Attach-1-SOW.pdf

DRINKING WATER WELL SPECIFICATIONS

1.1 SCOPE OF WORK:

The scope of work for this project includes mobilization and demobilization, the furnishing of all labor, tools, equipment, and material, performing all operations in connection with installing a water well, water lines (well and pumps), controls, well pump, and all system electrical wiring. The general location of Neches River NWR is shown on Map 1, “Location Map”. The specific location of the well on the site is shown on Map 2, “Well Site Location”.

1.2 SECTION INCLUDES

A. Drilling, collection of water samples, casing, screening, gravel pack, cement and or bentonite, developing, test pumping, and disinfecting of water supply well.

1.3 SPECIAL REQUIREMENTS

A. The well is to be drilled to the depth necessary to produce the required flow.

B. All materials to remain in the finished well shall be new and free of defects.

C. All equipment for well drilling, development, testing, and cleaning shall be furnished by the

Contractor.

D. Formation samples necessary for sizing the well appurtenances will be submitted by the Contractor.

E. Special materials and products to be used in well drilling and developing will be subject to

Refuge staff ’s approval prior to their use.

F. Mobilization and Demobilization:

1. The Contractor shall bring to the site, erect, and install all equipment and supplies necessary for the completion of the project

G. Well Location:

1. The location of the site on which the well will be drilled is shown on the Contract drawings.

See Map 2, “Well Site Location”. The Contractor shall coordinate access and the precise location with the Refuge staff prior to mobilization.

H. The well driller shall be licensed with the Texas Department of Licensing and Regulation and shall demonstrate significant past experience with well installation in the Northeast Texas area.

I. Contractor shall coordinate access with the Neches River NWR refuge manager for this project.

The Contractor shall be responsible for damage to sidewalks, landscaping or any other improvements impacted by well construction. If needed, the Contractor shall provide plywood sheets to protect maintained grasses. The Refuge staff has identified accessibility to the drill site.

The Contractor shall leave all affected areas in existing or better conditions.

J. Contractor shall grade the area around the well head to assure that drainage does not drain to the wellhead but away from it. The Contractor shall remove all remnants of construction including gravel, cement or concrete, bentonite, drilling mud or any other debris.

1.4 EQUIPMENT AND MATERIALS:

A. Well Pump and Discharge:

1. The well shall be equipped with a submersible pump capable of delivering a minimum 25 gpm at 750 ft. depth. Well performance of a minimum of 25 gpm at the discharge shall be verified prior to final payment. The Contractor shall submit pump curves for the pumps to be installed to the Engineer for approval prior to installation.

B. Electrical:

1. Electrical service is available to the site at the overhead power poles adjacent to the well site (see Map 2). The Contractor shall install electric service from this location to the well site and install power to the well.

C. Water Meter:

1. The well discharge shall be metered with a permanent water meter to ensure a minimum 25 gallon per minute flow rate prior to acceptance and final payment.

D. Electrical Connections:

1. The contractor shall furnish all electrical equipment internal to the operation of the well, pumps, and tanks. Power will be provided at Pump House and Electric Service location by others and available to the Contractor at the time of well completion. The contractor will be responsible for coordination of any electrical requirements/needs with the Refuge.

All electrical installation shall be completed by a licensed contractor in conformance with all applicable codes and regulations.

2. The control box shall be equipped with all transformers, switches, relays, terminals, connections, fuses and all other equipment necessary for the proper and long term operation of the well. The control box shall be sized to amply accommodate all of the necessary electrical equipment needed for pump control and operation.

3. The control system shall be installed by a licensed electrician.

4. A transformer and 15 amp, 110 power outlet shall be.

1.5 MATERIALS AND CONSTRUCTION

A. Well Casing:

1. The well casing diameter and length shall be of a sufficient size to produce the required flow.

The Refuge anticipates that the casing will be 4.5” in diameter to a depth of approximately 750 feet but the Contractor shall verify based on their experience in the formation and shall be ultimately responsible to produce the required flow rate from the well. The casing shall be steel. Connections shall be threaded and shall not be welded.

B. Well Screen:

1. The well screen diameter shall match the casing diameter and shall be thread connected to the casing. The screen shall be of sufficient length and diameter to produce the required flow. The Contractor shall verify based on their experience in the formation, data gathered during installation and shall be ultimately responsible to produce the required flow rate from the well.

The screen shall be Type 304 stainless steel or approved equal.

C. Gravel Pack:

1. A gravel pack shall be placed in the annular space between the drilled hole and the screen or blank casing and shall be filled from total depth to five feet above the well screen.

2. The gravel must be washed free of clays and other fine materials and produced as near the above gradation as local suppliers can provide. No crushed rock or gravel with angular faces may be used.

3. The Contractor shall be responsible for insuring that the gravel pack material is adequately disinfected during installation.

D. Well Fill:

1. The annular space between the hole and the screen shall be filled from five feet above the well screen to 35 feet below ground level with a sand bentonite mixture.

E. Cement Seal:

1. The annular space outside the well casing from five feet below ground level to 35 feet below ground level shall be filled with 2% bentonite cement.

2. EXECUTION

2.01 WELL DRILLING AND DEVELOPING

A. Well Production Hole:

1. The well production hole shall be drilled using a mud-rotary rig. The upper portion of the hole shall be sized appropriately for the proper casing and screen size to be installed.

B. Well Plumb-ness and Alignment:

1. The completed well shall be sufficiently plumb, round, and straight to allow free movement of the pump equipment through the depth of the well.

C. Well/Well Development:

1. The well shall produce a constant, 24-hour minimum of 25 gallons per minute (gpm) of water. The developing of this well will be done by the air lifting pumping method with the well driller’s equipment supplying the required air. Other methodology may be used following approval by the Engineer.

2. The well shall be thoroughly developed so that it will produce a 25 gpm minimum capacity and so that it will not produce fine sand.

3. The compressor equipment used for airlifting shall be capable of producing adequate airflow to lift water and sediment from the lower screens in the well. Airlifting shall proceed until the produced water is free of suspended sediment.

4. The Contractor shall furnish all plant, materials, and labor required to accomplish the well development.

D. Damage done to existing structures, roads or utilities, or any interference with them caused by the

Contractor shall be repaired at the Contractor's expense.

2.2 WELL CLEANING AND DISINFECTION

A. All materials, tools and debris shall be removed from the well once it is completed.

2.3 METAL CAP FOR CASING

A. The production casing shall extend a minimum of 18 inches above ground (concrete pad) level.

The casing shall be equipped with a pitless adapter, a watertight cap with a screened well vent.

2.4 CONTROLS

A. The controls including switches, fuses, terminals, buses, transformers, and timers shall be contained in an amply sized NEMA 3 enclosure mounted on pole supports between 3 and 4 feet of clearance above ground.

2.5 MISCELLANEOUS

A. The Contractor shall pour a 6’x6’x5” concrete pad reinforced with #3 rebar placed at 18-inch centers in both directions with 2 inches clear below the rebar centered around the well head.

B. Other appurtenances required for completion of the well such as the gravel chutes, breather pipe, bottom plug, torque arrestors, clamps, drilling mud, mud pit, well logs, bentonite, cement, and all other ancillary materials are to be furnished and installed by the Contractor.

Attachments:

Map 1. Location Map Map 2. Well Site Location

Map 1. Location Map.

Map 2. Well Site Location