S02_Attachment-2_Specifications_33 22 10 Irrigation Water Production Wells.pdf

IRRIGATION WATER PRODUCTION WELLS

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SECTION 33 22 10

USACE / NAVFAC / AFCEC / NASA UFGS-33 11 13 (August 2017)

Preparing Activity: USACE Superseding

UFGS-33 20 00 (April 2008)

UNIFIED FACILITIES GUIDE SPECIFICATIONS

References are in agreement with UMRL dated July 2018

SECTION TABLE OF CONTENTS

SECTION 33 22 10

08/17

PART 1 GENERAL

1.1 UNIT PRICES

1.1.1 Water Well

1.1.2 Geophysical Logging

1.1.3 Well Decommissioning or Abandonment

1.1.4 Cleanup

1.2 REFERENCES

1.3 ADMINISTRATIVE REQUIREMENTS

1.3.1 Notification

1.3.2 Delivery, Storage, and Handling

1.3.3 Project and Site Conditions

1.3.4 Water Well Design Requirements

1.3.4.1 Well Installation Plan

1.3.4.2 Sampling for Geotechnical Analysis

1.3.4.3 Geophysical Logging

1.3.5 Qualifications

1.4 SUBMITTALS

PART 2 PRODUCTS

2.1 CASING

2.1.1 Steel Casing and Couplings

2.2 WELL SCREENS

2.2.1 Metal Screen

2.3 BENTONITE SEAL

2.4 CEMENT AND BENTONITE GROUT

2.4.1 Cement Grout

2.4.2 Bentonite Grout

2.5 PERMANENT PUMP

2.6 CONTAINERS FOR DRILL CUTTINGS AND CORED ROCK SAMPLES

2.6.1 Containers for Drill Cuttings

2.6.2 Labelling of Drill Cutting Containers

2.6.3 Packaging of Cored Rock Samples

2.6.4 Labeling of Cored Rock Sample Containers PART 3 EXECUTION

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3.1 PREPARATION

3.1.1 Protection of Existing Conditions

3.1.2 Decontamination

3.1.3 Water Source

3.2 DRILLING, CONSTRUCTION AND TESTING

3.2.1 Well Drilling and Construction

3.2.1.1 General

3.2.1.2 Setting Outer Casing

3.2.1.3 Construction of Inner Casing and Screen

3.2.1.4 Construction of Filter Pack

3.2.1.5 Bentonite Seal Placement

3.2.1.6 Grout Placement

3.2.2 Well Development

3.2.2.1 Site Access and Predevelopment

3.2.2.2 Jetting

3.2.2.3 Intermittent Pumping

3.2.2.4 Surging

3.2.2.5 Well Development Criteria

3.2.3 Tests

3.2.3.1 Capacity Test

3.2.3.2 Test for Plumbness and Alignment

3.2.3.3 Water Quality Test

3.2.3.4 Sand Test

3.3 REQUIREMENTS AFTER TESTING

3.3.1 Installation of Permanent Pump

3.3.2 Disinfecting

3.3.3 Pumphouse and Slab

3.3.4 Site Clean-up

3.3.5 Drilling Waste Disposal

3.3.6 Surveys

3.4 FIELD QUALITY CONTROL

3.4.1 Well Decommissioning or Abandonment

3.4.2 Documentation and Quality Control Reports

3.4.2.1 Borehole Logs

3.4.2.2 Installation Diagrams

3.4.2.3 Well Development Records

3.4.2.4 Geophysical Logs

3.4.2.5 Well Decommissioning or Abandonment Records

3.4.2.6 Tests

3.4.2.7 Project Photographs

3.4.2.8 Survey Maps and Notes

ATTACHMENTS:

Water Quality Analysis Table

-- End of Section Table of Contents --

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PART 1 GENERAL

1.1 UNIT PRICES

Payment for each specified item will be made at the contract unit price for that item. Payment includes full compensation for equipment, materials and labor for drilling; removal and disposal of temporary casing, cuttings, and drill fluid; preparation of borehole logs; and sample handling, containers, storage, and testing. Measure depth, logging, installation, casing, riser pipe, and well screen by linear distance. Payment is not allowed for test wells or wells abandoned due to construction practices not in accordance with this specification, faulty construction practices or for the convenience of the Contractor.

1.1.1 Water Well

Compensation for the water well will be made at the contract unit price and includes material, equipment, and labor required to drill, develop, perform tests, and complete the permanent well.

1.1.4 Geophysical Logging

The "Geophysical Logging" unit price will include interpretation of the logs and their delivery to the Government.

1.1.5 Well Decommissioning or Abandonment

Permanent decommissioning or abandonment of wells will be paid for only if it becomes necessary to abandon a well as specified, and only for work completed and accepted as specified.

Paymen t includes compensation for drilling, casing removal, well sampling, materials, cement, mixing of cement, bentonite, and water, pumping of grout, equipment, removal of foreign objects, and transportation necessary to abandon the well or test well and for the required well or test well abandonment records.

1.1.6 Cleanup

Separate payment will not be made for cleanup of the site. Cleanup means restoring the site to its pre-construction condition, in accordance with paragraph SITE CLEANUP. Cleanup is considered part of and incidental to the drilling, construction, or decommissioning of the well.

1.2 REFERENCES

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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.

