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ALTON GEOSCIENCE GENERAL FIELD PROCEDURES FOR GROUND WATER MONITORING DEVELOPMENT AND SAMPLING Ground Water Monito_rina Well Development, New ground water monitoring wells were developed to clean the well and stabilize the sand, gravel, and aquifer materials around the perforated section of the well . Well development was conducted using one of several acceptable methods, such as bailing, mechanical air lift pumping, surging, or swabbing. Well development elopment continued until the well was thoroughly developed and if possible, free of sand, silt, and turbidity. The water generated from the development process was placed into labeled 55-gallon DOT-approved drums, pending laboratory results of the ground water samples, to determine the appropriate disposal method. Water disposal will conform to applicable hazardous waste requirements . Ground Water Monitori_ngk1gll Sampling Ground water monitoring and sampling were performed in accordance with the requirements and procedures of the Regional Water Quality Control Board, San Francisco Bay Region (RWQCB) . Prior to purging and sampling each well, total well depth and depth to ground water were measured to the nearest 0. 01 foot from a reference mark at the top of each well casing using an electric sounder. To ensure that the ground water sample is representative of the aquifer, the well was purged of 3 well casing volumes before sample collection. The purging was accomplished using a bailer or a pump. During purging, the sampler noted the following: ( 1 ) a description of the initial discharge of the ground water, (2 ) pH, temperature, and conductivity readings , (3 ) volume of water purged, and (4 ) recharge rates . Ground water samples were collected using a disposable bailer, observed for the presence of free product, and transferred to the appropriate clean sample containers for delivery to a California-certified laboratory. All samples were inverted to ensure that entrapped air was not present. The sampler wore nitril gloves during purging and sampling at all times . Purged ground water was stored onsite in DOT-approved, 55-gallon drums for proper disposal .