FEIS H-Revised Stormwater Management Plan

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Mahamudra Buddhist Hermitage FEIS, H-Revised Stormwater Management Plan, WSP SELLS

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FEIS H-Revised Stormwater Management Plan

  1. 1. Appendix HRevised Stormwater Management Plan
  2. 2. Stormwater Management PlanMAHAMUDRA BUDDHIST HERMITAGE TOWN OF WAWARSING ULSTER COUNTY Prepared for: Dharamakaya, Inc. 155 Buff Road Cochecton, NY 12726 Prepared by: Susan K. Fasnacht, P.E., Project Manager Chas. H. Sells, Inc. 555 Pleasantville Road Briarcliff Manor, NY 10510 914-747-1120 June 2006 Rev. June 2007
  3. 3. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGE TOWN OF WAWARSING, NYTable of ContentsBACKGROUND INFORMATION ............................................................................................... 1 INTRODUCTION ...................................................................................................................... 1 EXISTING CONDITIONS......................................................................................................... 1HYDROLOGICAL ANALYSIS .................................................................................................... 4 METHODOLOGY ..................................................................................................................... 4 PRE-DEVELOPMENT STORMWATER RUNOFF................................................................. 4 POST-DEVELOPMENT STORMWATER RUNOFF .............................................................. 5STORMWATER MANAGEMENT............................................................................................... 8 STORMWATER QUANTITY................................................................................................... 8 STORMWATER QUALITY.................................................................................................... 11EROSION AND SEDIMENT CONTROL .................................................................................. 14 TEMPORARY EROSION AND SEDIMENT CONTROL FACILITIES .............................. 14 Structural Measures .............................................................................................................. 14 Vegetative Measures............................................................................................................. 15 Maintenance and Inspection of Temporary Control Measures............................................. 16 PERMANENT EROSION AND SEDIMENT CONTROL FACILITIES............................... 17AppendicesAPPENDIX SMP-1 – PRE-DEVELOPMENT DRAINAGE ANALYSISAPPENDIX SMP-2 – POST-DEVELOPMENT DRAINAGE ANALYSISAPPENDIX SMP-3 – SOIL TEST RESULTSAPPENDIX SMP-4 – WATER QUALITY COMPUTATIONSList of FiguresFigure 1: Pre-Development Subbasins........................................................................................... 6Figure 2: Post-Development Subbasins ......................................................................................... 7Figure 3: Proposed Drainage Facilities........................................................................................ 10List of TablesTable 1: Design Storm Precipitation Amounts .............................................................................. 4Table 2: Existing (Pre-Development) Drainage Conditions........................................................... 5Table 3: Post-Development Drainage Conditions (without Mitigation)......................................... 5Table 4: Pre- Versus Post-Development Peak Discharges (with Mitigation)................................. 8Table 5: Drainage Area, Curve Number and Time of Concentration............................................. 9Table 6: Drainage Calculation Results ........................................................................................... 9Table 7: Water Quality Swales. Required Volumes and Dimensions .......................................... 12Table 8: Water Quality Swales. Discharges and Depths .............................................................. 12Table 9: Roof Buildings Water Quality Requirements................................................................. 13
