FEIS D-Malcolm Pirnie Letter and Leggette Brashears & Graham Response
Appendix DMalcolm Pirnie Letter and Leggette, Brashears, & Graham Response
JOHN NASO, JR. JOHN M. BENVEGNAWILLIAM K. BECKMANDAN C. BUZEA LEGGETTE, BRASHEARS & GRAHAM, INC. JOHN L. BOGNAR KIMBERLY R. BLOMKERJ. KEVIN POWERS JORMA WEBERFRANK J. GETCHELL PROFESSIONAL GROUND-WATER AND JOSEPH W. STANDEN, JR.CHARLES W. KREITLER ENVIRONMENTAL ENGINEERING SERVICES MICHAEL A. MANOLAKASJEFFREY B. LENNOX JAMES A. BEACHW. JOHN SEIFERT, JR. WILLIAM P. PREHODADAVID A. WILEY 4 RESEARCH DRIVE, SUITE 301 JEFFREY M. TROMMERROBERT F. GOOD, JR. SHELTON, CT 06484 DAVID S. HUMETIMOTHY L. KENYON 203-929-8555THOMAS P. CUSACKDAVID B. TERRY FAX 203-926-9140 BRUCE K. DARLINGMATTHEW P. PERAMAKI www.lbgweb.com KAREN B. DESTEFANIS____________________ JEFFREY T. SCHICK KENNETH D. TAYLORR. G. SLAYBACK ROBERT M. ROHLFSJOHN B. ASHWORTH WILLIAM G. STEIN June 18, 2007 JOHN W. NELSON WILLIAM H. AVERY ROY SILBERSTEIN PAUL M. JOBMANN Mr. Martin Lonstein, Planning Board Chair BRIAN C. KIMPEL Town of Wawarsing JOHN R. DIEGO MICHAEL SUSCA Town Hall KEITH J. SHORTSLEEVE BRAD CROSS 108 Canal Street MITCHELL KANNENBERG Ellenville, NY 12428 Dear Mr. Lonstein: Leggette, Brashears & Graham, Inc. (LBG) is providing responses to comments on the Mahamudra Buddhist Hermitage DEIS made by Malcolm Pirnie Inc. (MPI) in a March 20, 2007 letter. MPI was retained by the Town of Wawarsing Planning Board to review the hydrogeology aspects of the DEIS as a response to the concerns by the consultants for the Cragsmo or Association (CA). This letter addresses the MPI request for additional data and clarifications. Request No. 1 “a map showing the location of the discharge location of water pumped during the drawdown tests” Response: The discharge water from Well 1 and Well 2 was diverted through a 3-inch fire hose to a drainage basin on the western portion of the property. The well discharge locations were presented on figure 1 (attached) of the report entitled “Water-Supply Testing, Proposed Mahamudra Buddhist Hermitage, Cragsmoor, New York”. Discharge for Well 2 was directed to the northern location and discharge for Well 1 was directed to the southern location. These locations were agreed upon by LBG and the CA’s consultant prior to the initiation of the a quifer tests. Request No. 2 “the dimensions and locations of the recharge area to the Hermitage wells” CONNECTICUT• LOUISIANA • OHIO • ILLINOIS • SOUTH DAKOTA • PENNSYLVANIA • FLORIDA • NEW JERSEY • MINNESOTA TEXAS• WISCONSIN • NEW YORK • MISSOURI
Mr. Martin Lonstein -2- June 18, 2007Response: The Dharmakaya Water Supply Report discussed the recharge capabilities of the area,however, a map was not provided due to the nature of bedrock aquifers. Figure 1 shows theproperty boundary and the estimated upland watershed area that provides recharge to theproperty. The dimensions and locations of source-water or recharge areas for bedrock wells aregreatly affected by fracture geometry, orientation and density. These factors make it impossibleto accurately delineate recharge areas even in situations where the general fracture patterns arereasonably understood. Because of these difficulties, it is generally assumed that the rechar e garea for an individual well tends to mimic the land surface topography. This is a reasonableassumption on a regional scale or where fracture density is great enough that the system acts as aporous-media aquifer. However, on a local scale (as in the case of the Hermitage Wells, seefigure 1 in DEIS) where fractures cross topographic divides; the assumption can produce resultsthat are not technically defensible. Therefore, definitive recharge areas for the Hermitage Wellshave not been delineated.Request No. 3 “the groundwater flow direction”Response: The Dharmakaya Water Study contained an extensive discussion on the fractures in thearea’s bedrock and the role they play in the proposed Hermitage water supply which includesground-water flow process and its impact on the area. Because the ground-water flow in bedrockaquifers is strongly influenced by fractures in the rock formation, i must be understood that a twater-level configuration map for such aquifers is, at best, only an approximati n of the actual owater-level configuration, especially if the map is constructed from a network of monitor wellstapping fractures that are not interconnected. With this in mind, LBG constructed a water level -configuration map (figure 2) using depth-to-water and land-surface elevation information for thewells monitored during the aquifer tests completed in 2005. Land-surface elevation data wereestimated from a USGS topographic map. Figure 2 shows that ground water in the area flowsfrom north to southeast (generally mimicking the surface topography).
