Amendment 0001 W912EQ21B0002.pdf

W38XGR02607235

AMENDMENT OF SOLICITATION/MODIFICATION OF CONTRACT

Except as provided herein, all terms and conditions of the document referenced in Item 9A or 10A, as heretofore changed, remains unchanged and in full force and effect.

15A. NAME AND TITLE OF SIGNER (Type or print)

30-105-04EXCEPTION TO SF 30

APPROVED BY OIRM 11-84

STANDARD FORM 30 (Rev. 10-83) Prescribed by GSA

FAR (48 CFR) 53.243

The purpose of this amendment is to:

1. Change the bid due date from Monday 04 Jan 21 to Friday 08 Jan 21.

2. Update Section 33 26 00.00 11, Relief Wells and Section 33 28 00.00 11, Piezometers.

All other terms and conditions remain the same.

1. CONTRACT ID CODE PAGE OF PAGES

1 2

16A. NAME AND TITLE OF CONTRACTING OFFICER (Type or print)

16C. DATE SIGNED

BY 21-Dec-2020

16B. UNITED STATES OF AMERICA15C. DATE SIGNED15B. CONTRACTOR/OFFEROR

(Signature of Contracting Officer)(Signature of person authorized to sign)

8. NAME AND ADDRESS OF CONTRACTOR (No., Street , County, State and Zip Code) X W912EQ21B0002

X 9B. DATED (SEE ITEM 11)

04-Dec-2020

10B. DATED (SEE ITEM 13)

9A. AMENDMENT OF SOLICITATION NO.

11. THIS ITEM ONLY APPLIES TO AMENDMENTS OF SOLICITATIONS

X The above numbered solicitation is amended as set forth in Item 14. The hour and date specified for receipt of Offer X is extended, is not extended.

Offer must acknowledge receipt of this amendment prior to the hour and date specified in the solicitation or as amended by one of the following methods:

(a) By completing Items 8 and 15, and returning 1 copies of the amendment; (b) By acknowledging receipt of this amendment on each copy of the offer submitted;

or (c) By separate letter or telegram which includes a reference to the solicitation and amendment numbers. FAILURE OF YOUR ACKNOWLEDGMENT TO BE RECEIVED AT THE PLACE DESIGNATED FOR THE RECEIPT OF OFFERS PRIOR TO THE HOUR AND DATE SPECIFIED MAY RESULT IN

REJECTION OF YOUR OFFER. If by virtue of this amendment you desire to change an offer already submitted, such change may be made by telegram or letter, provided each telegram or letter makes reference to the solicitation and this amendment, and is received prior to the opening hour and date specified.

12. ACCOUNTING AND APPROPRIATION DATA (If required)

13. THIS ITEM APPLIES ONLY TO MODIFICATIONS OF CONTRACTS/ORDERS.

IT MODIFIES THE CONTRACT/ORDER NO. AS DESCRIBED IN ITEM 14.

A. THIS CHANGE ORDER IS ISSUED PURSUANT TO: (Specify authority) THE CHANGES SET FORTH IN ITEM 14 ARE MADE IN THE

CONTRACT ORDER NO. IN ITEM 10A.

B. THE ABOVE NUMBERED CONTRACT/ORDER IS MODIFIED TO REFLECT THE ADMINISTRATIVE CHANGES (such as changes in paying office, appropriation date, etc.) SET FORTH IN ITEM 14, PURSUANT TO THE AUTHORITY OF FAR 43.103(B).

C. THIS SUPPLEMENTAL AGREEMENT IS ENTERED INTO PURSUANT TO AUTHORITY OF:

D. OTHER (Specify type of modification and authority)

E. IMPORTANT: Contractor is not, is required to sign this document and return copies to the issuing office.

14. DESCRIPTION OF AMENDMENT/MODIFICATION (Organized by UCF section headings, including solicitation/contract subject matter where feasible.)

10A. MOD. OF CONTRACT/ORDER NO.

2. AMENDMENT/MODIFICATION NO. 5. PROJECT NO.(If applicable)

6. ISSUED BY

3. EFFECTIVE DATE

21-Dec-2020

CODE

US ARMY ENGINEER DISTRICT, MEMPHIS

KIRK A. MIDDLETON 167 N MAIN ST

MEMPHIS TN 38103-1894

W912EQ 7. ADMINISTERED BY (If other than item 6)

4. REQUISITION/PURCHASE REQ. NO.

CODE

See Item 6

FACILITY CODECODE

EMAIL:TEL:

W912EQ21B0002

SECTION SF 30 BLOCK 14 CONTINUATION PAGE

SUMMARY OF CHANGES

SECTION 00010 - SOLICITATION CONTRACT FORM

The required response date/time has changed from 04-Jan-2021 01:00 PM to 08-Jan-2021 01:00 PM.

The number of offeror copies required 1 has been added.

The contractor period of performance end date has increased by 170 days from 450 days to 620 days.

FAR 52.211-10 COMMENCEMENT, PROSECUTION, AND COMPLETION OF WORK (APR 1984)

The Contractor shall be required to (a) commence work under this contract within 10 calendar days after the date the Contractor receives the notice to proceed, (b) prosecute the work diligently, and (c) complete the base contract work ready for use not later than 270 calendar days after the date of receipt by him of notice to proceed. Option 1 contract time extension is 210 days and Option 2 contract extension is 140 days. The time stated for completion shall include final cleanup of the premises.

