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To account for data logger drift error, a linear correction was applied to all the water level data <br />measurements to average the drift error over the duration of the test. After the linear <br />corrections, the hourly depth to water measurements were normalized to elevations and <br />converted to an average daily value. This process was completed using a combination of a <br />software utilities, and databases queries. Tl1e utilities include a program from t11e data logger <br />manufacturer, In-Situ, that converts the raw binary data from the loggers (miniTrolls) unto <br />comma separated variable (*.csv) files. The second software utility was developed by CDM, <br />called TROLL.exe, which corrects for drift and organizes data from all data loggers alto a single <br />file t11at can be loaded into a database. An intermediary database, sinular in design to <br />HydroBase, is then used to convert depth to water to elevations and calculate daily average <br />water levels. This data is Olen provided to fl1e State for upload alto HydroBase. These utilities <br />and intermediary database along with associated documentation and instructions have been <br />provided to the state under separate cover. <br />There were issues with two of the data loggers during Phase 3. The data logger uz well DSSBP01 <br />was removed during t11is time for repair. After repair, the data logger was re-installed u1 <br />DSSBR01. Second, the data for DSSI9BBD from January 2006 to June 2006 was excluded from <br />t11e data to be subnutted for inclusion to HydroBase because the data were unreliable since the <br />drift error was 1.8 feet at the time of t11e download and the maximum water level change during <br />the period was 3.4 feet. The reason for the drift was believed to be caused by a loss in calibration <br />for the data logger, and therefore, the data logger was replaced during the June 2006 data <br />download. Currently, HydroBase does not include a field to identify water level data that are <br />suspect and so it was decided to not include records from this period with those that were <br />deternuned to be reliable. <br />Two issues were also encountered during the period covered by the Phase 4 water level data <br />do~nmload. There are no data from t11e Lower Dawson bedrock well (C03LTDW) from mid- <br />January 2007 to mid-May 2007 due to a data logger malfunction. During the May field event the <br />data logger was replaced. At DSSI7HND a data logger drift error of 2.27 feet, which is greater <br />than an expected drift error, and a maximum annual water level change of 9.3 feet was <br />observed. A linear correction was applied to the water level data, and data logger was replaced. <br />Because of the issues at these two sites, it is recommended future data downloads occur on a bi- <br />annualbasis so data logger issues can be corrected in a more timely fashion. <br />Hydrographs for each monitoring well, including all data since fl1e data loggers were installed, <br />are presented in Appendix E. All hydrographs present the same period of record on the x-axis. <br />Because of the large differences between alluvial and bedrock wells in the magnitude of water <br />level fluctuations, one scale for the y-axis was used for all alluvial wells, and a different y-axis <br />scale was used for all bedrock wells. Tl1e average daily water level measurements from Phase 4 <br />will be provided to the SPDSS project manager for inclusion alto HydroBase. Water level <br />monitoring is anticipated to continue at all wells equipped with data loggers through Phase 5. <br />2.2 Analysis of Continuous Measurements <br />The continuous water level measurements collected from t11e SPDSS monitoring wells provided <br />a detailed dataset for w~dertakuzg a variety of analyses. This section presents the results of <br />three analyses t11at were performed: an evaluation of water level trends, a comparison of <br />SPDSS Phase 4 Task 39 Technical Memorandum-Final 12 <br />O~i20%2008 <br />