Attachment 1 - Specifications - 33 26 00.00 10 Amendment 0001.pdf

Amendment 0001

SECTION TABLE OF CONTENTS

DIVISION 33 - UTILITIES

SECTION 33 26 00.00 10

RELIEF WELLS

PART 1 GENERAL

1.1 Scope

1.2 UNIT PRICES

1.2.1 Relief Wells

1.2.1.1 Payment

1.2.1.2 Measurement

1.2.1.3 Unit of measure

1.2.2 Drilling Through Obstructions

1.2.2.1 Payment

1.2.2.2 Measurement

1.2.2.3 Unit of Measure

1.2.3 Pump Tests

1.2.3.1 Payment

1.2.3.2 Measurement

1.2.3.3 Unit of measure

1.3 REFERENCES

1.4 STANDARD SPECIFICATIONS

1.5 SUBMITTALS

1.6 SHOP DRAWINGS

1.7 WELL DRILLING SPECIALIST

1.8 REGULATORY REQUIREMENTS FOR DRILLING AND WELL INSTALLATION

1.9 LOCATION

1.10 DISPOSAL OF DEBRIS

1.11 PROJECT/SITE CONDITIONS

1.11.1 Location

1.12 SUBSURFACE DATA

PART 2 PRODUCTS

2.1 WELL SCREEN

2.1.1 General

2.1.2 Stainless Steel Well Screen

2.1.2.1 General

2.1.2.2 Materials

2.1.2.3 Well Screen

2.1.2.4 Well Screen Couplings

2.2 STAINLESS STEEL RISER PIPE

2.3 WELL SCREEN BOTTOM PLUG

2.4 FILTER PACK

2.4.1 Filter Pack Gradation Analysis

2.5 RELIEF WELL CONCRETE

2.6 RELIEF WELL TYPES

2.6.1 "D"-Type Wells

2.6.1.1 Well Guard

2.6.1.2 Concrete Pad

SECTION 33 26 00.00 10 Page 1

2.6.1.3 Check Valve

2.6.1.4 Cover Plate

2.6.1.5 Well Numbering

2.6.2 "T"-Type Wells

2.6.2.1 Well Guard

2.6.2.2 Check Valve

2.6.2.3 Bronze Survey Markers

2.6.2.4 Manholes

2.6.2.5 Manholes Frames Lids

2.6.2.6 Manhole Steps

2.6.2.7 Flexible Watertight Performed Butyl Mastic Joint Sealants

2.6.2.8 Resilient Connectors

2.6.2.9 Backfill

PART 3 EXECUTION

3.1 RELIEF WELL DRILLING

3.1.1 General

3.1.2 Reverse Rotary Method

3.1.3 Temporary Casing

3.1.4 Obstructions Encountered

3.1.5 Temporary Drilling Pads

3.2 INSTALLATION OF RISER PIPE AND SCREEN

3.2.1 Assembly

3.2.2 Joints

3.2.3 Installation

3.2.4 Plumbness and Alignment

3.2.4.1 Alignment

3.2.4.2 Plumbness Test

3.3 FILTER PACK PLACEMENT

3.3.1 General

3.3.2 Tremie

3.3.2.1 Tremie Hopper

3.3.2.2 Tremie Pipes

3.3.3 Procedure

3.3.3.1 Filter Material

3.3.3.2 Temporary Casing

3.3.3.3 Prior to Development

3.4 DEVELOPMENT

3.4.1 General

3.4.2 Jetting and Air-Lift Pumping

3.5 PUMPING TEST

3.5.1 General

3.5.2 Equipment

3.5.2.1 Pump

3.5.2.2 Water Level

3.5.2.3 Flow Meter

3.5.2.4 Rossum Sand Sampler

3.5.3 Data

3.5.4 Procedure

3.5.4.1 Pump Testing

3.5.4.2 Discharge

3.5.4.3 Additional Testing

3.5.4.4 Material Infiltration

3.5.4.5 Abandonment

3.5.4.6 Completion

3.5.5 Additional Pumping Test Measurements

3.5.6 Records

3.6 BACKFILLING

SECTION 33 26 00.00 10 Page 2

3.7 INSTALLATION TOLERANCES

3.8 FINAL REPORTS

-- End of Section Table of Contents --

SECTION 33 26 00.00 10 Page 3

SECTION 33 26 00.00 10

RELIEF WELLS

PART 1 GENERAL

1.1 Scope

This section, in conjunction with the contract drawings and relief well designs, covers drilling and installing new Type "D" and Type "T" relief wells in their entirety including permits, drilling, screen, riser pipe, filter pack, concrete seals, well development, pumping tests and outlet works. All work shall conform to the requirements of the Illinois Water Well Construction Rules. Variances will be required from the Madison County Health Department before installing the wells as detailed on the drawings. All variances, permitting, licensing, and submittal requirements required by this work are the responsibility of the Contractor.

1.2 UNIT PRICES

1.2.1 Relief Wells

1.2.1.1 Payment

Payment will be made for costs associated with relief wells, which price shall constitute full compensation for drilling, assembling, and installing relief wells. No payment will be made for placement or replacement of temporary casings or repair of damage resulting from Contractor operations. No separate payment will be made for permits, screen, riser, check valves, filter pack, development, backfill, concrete/bentonite seals and slabs, or metal well guard. Separate payment will be made for Type "T" relief well manholes and discharge piping per the bid schedule.