(End of Summary of Changes)

White River Backwater Levee - Seepage Remediation For Advertisement

SECTION 33 26 00.00 11

RELIEF WELLS

11/29/11

PART 1 GENERAL

1.1 SCOPE

The work provided for herein consists of furnishing all plant, labor, material and equipment, and performing all operations required for proper execution of the relief well work as specified herein and/or indicated on the drawings. Such work includes installation of new relief wells; relief well outlets; guard posts; pump testing new wells; pilot hole borings and all work incidental thereto.

1.2 REFERENCES

The publications listed below form a part of this section to the extent referenced: Ref

ASTM INTERNATIONAL (ASTM)

ASTM A53/A53M (2012) Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless

ASTM A276 (2013a) Standard Specification for Stainless Steel Bars and Shapes

ASTM A312/A312M (2015) Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes

ASTM A555/A555M standard Specification for General Requirements for Stainless Steel Wire and Wire Rods

ASTM C1116/C1116M (2010a; R 2015) Standard Specification for Fiber-Reinforced Concrete

ASTM C117 (2013) Standard Test Method for Materials Finer than 75-um (No. 200) Sieve in Mineral Aggregates by Washing

ASTM C136 (2006) Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates

ASTM C33/C33M (2013) Standard Specification for Concrete Aggregates

ASTM C94/C94M (2015) Standard Specification for Ready-Mixed Concrete

SECTION 33 26 00.00 11 Page 1

AMERICAN WELDING SOCIETY (AWS)

AWS D1.2/D1.2M (2014) Structural Welding Code - Aluminum

FEDERAL SPECIFICATIONS (FS)

TT-E-489H Enamel, Alkyd, Gloss Low VOC content

SOCIETY FOR PROTECTIVE COATINGS (SSPC)

SSPC Paint 25 (1997; E 2004) Zinc Oxide, Alkyd, Linseed Oil Primer for Use Over Hand Cleaned Steel, Type I and Type II

U.S. ARMY CORPS OF ENGINEERS (USACE)

EM 1110-2-1906 (1986) Laboratory Soils Testing

1.3 SUBMITTALS

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

submittals not having a "G" designation are for information only. 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 permit and license ;

gravel pack installation procedure; ; G, EC-G

SD-02 Shop Drawings shop drawings ; G, EC-G shop drawings of the surge block ; G, EC-G

SD-03 Product Data well screens ; G, EC-G

Drilling fluid additives ; G, EC-G

SD-04 Samples gravel pack material from the source quarry ; G, EC-G soil samples

SD-05 Design Data well location and elevation survey results ; G, EC-G pilot hole locations ; G, EC-G

Form LMM 650 Jan '64 "Field Boring Log" ;

SD-06 Test Reports

SECTION 33 26 00.00 11 Page 2 gradation of the gravel pack material from the source quarry ; G, EC-G particle size distribution test for each well

Results of all well tests results of sieve analysis tests obtained from the pilot borings

"Well Development Data" sand infiltration test data sheet

Pump Test data on WES Form 796 ;

Relief Well Installation data on WES Form 797 ;

1.4 QUALITY CONTROL

1.4.1 General

The Contractor shall perform the inspection, sampling and testing, corrective actions, and reports required to substantiate his compliance with the technical provisions of this specification. Responsibility for quality control of relief well construction, rehabilitation, sampling and testing procedures shall be the Contractor's. The Contractor's quality control organization shall have personnel sufficient in number to monitor at all times the relief well activities.

1.4.2 Inspection

The Contractor's quality control organization shall be responsible to observe and control for compliance to technical specifications all relief well operations including but not limited to the following: survey layout, materials, drilling method, joints, bottom plug, materials storage, well pipe assembly and installation, backfilling, cleaning, development, pumps, pump testing, installation of outlets, chemical treatment, environmental compliance and safety. Completed relief wells shall be protected against damage and contamination. The detailed inspection may be assigned to the construction foreman supervising the work.

1.4.3 Sampling and Testing

The Contractor's quality control organization shall verify that the well pipe material and manufacturing conforms to the specifications before delivery to the project.

The gravel pack material from the source quarry and the gradation of the gravel pack material from the source quarry shall be approved for delivery by the Contracting Officer and meet the requirements of these specifications.

Upon delivery to site, the contractor shall stockpile the gravel pack material in seperate piles at each well location such that each pile of gravel pack material can be readily associated with a unique well. The contractor shall collect a representative sample of gravel pack material at each well site assign an ID associated with the cooresponding well and

SECTION 33 26 00.00 11 Page 3 perform a particle size distribution test for each well . The results of each particle size distribution test shall be furnished to the Government on ENG Form 2087 availale at the following website under the link "Relief Well Standard Forms":

http://www.mvm.usace.army.mil/BusinessWithUs/contracting/forms.aspx . For each well, the gravel pack material and its gradation shall be approved for placement by the contracting officer before any gravel pack material is placed within that well. The labs performing the particle size distribution tests shall be validated and meet all requirements as specified in Section 01 45 04.00 11 CONTRACTOR QUALITY CONTROL. The U. S.

Standard Sieves described in the paragraph below entitled, "GRAVEL PACK" shall be used to develop the gradations. The laboratory test procedure shall conform to that presented in EM 1110-2-1906 , Appendix V, a copy of which will be furnished the Contractor upon request.

A pumping and sand infiltration test and an alignment and plumbness test shall be performed in accordance with technical provisions herein specified.

1.4.4 Action Required

When quality control monitoring or testing detects non-conformance with specifications, corrective action shall be taken immediately. The details of the irregularities and the actions taken to correct them shall be reported immediately to the representative of the Contracting Officer and included in the daily Quality Control report. Also, corrective action shall include steps taken to prevent recurrence of the irregularity.