AMERICAN WATER WORKS ASSOCIATION (AWWA)

AWWA 10084 (2017) Standard Methods for the

Examination of Water and Wastewater

AWWA A100 (2015) Water Wells

AWWA B300 (2010; Addenda 2011) Hypochlorites

AWWA B301 (2010) Liquid Chlorine

AWWA C200 (2012) Steel Water Pipe - 6 In. (150 mm) and Larger

AWWA C206 (2017) Field Welding of Steel Water Pipe

AWWA C654 (2013) Disinfection of Wells

ASTM INTERNATIONAL (ASTM)

ASTM A139/A139M (2016) Standard Specification for

Electric-Fusion (ARC)-Welded Steel Pipe

(NPS 4 and over)

ASTM A312/A312M (2017) Standard Specification for

Seamless, Welded, and Heavily Cold Worked

Austenitic Stainless Steel Pipes

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

ASTM C136/C136M (2014) Standard Test Method for Sieve

Analysis of Fine and Coarse Aggregates

ASTM C150/C150M (2018) Standard Specification for Portland

Cement

ASTM D1586 (2011) Penetration Test and Split-Barrel

Sampling of Soils

ASTM D1587/D1587M (2015) Thin-Walled Tube Sampling of Soils for Geotechnical Purposes

ASTM D1784 (2011) Standard Specification for Rigid

Poly(Vinyl Chloride) (PVC) Compounds and

Chlorinated Poly(Vinyl Chloride) (CPVC)

Compounds

ASTM D1785 (2015; E 2018) Standard Specification for

Poly(Vinyl Chloride) (PVC), Plastic Pipe, Schedules 40, 80, and 120

ASTM D2216 (2010) Laboratory Determination of Water

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(Moisture) Content of Soil and Rock by

Mass

ASTM D2239 (2012) Standard Specification for

Polyethylene (PE) Plastic Pipe (SIDR-

PR) Based on Controlled Inside Diameter

ASTM D2487 (2017) Standard Practice for

Classification of Soils for

Engineering Purposes (Unified Soil

Classification System)

ASTM D2488 (2017; E 2018) Standard Practice for

Description and Identification of

Soils (Visual-Manual Procedure)

ASTM D4318 (2017; E 2018) Standard Test Methods for Liquid Limit, Plastic Limit, and

Plasticity Index of Soils

ASTM D5088 (2015) Decontamination of Field

Equipment Used at Nonradioactive Waste

Sites

ASTM D5299/D5299M (2017) Standard Guide for

Decommissioning of Ground Water Wells, Vadose Zone Monitoring Devices, Boreholes, and Other Devices for

Environmental Activities

ASTM D5521/D5521M (2013) Standard Guide for Development of

Ground-Water Monitoring Wells in

Granular Aquifers

ASTM D5608 (2016) Decontamination of Field

Equipment Used at Low Level Radioactive

Waste Sites

ASTM F480

U.S. ARMY CORPS OF ENGINEERS (USACE)

CED TR GL-85-3 (1985) Geotechnical Descriptions of

Rock and Rock Masses

U.S. ENVIRONMENTAL PROTECTION AGENCY (EPA)

EPA 600/4-79/020 (1983) Methods for Chemical Analysis of Water and Wastes

1.3 ADMINISTRATIVE REQUIREMENTS

1.3.1 Notification

Notify the Contracting Officer and the Engineer 21 days prior to drilling.

1.3.2 Delivery, Storage, and Handling

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Store and maintain well materials in a clean, uncontaminated condition throughout the course of the project. Do not allow filter pack material to freeze before installation.

1.3.3 Project and Site Conditions

Access to each well site, including any utility clearance, permits, licenses, or other requirements and the payment thereof necessary for execution of the work, is the responsibility of the [Contractor]. Furnish a copy of all permits, licenses, and other legal requirements necessary for execution of the work 30 working days before commencement of the work.

Obtaining rights-of-entry is the responsibility of the [Government]. Visit each proposed well location to observe any condition that may hamper transporting equipment or personnel to the site.

1.3.4 Water Well Design Requirements

1.3.4.1 Well Installation Plan

Submit a plan as specified herein describing the drilling methods, sampling, and well construction and well development 30 calendar days prior to beginning drilling operations. Mobilization activities may start prior to submittal of the plan. The plan must be approved and signed by an experienced geologist as specified in paragraph QUALIFICATIONS.

Incorporate the following requirements into the Well Installation Plan and follow them in the field. The design of the well is to be based on the various aspects analyzed and contained in this plan (boring log, geophysical log, geotechnical report, sieve analysis, etc.). The plan must include, but not be limited to, a discussion of the following:

a. Description of well drilling methods, and installation procedures, including any temporary casing used, placement of filter pack and seal materials, drill cuttings and fluids disposal, and soil and rock sample disposition.

b. Description of well construction materials, including well screen, riser pipe, centralizers, air line and gauge, tailpiece (if used), filter pack and filter pack gradation, bentonite or drilling mud, drilling fluid additives (if used), drilling water, cement, and well protective measures.

c. Description of quality control procedures to be used for placement of filter pack and seals in the boring, including depth measurements.

d. Forms intended for written boring logs, installation diagrams of wells, geophysical logs, well development records, well sampling data records, state well registration forms, and well abandonment records.

e. Description of contamination prevention and well materials and equipment decontamination procedures.

f. Description of protective cover surface completion procedures, including any special design criteria or features relating to frost heave prevention. Include the maximum frost penetration for the site in this description.

g. Description of intended well development methods.