  4. 4. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGE TOWN OF WAWARSING, NYBACKGROUND INFORMATIONINTRODUCTIONThis Stormwater Management Plan is being prepared in conjunction with construction of theproposed Mahamudra Hermitage. The purpose of this plan is to outline design and operationalmeasures of drainage facilities that will meet the requirements of the New York StateDepartment of Environmental Protection (NYSDEC) Phase II Stormwater Regulations tomitigate stormwater runoff quality and quantity impacts, as well as impacts from erosion andsedimentation during site construction.EXISTING CONDITIONSThe applicant, Mahamudra, Inc., proposes to develop a 91 acre property as a Buddhist house ofworship and related hermitage facilities. The site is located in the Hamlet of Cragsmoor in theTown of Wawarsing. It is situated west of Cragsmoor Road, which connects the Hamlet to NYSRoute 52, south of the Village of Ellenville. The proposed construction includes construction of17 buildings and infrastructure improvements such as access driveways, subsurface sewagetreatment systems, a central water supply from drilled wells, and landscaping in addition to thestormwater management facilities. In total the project could ultimately disturb approximately31.5 acres or 34.8% of the property.Stormwater runoff within the project site is generally in a south to southeast direction towardstributaries of the Platte Kill, which connects to the Wallkill River, a tributary to the HudsonRiver. The project site is situated in a watershed of approximately 152 acres. Within the overallwatershed, 36.7 acres drain in a general southeast direction and under Cragsmoor Road to anunnamed tributary of the Platte Kill, a portion of which traverses the northeast corner of theproperty. The other 115.5 acres drain south, off the property in small, semi-defined channels andultimately to the Platte Kill. None of the site is within the New York City reservoir watershed.Construction activities are expected to commence in 2007 with construction of buildings to bedone in phases that would continue until at least 2014. The initial phase of the work would bethe construction of the Milarepa Center, which would necessitate the construction of a portion ofthe internal driveway, the proposed well house and water lines, electric and communicationslines, and the septic system for the Milarepa Center.Soil disturbing activities associated with construction will include: clearing and grubbing;installing a stabilized construction entrance; installing erosion and sediment controls; excavatingfor and placing water, septic systems, electric and communications lines, stormwatermanagement facilities, and building foundations; constructing internal roads, parking areas, andretaining walls; grading; preparing for final planting and seeding.
  5. 5. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGEDrainage facilities and the erosion and sedimentation control measures will be designed andimplemented, in accordance with New York State Stormwater Management Design Manual(NYSDEC, Aug. 2003) and the New York State Standards and Specifications for Erosion andSediment Control (NYSDEC Aug. 2005), as well as the requirements for a SPDES GeneralPermit GP-02-01 for Stormwater Discharges From Construction Activities.According to the “Soil Survey of Ulster County” by the U.S. Department of Agriculture, SoilConservation Service, on-site soils include Bath gravelly silt loam (BgC), Bath and Mardin verystony soil (BRC), Volusia very stony soil (VSB). Outside of the project site, yet still within thedrainage basin, three other soil types are present; Mardin gravelly silt loam (MdB), Alluvial land(AA), and Nassau-Bath-Rock outcrop (NBF). Soil characteristics are as follows: Bath gravelly silt loam (BgC): This unit consists of deep, well drained, sloping soil formed in glacial till. It is near the crests of hills or on convex side slopes where water does not accumulate. Most areas are long and narrow in shape and are found on slopes ranging from 8% to 15%. The main engineering limitations of the soil include slow permeability and an erosion hazard during construction if proper vegetative cover is not maintained. This unit covers approximately 13.3% of the site, primarily at the northwestern flatter portion of the site. Bath and Mardin very stony soil (BRC): This unit consists mostly of well drained Bath soils and moderately drained Mardin soils that are mainly on the convex hilltops an hillsides and on foot slopes. These are deep, very stony soils formed in glacial till. Areas are oblong or irregular in shape and found on slopes ranging from 8% to 15%. The main engineering limitations of the soil include slow