Bore holes ordered abandoned prior to installation of well screen and riser due to no fault of the Contractor will be paid for at the contract unit price, per linear foot, for Relief Well Bore Hole Abandonment. There will be no separate payment for setup, drilling, downtime, etc. for bore holes ordered abandoned.

1.2.1.2 Measurement

Relief wells will be measured for payment by the linear foot of completed well from the relief well outlet elevation to the bottom of the well plug.

The sump (2-foot over drill) beneath the well plug shall be considered incidental to the work. For Type "T" relief wells, the depth from ground surface to the outlet elevation will also be considered incidental to the work. Completed wells ordered abandoned due to no fault of the Contractor, will be measured for full payment.

1.2.1.3 Unit of measure

Unit of measure: linear foot to the nearest 0.1 foot.

SECTION 33 26 00.00 10 Page 4

1.2.2 Drilling Through Obstructions

1.2.2.1 Payment

Payment will be made for costs associated with drilling through obstructions as defined in Part 3 of this specification section. This price will constitute full compensation for drilling advancement through obstructions via alternative drilling methods or tooling. This unit price is above and beyond the base unit price for drilling and installing Type "D" or Type "T" relief wells.

1.2.2.2 Measurement

Drilling through obstructions will be measured for payment by the linear foot of completed borehole through an obstruction. If borehole advancement is lost due to cave-off or settlement, the contractor will be compensated for the initial linear foot of advancement. Any secondary or tertiary attempts by the contractor will not be measured for payment.

1.2.2.3 Unit of Measure

Unit of measure: linear foot to the nearest 0.1 foot.

1.2.3 Pump Tests

1.2.3.1 Payment

Payment will be made for costs associated with pump test, which price shall constitute full compensation to perform a satisfactory pump test as specified. No payment will be made for pump test not successfully completed.

1.2.3.2 Measurement

Pump tests will be measured for payment for each pump test successfully performed as specified, and otherwise directed.

1.2.3.3 Unit of measure

Unit of measure: Each (EA).

1.3 REFERENCES

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

ALUMINUM ASSOCIATION (AA)

AA SAS-30 Specifications for Aluminum Structures

ASTM INTERNATIONAL (ASTM)

ASTM A312/A312M (2017) Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes

ASTM B98/B98M (2013) Standard Specification for Copper-Silicon Alloy Rod, Bar, and Shapes

SECTION 33 26 00.00 10 Page 5

ASTM C136/C136M (2014) Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates

ASTM F480 (2014) Thermoplastic Well Casing Pipe and Couplings Made in Standard Dimension Ratios (SDR), SCH 40 and SCH 80

U.S. ARMY CORPS OF ENGINEERS (USACE)

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

1.4 STANDARD SPECIFICATIONS

All work, installation, procedures, materials, etc. not specifically addressed in this technical specification shall be in conformance with the Standard Specifications for Road and Bridge Construction , adopted April 1, 2016 by the Illinois Department of Transportation (herein referred to as the Standard Specifications) or as modified by this Specification.

1.5 SUBMITTALS

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

submittals not having a "G" designation are for Contractor Quality Control approval. Submit the following in accordance with Section 01 33 00

SUBMITTAL PROCEDURES:

SD-02 Shop Drawings

Shop Drawings; G Relief Well Drilling; G Relief Well Details; G

SD-03 Product Data

Well Screen;G Well Screen Bottom Plug; G Riser Pipe; G Couplings; G Filter Pack; G

Check Valve; G Well Guard; G Cover Plate; G Relief Well Concrete; G

SD-06 Test Reports

Final Reports; G Relief Well Pumping Test Report; G Filter Pack Gradation Analysis; G

SD-07 Certificates

Well Drilling Specialist; G Stainless Steel Welding Certification; G

SECTION 33 26 00.00 10 Page 6

1.6 SHOP DRAWINGS

The Contractor shall construct the relief wells as described herein and as shown on the plans. All shop drawings shall be properly labeled with the relief well name, coordinates, stationing, offset and pilot hole reference. Show details of the proposed methods for drilling, coupling well screen and riser sections together, placement of centralizers, installing the well screen and riser, developing, pump testing, and limit(s) of backfilling. Show on the shop drawings the type of screen and size; slot size, shape and pattern; bottom plug material; and installation detail including the makeup lengths of each section of screen/riser. The Relief Well Details (riser pipe, check valve(s), housing, and well discharge details) shall also be shown on the shop drawings. Any Contractor proposed substitutes or alternates in material construction details or methods shall be indicated on the submittal and detailed on the shop drawings. No phase of the work shall be initiated until all shop drawings concerning that activity have been approved.

1.7 WELL DRILLING SPECIALIST

The Contractor shall designate a separate well drilling specialist for each work shift and/or crew. The well drilling specialist shall have a minimum of ten years experience in the water well industry, and shall be familiar with the operation of all equipment and machinery required to install high capacity water wells in Mississippi River alluvium. The Contractor shall submit summaries of qualifications and references for any and all well drilling specialists to the Contracting Officer for review and approval within 10 days of Notice to Proceed. Well drilling shall not proceed until the well drilling specialist has been approved. The well drilling specialist shall be at the field site at all times during drilling and installation of well materials, as well as during development and pump testing of installed wells.