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h. List of applicable publications, including state and local regulations and standards.

i. List of personnel assignments for this project, and personnel qualifications.

j. Description of well decommissioning or abandonment procedures.

k. Description of well capacity testing techniques.

l. Description and discussion of geophysical techniques to be employed at the site.

m. Description of permanent pump to be installed, and discussion of pump operating tests to be employed at the site.

n. Description of specific methods to be employed to control potential contamination or pollution arising from well installation activities.

o. Description of plumbness and alignment testing.

p. Description of specific methods employed to test for sand.

1.3.4.2 Sampling for Geotechnical Analysis

Take samples of all materials penetrated by each drilled well. Obtain soil samples with a [split][thin-walled] tube sampler using standard sampling techniques in accordance with [ASTM D1586][ASTM D1587/D1587M].

Extract samples from their in-situ environment in as near an intact, minimally disturbed condition as technically practical. Obtain samples continuously through the area expected to be screened. Provide sieve analyses of all drive-sampled material. Conduct sieve analyses in accordance with ASTM C136/C136M. Determine the gradation of the natural formation through the use of sieve analyses performed on formation samples taken from the areas to be screened. Place drive-sampled materials in airtight containers and label as specified in paragraph

SAMPLE CONTAINERS. Deliver samples to the [Contracting

Officer][designated facility]. Test representative soil samples for grain-size distribution by mechanical means (sieves down to the 0.074 mm, No. 200 size according to ASTM C136/C136M), moisture content according to ASTM D2216 and Atterberg limits according to ASTM D4318.

Describe and identify soils in accordance with ASTM D2488. Perform laboratory classification of soils in accordance with ASTM D2487.

Perform sampling to allow completion of the documents described in paragraph BOREHOLE LOGS.

1.3.4.5 Geophysical Logging

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1.3.5 Qualifications

Submit personnel qualification documentation. A geologist with at least 3 years’ experience in soil and rock logging, and well installation, [registered in the state of Texas must be on site during drilling, installation, and testing activities, and be responsible for all geophysical and borehole logging, drilling, well installation, developing and testing activities. Employ a driller licensed in the state of Texas according to the state requirements. Geophysical logs must be interpreted by a qualified log analyst. Demonstrate the log analyst competence through background, training, and experience when so called upon. Document a minimum of 10years of well installation experience and have personnel qualified to perform the necessary chemical sampling as presented in the approved Sampling and Analysis Plan.

1.4 SUBMITTALS

SUBMITTAL PROCEDURES:

SD-02 Shop Drawings

Installation Diagrams;.

SD-03 Product Data Well

Material

Geophysical Logging

Cement and Bentonite Grout

Drilling Mud

Well Screens SD-

05 Design Data

Well Installation Plan; l SD-06 Test

Reports

Water Source;. Filter Pack

Capacity Test

Test For Plumbness And Alignment Water

Quality Test

Sand Test Tests

SD-07 Certificates Site

Conditions

Project Photographs

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Qualifications Casing

Air Line and Gauge Graveling

Equipment list Construction of

Filter Pack

SD-11 Closeout Submittals Survey

Maps And Notes; Well

Development Records

Geophysical Logs

Decommissioning or

Abandonment Record

PART 2 PRODUCTS

2.1 CASING

All casing, screen, and other well material must be of compatible materials to prevent galvanic reaction between components of the completed well.

Submit catalog data, and name of supplier, for well screens (to include the screen slot size), casing, riser pipe, filter pack material, bentonite, cement, centralizers, surface protective covers, well vaults, locking caps, airline oil filters for pneumatic drilling, dedicated sampling equipment, pumps, and chemical specifications on drill lubricants, tracers, disinfecting agents, and drill fluid additives, if used. Catalog data must include any information, supplied by the manufacturers or suppliers of the above listed items.

2.1.1 Steel Casing and Couplings

Steel casing must be new carbon steel, conforming to ASTM A139/A139M Grade

B] schedule 5S meeting the requirements of ASTM A312/A312M, as applicable.

Joints must be either threaded and coupled, or field welded in accordance with AWWA C206. [Provide casings with [drive shoes].]

2.2 WELL SCREENS

a. Well Screens must be a minimum of at least 10 inches nominal diameter, and must be directly connected to the bottom of the inner casing by an approved method. The length of the screen must be sufficient to provide an intake area capable of passing not less than the minimum required yield of the well, at an entrance velocity not exceeding 0.1 fps.

b. The opening, or slot size of the screen, must be designed based on

33 22 10 - 10 analysis of the distribution of the grain size of the aquifer materials encountered during drilling]], be compatible with the material surrounding the screen. Submit as part of the well installation plan.

c. The well screen must be of sufficient size and design to hold back and support the gravel used in the filter pack envelope and in-situ material surrounding the screen.

d. Use screen and all accessories required for satisfactory operation that are standard products of manufacturers regularly engaged in the production of such equipment. Field constructed screen is not acceptable.

e. "Blanks" in the well screen may be utilized in nonproductive zones, or where centering devices are needed in the screened area, and area considered "casing."

f. Seal the bottom section, below the screen, watertight by means of a end cap of the same material as the well screen.

2.2.1 Metal Screen

Metal screen must be an approved wire-wound type of [type 304 ]stainless steel, conforming to the applicable requirements of AWWA A100. A wire-wound screen manufactured with supporting bars or core of material different from the wire will not be acceptable. Make joints of threaded couplings of the same material as the screens or by brazing or welding in accordance with

AWWA C206.