Mr. Martin Lonstein -3- June 18, 2007Request No. 4 “the zone of influence of the Hermitage wells”Response: As explained in the previous response, the bedrock nature of the aquifer stronglyinfluences the extent and potential impacts that may be created by the Dharmakaya project. Thisis fully explained in the Dharmakaya Water Study. Therefore, because the Hermitage wells arecompleted in a fracture-controlled bedrock aquifer, no clearly defined zone of influence can bedelineated. Results from the aquifer test showed that only two of the ten offsite wells (49 and71 Old Inn Road) monitored during the aquifer tests showed discernable drawdown interferenceeffects from pumping of the onsite wells. Figure 1 shows that the wells monitored at 49 and71 Old Inn Road were located approximately 840 feet and 500 feet to the north and east,respectively, of Well 2 (the nearest onsite production well). However, because of the fracturednature of bedrock systems, it cannot be concluded that the area of influence would be radial innature or that wells completed in close proximity to the impacted wells would also be impacted.For example, no discernable interference effects were observed in the well located at 95 Old InnRoad during the Well 2 aquifer test, even though it is located closer to Well 2 than a well (49 OldInn Road) impacted by pumping during the test. It has been argued by others that aquifer parameters developed from the pumping testsshould be used to estimate the area of influence of the Cragsmoor wells. The use of aquiferparameters to anticipate interference of the wells completed in bedrock, as proposed, is nottechnically appropriate. As discussed above, ground-water flow in bedrock aquifers is stronglyinfluenced by fractures in the rock formation. Consequently, the conventional well-flowequations, developed for isotropic homogeneous aquifers of infinite aerial extent, do notadequately describe the flow in fractured rock, except in rare instances where the fracture densityis great enough that the system acts as a porous-media aquifer. This expectation is not the casein the study area. Another complicating factor when attempting to use aquifer parameters in this manner isthat the extent of the fracture pattern is typically unknown. This may lead to instances whereattempts are made to calculate regional aquifer parameters (so that long-term yield and wellinterference effects can be estimated) from a network of monitor wells tapping fractures that are
Mr. Martin Lonstein -4- June 18, 2007not interconnected. If the aquifer parameters calculated for the above-described monitor wellnetwork were used to estimate long-term well yield, the results would be grossly inaccurate.Added to this complexity is the fact that the theory of fluid flow in fractured rock i not as sestablished as that in porous media. Because of this, contradictory results sometimes occur whenanalyzing drawdown data, even if the fracture pattern is reasonably understood (Kruseman andRidder, “Analysis and Evaluation of Pumping Test Data”, International Institute for LandReclamation and Improvement, The Netherlands, 1990). Therefore, the resulting regionalaquifer parameters would once again produce inaccurate estimates of the wells’ area ofinfluence. Even if the wells proposed for testing were located in a sand and gravel aquifer(i.e., essentially treatable as a homogeneous isotropic aquifers of infinite areal extent) rather thana bedrock aquifer, the methodology proposed would be inappropriate to estimate potential wellinterference. The analytical equations utilized to estimate aquifer parameters do not account forimpacts due to aquifer boundaries, leakage to and from surface water bodies, variations