1.8 REGULATORY REQUIREMENTS FOR DRILLING AND WELL INSTALLATION

Drilling, backfilling and relief well installation shall be performed in accordance with Illinois state statutory and regulatory requirements.

Permits, variances and/or waivers shall be obtained as required from the Madison County Health Department to install and abandon the wells as detailed on the drawings and as described in this specification.

1.9 LOCATION

Relief well locations shall installed at the indicated locations. The final relief well locations should not be field adjusted without the approval of the Contracting Offier. Any field adjust shall be at no additional cost to the Government.

1.10 DISPOSAL OF DEBRIS

The Contractor shall dispose of all debris resulting from relief well construction or abandonment operations off-site.

1.11 PROJECT/SITE CONDITIONS

1.11.1 Location

The coordinates of each pilot hole and relief well will be provided by Government.

SECTION 33 26 00.00 10 Page 7

1.12 SUBSURFACE DATA

Subsurface soil boring logs are shown on the drawings. These data represent the most recent subsurface information available; however, variations may exist in the subsurface between boring locations.

Groundwater levels indicated in the soil boring logs were at the time of exploration. The groundwater table may vary significantly depending on time of year and river stage level.

PART 2 PRODUCTS

2.1 WELL SCREEN

2.1.1 General

Well screen, screen intervals, filter pack and riser lengths are provided on the contract drawings. Materials for relief wells shall be of the type specified below, and shall be of the dimensions specified. 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 screen shall be approved by Contracting Officer.

2.1.2 Stainless Steel Well Screen

2.1.2.1 General

The well screen shall be of the continuous slot, wire-wound design. It shall be fabricated by circumferentially wrapping a triangularly shaped wire around a circular array of internal rods. The wire configuration shall produce inlet slots with sharp outer edges, widening inwardly to minimize clogging. Each juncture between the horizontal wire and the vertical rods shall be fusion welded under water by the electrical resistance method. End fittings shall be welded to the screen body.

2.1.2.2 Materials

All pipes, rods, bars, wire, and fittings shall be stainless steel conforming to ASTM A312/A312M , Grade TP 304.

2.1.2.3 Well Screen

The slot size and screen length have been provided to the Contractor.

Collapse, column, and tensile strengths of the well screens shall be adequate to allow safe installation and development of the wells. In addition, contractor shall have available, prior to drilling each well, two (5) five-foot sections of screen for each slot size to allow for field changes during installation, if necessary. Additionally, the contractor shall also be able to field modify the bottom section of screen by cutting and welding a plug on a shorter section of screen to maximize aquifer penetration in the event the well requires adjustment due to obstructions.

The contractor shall submit the stainless steel welding certification of the individual(s) so certified to perform welding of stainless steel.

2.1.2.4 Well Screen Couplings

End fittings for the stainless steel well screens shall be furnished with Schedule 40 flush threads compatible with ASTM F480 requirements, and of the same alloy as the well screen and riser pipe. Flush joint fittings

SECTION 33 26 00.00 10 Page 8 which join well screen to riser pipe shall adequately provide for the transition from well screen to riser pipe. Joints shall be designed and constructed to support the weight of the screen and/or pipe as it is lowered into the hole. All fittings shall contain a Viton O ring on the male end.

2.2 STAINLESS STEEL RISER PIPE

The new relief well riser pipe and fittings shall be manufactured from stainless steel conforming to ASTM A312/A312M , Grade TP 304. The pipe roundness, wall thickness, and straightness shall meet the ASTM specifications. The riser pipe shall be Schedule 40 wall thickness with a minimum inside diameter of 10 inches. Riser discharge shall conform to the details shown on the contract drawings. Couplings for new relief wells between the riser pipe and the well screen and between adjacent pieces of riser pipe sections shall be as specified for well screen pipes.

2.3 WELL SCREEN BOTTOM PLUG

The bottom plug for each well screen shall be made of the same material and at least the same minimum thickness as the screen. Plugs shall be the same diameter as the outside of the screen and fastened to the bottom screen portion in an approved manner.

2.4 FILTER PACK

Submit proposed filter pack material and its gradation, two weeks prior to placement for approval by the Contracting Officer. Material for the filter pack shall be manufactured by Red Flint Sand and Gravel, LLC, Eau Claire, WI. The filter pack material shall contain no detrimental quantities of organic matter nor soft, friable, thin, or elongated particles. The filter pack shall meet the gradation requirements provided below.

2.4.1 Filter Pack Gradation Analysis

The particle size distribution of the filter pack shall be sampled and tested by the Contractor using U.S. Standard Sieve Nos. 8, 10, 12, 14, 16, 18, 20, 25, and 30. Factory gradation analyses shall be performed on a minimum of every 4 bags shipped to the project site and field sampled and tested by a USACE approved lab once for every 5 relief wells installed.

The laboratory test procedure shall conform to that presented in ASTM C136/C136M. All points on individual grading curves obtained from representative samples of filter material shall lie between the boundary 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, which would be detrimental to the proper functioning of the filter.