2.3 FILTER PACK

Provide filter pack material that is a product of a commercial sand and gravel supplier, sized and graded for the surrounding soil encountered, and composed of clean, round, hard, waterborne siliceous material, free of flat or elongated pieces, organic matter, or other foreign matter. Submit filter pack material test results; sieve and chemical analyses, within five working days after completion of the test well. Size the filter material which will allow the maximum flow of water into the well and prevent the infiltration of sand and silt. The gradation of the filter material must have a uniformity coefficient of not more than 2.5. The filter material must be thoroughly sterilized with chlorine or hypochlorite immediately before being placed.

2.4 CEMENT GROUT

2.4.1 Cement Grout

Provide cement grout consisting of Portland cement conforming to

ASTM C150/C150M, Type I or II, sand and water. Proportion cement grout not to exceed 2 parts, by weight, of sand to 1 part of cement with not more than 6 gallons of water per 42.6 kg (94 lb) bag of Portland cement, with a mixture of such consistency that the well can be properly grouted. No more than 5 percent by weight of bentonite powder may be added to reduce shrinkage.

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2.5 PERMANENT PUMP

Permanent pump must be an approved submersible with a capacity sufficient to deliver 850 gpm. Connect the pump to the pump controls by a three-wire drop line. Provide [polyethylene pipe conforming to ASTM D2239] piping for the well drop line. Operate the pump on4160 volts, 60 Hz,3-phase power, with the motor of sufficient size to operate the pump under the maximum operating conditions without exceeding its rating. Equip the pump with necessary controls to provide for automatic operation of the pump. The pump and motor unit must be no larger than [12] inches in diameter at any point.

2.6 CONTAINERS FOR DRILL CUTTINGS AND CORED ROCK SAMPLES

2.6.1 Containers for Drill Cuttings

Drill cuttings and driven samples required for geotechnical purposes are to be sealed in air-tight pint size plastic containers. Place individual sample containers in partitioned [cardboard]boxes.

2.6.2 Labelling of Drill Cutting Containers

Label individual sample containers with the project name, date of sample, well number and depth at which the sample was taken. Label both the container and lid in permanent indelible ink. Label partitioned cardboard box with project number and well number.

2.6.3 Packaging of Cored Rock Samples

Place cored rock samples in wooden core boxes as indicated. Place spacers in the proper positions in the core boxes to show the location and actual extent of voids and core losses as clearly as possible. Make the spacers of wood or some other relatively light material which is of sufficient strength to withstand jarring and crushing in handling. Spacers must be of a strongly contrasting color pattern so that core losses will be accented either by direct observation or in photographs. In the smaller sizes, up to and including 6 inches, provide spacers the same width as the cores.

Place the core in the core box starting at the left hand corner on the hinge side and running to the right. Place successive cores down the hole in successive troughs, starting from the back and working toward the front of the box so that the core can be read in the same manner as a printed page, from left to right, when standing in front of the open box.

2.6.4 Labeling of Cored Rock Sample Containers

Label the outside and the inside of the core box lid with the project name, hole number, date sampled, location, surface elevation, core box number, and interval of depth of core. The information on the label must be such that it can clearly be read in photographs of the core box. Also, label both ends of the core box with the hole number and box number.

PART 3 EXECUTION

3.1 PREPARATION

3.1.1 Protection of Existing Conditions

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Maintain existing survey monuments and wells, and protect them from damage from equipment and vehicular traffic. Repair any items damaged during this work. Reinstall wells requiring replacement due to Contractor negligence according to these specifications. Protect wells scheduled for abandonment from damage so that abandonment may be performed according to these specifications. Prior to commencement of drilling, obtain written approval from the Contracting Officer to drill at each site.

3.1.2 Decontamination

Clean the drill rig, drill rods, drill bits, augers, temporary casing, well developing equipment, tremie pipes, grout pumping lines, and other associated equipment prior to drilling at each well location. Clean screen and well casing immediately prior to installation in the well. The use of factory sealed screen and well casing does not waive this requirement for pre-installation cleaning. Decontaminate samplers in accordance with the

Sampling and Analysis Plan. Use water for cleaning from a Government approved source.

3.1.3

3.2 DRILLING, CONSTRUCTION AND TESTING

3.2.1 Well Drilling and Construction

Locate the wells where shown on construction plans, and construct in accordance with these specifications. Install each well to prevent aquifer contamination by the drilling operation and equipment, intra- and inter-aquifer contamination, and vertical seepage of surface water adjacent to the well into the subsurface, especially the well intake zone.

If a well of the required capacity is not constructed, or if the well is abandoned because of loss of tools, or for any other cause, abandon the hole as specified in paragraph WELL DECOMMISSIONING OR ABANDONMENT.

3.2.1.1 General

a. Use the drilling method approved by the Contracting Officer and in conformance with all state and local standards for water well construction. Execute the work under the direct supervision of an experienced well driller. The drilling method must prevent the collapse of formation material against the well screen and casing during installation of the well.

b. The inside diameter of any casing used must be sufficient to allow

33 22 10 - 13 accurate placement of the screen, riser, centralizer(s), filter pack, seal and grout. Any drilling fluid additive used must be inorganic in nature, but phosphate free. Grease or oil on drill rods, casing, or auger joints is not permitted; however, PTFE tape or vegetable oil (in solid phase form) are acceptable. The drill rig must be free from leaks of fuel, hydraulic fluid, and oil which could contaminate the borehole, ground surface or drill tools.

c. Use casing pipe, well screens, and joint couplings of compatible materials throughout each well.

d. The well must be a filter pack well-activated in the [stratum based on test well data.

e. Drill the well straight, plumb, and circular from top to bottom.