inaquifer thickness, or the dewatering of significant shallow fractures. All of theseunaccounted-for parameters help determine the amount of replenishment available to a well.Therefore, even under the best conditions, the use of the aquifer parameters (generated from theanalytical equations) can produce results that are not technically defensible.Request No. 5 “a discussion of the impacts of operational pumping rates of the Heritage wells and thearea’s recharge rates on wells downhill from the Hermitage site, including potential impacts towells not monitored (shallow wells as well as inaccessible ones)”Response: The Dharmakaya Water Study did discuss the fact that there should be no impacts onneighboring wells with the operational pumping rates for the Hermitage. One of thedowngradient wells, 19 Cragsmoor Road, was a shallow well at 22 btoc. This well did not showany impacts during the well testing program and would be representative of others in the area.Water-demand estimates provided by Chas. H. Sells Inc. indicated that the total potable waterdemand for the project for the reduced impact layout is 8,496 gpd, or 5.9 gpm. In November
Mr. Martin Lonstein -5- June 18, 20072005, a 24-hour aquifer test was completed on Well 2. During the test, Well 2 was pumped at25 gpm (or over four times the anticipated demand). Results from the aquifer test showedthatthe offsite wells at 49 and 71 Old Inn Road were the only offsite wells that showed discernibledrawdown interference effects from pumping. The maximum observed drawdowns at the wellsat 49 and 71 Old Inn Road were 2.6 feet and 3.9 feet, respectively. The wells at 49 and 71 OldInn Road are located approximately 850 feet and 510 feet from Well 2, respectively. Thedrawdown observed in these wells under normal operation of the onsite wells (12-hour dailypumping cycles at 5.9 gpm- approximately 24 percent of the tested production) would beconsiderably less. This, coupled with the fact that any potential impact would diminish withdistance and that no impact was observed in the deep bedrock wells located on Clarks Road andCragsmoor Road (located over 1,200 feet away), suggests that the onsite wells will not impactshallow wells downgradient of the site. The applicant has agreed to monitor the two wellsimpacted during testing for a two-year period following full build-out of the proposed project.This additional monitoring will determine significant impacts, if any, under normal operation ofthe proposed well source. Although the locations of the well recharge areas have not been delineated, the size of therecharge area is estimated to be approximately 16 acres (less than 18 percent of the 91-acreparcel). The size of the recharge area under average conditions was estimated by calculating theradius that has a volume equal to the volume of water pumped over one year and a height equalto the annual recharge rate. The radius was then used to calculate the recharge area. The onlyparameters used for this estimate are an average annual recharge and the well field pumping rate.Therefore, this approximation does not incorporate fracture geometry, location, or density orother variables that may influence the size of the recharge area. The estimated recharge area foreach Hermitage well at 5.9 gpm (projected average demand) with an average recharge to bedrockof 7 inches per year (the more conservative USGS annual recharge estimate presented in theDEIS) was calculated using the following equation: A= (Q*268,383/R)* /43,560Where: A = Estimated Recharge Area (in acres) Q = pumping rate (gpm) R = average annual recharge to bedrock (inches) Note: The equation was derived using the formulas for the volume of a cylinder and the area of a circle.