SPECIFIED GRADATION PERCENT PASSING RANGES FOR RELIEF WELL FILTER PACKS

U.S. SIEVE NO. RF#40 RF#30

FROM TO FROM TO

#8 99.0 100.0

SECTION 33 26 00.00 10 Page 9

SPECIFIED GRADATION PERCENT PASSING RANGES FOR RELIEF WELL FILTER PACKS

#10 90.0 100.0 99.0 100.0

#12 80.0 96.0 86.0 100.0

#14 45.0 63.0 65.0 81.0

#16 16.0 32.0 42.0 58.0

#18 0.0 12.0 15.0 31.0

#20 0.0 2.0 0.0 15.0

#25 0.0 1.0 0.0 3.0

#30 0.0 0.0 1.0

2.5 RELIEF WELL CONCRETE

All concrete shall conform to Section 03 31 01.00 10 CAST-IN-PLACE STRUCTURAL CONCRETE FOR CIVIL WORKS or as shown on the drawings.

2.6 RELIEF WELL TYPES

2.6.1 "D"-Type Wells

The outlet works shall consist of a well guard with check valve, cover plate, concrete pad, numbering/welding and other appurtenant items.

2.6.1.1 Well Guard

The well guard shall consist of a section of 20-inch diameter, stainless steel Type 304, continuous slot well screen. It shall be fabricated by circumferentially wrapping a triangularly shaped wire around a circular array of internal rods. The wire configuration shall produce inlet slots with sharp outer edges, widening inwardly to minimize clogging. Each juncture between the horizontal wire and the vertical rods shall be fusion welded under water by the electrical resistance method. End fittings shall be welded to the screen body. The width of the clear space between the wire wrappings shall be 0.250 inches. The wire wrappings shall be composed of "130" wire. Welding rings shall be furnished on both ends of the screen and stainless steel 3x3 angles (4) welded to the weld rings.

The guard screen shall be attached to the concrete pad by bolting of well guard by the angles to the embedded bolts of the concrete pad as shown on the drawings.

2.6.1.2 Concrete Pad

Dimensions and details of the concrete are shown in the drawings.

Requirements for the concrete are contained in 03 31 01.00 CAST-IN-PLACE

STRUCTURAL CONCRETE FOR CIVIL WORKS.

2.6.1.3 Check Valve

The 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 T 4, or T6. The 3/8 inch diameter aluminum guide rods shall be carefully bent to avoid flattening at the bends. The seat for the check valve shall be constructed of two 1/4-inch aluminum plates and a neoprene gasket, all bolted together as indicated on the drawings. The bolt holes shall be formed by drilling or punching the aluminum plates and neoprene

SECTION 33 26 00.00 10 Page 10 gasket. The neoprene gasket shall have a thickness of 1/2-inch and shall be fabricated from neoprene gasket material. The aluminum guide rods and aluminum lifting ring shall be connected to the plates by welding conforming to the applicable provisions of AA SAS-30 . The check valve shall be temporarily installed on top of the riser pipe immediately after completion of the development pumping, and thereafter shall be kept in place on the pipe at all times, except during pumping, cleaning operations, and actual addition of riser pipe during installation until the total length of the riser pipe is installed. Immediately after the riser pipe is installed to final height, the top of the riser pipe shall be modified for proper fitting of the check valve.

2.6.1.4 Cover Plate

The top of the well guard shall be fitted with a detachable Type 304 stainless steel cover plate as shown on the drawings. 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 brass 5/8-inch bolts, and stainless steel washers and nuts. The nuts shall be tack-welded onto the underside of the angles attached to the weld ring of the outlet works.

2.6.1.5 Well Numbering

On all new Type "D" well guards installed, the well numbers shall be cut out of 1/4-inch thick Type 304 stainless steel and then tack-welded to the cover plate, facing the levee crown. Numerals shall be 5 inches tall.

2.6.2 "T"-Type Wells

The outlet works shall consist of precast concrete manholes, lateral pipes, check valve, embedded bronze survey markers, and other appurtenant items. Requirements for concrete are contained in 03 31 01.00 10

CAST-IN-PLACE STRUCTURAL CONCRETE FOR CIVIL WORKS.

2.6.2.1 Well Guard

The well guard shall consist of a section of 48-inch diameter manhole extending from the concrete well pad to existing ground elevation. The well guard manhole shall be provided with access ladder rungs, which shall support the weight of a 250 lb. person, shall meet the safety requirements of EM 385-1-1 , and shall not restrict access to the top of the 10-inch riser pipe and check valve movement.

2.6.2.2 Check Valve

The 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 T 4, or T6. The 3/8 inch diameter aluminum guide rods shall be carefully bent to avoid flattening at the bends. The seat for the check valve shall be constructed of two 1/4-inch aluminum plates and a neoprene gasket, all bolted together as indicated on the drawings. The bolt holes shall be formed by drilling or punching the aluminum plates and neoprene gasket. The neoprene gasket shall have a thickness of 3/8-inch and shall be fabricated from neoprene gasket material. The aluminum guide rods and aluminum lifting ring shall be connected to the plates by welding conforming to the applicable provisions of AA SAS-30 . The check valve shall be temporarily installed on top of the riser pipe immediately after completion of the development pumping, and thereafter shall be kept in

SECTION 33 26 00.00 10 Page 11 place on the pipe at all times, except during pumping, cleaning operations, and actual addition of riser pipe during installation until the total length of the riser pipe is installed. Immediately after the riser pipe is installed to final height, the top of the riser pipe shall be modified for proper fitting of the check valve.

2.6.2.3 Bronze Survey Markers

The bronze survey markers shall be made from silicon bronze bar, orbitally formed, and conforms to ASTM B98/B98M. The survey marker shall have a 4-inch diameter domed cap, "C" style (U.S. Army Corps of Engineers Type 1 Disc) with a minimum 0.75-inch diameter, 3-inch long split-style tapered stem. One survey marker shall be installed on the top of each Type "T" well manhole with the relief well name stamped in the center of the marker, e.g. RW-100X.

