Appendix 5-E Part 1 Well Pump Test Report
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Draft Environmental Impact Statement Cricket Valley Energy Project – Dover, NY Appendix 5-E: Well Test Report Cricket Valley Energy Ground Water Well Test Report Table of Contents Introduction Page 1 Geology Page 2 Test Well Drilling Page 5 Off-Site Monitoring Page 5 On-Site Monitoring Wells Page 7 Pumping Test Program Page 9 Weather during Monitoring/Test Period Page 10 Pumping Test Results Page 10 On-Site Monitoring Results Page 11 Off-Site Monitoring Results Page 11 Conclusions Page 12 Figures Figure 1, Bedrock Geology Page 3 Figure 2, Surficial Geology Page 4 Figure 3, Off-Site Monitoring Locations Page 6 Figure 4, On-Site Monitoring Locations Page 8 Figure 5, Test Well Locations Page 9 Figure 6, Climate Chart Page 10 Figures 7 through 36, Pumping Test and Monitoring Data After Page 13 Tables Table 1, Test Well Completion Page 5 Table 2, Off-Site Wells Page 6 SSEC Hydrogeology, Geology, Environmental Investigation 4 Deer Trail, Cornwall New York 12518 (845) 534 3816 FAX (866) 334 1883 [email protected] Cricket Valley Energy Ground Water Well Test Report Introduction The Cricket Valley Energy project (CVE) has been planned to significantly minimize water demand through the use of air cooling, and a zero-liquid discharge (ZLD) system, which eliminates the need for wastewater discharge in part by maximizing water recycling and reuse. Given these features, it is anticipated that the summer nominal water needs will be approximately 72,000-86,400 gallons per day (gpd) of water, the equivalent of 50-60 gallons per minute (gpm) for 24 hours. Short term, instantaneous supply rate of up to 120 gpm may be required for the facility during operational transient or unexpected upset conditions, such as startups, well supply system maintenance, boiler chemistry upsets, or emergencies. The CVE project plans to utilize a roof-top rain capture system, implemented to manage stormwater rain quantities per the New York State Stormwater Management Design Manual, as supplemental water supply. The nominal annual rainfall in the Ten Mile Watershed and Dutchess County is approximately 44 and 41 inches, respectively. Using the lower Dutchess County precipitation rate of 41 inches, the CVE roof-top rain capture system can nominally yield up to approximately 7.2 gpm or 10,400 gpd of supplemental water supply. But for the purpose of conservatism, the water yield from roof-top rain capture will not be considered in this analysis. CVE considered various options for the project’s water supply source, such as long distance municipally-supplied water, water withdrawal from the adjacent Swamp River, or the development of on-site wells. It was determined that the preferred approach would be to develop an on-site bedrock well system to meet project water needs. Review of aquifer mapping and surficial field reconnaissance confirmed appropriate subsurface conditions, and six well locations were identified to be drilled and tested on the site. Bedrock test wells were drilled in July/August 2009 and February 2010 to determine if adequate and reliable water supply is available for CVE. Two of the wells, (Wells 1 and 2) had unsuitably low yields (less than 5 gpm), and were therefore removed from consideration for project water supplies. These wells were instead used as monitoring wells during subsequent pump testing. Initial test yields from the remaining four wells (Wells 3, 4, 5, and 6) were found to be productive enough to warrant longer-term testing, the subject of this report. The testing program was intended to demonstrate that the completed wells had sufficient production to supply a continuous 60 gallons per minute, the anticipated summer water demand, and a short-term supply of 120 gpm, the maximum amount required during operational transients and unanticipated upset conditions. An important consideration of the pumping test program was to demonstrate that the extraction of up to 120 gpm from the bedrock aquifer would not have an adverse impact on private well supplies in the areas surrounding CVE (up to 2,500 feet from the Project Development Area), the wetlands within and adjacent to the CVE Property, and the Swamp River. The pumping test program required the installation and monitoring of several piezometers within and adjacent to the wetlands and Swamp River located within the Property. In addition, inquiries were made to neighboring well owners to allow for the monitoring of their wells during the pumping test program. In total, requests were made to 17 nearby well owners within 2,500 feet of the Property, of whom 8 chose to participate in the test. Page 2 September 28, 2010 Geology The CVE site is located within the Stockbridge Marble unit, dolomitic marble that ranges from white to pink to light gray, Figure 1. Since the