permeability and slight seasonal wetness. The hazard of erosion during construction may be severe in some areas, if not protected by proper soil and erosion control measures. This unit covers approximately 75.9% of the site, through the center of the parcel. Volusia very stony soil (VSB): This unit consists of deep, very stony, somewhat poorly drained soils formed in glacial till. They are found that on foot slopes and on undulating hilltops and plains. The soil is found on concave and uniform slopes that range from 3% to 8%. The main engineering limitations of the soil include slow permeability in the fragipan, seasonal wetness, and stoniness. This unit covers approximately 10.6% of the site, primarily along the stream at the northeast end of the parcel and in an area on the eastern side close to Cragsmoor Road. Mardin gravelly silt loam (MdB): This unit consists of deep, gently sloping, moderately well drained soil formed in glacial till that is mainly on the convex hilltops an hillsides and slightly concave foot slopes. Areas are oblong or irregular in shape and found on slopes ranging from 3% to 8%. The main engineering limitations of the soil include slow permeability in the fragipan and substratum, and a seasonal high water table. This unit covers a very small portion of the site of less than 1,700 square feet, at the northern end of the parcel adjacent to Old Inn Road. Alluvial land (AA): This unit consists of deep, unconsolidated alluvium soil that is commonly shifted or redeposited by stream overflow. Its texture varies widely within a short distance and the soil has little or no profile development. The frequent flooding and the variability of its texture and drainage within short distances severely affect most uses. Page 2 of 17
  6. 6. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGE This unit covers approximately 0.2% of the site, along the stream bed just before it passes under Cragsmoor Road and off-site on the east side of Cragsmoor Road. Nassau-Bath-Rock outcrop (NBF): This unit consists of shallow, somewhat excessively drained Nassau soils; deep, well drained Bath soils; and Rock outcrop, or bedrock exposures that are intermingled mainly with the Nassau soils. These soils are formed in glacial till with the Nassau soil generally on the upper one-half to two-third of the slope, and the Bath soils on the lower part. Rock outcrops are found on hillsides, valleysides, and mountains. Slopes range from 35% to 65%. The main engineering limitations of the soil result from the very steep slopes and rock outcrop, which make construction difficult. This unit is located just west of the parcel and is not present within the site itself.Extensive soils tests were conducted for the design of the subsurface sewage disposal systems(SSDS). The tests consisted of percolation tests to determine the permeability of the soils and thedigging of deep test holes to observe soil types and look for evidence of soil mottling. Theresults of these soil tests are found in Appendix SMP-3.There are four broad vegetative cover types within the Hermitage property. These includewetlands/water courses, mature forest communities, young woods, and upland meadows. Thewetlands/water courses are present in two locations along Cragsmoor Road, one location alongthe western property line, and at a vernal pool near the center of the property. None of theseareas are being disturbed by the proposed development. The mature forest occupies about 50acres of the parcel, along the south and western areas. The young woods with approximately 32acres are situated in the northwest and eastern corners of the parcel. The upland meadow, whichcovers about 8 acres in the north central part of the property, had previously been a fairway for agolf course (pre mid-1960’s).The site lies on a shoulder of Bear Hill just east of the Shawangunk Mountain ridge line. Thiscreates a topography that slopes down hill from the north portion of the property to the south.The highest part of the parcel is found where it fronts on Old Inn Road, where the elevation is1,831 feet. The is also is a small “knoll” located east and slightly south of the Old Inn Roadfrontage at elevation 1,794 feet. From each of these high areas, the land slopes downward to thesouth and east with varying grades.The lowest elevation on the property, 1,535 feet, is found at the southwest corner. At thesoutheast corner adjacent to Cragsmoor Road the elevation is 1,562 feet. Elevations varyapproximately 296 feet across the property.A few shallow watercourses originate north of the site and drain south into Platte Kill. The threeculverts located at the eastern side of the property collect runoff from sections of the site anddischarge on the other side of Cragsmoor Road. Page 3 of 17