2.6.2.4 Manholes

The relief well manholes shall conform to the lines, grades, and dimensions as shown on the drawings. The manhole sections shall be 48-inch interior diameter (ID) precast reinforced concrete manhole sections. The precast concrete manhole sections shall conform to ASTM C478 and Section 1042 - "Precast Concrete Products" of the Standard Specifications. The finish floor of the manholes shall be constructed of concrete conforming to Section 03 31 01.00 10 CAST-IN-PLACE STRUCTURAL CONCRETE FOR CIVIL WORKS or as shown on the drawings. Manhole sections shall be complete with risers, adapter rings, precast concrete manhole covers and shall be designed and manufactured in accordance with ASTM C478. The manhole cover opening frame and bronze survey marker shall be cast into each manhole cover at the time of manufacture. Manhole steps shall be embedded into the wall a minimum of 3.0 inches but shall not be extended on the outside of the structure. Manhole steps shall be cast into the reinforced concrete manhole wall at locations as shown on the drawings. Flexible watertight preformed butyl mastic joint sealants shall be used conforming to ASTM C990. Prior to placing the butyl mastic joint sealants, the concrete joint surfaces shall be clean and dry. Double rings, coils, or ropes of butyl mastic joint sealants shall be applied to each concrete joint per the manufacturer's product instructions.

2.6.2.5 Manholes Frames Lids

The Contractor shall place a manhole frame and lid on top of each relief well manhole. Locations for flat top relief well manholes shall be as designated in the plans. Flat top manhole frames and hinged lids shall be heavy duty, constructed of cast gray iron conforming to ASTM A48/A48M, Class 35B, and shall have a minimum tensile strength of 35,000 pounds per square inch. The frames and hinged lids shall be designed for AASHTO H-20 loadings. The relief well manhole frames shall have clear square openings of 29 inches X 29 inches with hinged lids. The lids shall be constructed with stainless steel butt hinges and waterproof lift handles. The frames shall be embedded into the precast manhole covers in accordance with manufacturer's recommendations. The lids shall be bolted to the frame with tamper-proof bolts. See Neenah Foundry R-6665 or approved equal.

2.6.2.6 Manhole Steps

The manhole steps shall be constructed of cast gray iron, copolymer polypropylene plastic coated 1/2-inch, grade 60 steel reinforcement step, or ductile iron castings. The step materials shall have a minimum tensile

SECTION 33 26 00.00 10 Page 12 strength of 35,000 pounds per square inch. The gray iron castings shall conform to ASTM A48/A48M, Class 35B. The ductile iron castings shall conform to ASTM A536, Grade 80-56-06.

2.6.2.7 Flexible Watertight Performed Butyl Mastic Joint Sealants

The flexible watertight preformed butyl mastic joint sealants shall conform to ASTM C990 or AASHTO M 198 Type B. The sealants shall consist of high quality butyl rubber with at least 98% solids to minimize hardening, shrinkage, and oxidation. The joint sealants shall be at least 1/2-inch, preformed coils or ropes and supplied in ready-to-apply forms. The preformed joint sealant coil or rope shall be applied so the ends meet and do not overlap.

2.6.2.8 Resilient Connectors

Flexible, watertight connectors used for connecting all pipe to manholes and inlets shall conform to ASTM C923. The connector shall be the A-LOK Premium Connector as manufactured by A-LOK Products, Inc., Tullytown, PA or approved equal.

a. Connect the pipe to the structure wall by casting the connector integrally with the structure wall during the manufacturing process in a manner that it will not pull out during pipe coupling. The connector shall also be capable of being cast into a round structure by curving the connector in a manner that allows it to remain centrally located within the structure wall and perpendicular to the pipe. This configuration will result in no loss of seal or deflection of pipe entering a concrete structure.

b. The seal between the connector and the pipe shall be made by the compression of the connector between the outside circumference of the pipe and the interior hole opening of the structure. The connector shall be the only component to affect the seal between the pipe and structure.

c. The connector shall be sized specifically for the type of pipe being used and shall be installed in accordance with the recommendations of the manufacturer.

2.6.2.9 Backfill

The backfill for the Type "T" relief wells shall conform to the requirements as specified in the drawings. The final backfill surface including the topsoil shall be flush with the surrounding ground surface.

All disturbed areas shall be dressed smooth and rolled with a smooth drum roller for the establishment of turf.

PART 3 EXECUTION

3.1 RELIEF WELL DRILLING

3.1.1 General

Wells shall be drilled by the reverse rotary method, in such a manner to ensure proper placement and plumbness and alignment of the well screen, riser pipe and filter pack. Drilling and installation of well screen and filter pack shall be completed for each well without interruption. Drill cutting material shall be disposed of as specified. Before the drilling

SECTION 33 26 00.00 10 Page 13 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 bore hole or well because of lack of material, inadequate or faulty equipment, not meeting plumbness and alignment requirements or careless operating procedures will be considered cause for an abandoned well due to fault of the Contractor.

The digging of mud pits or similar excavations will not be allowed.