Stockbridge Marble is a carbonate rock (marble is a metamorphosed limestone or dolostone), it has a tendency to form solution cavities. However the solution cavities that form in marble bedrock tend to be small and free of iron oxide mud that is typical of solution cavities that form in limestone. Therefore water drawn from marble bedrock wells tend not to have the colloidal turbidity common in limestone bedrock wells. Unlike limestone, marble tends to degrade to fine calcareous sand that is evident when a marble bedrock well is first drilled and developed. Under constant, even, pumping, with time the amount of sand produced by these wells diminishes and disappears. Agitation of the well, such turning the pump on an off at full power, could cause short-term production of sand. Therefore, a slow start [variable rate] pump is preferred for such wells. The overlying geologic materials in the main part of the Project Development Area are ground moraine, commonly called glacial till, which is composed of materials derived from the grinding of bedrock by advancing glaciers. Glacial till typically has a low permeability, primarily consisting of compressed rock flour with sand, gravel, and cobbles imbedded within the finer materials. The western side of the Property (i.e., west of the Metro-North railroad line) is underlain by alluvial deposits related to the adjacent Swamp River. The alluvial deposits are associated with the flood plain of the Swamp River and adjacent wetlands and are generally fine silty sand with occasional gravel lenses. Possibly present within the CVE site, specifically the northwestern portion of the site, are underlying glacial outwash deposits that have been mapped by the New York State Museum (Cadwell). The possible presence of such deposits would indicate an increased ability to recharge the underlying bedrock aquifer because the higher permeability sand and gravel deposits allow more water to pass into the bedrock aquifer than would lower permeability materials such as silts and clays, Figure 2. Page 3 September 28, 2010 Page 4 September 28, 2010 Page 5 September 28, 2010 Test Well Drilling Wells 1 through 4 were drilled during the period of July 28, 2009 to August 6, 2009 under the guidance of ARCADIS U.S., while wells 5 and 6 were completed under SSEC’s oversight between February 8 and 22, 2010. All wells were drilled by Boyd Artesian Well Co. Wells 1 and 2 were drilled to depths of 855 and 630 feet, and produced insufficient water to be considered for testing (less than 5 gpm). Wells 3 and 4 were drilled to depths of 805 feet and 605 feet and produced 44 and 70 gpm during preliminary tests. The yields of Wells 3 and 4, although significant, were not considered sufficiently productive to meet the project’s reliability and backup criteria and therefore two additional wells were drilled, Wells 5 and 6. Wells 5 and 6 were drilled to depths of 957 and 1109 feet and produced an additional 30 and 12 gallons per minute. The four test wells (Wells 3, 4, 5, and 6) were further developed using a standard surging technique to remove sediment from the bedrock fractures and improve connectivity to the aquifer. Table 1, Test Well Completion Table Casing amount in feet in amount Casing feet in Depth Total (gpm) ofproductive (ft)/Yield Depth Fractures top below feet in Level Water Static gpm in Yield Tested feet in Drawdown Total Feet 180 in drawdown Projected Well Completed Date 3 8/6/2009 51 805 30 /30 , 410 /15, 455/25 46 45 152 160 4 8/3/2009 51 605 65/30 , 255/20 , 335/20 26 120/60 132/20 180/30 5 2/9/2010 51 959 200/30 32 30 102 210 6 2/22/2010 51 1109 640/7, 800/5 49 25 195 220 Off-site Monitoring Requests for the voluntary participation of nearby property owners in an off-site monitoring program were mailed to property owners within approximately 2,500 feet of the test wells. The request was sent in the form of a letter (sent by mail or hand delivered) detailing the test procedure and including a questionnaire. Letters were sent to 17 well owners with 8 well owners agreeing to take part in the voluntary monitoring program. Additionally, the two closest wells at the Knolls of Dover project were also monitored during the pumping test. Table 2 and Figure 3 list the off-site monitoring well locations. Data loggers (an instrument that contains a water level measuring device and an on-board computer to store water level measurements) were installed to collect water level information from the neighboring wells, with the initial intention of monitoring water levels for a minimum of 48 hours prior to the start of the pumping test and for a minimum period of 24 hours after the conclusion of the test. However, given the delay in the start of pumping test, data loggers were installed in early May and monitored until late June, thus providing a robust data set of ten-minute intervals for comparison.