Initially drill the well from the ground surface to the uppermost level of the water bearing strata and the bottom of the outer casing set at this elevation. The hole below the outer casing must penetrate the water bearing stratum a sufficient depth to produce the required amount of water without causing excessive velocities through the aquifer.

f. During construction of the wells, use precautions to prevent tampering with the well or entrance of foreign material. Prevent runoff from entering the well during construction.

g. If there is an interruption in work, such as overnight shutdown or inclement weather, close the well opening with a watertight uncontaminated cover. Secure the cover in place or weigh down so that it cannot be removed except with the aid of the drilling equipment or through the use of drill tools.

3.2.1.2 Setting Outer Casing

The outer casing must not be less than 24 inches in diameter. The hole must be of sufficient size to leave a concentric annular space of not less than

[3] inches between the outside of the outer casing and the walls of the hole. Fill the annular space between the outer casing and the walls of the holes with cement grout. Acceptable methods of grouting are detailed in

AWWA A100; select a method specifying the forcing of grout from the bottom of the space to be grouted towards the surface. Provide a suitable grout retainer, packer, or plug at the bottom of the outer casing so that grout will not leak into the bottom of the well. Continuously grout to ensure that the entire annular space is filled in one operation. After grouting is completed, do not resume drilling operations for at least 72 hours to allow proper setting of the grout.

3.2.1.3 Construction of Inner Casing and Screen

After the grout has set, ream the hole below the outer casing at the required diameter, to the required depth, by an approved method which prevents caving of the hole before or during installation of the filter pack, well screen and inner casing. Contractor may elect to increase the size of the outer casing and drill to the diameter of the filter pack with an annular space between the inner casing and outer casing equal to the thickness of the filter pack. Firmly attach the well screen and inner

33 22 10 - 14 casing, and lower into the hole by a method which allows for control of the rate of fall of the well screen and inner casing at all times. Do not drop well screen and inner casing, or allow to fall uncontrolled into the hole.

Extend the inner casing up through the outer casing to [1300] feet more or less below the ground surface. Install 3 approved centering devices spaced at 120 degrees between the outer casing and inner casing prior to well construction at [intervals not exceeding [25] feet along the length]

[the top of the inner casing and the bottom of the outer casing]. If the screen length is greater than 25 feet, place a [3] foot length of blank casing in the middle of the screen interval for placement of centering devices. Do not place centering devices on the screened interval.

3.2.1.4 Construction of Filter Pack

a. After the screen and inner casing have been concentrically set in the hole below the outer casing, construct the approved filter pack around the screen by filling the entire space (annulus) between the screen and the wall of the hole in the water bearing stratum with filter pack material. Extend filter pack 30 feet into the annulus between the inner casing and the outer casing.

b. Lower a tremie pipe having an inside nominal diameter of not less than

[2 1/2] inches to the bottom of the well between the hole and screen

(i.e., the annulus). Arrange and connect the tremie pipe, at the surface of the ground, to water pumping and graveling equipment so that water and filter material, fed at uniform rates, are discharged as the filter material fills the hole from the bottom up. Raise the tremie pipe at a rate that will keep the bottom of the pipe no more than [3] feet above the filter material level at all times.

c. If there is a desire to use methods of placing filter material other than those specified, submit the details of the method and equipment proposed to the Contracting Officer, before filter pack placement begins; however, dumping filter pack material from the surface of the ground and agitating the well in an effort to settle the filter will not be allowed.

d. Install the filter pack continuously and without interruption until the filter pack has been placed to within 20 feet of the top of the inner casing]]. Directly measure and record the depth to the top of the filter pack.

e. Protect filter pack material from contamination prior to placement by either storing it in plastic lined bags, or in a location protected from the weather and contamination on plastic sheeting. Do not allow filter pack material to freeze before installation. Transport filter pack material to the well site in a manner which prevents contamination by other soils, oils, grease, and other chemicals.

f. Temporary drill casing, if installed, or hollow stem auger, must be removed simultaneously with the above operation.

g. Place filter pack material in no greater than 3 foot lifts prior to retraction of the temporary casing or auger. A minimum of 6 inches of filter pack must remain in the temporary casing or auger at all times

33 22 10 - 15 during filter pack installation. Make frequent measurements inside the annulus during retraction to ensure that the filter pack is properly placed.

3.2.2 Well Development

Develop the well within 7 days of completion of each well, but no sooner than [48] hours after cement grouting is completed. The 48 hour period does not apply to well predevelopment or development after the filter pack has been installed, but before the annular seal is installed. Develop the well in accordance with the Well Installation Plan, by approved methods until the water pumped from the well is substantially free from sand, and until the turbidity is less than 5 on the Jackson Turbidity Scale specified in AWWA 10084. Developing equipment must be of an approved type and of sufficient capacity to remove all cutting fluids, sand, rock cuttings, and any other foreign material. Thoroughly clean the well from top to bottom before beginning the well tests. Perform development using only mechanical surging, over pumping, or jetting, or a combination thereof in accordance with ASTM D5521/D5521M. Include details of the proposed development method in the Well Installation Plan. The well must be free of drawdown or surcharge effects due to pump testing, developing or drilling at another location at the time of development of any well.