Mr. Martin Lonstein -6- June 18, 2007 This analysis shows that the recharge potential to the property significantly exceeds theestimated project demand. Based on this result, it is concluded that there would be nodiscernable impact to the shallow wells downgradient of the Hermitage site resulting fromnormal use and operation of the bedrock wells even if on-site recharge of wastewater is notincluded in the recharge analysis. If the on-site recharge of wastewater were include in theanalysis (assuming 15 percent consumptive use), the total consumptive use (or water lost fromthe ground-water system) would be approximately 0.9 gpm, resulting in a recharge area ofapproximately 2.5 acres or (approximately 3 percent of the parcel).Request No. 6 “a discussion of the effects of drought conditions on the water supply”Response: A discuss of drought conditions was contained in the Dharmakaya WaterStudy underthe “Groundwater Balance” section. In addition, the data from the two aquifer test suggests that,in their present condition, Wells 1 and 2 can both be pumped at twice the daily demand, whichwould be 12 gpm for at least 72-hours in the case of Well 1 and 12 gpm for at lest 24-hours inthe case of Well 2. To evaluate the maximum withdrawal that can be maintained by each wellduring an extended dry period, the available drawdown was projected for 180 days of continuouspumping at 50 gpm and 25 gpm for Wells 1 and 2, respectively. The projected drawdown inWells 1 and 2 were calculated to be approximately 55.4 feet and 33 feet, respectively. The pumpsetting in each well was 350 ft btoc. Based on these figures, the estimated available drawdownin Wells 1 and 2 after 180 days of constant pumping would be approximately 194 feet and206 feet (discounting 100 feet above each of the pumps for a safety factor). This analysis is notintended to imply that the test rates can be sustained for 180 consecutive days, especiallyconsidering that the wells are completed in bedrock where fracture dewatering can occur. Thissimple extrapolation, does suggest, however, that Wells 1 and 2 should be able to withdraw theaverage daily demand of 5.9 gpm during drought conditions.
Mr. Martin Lonstein -7- June 18, 2007Concerns Raised By Cragsmoor Association Consultants The aquifer did not recover to at least 90 percent of the drawdown within 24 hours during the recovery portion the aquifer tests, as per NYSDOH regulations. Which suggest that the test rate may not be sustainable for an extended period of time. As stated by the Planning Board’s consultant, “Taking into consideration the fact that the applicant stressed the aquifer at approximately seven times the daily demand for 72 hours and the on-site recharge greatly exceed the seven gpm demand, the loss of storage should not affect the water system’s ability to meet the seven gpm demand”. Were enough homes monitored to the north or the property to adequately protect the homes in the area? The NYSDOH requires an applicant to monitor 6 to 10 homes surrounding the site; ten were monitored during the tests on the Hermitage Wells. In addition, the Planning Board’s consultant concluded that the aquifer tests were conducted in accordance with the NYDOH regulations. Concerns related to offsite pumping impacts, the water supply system’s ability to meetsystem demands during and drought and the use of aquifer parameter to evaluated area ofinfluence have been addressed above and by the Planning Board’s consultant in theMarch 25, 2007 letter. In the summary of their recommendations, MP requested that the applicant measure thepump setting at 49 Old Inn Road and the pump setting and depth of the well at 71 Old Inn Road.During the well study, LBG attempted to obtain the requested data but was unable to do sobecause of the well completion at each of the locations. We also attempted to obtain therequested information from other sources (Ulster County Health Department and the individualhomeowners). In each case, the wells are so old that no records exist. Additionally, thehomeowners do not have any information on the wells, including the name of the original welldriller. Because of the type of well completion at each of the locations, it would be difficult toobtain the requested data without potentially compromising or damaging the wells and/or pumps.Thus, it is LBG opinion that any potential information gained by collecting this data isoutweighed by potential risk of collecting the data. Especially considering that, both of the wellswould be included in the proposed monitoring program and any potential impacts related towithdrawals from the applicant’s water-supply system would be noted prior to adverselyimpacting the homeowner.
Mr. Martin Lonstein -8- June 18, 2007 Please contact me if you have any questions or concerns at (203) 929-8555. Very truly yours, LEGGETTE, BRASHEARS & GRAHAM, INC. Kenneth Taylor AssociateReviewed by:R.G. Slayback, CPGSenior ConsultantKT:nvEnclosurescc: Mary Lou Christiana, Esq.-Town of Wawarsing Planning Board Attorney David Stolman – Frederick P. Clark Associates, Inc Susan Fasnacht – Chas. H. Sells, Inc. Daniel St. Germain – Malcolm PirnieH:Buddist HermitageDEIS Comment Letter - revised III.doc