3.1.2 Reverse Rotary Method

The diameter of the hole shall be such that will permit the placement of the thickness of filter pack as shown on the drawings. The use of a bentonite drilling fluid is prohibited. Any proposed drilling fluids must be submitted to and approved prior to use. If the walls of the hole above the top of the filter pack require support during development operations, a temporary casing shall be placed so as to extend from the ground surface to at least one foot below the planned top of the filter material. The Contractor shall be responsible for establishing and maintaining a minimum 7-foot head differential in the drill hole above the piezometric level in the sand aquifer.

3.1.3 Temporary Casing

A new or used temporary well casing of either iron or steel may be used to support the sides of the entire hole during drilling and placement of screen, riser pipe, and filter 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 filter thickness, 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 filter or riser pipe. Methods of installation that will create a cavity outside the temporary casing are prohibited. In the event the temporary casing should become unduly distorted or bent it shall be discarded and a suitable casing shall be used.

3.1.4 Obstructions Encountered

The Contractor shall provide and use drills and equipment that are capable of drilling through in-situ tree logs within the alluvium and capable of removing cobbles up to 5 1/2 inches in the largest dimension. The presence of cobbles up to 5 1/2 inches in the largest dimension or in-situ wood which may be encountered during drilling, shall not be considered as obstructions or sufficient reason for abandonment of a well.

Standard drilling methods and tooling shall be utilized until it is demonstrated to Contracting Officer that further efforts to advance the bore hole are impracticable. Such demonstration shall include, but not be limited to, continuing standard drilling operations when no gain in depth is being made for a period of 30 minutes. "No gain in depth" is defined as

0.0 feet of advancement in a period of 30 minutes.

It is anticipated that obstructions greater than 5 1/2 inches will be encountered in this reach. When it is agreed that 0.0' of advancement has been made for a period of 30 minutes, the contractor shall be prepared to

SECTION 33 26 00.00 10 Page 14 utilize alternative drilling methods or tooling to advance through the larger obstructions. All alternative methods and tooling shall be approved by Contracting Officer prior to utilization in the field. Alternative t ool i ng successf ul l y ut i l i zed i n s i mi l ar condi t i ons i n t he past i ncl ude:

Zubl i n Bi t s and Hol e Opener Reamer Bi t s.

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 and construct another well at an adjacent site, or to continue drilling using alternative approved tooling capable of drilling through and/or removing the obstruction.

3.1.5 Temporary Drilling Pads

The Contractor shall construct any required drilling pads to the minimum dimensions needed to perform the work in a safe manner and maintain the minimum head differential in the drill hole above the piezometric level in the sand aquifer. Material used in the construction of the pads shall consist of crushed stone, earth, crane mats, or other materials approved by the Contracting Officer. Construction of temporary drilling pads shall be incidental to the work to be performed for this project.

3.2 INSTALLATION OF RISER PIPE AND SCREEN

3.2.1 Assembly

All riser pipe and screen shall be 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 bore hole. Centralizers shall be attached to the assembled riser pipe and screen in such numbers and of a type that they will satisfactorily center the riser pipe and screen in the well and will hold it securely in position while the filter pack material is being placed.

3.2.2 Joints

Sections of relief well pipe shall be joined together as specified.

Joints shall be designed and constructed to have sufficient strength to support the weight of the relief well string as it is being lowered into place in the well.

3.2.3 Installation

The assembled riser pipe and screen shall be placed in the bore hole in such manner as to avoid jarring impacts and to ensure that the assembly is centered and not damaged or disconnected. The screen shall be suspended in the hole and shall not rest on the bottom of the hole. After the screen and riser pipe have been placed, a filter pack shall be constructed around the screen section as specified. The top of the riser pipe shall be held at the designated elevation during placement of the filter pack.

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3.2.4 Plumbness and Alignment

3.2.4.1 Alignment

Each well shall be installed and maintained straight and plumb during placement of filter and development. Immediately before placing the filter pack and with the top of the well fastened securely in a vertical and horizontal position, the Contractor shall perform an alignment test. This test shall consist of lowering a pipe 20 feet in length with an outside diameter 1/2 inch smaller than the inside diameter of the well to the full depth of the well and withdrawing it without binding against the sides of the well screen or riser pipe. Furnish the pipe and perform the alignment check and plumbness check in the presence of the Contracting Officer. If the well fails to conform to the standard described above, the alignment of the well shall be corrected by the Contractor at no additional expense to the OWNER.

3.2.4.2 Plumbness Test

After completion of the alignment test the Contractor shall perform a plumbness test before placement of the filter pack. This test will consist of a plumb line run from the top of the well to the bottom of the well. A variation of 6 inches per 100 feet will be permitted in the combined length of screen and riser pipe of the well. If the well fails to conform to the standard described above, the plumbness of the well shall be corrected by the Contractor at no additional expense to the OWNER.

In addition, at least one plumbness check and alignment check shall be performed on each well after placement of the filter pack and backfill.

Additional tests may be made during the performance of the work at the option of the Contractor. If the well fails to conform to the standards described above, the well will be abandoned due to the fault of the Contractor and a new well installed at no additional expense to the OWNER.

3.3 FILTER PACK PLACEMENT

3.3.1 General

After the screen and riser pipe have been placed and alignment surveys and plumbness surveys are conducted, the check valve shall be placed on the top of the well riser to prevent any material from entering the interior of the well. The Contractor shall place the filter pack using the tremie method. The filter pack shall be disinfected during placement by the addition of 70% hypochlorite to the pack in the proportion of 2 lbs. per ton.