  7. 7. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGEHYDROLOGICAL ANALYSISMETHODOLOGYComputations of existing runoff amounts were completed for the Type II, 1-, 10-, and 100-year,24-hour design storms using the Soil Conservation Service, Technical Release – 55 (TR-55)methodology. The TR-55 method of stormwater modeling is accepted by both the USDA SoilConservation Service and the U.S. Army Corps of Engineers, and meets the SEQRA scopinggoals for this project, as well as the requirements of NYSDEC. PondPack®, Version 10.0 byHaestad System, which uses a hybrid of the strengths of HEC-1 (U.S. Army Corps of Engineers)and TR-20 (SCS) was used for completing the stormwater analyses for the project.The software forecasts the rate of surface water runoff and watercourse flow rates based onseveral factors. The input data includes information on land use, soil types, vegetation, watershedareas, time of concentration, rainfall data, storage volumes, and hydraulic capacities of thehydraulic structures. The computer model predicts the amount of runoff as a function of time,including the attenuation effect due to dams, lakes, large wetlands, and floodplains. Runoff ratesduring specific rainstorms may vary due to different assumptions concerning soil moisture, waterlevels in ponds, snowmelt, and rainfall patterns. The input data for rainfalls with statisticalrecurrence frequencies of 1-, 10- and 100-years were obtained from the U.S. Weather BureauTechnical Papers. The National Weather Service developed four synthetic storms to simulaterainfall patterns around the country. For analysis in Ulster County, the Type II rainfall patternwith a 24-hour duration is valid.The design storms analyzed correlate to the requirements of the NYSDEC for the Phase IIStormwater Regulations in which stormwater management practices must mitigate the CPv(Channel Protection Volume – 1 Year Storm Event), the QP (Overbank Flood Control – 10 YearStorm Event) and QF (Extreme Flood Control – 100 Year Storm Event) storm events.Precipitation for the required storms is contained in Table 1.Table 1: Design Storm Precipitation Amounts Design Storm Precipitation Amount (Inches)1-Year (CPv) 3.510-Year (QP) 6.0100-Year (QF) 8.0PRE-DEVELOPMENT STORMWATER RUNOFFIn order to determine the pre-development conditions for the site that will ultimately be used todetermine the stormwater detention needs for the proposed development, five analysis points (A,B, C, D, and E) with the corresponding watersheds were chosen in relationship with the possibleimpact downstream of the developed areas (See Figure-1, Pre-Development Subbasins). Ananalysis of the drainage basins was run to compute the peak runoff rates during each of thedesign storms. A printout of the complete results is contained in Appendix SMP-1. The input Page 4 of 17
  8. 8. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGEparameters for drainage area, time of concentration (TC) and composite curve number (CN), aswell as the analysis results for pre-development are summarized in Table 2.Table 2: Existing (Pre-Development) Drainage Conditions Travel Peak Runoff Rate Drainage Drainage Curve Time (cfs) Basin Area No. (TC) 1-Year 10-Year 100-Year (Acres) (CN) (hr) (CPv) (QP) (QF) A 14.65 71 0.19 19.5 56.0 88.5 B 11.53 70 0.30 12.1 35.6 57.2 C 12.30 71 0.29 14.0 40.0 63.5 D 38.70 70 0.21 47.4 139.1 221.1 E 75.05 73 0.59 63.4 174.8 273.4POST-DEVELOPMENT STORMWATER RUNOFFFor the post-development condition similar watersheds were used, however one (Subbasin D)was further subdivided and modified to reflect the changes of the site to analyze the hydrologyunder proposed conditions (See Figure-2, Post-Development Subbasins). Input parameters weremodified to reflect changes in the drainage basin boundaries, plus changes to the times ofconcentration and curve number that result because of the development of the site. The completeanalysis for the post-development condition is contained in Appendix SMP-2. The inputparameters for drainage area, TC and CN, as well as the analysis results for pre-development aresummarized in Table 3. These values reflect the peak runoff rate prior to the design of anystormwater peak discharge mitigation measures.Table 3: Post-Development Drainage Conditions (without Mitigation) Curve Travel Peak Runoff Rate Drainage Drainage No. Time (cfs) Basin Area (CN) (TC) 1-Year 10-Year 100-Year (Acres) (hr) (CPv) (QP) (QF) A 11.29 71 0.19 15.0 43.2 68.2 B 17.36 73 0.23 24.9 66.6 102.7 C 6.04 72 0.28 7.4 20.8 32.6 D1 18.14 76 0.21 31.0 77.8 118.1 D2 13.85 70 0.17 18.0 52.8 83.8 D3 10.60 72 0.14 16.4 44.5 70.0 E 74.95 73 0.59 63.3 174.6 273.0 Page 5 of 17
