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1.04 QUALITY CONTROL <br />A. General. The Contractor shall establish and maintain records of quality control for all slurry wall <br />construction operations to assure compliance with contract requirements. All test to be performed <br />in the presence of the engineer. The materials to be tested, test methods, sample and/or test <br />locations, frequencies, test specifications and failure response actions for the quality control <br />program are summarized below. <br />1. Contractor Quality Control Testing <br />A. Bentonite Slurry: <br />1. Bentonite - Provide Manufacturers certificate of compliance with API Code RP <br />13a Oil Well Drilling Materials for each shipment of bentonite. <br />2. Water - Measure the pH of the water at least once per week on smaples of water <br />being used in the preparation of the bentonite slurry. <br />3. Freshly Mixed Bentonite Slurry - Measure the viscosity density, filtrate loss and <br />pH of the freshly mixed bentonite slurry using the Marsh Funnel test method, API <br />RP 13B. The test shall be performed at least 2 times per shift on samples of <br />bentonite slurry obtained from the point of introduction into the trench. <br />4. Bentonite Slurry Inside the Excavated Cutoff Wall Trench - Measure the viscosity, <br />density and filtrate loss of the bentonite slurry inside the excavated trench using <br />the mud balance test method, API RP 136, and filter press test methods, API PP <br />13B, respectively. Two density tests shall be performed every 4 hours of work, or <br />as directed by the engineer, one from the upper half of trench and one from the <br />lower half of the trench or as directed by the engineer. The sampling device shall <br />be furnished by the contractor and subject to approval by the engineer. <br />2. Engineer Quality Assurance Testing <br />A. Bentonite Slurry: <br />1. Bentonite Slurry Mix - Viscosity of mixed bentonite slurry obtained from the point <br />of introduction into the trench using the Marsh Funnel testing method, API RP <br />13B. The frequency if test will be determined by the engineer. <br />2. Bentonite Slurry Inside the Trench Excavation - Density and filtrate loss of the <br />bentonite slurry inside the excavated trench using the mud balance test, API RP <br />136, and filter press test, API PP 131B, respectively. Samples of the bentonite <br />slurry inside the excavated trench and shall be obtained by the contractor from <br />the bottom 50 percent of the trench and upper 50 percent of the trench. The <br />frequency of tests will be determined by the engineer. <br />B. Soil-Bentonite Backfill: <br />1. Field Quality Testing - Density and slump of the soil-bentonite backfill using the <br />unit weight test method, ASTM D 6023, and concrete slump test method ASTM <br />C 143. Samples of soil-bentonite backfill shall be obtained from the point of <br />introduction into the trench. The frequency of tests will be determined by the <br />engineer. <br />2. Laboratory Quality Control Testing - Grain size distribution and hydraulic <br />conductivity of soil-bentonite backfill. One grain size distribution and one <br />hydraulic conductivity test will be performed for every 200 lineal feet of trench or <br />a minimum of one per day. Samples of soil-bentonite backtll shall be obtained <br />from the point of introduction into the trench.