3.3.2 Tremie

3.3.2.1 Tremie Hopper

The filter pack shall be placed in a tremie hopper so constructed and balanced that filter material will feed freely and equally to two tremie pipes located at 180 degrees on each side of the screen. 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.

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3.3.2.2 Tremie Pipes

Tremie pipe shall consist of two rigid 4 inch inside diameter tremies with no obstructions. The tremie pipes shall consist of equal 5 foot lengths of 4-inch iron pipe size (IPS) steel pipe with 1/16-inch wide equally spaced slotted openings. Tremie pipe shall be free of dents, flat spots, damaged threads, and holes, and shall be reamed and/or deburred to full inside diameter of the pipe. The tremie guide shall consist of a metal ring or rings of sufficient 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 pipe in place.

3.3.3 Procedure

3.3.3.1 Filter Material

The Contractor shall be equipped to quickly and efficiently add filter material to the hopper in any position from the ground surface to the maximum height of the hopper. No filter pack material shall be allowed to enter the well except through the tremie pipes. At no time shall tremie guide or pipes be raised, lowered or supported by only one pipe. Ten feet of tremie pipe shall be installed below the lower tremie guide. The filter pack material shall be placed using clean water introduced at bottom of hopper and without significant segregation.

3.3.3.2 Temporary Casing

If temporary casing is used, the filter 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 filter pack placed, except that at no time prior to the completion of placement of the filter pack shall the bottom of the casing be less than 1 foot below the top of the filter pack in the hole. The Contractor shall provide a means of measuring the filter pack depth in the hole. The alternate placing of filter pack material and withdrawing of the tremie and temporary casing shall be continued until the filter pack has been placed to the level shown on the drawings.

3.3.3.3 Prior to Development

During development of the well, the top of the filter pack material shall be maintained at the level specified. Prior to and during placement of the filter pack, the top of the temporary casing or hole shall be covered or otherwise shielded to prevent the filter pack from entering the space around the well except through the tremie pipe. Material that may have entered the well screen and riser pipe shall be removed before development of the well is commenced. Construction of the relief well outlet works shall not commence until the development of the well is completed and the filter pack has been placed to the elevation specified.

3.4 DEVELOPMENT

3.4.1 General

Following placement of filter pack materials, the Contractor shall develop the relief well by high velocity jetting and simultaneous airlift pumping. At the time of development, the well shall be free of drawdown or surging effects due to pump testing, developing or drilling at another location within a radius of 500 feet of well being developed. The

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Contractor shall be responsible for maintaining the needed access and work areas at the relief well and the necessary clearance in the relief well 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 areas to prevent damage and contamination of any relief wells. This may require running the discharge lines over the levee and discharging on splash protection at the toe of the levee on the riverside. Development shall be conducted to achieve a stable well of maximum efficiency and shall be continued until little or no material from the foundation or filter pack can be pulled into the well by pumping. As development proceeds, filter pack material shall be added to the annular space around the screen to maintain the top elevation of the filter pack at the specified elevation. The Contractor shall provide a bubbler tube or other approved means for accurately determining the water level in the well under all conditions. If at any time during the development process it becomes apparent, in the opinion of the Contracting Officer, that the well may be damaged, operations shall be immediately stopped. The Contracting Officer may require a change in method if the Contractor's method does not accomplish the desired results. If after initial development and 6 hours of additional development, a well continues to produce excessive sand, the Contracting Officer may order the Contractor to abandon the well. All materials pulled into the well by the development process shall be removed prior to performing the pumping test.

3.4.2 Jetting and Air-Lift Pumping

The well development shall be accomplished by high-velocity, horizontal jetting and simultaneous airlift pumping. The outside diameter of the jetting tool shall be 1/2 to 1 inch smaller than the inside diameter of the screen. The exit velocity of the jetting fluid shall be between 150 and 300 fps and have a pressure at the nozzle of approximately 200 psi.

Circulation of the jetting water will not be allowed. The jetting shall proceed from the bottom of the screen to the top. The tool shall be rotated at a speed of 1 rpm. It shall be positioned at one level for not less than 2 minutes and shall then be raised to the next level.

Individual jetting levels shall be spaced no more than 6 inches vertically apart. Sizing of the eductor pipe, air line, and air compressor shall be adequate to efficiently pump the well at a rate from 10 to 20 percent more than the volume of water introduced through the jetting tool. The eductor pipe shall be placed no more than 5 feet above the top of the jetting tool during development. At the start of the airlift pumping the quantity of air injected shall be limited to that required to initiate flow through the screen.

3.5 PUMPING TEST

3.5.1 General

The Contractor shall perform "3 step" step drawdown pump tests to determine whether the new wells have been adequately developed. Prior to the pump test the water level shall be allowed to reach static level. The well will be considered "static" when the water level fluctuates less than

0.1 foot in 30 minutes and the contractor shall determine that ground water levels are sufficient to cover the well screen. In the event that ground water levels are low enough to expose the well screen when the well is pumped at the three rates selected by the contracting officer, no pump test shall be performed until the static water levels rise to sufficient elevations. The pump test shall continue until the sand content of the

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Highlight discharge from the well averages no more than 5 parts per million (ppm) by volume of sand in the discharge water for a complete pumping cycle duration of at least 3 hours when pumping at the selected flow rates.