3.2.2.1 Site Access and Predevelopment

Maintain the needed access and work area and clearance, necessary to accomplish development at the well site. 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].

Conduct development to achieve a stable well of maximum efficiency and continue until a satisfactory sand test, as specified in paragraph SAND

TEST, is obtained. During predevelopment of the well, add filter pack material to the annular space around the screen to maintain the top elevation of the filter pack to the specified elevation. Provide an open 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, immediately terminate development operations. The Contracting Officer may require a change in method if the method selected does not accomplish the desired results. The Contracting

Officer may order that wells which continue to produce excessive amounts of fines after development for [8] hours be abandoned, plugged, and backfilled, and may require the Contractor to construct new wells nearby.

Remove all materials pulled into the well by the development process prior to performing the pumping test.

3.2.2.2 Jetting

a. Perform jetting using either a single or double ring jet. If a double ring jet is used the rings should be 2 feet apart.

b. Construct the jetting tool of high-strength material and conservatively designed and proportioned so that it will withstand high pressures. The jetting tool must have [two [1/4] inch diameter

33 22 10 - 16 hydraulically balanced nozzles spaced 180 degrees][four [1/4] inch diameter holes spaced 90 degrees] apart and exert the jetting force horizontally through the screen slots.

c. Construct the rings such that the tips of the jets are within 1/2 inch from the inner surface of the well screen.

d. The pump used in conjunction with the jetting tool must be capable of providing [pressures up to [250][psi.] [a minimum jetting fluid exit velocity of 150 f/s].

e. Prior to commencing jetting, and following each jetting cycle, remove all sand and other materials from inside the screen. Start the jetting process at the bottom of the screen and rotate the jetting tool [slowly] while rotating the pipe [180] degrees for two minutes at each location then raise the pipe [6] inches.

f. Pump all wells, more than 4 inches in diameter, during the jetting cycle to remove incoming sand and other material. Pump at a rate not less than 115 percent of the rate at which fluid is introduced through the jetting tool. This will allow a flow of material into the well as it is being developed.

g. Ensure water introduced into the well during this jetting process is free of sand.

h. The Contracting Officer may require other means of developing the well such as intermittent pumping method, variation of the intermittent pumping method, or surge block if it appears that the development of the well is not producing the desired results.

3.2.2.3 Surging

Surging of the well requires use of a circular block, or multiple blocks, which are approximately 1 inch smaller in diameter than the inside diameter of the well and is constructed of a material which will not damage the screen if the block comes in contact with the screen, and a bailer or pump to remove materials drawn into the well. Continue the surging for a period of approximately [one] hour, or until little or no additional material from the foundation or filter pack can be pulled through the screen. Move the surge block by a steady motion up and down the full length of the well screen. Prior to commencing surging, and periodically during development by this method, remove all sand and other materials from inside the screen. Remove all materials pulled into the well by the surging process.

3.2.2.4 Well Development Criteria

Maintain a well development record in accordance with paragraph WELL

DEVELOPMENT RECORDS. Development is complete when all of the following criteria are met:

a. Well water is clear to the unaided eye[, and turbidity less than or equal to [5] Nephelometric Turbidity Units (NTUs)], 33 22 10 - 17

b. Sediment thickness in the well is less than [1 percent of the screen length],

c. A minimum of three times the standing water volume in the well is removed plus three times the volume of all added water and drilling fluid lost during drilling and installation of the well is removed, and

d. Temperature, specific conductivity, pH, oxidation-reduction potential

(ORP), dissolved oxygen (DO), and turbidity readings, measured before, twice during and after development operations, have stabilized.

Stabilization is defined as [variation of less than 0.2 pH units, variation of plus or minus +0.5 degrees C, +3 percent change in specific conductance; and less than a +10mV for ORP; and +10 percent for DO, and turbidity, measured between three consecutive readings with one casing volume of water removed between each reading] .

Determine ORP in accordance with AWWA 10084. Conduct temperature, specific conductance, DO, turbidity, and pH readings in accordance with EPA 600/4-79/020. At completion of well development, collect approximately 0.5 liter of well water in a clear glass jar. Label the jar with project name, well number and date; and digital photograph.

The photograph (minimally 5 x 7 inch) must be a suitably backlit close-up which shows the clarity of the water and any suspended sediment. The photograph and digital copy become a part of the well development record. Water removed during development and testing operations must be [discharged to the ground surface at least [200] feet from the well in a down gradient area].]

3.2.3 Tests

After the wells have been developed, notify the Government and make the necessary arrangements for conducting the capacity tests. The well must be free of drawdown or surcharge effects caused by pumping tests, well development, or well drilling at another location during capacity testing and the recovery testing after completion of capacity testing. If the capacity test indicates that the required capacity can be obtained, perform the tests for quality of water. If the capacity and quality tests indicate that the required capacity and quality can be obtained, complete the permanent well, as specified, at that depth. Submit Test Reports within [24] hours following the conclusion of each test. Prior to making quality tests, clean drilling equipment, tools and pumps contacting well water with live steam.

3.2.3.1 Capacity Test

a. Provide an approved temporary test pump, with discharge piping of sufficient size and length to conduct the water being pumped to [point of discharge], and equipment necessary for measuring the rate of flow and water level in the well.

b. Run an [8] hour [constant-rate][step-drawdown] capacity test with the pumping rate and drawdown at the pump well and observation wells recorded every [][1/2 minute during the first 5 minutes after starting the pump; then every 5 minutes for an hour; then every 20 minutes for

2 hours].