  9. 9. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGESTORMWATER MANAGEMENTSTORMWATER QUANTITYTo evaluate the change from pre- and post-development conditions, the peak flows for several ofthe subbasins were hydrologically added to compute peak runoff rates at common downstreampoints, in addition to being compared individually. In the case of subbasins A, B and C, thecommon point would be where subbasin C joins the stream along the east side of CragsmoorRoad. These basins are also compared individually, pre- and post-development, to ensure there isno increase in peak runoff to the culverts under Cragsmoor Road. For subbasin D, the post-development area would have a common discharge point where the pre-development subbasin Dexits the property. Subbasin E has the same discharge point, pre- and post-development. Usingthese common discharge points a comparison was made for pre- and post-development peakrunoff rates for the site and is shown Table 4.Table 4: Pre- Versus Post-Development Peak Discharges (with Mitigation) Pre-Development Post-Development Peak Runoff Rate Peak Runoff Rate Drainage (cfs) (cfs) Basin 1-Year 10-Year 100-Year 1-Year 10-Year 100-Year (CPv) (QP) (QF) (CPv) (QP) (QF) A, B, C 44.8 129.5 204.4 30.7 79.8 131.2 D 47.4 139.1 221.1 34.4 97.7 163.4 A 19.5 56.0 88.5 15.0 43.2 68.2 B 12.1 35.6 57.2 11.1 26.1 53.2 C 14.0 40.0 63.5 7.4 20.8 32.6 E 63.4 174.8 273.4 63.3 174.6 273.0As can be seen in the above tabulation, without detention there would be small increases in thepeak runoff rates. To mitigate any increases, several detention basins have been proposed. Thefirst basin is located north of the Welcome Center and detains runoff from subbasin B. The basinhas approximately 2.55 acre-feet (111,000 cubic feet) of storage and will mitigate any increase inpeak runoff for the 1-, 10-, and 100-year design storms at the common discharge point C. Ingeneral, this includes runoff from the Milarepa Center and portions of Road B.The second area of detention, located south of the main parking lot, consists of two ponds, onewith a volume of 2.0 acre-feet (87,000 cubic feet) and the second a volume of 2.28 acre-feet(99,300 cubic feet). These ponds will mitigate any increase in the peak discharge for the 1-, 10-,and 100-year design storms for flows emanating mainly from the Bodhisattva Center, portions ofRoad B, the Common House and the main parking lot – subbasins A, B, and C. Figure-3 showsthe location of the proposed detention basins. The computations for the sizing of the detentionbasins are contained in Appendix SMP-2.Peak stormwater runoff rates for Subbasins D and E will be handled through the use of cisternsand dry wells. The cisterns will be incorporated into the building construction and site Page 8 of 17
  10. 10. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGEdevelopment of all buildings and be sized to collect stormwater runoff that has been pretreated inaccordance with the “Alternative Stormwater Management Practices” section of the New YorkState Stormwater Management Design Manual. Water collected in the cisterns will be used forwatering of landscaping and other non-potable water uses.The stormwater design software StormCAD version 5.6 was used to analyze the hydrology andhydraulics for the proposed drainage system. The times of concentration were estimated using acombination of overland flow and gutter or grassed waterway flow times. Runoff coefficientswere estimated based solely on land use types. “n” value of 0.9 for impervious areas and 0.25value for grass areas were used. Drainage data and calculations are shown in Table 5 and Table6. The proposed drainage system is capable to convey a 100-year frequency storm to thedetention basins.Table 5: Drainage Area, Curve Number and Time of Concentration Drainage Location Area C Tc (Ac) (min) CB1 5.20 0.27 23 CB2 Negligible CB3 1.82 0.40 19 CB4 1.84 0.38 26 CB5 4.20 0.36 26Table 6: Drainage Calculation Results Size Section (in) Discharge (ft3/s) Velocity (ft/s) 25-yr 100-yr 25-yr 100-yr CB1- 15” CB2 hdpe 3.4 3.8 13.6 14.0 CB2- 15” CB3 hdpe 3.4 3.9 11.3 11.7 CB3- 15” Outl. hdpe 6.6 7.8 5.4 6.4 CB5- 15” MH2 hdpe 6.2 7.7 15.8 16.8 MH2- 18” MH1 hdpe 6.2 7.7 5.0 4.4 MH1- 18” Outl. hdpe 6.0 7.5 3.4 4.2 Page 9 of 17