The "step drawdown" pump tests and the associated sand tests shall be performed under the supervision of the Contracting Officer. The Contractor shall test each well by pumping continuously for a period of 1 hour at each of the three selected flow rates, for a minimum of 3 hours. The selected flow rates for the 3 steps are anticipated to range between 250 - 1000 GPM as determined and directed by the contracting officer. The well will be considered "static" when the water level fluctuates less than 0.1 ft in 30 minutes. After the drawdown fluctuates less than 0.1 ft at or after 60 minutes at the specified pumping rate, the pumping rate shall increase as directed by the contracting officer, and repeated. Pump tests shall not exceed 6 hours. The Contractor shall employ a flow control valve or a variable speed pump to dial in the required flow rate to within +/-10 gpm. The flow control valve shall be adjusted as needed throughout the test to ensure a constant flow rate for the entire duration of each step. The water level in the well shall be measured to the nearest 0.01 ft and recorded at each of the following time steps (in minutes): 0, 1, 2, 3, 4, 5, 10, 15, 30, 45, and 60 minutes, or as directed by the Contracting Officer. Sand content measurements shall be taken at equal 15-minute intervals to permit plotting sand content as a function of time and discharge and determination of average sand content for each cycle.

Contractor shall calculate sand content in accordance with instructions provided by the manufacturer of the sand sampler. The flow through the sand sampler shall be measured for every pumping test, in addition to sand volumes accumulating in the graduated tube. After completion of the test, the depth of the well shall be measured, by means of an approved method.

3.5.2 Equipment

3.5.2.1 Pump

The Contractor shall provide a deep-well submersible pump capable of producing the specified discharge over a period sufficient to satisfactorily perform the pumping test specified. The Contractor shall provide, without additional cost to Government, the electrical power, control box and the necessary wiring which shall be removed at the completion of the pumping test.

3.5.2.2 Water Level

The Contractor shall accurately measure the water level in the well to within 0.01 foot before,during, and after the pumping test.

3.5.2.3 Flow Meter

The Contractor shall furnish and install a calibrated flow meter of standard design for measuring the discharge from the well during the pumping test. The calibration of the flow meter shall have been completed with in the last 12 months. The meter shall be installed in strict accordance with the manufacturer's recommendations. The meter shall be accurate to within 1% of the measured flow.

3.5.2.4 Rossum Sand Sampler

The Contractor shall furnish an approved Rossum centrifugal sand sampler and appurtenant piping and valving for accurate determination of the

SECTION 33 26 00.00 10 Page 19 discharge sand content. Contractor shall measure the flow through the sampler for every sand content test.

3.5.3 Data

The following test data shall be obtained and recorded by the Contractor on WES Form 796 "Relief Well Pumping Test Report". The form shall be completely filled out to include the well number and station and offset.

a. Time of water level measurement.

b. Depth of water in well before, during, and after pumping. The time intervals for measuring the water levels shall be every one minute for the first five minutes, then 5 minute intervals to 30 minutes, then 15 minute intervals thereafter for the duration of the pumping test.

c. Flow in gpm.

d. Depth of water in well before and after pumping measured from the same fixed point (to 0.01 ft.).

e. Depth of water in the four closest adjacent wells or piezometers from the same fixed point before and during pumping (to 0.01 ft.).

f. The depth of sand in well before, during, and after pumping.

g. Sand content of discharge in ppm and time of measurement/pumping. Each sand content shall be calculated based on two sand volume measurements. The flow through the tester shall be measured and reported for every sand test.

The Contractor shall furnish the field WES form and digital (excel format) Relief Well Pumping Test Report with Sanding Reports within 2 working days (M-F, except holidays) from completion of the test.

3.5.4 Procedure

3.5.4.1 Pump Testing

The pumping and sand infiltration tests shall be conducted under the direction of the Contracting Officer. The Contractor shall test each well by pumping continuously for a minimum of three hours. For 10-inch diameter wells, the three pumping rates shall be at the rates chosen by the contracting officer sufficient to produce a discharge ranging between 250 to 1000 gpm. No test pumping of a well will be permitted concurrently with drilling or pumping of any other well within a radius of 500 feet. In the event that the test is interrupted prior to the completion of the specified period of continuous operations, the water level in the well shall be allowed to recover to the original static level and the test shall be re-run at no additional expense to the government.

3.5.4.2 Discharge

The Contractor shall furnish, install or construct the necessary discharge line to convey the discharge to the riverside toe of the levee. The discharge line shall be turned upward in a saxophone-like outlet to dissipate the energy/pressure through free fall. Plastic sheeting, 6 mil minimum, shall be placed under the discharge line outlet and in the

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Highlight vicinity of the discharge, so the flow does not damage the levee turf.

Any damage shall be repaired by the Contractor at no additional cost to the Government. The Contractor shall make provisions to keep the plastic in place even on windy days. The Contractor shall place the discharge line so that it does not disrupt local traffic.

3.5.4.3 Additional Testing

In addition to the test described above, the Contracting Officer may direct the Contractor to perform additional testing. Such additional testing shall conform in general to the requirements specified above with the exception that the duration of the tests and the approximate drawdown will be determined by the Contracting Officer. The test, to be successful, shall be continuous throughout the specified period.

3.5.4.4 Material Infiltration

In the event that sand or other material infiltrates into the well as a result of the pumping test, the following procedure shall be…