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c. [From this point on, readings taken at hourly intervals, until the water level stabilizes, are sufficient.] [During the step-drawdown test, increase the pumping rate in steps at [[2] hour] intervals.

Measure specific capacity for each step.]

d. Begin the test at the rate of [the expected capacity of well] [[850] gpm] and at least that rate maintained throughout the duration of the

[step interval]. [The well must be "step" tested at rates of approximately [1/2, 3/4, 1 and 1 1/2] times the design capacity of

[850] gpm.]

e. When the pump is shut off, take water level readings during the rebound period for the same intervals of time as the drawdown test until static water level is reached.

f. Submit the record of the test.

3.2.3.2 Test for Plumbness and Alignment

Upon completion of the permanent well, test for plumbness and alignment by lowering into the well, to the total depth of the well, a plumb [40][] feet long or a dummy of the same length. The outer diameter of the plumb must not be more than 1/2 inch smaller than the diameter of that part of the hole being tested. If a dummy is used, it must consist of a rigid spindle with three rings, each ring being [12] inches wide. Use cylindrical rings spaced one at each end of the dummy and one in the center. The central member of the dummy must be rigid so that it will maintain the alignment of the axis of the rings. Decontaminate the dummy as specified in paragraph DECONTAMINATION, before use. If the plumb or dummy fail to move freely throughout the length of the casing or well screen for the depth of well or should the well vary from the vertical in excess of two-thirds the inside diameter of that part of the well being tested for each 100 feet of depth, correct the plumbness and alignment of the well. If the faulty alignment and plumbness is not correctable, as determined by the

Contracting Officer, abandon the well as specified in paragraph WELL

DECOMMISSIONING OR ABANDONMENT and drill a new well at no additional cost to the Government.

3.2.3.3 Water Quality Test

When the capacity test in the test well has been completed, and again after the yield in the permanent well and drawdown test or capacity test have been completed, secure samples of the water in suitable containers, and of sufficient quantity, to have bacterial, physical, and chemical analyses made by [a recognized testing laboratory], except that the bacterial analysis may be made by the applicable State Board of Health, if desired.

Water Quality Analysis must address each item specified in the Water

Quality Analysis Table at the end of this specification. Expenses incident to these analyses are borne by the Contractor and the results of the analyses submitted to the Contracting Officer. Perform all sampling and analyses using EPA and State approved methods, procedures, and holding times.

3.2.3.4 Sand Test

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As part of each capacity test, or at the end of each intermittent pumping, perform a determination of the amount of sand (filter pack and foundation material) a well is producing. Remove all material from the bottom of the tailpipe prior to starting the sand test. Test each well by pumping at a rate [of [850 gpm] [sufficient to produce approximately [180] feet of draw-down]. After the pump is at the desired pumping rate, divert the flow from the discharge [into a container that will collect all the sand being carried by the water][through a Rossum Sand Tester]. Development of the well is satisfactory if the amount of sand collected is less than 1 pint per 25,000 gallons of water pumped at the specified rate. Upon completion of the test, determine the amount of sand in the tailpipe to verify that no material is being deposited in the bottom of the well.

3.3 REQUIREMENTS AFTER TESTING

3.3.1 Installation of Permanent Pump

NOTE: The yearly change in the regional water table should be determined before specifying the minimum pump depth.

Install the permanent well pump in the well at a minimum depth of

[1340] feet below ground.(Subject to test well results). Secure the pump at the required elevation as recommended by the pump manufacturer. After installation of the pumping units and appurtenances is complete, carry out operating tests to assure that the pumping installation operates properly. Tests must assure that the pumping units and appurtenances have been installed correctly, that there is no objectionable heating, vibration, or noise from any parts, and that all manual and automatic controls function properly.

3.3.2 Disinfecting

a. After completion of tests of well, or installation of permanent pump, or at time of tests for yield and drawdown test, whichever is later, disinfect the wells by adding chlorine, conforming to AWWA B301, or hypochlorite, conforming to AWWA B300, in sufficient quantity so that a concentration of at least 50 ppm of chlorine is obtained in all parts of the well.

b. Prepare chlorine solution and introduce into the well in an approved manner, and leave in the well for period of at least 12 hours but not more than 24 hours. Information on methods for preparing chlorine solution and introducing it into the well can be found in AWWA C654.

c. After the contact period, pump the well until the residual chlorine content is not greater than 1.0 ppm.

d. Pump the well to waste for an additional 15 minutes with less than 1 ppm chlorine residual, after which take two samples not less than 30 minutes apart and test for the presence of coliform bacteria.

e. Disinfect and re-disinfect the well as required until two consecutive samples are free from coliform bacteria.

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f. All water containing chlorine shall be dechlorinated prior to discharge down gradient to an approved location.

g. Dechlorinate the well discharge as required to comply with State and

NPDES requirements.

3.3.3 Pumphouse and Slab

Provide reinforced concrete slab preventing the infiltration of surface water or precipitation into the well as shown in the construction plans.

Extend the top of the outer casing [12][] inches above the top of the slab.

3.3.4 Site Clean-up

After completion of the work, remove tools, appliances, surplus materials, temporary drainage, rubbish, and debris incidental to work.

