Attachment_0004_LaBarge_Water_Wells_Testing.pdf

DIVISION 2 SECTION WY-02672

SITEWORK WELL TESTING

Rev. 06-90

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HIGH DESERT DISTRICT NORTH LABARGE COMMON WATER WELLS

PART 1: GENERAL

1.1 SUMMARY:

A. Section Includes: Well testing.

1.2 RELATED WORK:

A. Specifications Sections:

General Information and Requirements Section 01009 Water Wells Section 02670 Well Drilling and Casing Section 02671

1.3 SUBMITTALS:

A. Submittals shall be in accordance with Section 01009-General Information and

Requirements.

B. Records: Written documentation of final yield test, pumping test, and water quality analyses shall be furnished to the Contracting Officer in the format agreed upon at the Pre-Work Conference.

PART 2: PRODUCTS

2.1 EQUIPMENT:

A. Well Testing: All testing equipment shall be furnished by the Contractor.

1. Pumping Test Equipment: Equipment must at a minimum be able to test the well at 1- 1/2 times the rate of flow stated in the Work Data Sheet. The pumping unit shall be equipped to regulate flow for the purpose of establishing yields at various depths.

2. Air Method: Furnish air compressors, hoses, air lines, and any other equipment needed for the air method.

3. Water Level Measurement: Equipment capable of measure water levels before, during and after testing and development (e-tape, airline, and/or transducer…) capable of a minimum accuracy of 0.1 feet.

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4. Discharge Measurement: Flow meter for accurately measuring instantaneous and cumulative discharge to +/- ¼ GPM.

5. Flowing Well Pressure: Pressure gauge capable of accuracy to 0.5 PSI and equipment to facilitate shutting in the well.

PART 3: EXECUTION

3.1 PRELIMINARY YIELD TESTING OF THE WELL:

A. General: The Contractor shall make preliminary yield tests or estimates during drilling operations on each water-bearing stratum penetrated as requested by the Contracting Officer and only if the test will not compromise the bore-hole integrity. These tests are typically air-lift or air-lift/recovery tests that do not require the removal of the drill string.

After the well has been completely constructed and cleaned, the Contractor shall make a final preliminary yield test during the development of the well. The test may be conducted by air lift, bailer, or submersible pump. The Contracting Officer shall have the option of rejecting the air lift method on low yielding wells. If the Contracting Officer rejects the air lift method for determining yield, the Contractor will then be allowed to determine the approximate yield of the zone by calculating the gallons of water coming into the bore hole over a 20-minute period of time.

3.2 FINAL YIELD TESTING OF THE WELL:

A. General: After the well has been completely constructed and developed, the Contractor shall make a final determination of the hydraulic characteristics of the well (yield, specific capacity, pumping water level(s), static water level). The Contractor will utilize the pumping method for making final yield determinations on the well. The Contractor shall perform the yield test in the presence of the Contracting Officer. The Contractor shall provide a one working day notice to the Contracting Officer prior to performing the test.

B. Pumping Test Procedures:

1. Measure and record the depth from the ground surface to the static water level.

2. Test the well utilizing a test pump.

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a. Install a submersible pump in the bottom of the well (or at a depth approved by the contracting officer).

b. Perform a step-rate test at ½, 1, and 1 ½ the required minimum acceptable rate as listed on the Work Data Sheet. If the test pump has capacity above 1 ½ times the acceptable rate, pump for a fourth step at maximum pump capacity to produce a maximum drawdown or to pump capacity, whichever is controlling. Pump capacity must be at least 1-1/2 times the desired well yield.

3. Divert and measure the flow of water pumped out of the well through a metering or collection system capable of measuring accurately to within 1/4 gallon per minute (or better). Record a minimum of one reading every 10 minutes. Continue test until the rate of flow has not changed in a 60-minute period.

4. Immediately after pumping is discontinued, measure and record the elapsed time and water levels from the ground surface in 10-minute intervals until the water level has recovered to at least 90% of the static water level (recovery test).

C. Water Sample: Before completing the final pumping step of the Pumping Test, collect water samples for laboratory analysis as directed by the Contracting Officer and in containers provided by the Contracting Officer.

D. Cleaning: When testing is complete, remove sand and foreign material that may have collected in the well during the yield test.

E. Increasing yield: The Contracting Officer may direct the Contractor to attempt to increase the yield by bailing, surging, or other means of development if the desired minimum yield is not met.

PART 4: MEASUREMENT AND PAYMENT

4.1 METHOD OF MEASUREMENT:

A. General:

1. Rig or Standby time will not be paid for.

2. No payment will be made for time spent developing and testing wells which occur prior to the well being completed (cased, gravel packed and grouted).

B. Units:

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1. Final testing will be measured and paid for by the number of hours beginning when the pumps, compressors, and other equipment have been installed and actual testing has commenced. No payment will be made for time spent in set-up and tear-down.

2. Standby time will not be paid.

3. Time utilized in assembling, servicing, repairing equipment or any other nonproductive time shall not be paid.

4.2 BASIS OF PAYMENT:

A. Payment: Prices and payment will be full compensation for the work described in this section. Payment will be made under:

Pay Item Pay Unit

WY-02672 (1) Well Testing ....................................................................................Hour

END OF SECTION