish an acceptable stand of grass.

3.11.3 Protection of Surfaces

Protect newly backfilled, graded, and topsoiled areas from traffic, erosion, and settlements that may occur. Repair or reestablish damaged grades, elevations, or slopes.

3.12 FIELD QUALITY CONTROL

3.12.1 Sampling

Take the number and size of samples required to perform the following tests.

3.12.2 Testing

Perform one of each of the following tests for each material used. Provide additional tests for each source change.

3.12.2.1 Fill and Backfill Material Testing

Test fill and backfill material in accordance with ASTM C 136 for conformance to ASTM D 2487 gradation limits; ASTM D 1140 for material finer than theNo. 200 sieve; ASTM D 4318 for liquid limit and for plastic limit;

ASTM D 698 or ASTM D 1557 for moisture density relations, as applicable.

3.12.2.2 Select Material Testing

Test select material in accordance with ASTM C 136 for conformance to ASTM D 2487 gradation limits; ASTM D 1140 for material finer than the No.

200 sieve; ASTM D 698 or ASTM D 1557 for moisture density relations, as applicable.

3.12.2.3 Pervious Granular Fill Testing

Test pervious granular fill in accordance with ASTM C 136 for conformance to gradation specified in ASTM C 33.

3.12.2.4 Density Tests

Test density in accordance with ASTM D 1556. Perform an ASTM D 1556 density test at the start of the job and as follows:

a. Density testing per the following will be required at the expense of the Contractor.

b. Bedding and backfill in trenches and tank foundations: One test per 50 linear feet in each lift.

c. Other site areas as follows:

Material Type Location of Material Test Frequency

Undisturbed native soil Structures & Foundations Two random tests in structure footings and two tests on subgrade within structure line.

Fills and backfills Structures One test per structure per 2,000 sq. in each lift

Material Type Location of Material Test Frequency

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