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is, two consecutive sets of similar field measurements will be ob- tained. Purged water is stabilized when (1) the pH is within ±0.1 pH units, (2) specific conductance is within ±5 percent, or (3) tempera- ture is within ±1 .0°F. All records of the above data will be kept on a field data sheet. Figure A-1 shows an example of the Water Sample Field Data Sheet. Copies of the field data sheets will be subjected to review by the sampling supervisor upon completion of the sampling event. The pH, specific conductance, and temperature meter will be calibrated daily prior to initiating field activities. The calibra- tion will be checked once each day to verify meter performance. Sampling Procedures Samples will be collected after the calculated purge volume has been removed and the pH, conductance, and temperature have stabilized. With as little interruption in pumping rates as possible, the bladder pump effluent will be directed into appropriate containers. The pump flow will be regulated when collecting samples for volatile organic analysis. The flow will be set to approximately 100 milliliters per minute to minimize turbulence and aeration of the pump effluent. Sample bottles for volatile organics analysis will be filled complete- ly to prevent any air from remaining in the bottle. A positive menis- cus forms when the bottle is completely full . A convex, Teflon-lined septum will be placed over the positive meniscus to seal the contain- er. After capping, the bottle will be inverted and tapped to check that no air bubbles are present. All samples will be collected in duplicate. The sample containers for other parameters will be filled, preserved as required, and capped. Samples for metals analysis will be filtered in the field prior to preservation with nitric acid. Filters will be discarded after each use. PJ9 9390207.00D A-3