1.4.5 Relief Well Reports

Reports shall include, for each completed pilot hole boring:

LMM Form 650 Jan '64 "Field Boring Log, Sieve analysis for Sand samples from Pilot holes

Reports shall include, for each completed relief well:

WES Form 797 "Relief Well Installation Report,"

WES Form 796, "Relief Well Pumping Test Report,"

"Well Development Data Sheet"

Sand Infiltration Test Results

ENG Form 2087, "Gradation Curves" for the gravel pack

A copy of each report form is located at the following website:

http://www.mvm.usace.army.mil/BusinessWithUs/contracting/forms.aspx . The reports shall be completely filled out and shall be submitted to the Contracting Officer as part of the daily quality control report specified in Section 01 45 04.00 11 CONTRACTOR QUALITY CONTROL. A copy of these records and tests as well as the records of corrective action taken, shall be furnished to the Government.

1.4.6 Licenses and Permits

The contractor shall be responsible for obtaining and having on site all

SECTION 33 26 00.00 11 Page 4 licenses and permits required to meet all state and/or federal requirements needed to install relief wells in the particular state or states for the proposed relief wells as stated for this project. Submit a copy of each permit and license to the Contracting Officer for information.

PART 2 PRODUCTS

2.1 WELL SCREEN

2.1.1 General

Well screen shall be stainless steel and shall be of the dimensions hereinafter specified. The inside diameter of the screen shall be equal to the nominal well diameters provided on the drawings +/-0.2 inches.

Screen openings shall be uniform in size and pattern, and shall be spaced approximately equally around the circumference of the pipe. Before installation, all well screens shall be approved by the Contracting Officer.

2.1.2 Stainless Steel

2.1.2.1 General

Stainless steel well screen shall be fabricated by circumferentially wrapping a triangular shaped wire around a circular array of internal bars on one-inch centers. The wire configuration must produce inlet slots with sharp outer edges, widening inwardly so as to minimize clogging.

Additionally, the well screen should have material properties a non-clogging wire-wrapped continuous slot strainer. Additionally, the well screen should have material properties approved by the Contracting Officer which include at a minimum the collapse strength, tensile strength, and maximum recommended hanging weight. All pipes, rods, bars, and wire shall be stainless steel conforming to ASTM A276, ASTM A312/A312M or ASTM A555/A555M for Grade TP-304 as applicable. The width of the clear space between the wire wrappings for the 8-inch wells shall be 0.08 inch (80-slot well screen) and shall provide a total opening of not less than 150 square inches per foot of 8 inch diameter screen.

2.1.2.2 Coupling

Couplings for stainless steel well screen shall consist of the same material as the well screen and shall be welded joint couplings.

Connections between the well screen and the riser pipe shall be welded joint couplings. End fittings for stainless steel well screens shall be suitably beveled and furnished with welding rings of the same alloy as the well screen and riser pipe. Welding rings that join well screen to riser pipe shall adequately provide for the transition from well screen to riser pipe. Joints in riser pipe shall be single or double bevel welded and shall have strengths equal to the pipe being joined. Deposited weld metal shall have a resistance to corrosion equal to or greater than that of the pipe used. Joints shall be designed and constructed to support the weight of the screen and/or pipe as it is lowered into the hole. Welding shall be performed by a certified welder using approved welding rods, and performed in a manner which will not cause the screen sections to deviate from a straight alignment.

2.1.3 Bottom Plug for Well Screen

The bottom plug for each well screen shall be made of the same material

SECTION 33 26 00.00 11 Page 5 and at least the same minimum thickness as the riser pipe. Plugs shall be the same diameter as the outside of the screen and fastened to the bottom of the screen in an approved manner.

2.2 RISER PIPE

The relief well riser pipe material and method of manufacture shall conform to the requirements specified in the paragraph above entitled, "STAINLESS STEEL" above and shall be schedule 10 wall thickness. The relief well riser pipe shall have a minimum inside diameter approximately equal to the nominal well diamters provided on the drawings but not less than the inside diameter of the well screens to which they are attached.

Discharge details shall be as shown on the drawings. Couplings to the well screen and between riser pipe sections shall be as specified for well screen pipes.

2.3 GRAVEL PACK

Material for the gravel pack around the riser pipes and screens shall be washed gravel composed of hard, tough, durable particles free from adherent coating. Limestone, dolomite, or carbonate materials will not be acceptable materials. The gravel pack material shall contain neither detrimental quantities of vegetable matter nor soft, friable, thin, or elongated particles. The gravel pack shall meet the following gradation requirements:

U. S.Standard Percent by Weight Sieve No. Passing 3/8 inch 90-100 No. 4 65-95 No. 8 30-60

NO. 10 26-50

No. 16 13-30 No. 20 5-15 No. 30 0-8

Materials shall be uniformly graded between the limits specified above.

All points on individual grading curves obtained from representative samples of gravel pack material shall lie between the boundary limits as defined by smooth curves drawn through the tabulated grading limits plotted on a mechanical analysis diagram. The individual grading curves within these limits shall not exhibit abrupt changes in slope denoting skip grading, scalping of certain sizes or other irregularities that would be detrimental to the proper functioning of the gravel pack.

2.4 SAND

Sand placed on top of the gravel packing shall conform to fine aggregate for concrete as specified in ASTM C33/C33M.