Backfill and dress excavation and vehicular ruts to conform with the existing landscape. Repair of replace utilities, structures, roads, fences, or any other pre-existing item damaged due to the Contractor's negligence; this must be accomplished prior to completion of this contract.

3.3.5 Drilling Waste Disposal

Dispose of slurry, drill cuttings, rock core; other solid or liquid material bailed, pumped, or otherwise removed from the borehole during drilling, installation, completion, well development procedures and testing; and fluids from material and equipment decontamination activities by disposing of same at an approved offsite location.

3.4 FIELD QUALITY CONTROL

3.4.1 Well Decommissioning or Abandonment

a. Any well disapproved by the Contracting Officer, or any well decommissioned or abandoned by the Contractor for any reason must be decommissioned or abandoned according to the requirements of the

State of [Texas], [ASTM D5299/D5299M,] and the requirements of these specifications. Well decommissioning or abandonment includes the removal of all materials left in the borehole or well, excluding the filter pack, and including backfill materials, casing, screen, and any other material placed into the hole before the decision was made to abandon the borehole or well.

b. Grout wells decommissioned or abandoned for any reason from the bottom to [3] feet of the ground surface according to the protocol for grout or bentonite placement established in paragraph GROUT

PLACEMENT, using the grout mix specified in paragraph CEMENT AND

33 22 10 - 21

BENTONITE GROUT. Backfill the top [3] feet with [material appropriate for the intended land use].

c. Maintain a well decommissioning or abandonment record as specified herein.

d. If encountered before the decision is made for decommissioning or abandonment, measure groundwater levels in all borings prior to backfilling. Include these water levels in the well decommissioning or abandonment records.

e. No well may be decommissioned or abandoned without the approval of the Contracting Officer.

3.4.2 Documentation and Quality Control Reports

Establish and maintain documentation and quality control reports for well construction, development, and testing to record the desired information and to assure compliance with contract requirements, including, but not limited to, the following:

3.4.2.1 Borehole Logs

Complete a borehole log for each boring drilled. Borehole logs must be prepared by the geologist present onsite during all well drilling and installation activities. Use a log scale of [1] inch equals [1][] foot. Keep copies of complete well logs current in the field at each well site and make available at all times for inspection by the

Contracting Officer. As a minimum, provide the follow information on the logs:

a. Name of the project and site.

b. Boring or well identification number.

c. Location of boring (coordinates, if available).

d. Make and manufacturer's model designation of drilling equipment and name of drilling firm.

e. Date boring was drilled.

f. Reference data for all depth measurements.

g. Name of driller and name and signature of geologist preparing log.

h. Nominal hole diameter and depth at which hole diameter changes.

i. Total depth of boring.

j. Method of drilling, including sampling methods and sample depths, including those attempted with no recovery. Indication of penetration resistance such as drive hammer blows given in blows per 6 inches of driven sample tubes. Information must include hammer weight and drop distance. Record information such as rod size, bit type, and pump type.

33 22 10 - 22

Include a description of any temporary casing used, drill fluids and fluid additives used, if any, including brand name and amount used, along with the reason for and start (by depth) of its use. If measured, record mud viscosities and weight.

k. Depth of each change of stratum. State if location of strata change is approximate.

l. Description of the material of which each stratum is composed, in accordance with [ASTM D2488], or standard rock nomenclature in accordance with [CED TR GL-85-3], as necessary. Soil parameters for logging must include, but not be limited to, classification, depositional environment and formation, if known, Unified Soil

Classification Symbol, secondary components and estimated percentages, color, plasticity, consistency (cohesive soil), density (non-cohesive soil), moisture content, structure and orientation, and grain angularity. Rock core parameters for logging must include, but not be limited to, rock type, formation, modifier denoting variety (shaley, calcareous, siliceous, etc.), color, hardness, degree of cementation, texture, crystalline structure and orientation, degree of weathering, solution or void conditions, primary and secondary permeability, and lost core. Include the results of any chemical field screening on the boring log. Prepare classification in the field at the time of sampling.

Also, duly note and record the results of visual observation of the material encountered, and any unusual odor detected.

m. Depth of any observed fractures, weathered zones, or any abnormalities encountered.

n. Depth and estimated percent of drill fluid loss or lost circulation.

Measures taken to regain drill water circulation. Significant color changes in the drilling fluid return.

o. Box or sample number. Record depths and the number of the core boxes and samples at the proper interval.

p. Percent Rock Core Recovery. Show the percent core recovery for the individual drill runs, if rock is cored.

q. Submit [five] prints of the graphic boring log prepared to scale showing the required details, within [14] working days after completion of the test well. Use this drawing to aid in determining the well design, design of the filter pack, well screen location and screen openings.

3.4.2.2 Installation Diagrams

The well will not be accepted before the geologic logs and installation diagrams are received. Submit As-built installation diagram for each well installed, prepared by the geologist present during well installation operations, within [14] working days of the completion of the well installation procedure. The diagram must illustrate the as-built condition of the well and include, but not be limited to, the following items:

a. Name of the project and site.

b. Well identification number.

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c. Name of driller and name and signature of the geologist preparing diagram.

d. Date of well installation.

e. Description of material from which the well is constructed, including well casing or riser pipe and screen material, centralizer composition, if used, diameter and schedule of casing and screen, gradation of filter pack, lithologic description, brand name (if any), source, and processing method, and method of placement of the filter pack, bentonite seal type (pellets, granules, chips, or slurry), grout type (cement or high-solids bentonite) and type of protective cover

(protective casing or…