Planning/Design/Engineering/Environmental Documentation. Assessment and Evaluation
Planning/Design/Engineering/Environmental Documentation. Task 3: Assessment and Evaluation
1. In 2004 USGS completed an “Evaluation of Geohydrologic Framework, Recharge Estimates, and Ground-Water Flow of the Xxxxxx Tree Area.” The geohydrology was refined by collecting and interpreting water-level and water-quality data, geologic and electric logs, and gravity data. Major findings were that the ground-water subbasins are as deep as 4,500 feet east of the center of Xxxxxx Tree, and 2,000 feet beneath Coyote Lake. Water-bearing deposits were divided into three aquifers. The characteristics of each were identified. Ground-water withdrawals have resulted in as much as 35 feet of drawdown in the Xxxxxx Tree subbasin. The study further identified water quality characteristics and estimated that there is very little, if any, net natural ground water recharge. As part of the study, a ground-water flow model was developed. The model estimates 123 acre-feet per year of streamflow infiltration and 84 acre feet per year of underflow across the Yucca Barrier from the Xxxxxx ground-water model. It also indicates that an average of about 200 acre feet per year leaves the basin.
2. Based on the USGS study above, Xxxxx Engineering conducted a ground water availability evaluation to simulate the effects of future pumping. Various growth scenarios were determined. The study also included simulating septic leachate migration to the groundwater table to estimate when recharge from septic systems will likely impact ground water.
3. During the past five years USGS has conducted extensive studies to evaluate the potential recharge sites and to determine effect of septic discharge on the aquifer. Several sites were evaluated to identify the preferred site. Two xxxxx were constructed at the preferred site of the recharge pond to confirm that there were no strata that would inhibit artificial recharge; and to estimate the rate of infiltration. In a different location two xxxxx were drilled to study the impacts of septic discharge on the aquifer. With the data from these two xxxxx an unsaturated zone flow and transport model has been developed to allow a detailed, local-scale investigation of the effects of land use, and subsequent septic load on ground water quality on the Xxxxxx Tree groundwater subbasin. The data have been collected and the model has been implemented. The USGS report is now being written and is expected to be available in the spring of 2013.
Planning/Design/Engineering/Environmental Documentation. Planning, design, engineering, and environmental documentation are not required in this project.
Planning/Design/Engineering/Environmental Documentation. The design of project facilities is planned to be completed in concurrent efforts for each of the major engineering components: collection system, treatment system, and disposal/reuse system. Although design will occur concurrently, the design packages will be completed at different times, allowing construction to begin in phases as designs are completed. Each of these designs will be according to civil and mechanical engineering industry best practices with national standards used for materials, piping, equipment, and general construction specifications. Construction documents and contracts will include Section 7 Caltrans State Standard Specifications and the requirements of the State labor code for Public Works projects in accordance with the Labor Compliance Plan.