2.5 GROUT

Grout mix placed on top of the sand shall consist of one bag (94 pounds) of cement to 5 gallons of water. It shall have a bentonite-cement ratio of 1 part bentonite to 30 parts cement by weight.

SECTION 33 26 00.00 11 Page 6

2.6 OUTLET FOR RELIEF WELL

2.6.1 Well Guard

Each outlet shall consist of a metal well guard as shown on the drawings.

The well guard shall consist of a section of 20-inch outside diameter (O.D.) stainless steel well screen constructed using the wire-wrapped continuous slot design method. The well guard shall be fabricated by circumferentially wrapping a triangularly shaped wire around a circular array of internal bars on one-inch centers. The wire configuration must produce inlet slots with sharp outer edges, widening inwardly so as to minimize clogging. For maximum collapse strength each juncture between the horizontal wire and the vertical bars will be fusion welded under water by the electrical resistance method. The minimum wire/weld strength shall be 650 pounds (lbs). The well guard and attached fittings shall be completely fabricated of stainless steel conforming to ASTM A555/A555M , Grade TP 304. The width of the clear space between the wire wrappings shall be 0.250 inch. The wire wrappings shall be composed of "190" wire.

The surface of the well guard shall be free of pits, slag and discoloration. All welds shall be ground and brushed. After the wells are completely installed, all well guards should be numbered (letter designation and number or number only) according to the Contracting Officer taking into account any field changes. Each number should be made from stainless steel and be sized 2 inches wide by 4 inches tall and 1/4-inch thick.

2.6.2 Cover Plate

The cover plate and fittings shall be fabricated of stainless steel conforming to ASTM A276/A276M , Grade TP 304. The plate shall be 1/4 inch in thickness and shall have a diameter of 21 inches. The cover plate shall be attached to the well guard using 3/8 inch socket head cap screws. A slotted lug shall be welded on the well screen to serve as a hinge and to prevent removal of the cover plate.

2.6.3 Check Valves

The aluminum check valves shall be fabricated in accordance with details shown on the drawings and as specified herein. The aluminum parts, at the Contractor's option, may be any one or a combination of aluminum alloys 3005-H14, 6061-T4, or T6. Rods shall be carefully bent to avoid flattening at the bends. The seat for the check valve is to be constructed of two 1/4 inch aluminum plates and a 1/4 inch thick neoprene rubber gaskets, all bolted together as indicated on the drawings.

Drilling or punching the aluminum plates and neoprene rubber gasket shall form the bolt holes. The neoprene rubber gasket shall have a thickness of 1/4 inch and shall be fabricated from neoprene rubber gasket material.

The aluminum guide rods and aluminum lifting ring shall be connected by welding. Welding of aluminum shall conform to the applicable provisions of the AWS D1.2/D1.2M Aluminum Association Specifications for Aluminum Structures.

2.6.4 Angular Face Ring

An angular face ring shall be fabricated or purchased from a supplier conforming to ASTM A276/A276M , Grade TP 304L or 316L stainless steel as shown on the drawings and the flange shall be a minimum of 3/16 inch in thickness. The angular face ring shall be at least the same diameter or slightly larger than the aluminum top plate of the check valve as shown on

SECTION 33 26 00.00 11 Page 7 the drawing.

2.7 RELIEF WELL GUARD POSTS

Steel pipe shall be black steel pipe conforming to the requirements of ASTM A53/A53M, Schedule 40. Concrete shall conform to the requirements of the paragraph entitled, "CONCRETE" below. After installation, the aboveground portions of the pipe guard posts shall be given one coat of paint conforming to the requirements of SSPC Paint 25 , followed by two coats of yellow paint conforming to the requirements of Federal Specification (FS) TT-E-489H , the specifics color to be selected by the Contracting Officer. The identifying number corresponding to the relief well or piezometer shall be identified with black paint on two guard posts at each well location. The number shall be painted so that it can be read from the centerline of the levee and shall be identified on a guard post facing away from the levee.

2.8 CONCRETE

2.8.1 Surface Preparation

Prior to placing concrete, all surfaces upon which the concrete is to be placed or placed against, shall be wetted.

2.8.2 Concrete Mix Requirements

Concrete shall conform to the requirements of ASTM C94/C94M. Concrete shall have a minimum compressive strength of 4,000 pounds per square inch (psi) at 28 days in accordance with ASTM C39/39M. Concrete mixture shall have a nominal maximum sized aggregate of 1-inch and produce a slump between 1 and 4 inches measured in accordance with ASTM C143/143M .

Entrained air shall be 6 (six) percent, plus or minus 1-1/2 percent measured in accordance with ASTM C231/231M . The concrete shall be reinforced with Type III Synthetic Fiber as specified in ASTM C1116/C1116M .

The concrete shall be mixed in a manner so as to produce a mixture having a consistency that will permit placement as indicated on the drawings.

2.8.3 Concrete Placement

Concrete mixed at the job site shall be placeded in the work within 45 minutes after mixing. Concrete mixed at a commercial mixing plant and transported to the job site in trucks shall be placed in the work within 1-1/2 hours after mixing. Retempering of concrete will not be allowed.

Concrete shall not be placed when the ambient temperature is below 40 degrees F or above 85 degrees F unless otherwise approved by the Contracting Officer in writing; nor when the concrete, without special protection, is likely to be subjected to freezing temperatures before final set has occurred. Concrete shall be thoroughly consolidated after placement by suitable vibrators or by rodding.

