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• APPENDIX A MEASUREMENT OF PIEZOMETRIC LEVEL <br />A. 1 ELECTRIC WATER LEVEL INDICATOR <br />The electric water level indicator consists of a contact electrode that is <br />suspended by an insulated electric cable from a reel that has an ammeter <br />or other closed circuit indicator attached. The indicator shows a closed <br />circuit and flow of current when the electrode touches the water surface. <br />The electric sounder is marked at 5-foot intervals. These marks should be <br />periodically calibrated and remarked where necessary. <br />The procedure for measuring water levels with an electric sounder is as <br />follows: <br />I. Switch on. <br />2. Lower the electric cable into the well until the ammeter <br /> indicates a closed circuit. Shake the cable to make sure that <br /> it is not a false water level reading caused by condensation on <br /> the casing. <br />3. Raise and lower the electric cable slightly until the shortest <br /> length of cable that gives the maximum response on the indicator <br /> is found. This is normally most easily accomplished by resting <br /> one hand on the casing with the cable held loosely between the <br /> thumb and index finger and using the other hand to raise and <br />• <br />4. lower the cable. <br />Grab the cable firmly between the thumb and forefinger using the <br /> thumbnail to indicate the point on the cable which was at the <br /> measuring point when the maximum reading was found. <br />5. Since the cable is usually graduated into 5-foot intervals, use <br /> a pocket ruler or tape to interpolate between consecutive 5-foot <br /> marks. Care must be taken that the tape measurements are added <br /> to the graduated mark footage when the level hold point is above <br /> the mark and subtracted when it is below the mark. Also, the <br /> tape measurements should always be made from the lower end <br /> (downhole end) of the mark. <br />6. Record readings to the nearest 0.1 foot on the Data Collection <br /> Form. <br />A. 2. DIRECT READING WITH POCKET TAPE OR RULER <br />If the water level in a well is shallow (generally less than 5-feet deep) <br />and the water surface is easily visible, it may be possible to directly <br />measure the depth to water with a pocket tape or ruler. The procedure for <br />performing this type of measurement is as follows: <br />I. Slowly lower the ruler into the well until the end of the ruler <br />just touches the water surface. This is usually indicated by <br />the rippling of the water surface. <br />• <br />A-I <br />