2.8.4 Concrete Finish and Curing

Concrete shall be given a trowel finish and shall be cured by keeping the surface continuously wet for a period of not less than 72 hours or by application of an approved curing compound. Submittals shall conform to the requirements of Section 01 33 00 SUBMITTAL PROCEDURES.

SECTION 33 26 00.00 11 Page 8

2.9 DRILLING FLUID ADDITIVE

The drilling fluid (not a bentonite or other expansive clay system) shall be a suspension of fine-grained soil or shall be a commercial product of a recognized manufacturer. Drilling fluid additives intended for use shall be submitted to the contracting Officer prior to use. The drilling fluid shall have the characteristic of being readily removable from the gravel pack and the walls of the formation by development methods as specified in the paragraph entitled, "DEVELOPMENT" below.

PART 3 EXECUTION

3.1 GENERAL - RELIEF WELLS

3.1.1 Shop Drawings and Field Procedures

The Contractor shall submit shop drawings which present details of his methods for drilling, coupling well screen and riser sections together, installing the well screen and riser, backfilling, developing and pump testing the well. The shop drawings shall show the well screen material, size, perforation size, shape and pattern and bottom plug material and installation detail. Also, the riser pipe and well discharge details shall be shown on the shop drawings. Any Contractor proposed substitutes or alternates in material, construction details, or methods must be presented in the shop drawings. No phase of the work shall be initiated until all shop drawings concerning that activity, have been approved.

3.1.2 Location

The location and elevation requirements for the wells are shown on the drawings. The location for each well shall be clearly staked and identified by number and elevation in the field. The well location and elevation survey results shall be submitted to the Contracting Officer .

The Government shall have 5 working days to review the surveyed locations of the relief wells. The location of the wells may be field adjusted by the Contracting Officer prior to approval of the survey results. The top of the relief wells shall be installed no higher than the maximum elevation for each well as shown on the drawings except as directed by the Contracting Officer.

3.1.3 Depth-of-Well

The length of well screen and length of riser pipe shall conform to the elevations shown on the drawings and to the final design as presented after the pilot hole boring data has been furnished and evaluated.

3.2 PILOT HOLE BORINGS

The relief well screen and riser pipe lengths shown on the plans are considered preliminary based on the subsurface information available. The intent of the pilot hole borings is to obtain location specific detail of stratigraphy and material gradations at each well location. Therefore the preliminary designs shown on the project plans are subject to changes and the changes will be based on the results of the pilot hole boring data.

3.2.1 Location

Prior to drilling the relief wells, the Contractor shall drill a pilot hole within 5-feet of the well locations that are indicated on the

SECTION 33 26 00.00 11 Page 9 drawings and have been located in the field as described in the paragraph entitled, "LOCATION" above. Pilot hole borings shall also be drilled at any additional locations determined necessary by the Contracting Officer.

A wooden survey stake marked with well number and existing ground elevation shall identify each pilot hole location and shall be of sufficient height to be easily seen in the field. Prior to commencement of pilot hole borings, the staked out locations of the pilot holes may be field adjusted by the Contracting Officer. The elevation of the existing ground surface at the pilot hole locations shall be surveyed by the contractor and submitted to the Contracting Officer along with the results of the pilot hole sieve analyses data. Upon completion of the pilot hole, the survey stake shall be placed as close as feasible to the location at which the boring was taken. The pilot holes shall be located within 5 feet of the well locations.

3.2.2 Method

Pilot holes may be drilled by any method approved by the Contracting Officer which will allow the recovery of samples as described below.

Samples shall be obtained with a standard split spoon sampler, (inside diameter of 1-3/8 inch), and shall be driven by any method approved by the Contracting Officer to obtain samples 18 inches in length. Blow counts will not be required unless as specified below. Drilling fluid additives shall be as specified in the paragraph entitled, "DRILLING FLUID ADDITIVE" above.

3.2.3 Intervals

Pilot holes shall be continuously drilled to an elevation 10 feet above the approximate elevation of the bottom of the riser pipe as shown in the drawings as measured from the ground surface. Sampling shall begin at this elevation unless sand is encountered during the continuous drilling of the hole. If sand is encountered, then sampling shall begin at the clay/sand interface. Samples shall be taken at 2-1/2 foot intervals or change of strata, whichever occurs first for the next 40 feet. After 40 feet of sampling, the sampling interval shall change to every 5 feet for the remainder of the hole. The bottom elevation of the pilot holes shall be 15 feet below the elevation of the bottom of the well screen as indicated on the drawings, as applicable to each well location.

3.2.4 Sampling

Samples shall be taken at 18 inches lengths in the intervals described above. However, samples may be removed less than 18 inches if the total blow counts for the sample reaches 180. If samples are removed before reaching 18 inches in length due to the maximum blow count per sample, then the blow counts shall be documented by the driller.

3.2.5 Testing

Beginning with the first non-cohesive sample, all samples shall be washed in accordance with ASTM C117 and shall undergo a sieve analysis test in conformance with ASTM C136. Samples taken shall assist in determining the elevation at which the well screen and riser pipe shall be set and to assist in confirming the possible location of blank areas.

3.2.6 Documentation

A field-boring log shall be maintained for each pilot hole drilled. This

SECTION 33 26 00.00 11 Page 10 data shall be recorded on Form LMM 650 Jan '64 "Field Boring Log" , a copy of which is availale at the following website under the link "Relief Well Standard Forms":

http://www.mvm.usace.army.mil/BusinessWithUs/contracting/forms.aspx . The Contractor shall submit the logs of the pilot borings, the soil samples and results of sieve analysis tests obtained from the pilot borings with the depths from which samples were obtained, the elevations at which soil strata changes occur, and any other information available from the pilot boring to the Contracting Officer. The elevations of changes between materials shall be recorded to the nearest 0.1 foot. The Contracting Officer shall then make a determination as to the lengths and locations of well screen, blank pipes between screen sections and riser pipe to be installed in each well. The Contractor shall provide the sieve analyses data through a Microsoft Excel spreadsheet provided by the Memphis District for each boring. The testing laboratory shall retain a portion of each unwashed sieve sample that exceeds the amount required to perform testing in accordance to ASTM C117 and ASTM C136 for future test verification. This small sample must be retained until all sieve data has been reviewed by the Memphis District. A copy of each sieve analysis results shall be emailed to representatives from both the Memphis District Geotechnical Engineering Branch and the Wynne Area Office .

E-mail addresses will be provided during pre-work conferences. After receipt of the required information from the pilot hole described above, the Contracting Officer will make a determination and convey it to the Contractor within 10 working days.

3.2.7 Pilot Hole Abandonment

Each pilot hole shall be backfilled to within 12 feet of the surface with concrete sand meeting the requirements of ASTM C33/C33M. The remainder of the pilot hole shall be filled with 10 feet of grout capped by 2 feet of compacted impervious soil from the cuttings. The grout shall be tremied through a pipe and forced upwards toward the ground surface. When the grout reaches the surface, it shall be allowed to flow to waste until the Contracting Officer determines that the grouting has been satisfactorily accomplished. The grout mix shall consist by weight of one part Portland cement, 4 parts sand, 2 parts Bentonite and shall be mixed with sufficient water to provide a 6 to 8 inch slump.

3.3 DRILLING

3.3.1 General

Wells shall be drilled by the reverse rotary method, in such a manner to insure proper placement of the well screen, riser pipe and gravel pack. At all times during the drilling and construction process, the water level in the drill hole shall be maintained at a minimum level of 10 feet above the in-situ groundwater level. Temporary Drilling Pads, similar to the examples shown on the plans, may be required to achieve this requirement.

The minimum required height of the Temporary Drilling Pad can be calculated as [Height = 10ft - (Ground Elevation at Well - Groundwater Elevation of Nearest Well or Piezometer)]. The use of Temporary Drilling Pads at locations other than what are indicated on the plans require the prior approval of the Contracting Officer. Methods which involve radical displacement of the formation, or which may reduce the yield of the well, will not be permitted. Only drilling fluid additives approved by the

SECTION 33 26 00.00 11 Page 11 contracting officer may used for drilling. However, the use of a bentonitic type drilling fluid is prohibited. Drilling and installation of well screen and gravel pack shall be completed for each well without interruption. Excavated material shall be disposed of as directed by the Contracting Officer. Before drilling operation begins on each well, the Contractor shall demonstrate that all material, equipment, and experienced personnel are mobilized and that all equipment necessary for the job is adequate for an efficient operation and is operating in a satisfactory manner. Loss of a hole or well because of lack of material, inadequate or faulty equipment, or careless operating procedures will be considered cause for an abandoned well due to fault or negligence of the Contractor.

3.3.2 Reverse Rotary Method

The diameter of the hole shall be such as shall permit the placement of the minimum thickness of gravel pack as specified in the paragraph entitled, "GRAVEL PACK" above. If the walls of the hole above the top of the gravel pack require support during development operations, a temporary casing similar to that specified in the paragraph below entitled, "TEMPORARY CASING" shall be placed so as to extend from the ground surface to at least three feet below the top of the gravel pack material.

Drilling fluid additives, if used, shall be as specified in the paragraph entitled, "DRILLING FLUID ADDITIVE" above.

3.3.3 Temporary Casing

A temporary well casing of either iron or steel, new or used, may be used to support the sides of the entire hole during drilling and placement of screen, riser pipe, and gravel pack and to support the sides of the unbackfilled portion of the hole during development of the well. Any temporary casing shall have an inside diameter large enough to provide the minimum gravel pack thickness, as specified in the paragraph below entitled, "PLACING GRAVEL PACK", entirely around the well screen or riser pipe and shall have sufficient thickness to retain its shape and maintain a true section throughout its depth, and may be in sections of any convenient length. The temporary casing shall be securely anchored to the drill rig or ground surface at all times until removed. The temporary casing shall be such as to permit its removal without interfering with the gravel pack or riser pipe. Methods of installation that will create a cavity outside the temporary casing will not be permitted.

3.3.4 Obstructions Encountered

If obstructions are encountered in the foundation which, in the opinion of the Contracting Officer, render it impracticable to complete the well to the directed depth, the Contracting Officer may adjust the depth to conform to that of the obstruction. Alternatively, the Contracting Officer may direct the Contractor to abandon the well, plug the hole by backfilling in accordance with the paragraph below entitled, "PLUGGING ABANDONED HOLES" and construct another well at an adjacent site. The Contractor shall be required to provide and use drills and equipment that are capable of drilling through insitu wood deposits within the alluvium and capable of removing cobbles up to 5-1/2 inches in diameter. The presence of cobbles up to 5-1/2 inches in diameter or insitu wood that may be encountered during drilling shall not be considered as obstructions or sufficient reason for abandonment of a well. Where obstructions are encountered, drilling shall be continued until it is demonstrated to the Contracting Officer that further efforts to advance the drill hole are impracticable. Such demonstration shall include, but not be limited to, SECTION 33 26 00.00 11 Page 12 continuing drilling operations when no gain in depth is being made for a minimum of 15 minutes. Wells which are abandoned because of impracticability of completion to the desired depth will be paid for as specified in Section 01 22 00.00 11 MEASUREMENT AND PAYMENT, except that payment will not be made if abandoned because of faulty operation or neglect of the Contractor.

3.4 INSTALLATION OF RISER PIPE AND SCREEN

3.4.1 Assembly

All riser pipe and screen shall be new and in good condition before installation and all couplings and other accessory parts shall be securely fastened in place. The successive lengths of pipe shall be arranged to provide accurate placement of the screen sections in the soil strata. The use of lengths of screen and riser shorter than 15 feet long will not be permitted unless previously approved by the Contracting Officer.

The bottom of the screen and riser assembly shall be equipped with an appropriate centering guide which will satisfactorily center the assembly in the hole and hold it securely in position while the gravel pack material is being placed. The centering guide should be placed on the bottom of the screen and have a minimum diameter no less than 1-1/2 inches of the diameter of the drilled hole and ensure minimum clearance needed for placement of the gravel pack. The centering guide or guides should be designed and attached so that natural material removed from the sides of the drilled hole during installation shall be at a minimum. Centering guides, also at a minimum diameter of 1-1/2 inches less than the diameter of the drilled hole, may be placed at other locations along the screen and riser pipe assembly provided they do not interfere with placement of gravel pack material as specified in the paragraph entitled, "PLACING GRAVEL PACK" below. If a centering guide apparatus or ring is used for placement of the gravel pack that will slip around the well screen and riser pipe, then the guide apparatus shall also have a minimum diameter of 1-1/2 inches less than the diameter of the drilled hole (or on all four sides) ensuring correct alignment along the entire length of the relief well.

3.4.2 Joints

Sections of relief well pipe shall be jointed together as specified in the paragraph entitled, "COUPLING" above. Joints shall be designed to provide strength capable of supporting the weight of the relief well stem as it is lowered into the hole.

3.4.3 Installation

The Contractor shall be required to install, develop and test at least one well to insure compliance with the specifications before installation of the 6th well is allowed. Results of all well tests must be submitted to the Contracting Officer prior to beginning the installation process of the 6th well. The assembled riser pipe and screen shall be placed in the hole in such manner as to avoid jarring impacts and to insure that the assembly is centered and not damaged or disconnected. All mud and undesirable material shall be washed free of from the well screen prior to placing in the hole. After the screen and riser pipe have been placed, a gravel pack shall be constructed around the screen section as specified in the paragraph below entiteld, "PLACING GRAVEL PACK" and the well developed as specified in the paragraph entitled, "DEVELOPMENT" below. The top of the

SECTION 33 26 00.00 11 Page 13 riser pipe shall be held at the designated elevation as shown on the drawings during placement of the gravel pack. Immediately after the installation of the well screen and riser pipe assembly, the depth of the well shall be measured by means of an approved sounding device.

3.4.4 Plumb and Alignment

Each well shall be installed and maintained straight and plumb during placement of gravel pack and development. Immediately before placing the gravel pack and with the top of the well fastened securely in a vertical and horizontal position, an alignment test shall be conducted in the presence of the Contracting Officer. Excessive misalignment or deviation from plumb shall be corrected before placing the gravel pack. The alignment test shall consist of two 10-foot sections of standard 6 inch diameter pipe coupled together with a 7.39 inch outside diameter (O.D) coupling lowered inside the well for the full depth of the well and withdrawn without binding against the sides of the well screen or riser pipe for 8 inch diameter wells. The Contractor shall furnish the above apparatus and shall perform the alignment tests. The Contractor shall notify the Contracting Officer a minimum of 24 hours prior to performing the alignment tests. After completion of the alignment test, the Contracting Officer may elect to perform a plumb test before placement of the gravel pack. This test, if performed, will be at the expense of the Government using Contractor-furnished equipment and shall consist of a plumb-line run from the top of the well to the bottom of the well. A variation of up to 12 inches per 100 feet, will be permitted in the combined length of screen and riser pipe of the well. In the event the Contracting Officer elects to perform the plumb survey prior to gravel pack placement and the well fails to conform to the standard described above, the Contractor, at no additional expense to the Government, shall correct the plumb of the well. The Contractor shall provide assistance to the Contracting Officer in performing the plumb test, if requested.

3.5 PLACING GRAVEL PACK

3.5.1 General

After the screen and riser pipes have been placed, and alignment surveys and plumb surveys (if performed) are conducted, the gravel packs shall be placed through two 4 inch inside diameter (I.D.) tremies with no obstructions.

3.5.2 Tremie Pipe

The tremie hopper shall be so constructed and balanced that gravel pack material will feed freely and equally to two tremie pipes located at 180 degrees on each side of the screen. Tremie pipe shall consist of equal 10 foot lengths of standard 4-inch pipe with 1/16 inch wide equally spaced slotted openings. Connections between the tremie pipe and the hopper shall be designed for quick connection or disconnection for adding or removing tremie pipe with least possible delay. Tremie pipe shall contain no dents, flat spots, damaged threads, or holes, and shall be reamed and/or deburred to the full inside diameter (I.D.) of the pipe.

3.5.3 Tremie Guide

The tremie guide shall consist of a metal ring or rings of sufficient inside diameter to slip freely over riser pipe and screen with 4-inch collars welded to the guide at 180 degrees to securely hold the tremie

SECTION 33 26 00.00 11 Page 14 pipe in place. If this metal ring/rings or apparatus is also used as a centering device for correct alignment of the relief wells, then the ring/rings or apparatus shall have a minimum outside diameter of 1-1/2 inches less than the diameter of the drilled hole for each well. This apparatus does not have to be continuous in diameter around the relief well pipe but shall have the minimum clearance on all four sides ensuring that the relief well pipe will be centered in the hole and the gravel pack will be evenly distributed around the pipe. At no time shall tremie guide or pipes be raised, lowered or supported by only one pipe.

3.5.4 Gravel Pack Placement (Gravity)

Prior to and during placement of the gravel pack, the top of the temporary casing or hole shall be covered or otherwise shielded to prevent the gravel pack from entering the space around the well except through the tremie pipe. No material shall be allowed to enter the well except through the tremie pipes. The Contractor shall be equipped to efficiently add gravel pack material to the hopper in any position from the ground surface to the maximum height of the hopper. The tremie pipe shall be installed to a length of 10 feet below the lower tremie guide. The gravel pack material shall be placed in an approved manner and without significant segregation. The gravel pack shall have a minimum thickness of 6 inches between the outside of the well screen and the outside of the gravel pack and shall be placed above the top of the well screen to the level shown on the drawings. At the commencement of placing operation, the tremie shall rest on the bottom of the hole and it shall be filled with gravel pack material. The tremie shall then be raised in increments approximately equal to the increments of the gravel pack placed. At all times during the placing of the gravel pack, the tremie pipe shall be kept filled with gravel to five (5) feet above the top of the well.

3.5.5 Gravel Pack Placement (Pumping)

The filter material may be pumped into the well using two 4-inch tremies with no obstruction as stated above provided the Contractor can pump the gravel pack without significant segregation of the gravel pack material and can pump in a continuous manner. A plan shall be submitted to the Contracting Officer and, if approved, a well shall be installed and tested before production installation proceeds.

3.5.6 Temporary Casing

If temporary casing is used, the gravel pack shall be placed in increments not to exceed 2 feet; the tremie and temporary casing shall be raised in small increments approximately equal to the increments of the gravel pack placed, except that at no time prior to the completion of placement of the gravel pack shall the bottom of the casing be less than 1 foot below the top of the gravel pack in the hole. The Contractor shall provide a means of measuring the gravel pack in the hole and also provide a means of measuring the gravel pack depth. The alternate placing of gravel pack material and withdrawing of the tremie and temporary casing shall be continued until the gravel pack has been placed to the level shown on the drawings.

3.6 CONCRETE SLAB

A concrete slab with concrete conforming to the requirements as specified in the paragraph above entiteld, "CONCRETE" shall be placed above the grout, as shown on the drawings. The top elevation of the concrete slab

SECTION 33 26 00.00 11 Page 15 shall be set a minimum of 4" below the maximum relief well head elevation. In some areas grading will be required to install the concrete pad at this required elevation. In areas where the existing ground surface will result in a top of concrete pad elevation lower than the maximum allowable, no grading shall be performed.

3.7 INSTALLATION OF ANGULAR FACE RING

The riser pipe shall be cut no higher than the specified elevation for each relief well. Four-inches of riser shall be left above the top of the concrete slab. The cut shall be square, smooth and even along the top of the riser pipe. The angular face ring shall be welded to the top of the riser pipe with the top of the ring 1/4-inch above the smooth cut on the riser pipe. The weld shall be a continuous weld along the inside of the angular face ring along the top of the riser pipe. The finished product shall result in a smooth surface with no rough edges and provide continuous support between the silicone sponge rubber gasket of the check valve and top of the angular face ring.

3.8 INSTALLATION OF CHECK VALVE

The top of the riser pipe for each well shall be fitted with an aluminum check valve. The check valve and/or a temporary cover as approved by the Contracting Officer shall be installed on top of the riser pipe immediately after installation of the riser pipe and filter gravel. The temporary cover as approved shall be used during the installation and development process only. The aluminum check valve or temporary cover shall remain in place at all times throughout the well installation and development process to prevent possible contamination or damage to the well. The only time the check valve or temporary cover shall be removed will be during pumping, development and cleaning operations. The aluminum guide rods shall also slide freely up and down inside the riser pipe and shall be dimensioned as shown on the drawings to ensure proper seating of the check valve for the life of the relief well. The installation of the check valve shall be inspected and approved by the Contracting Officer prior to installation of each relief well outlet.

3.9 DEVELOPMENT

3.9.1 General

Following placement of gravel pack materials, the Contractor shall develop the relief well to remove all fines from the well and gravel pack so as to produce a stable well of maximum efficiency. Well development shall consist of chemical treatment, mechanical development (surging) and pumping. The Contractor will start the well development and testing process for the first well drilled no later than 5 days from the installation of well screen, riser and gravel pack and prior to the installation of the sixth well drilled. The Contractor will start the well development and testing process for each remaining well no later than 5 days from the installation of well screen, riser and gravel pack. The Contractor shall be responsible for maintaining at the relief well the needed access and work area and clearance in the relief well necessary to accomplish development. The Contractor shall furnish, install or construct the necessary discharge line and troughs to conduct and dispose of the discharge a sufficient distance from the work area to prevent damage. Development shall be conducted to achieve a stable well of maximum efficiency and shall be continued until little or no additional material from the foundation can be pulled through the gravel pack.

SECTION 33 26 00.00 11 Page 16

Drainage shall be provided prior to any pump testing or development of constructed wells. Any water discharged during the development process must be conveyed by way of collector ditches and outlet ditches.