  11. 11. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGESTORMWATER QUALITYSeveral Stormwater Management Practices (SMPs) are incorporated into the stormwatermanagement system design to maintain water quality. The methodology used for the design ofthe SMPs will follow the guidelines contained in New York State Stormwater Design Manual tomeet the Phase II Stormwater Regulations.Where appropriate, low-impact design principles were incorporated into the design of thestormwater management system. For the most part, road curbing has been eliminated to promotesheet flow of stormwater from paved surfaces into lawn areas, grassed swales, and vegetatedfilter strips. This allows for natural infiltration and filtering of runoff through vegetated areas.Additionally, pervious paving materials will be used wherever practical on-site forroads/driveways and walkways, which allows for natural infiltration of runoff.Several SMPs were used to mitigate water quality. These include wet ponds/micropools, dryswales, plunge pools, vegetated filter strips, and dry wells/infiltrator chambers (See Figure 3). Wet Ponds/Micropools: A large wet pond is proposed at the southern end of the entrance circle to the Bodhisattva Center. This pond will treat runoff from the area of the Bodhisattva Center, as well as portions of Road B and the main parking lot. Micropools and extended detention areas will be incorporated into the three main detention basins to provide additional water quality treatment. Dry swales will be constructed in several locations through out the Hermitage site. The swales will be used to provide water quality treatment for areas such as the Naropa Center, Teacher’s House, Guest Teacher’s House and the main parking area where grades preclude connection to wet ponds or micropools. At the upstream end of the dry swales, plunge pools will be constructed to pretreat 25% of the water quality volume. Water quality swales reduce the velocity, temporarily store stormwater runoff and promote infiltration. Pollutant removal mechanisms in water quality swales include sedimentation, adsorption, biological treatment and microbial breakdown. Two types of swales were provided; Type A with 3.0 feet bottom and Type B with a 6.0 feet bottom. Both are trapezoidal with a 3:1 slope and were designed for a minimum od 10 minutes detention time. Table 7 and Table 8 show the quality swale design data. Page 11 of 17
  12. 12. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGETable 7: Water Quality Swales. Required Volumes and Dimensions WaterWater Drainage Quality Required ProvidedQuality Area Volume- Type Length (ft) LengthSwale (Ac) WQV (ft) (ft3)WQS1 0.16 272 A 36 100WQS2 0.96 886 B 36 150WQS3 2.3 2570 B 108 220WQS4 5.7 4370 B 126 270WQS5 0.29 256 A 48 125WQS6 4.6 3005 B 102 240WQS7 0.84 1171 B 84 120Table 8: Water Quality Swales. Discharges and Depths Water Exist. Condition Prop. Condition Proposed Condition Quality Discharges (ft3/s) Discharges Water Depth Swale (ft3/s) (ft) CPv QP QF CPv QP QF QWQ CPv QP QF QWQWQS1 0.2 0.7 1.1 0.3 0.8 1.2 0.01 0.4 0.6 0.7 0.2WQS2 1.4 4.1 6.5 2.1 5.1 7.6 0.03 0.7 1.2 1.5 0.1WQS3 3.4 9.9 15.8 5.3 12.6 18.8 0.3 1.2 1.8 2.2 0.1WQS4 8.1 23.6 37.5 11.8 29.7 44.9 0.4 1.8 2.8 3.4 0.3WQS5 0.4 1.2 2.0 0.6 1.5 2.2 0.02 0.5 0.8 1.0 0.7WQS6 6.6 19.3 30.9 8.3 21.9 33.7 0.2 1.5 2.4 2.9 0.2WQS7 1.2 3.6 5.8 1.9 4.6 6.7 0.1 0.9 1.4 1.6 0.2 The vegetated filter strips are grassed or close-growing native plants areas located just downstream of the pollutant source. The vegetated filter strips typically treat sheet flow directly from adjacent impervious surfaces. The vegetative strips, in general, will encompass disturbed areas adjacent to roads and buildings to provide a level of pretreatment and runoff reduction. First flush runoff volumes from roof areas will be collected in drywells with pretreatment chambers as required to provide the volume of water quality treatment prescribed by NYSDEC guidelines. Overflow from the drywells will be connected to cisterns for use in Page 12 of 17
  13. 13. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGE irrigation and other non-potable water uses . The required roof runoff quality volumes are shown in Table 9.Table 9: Roof Buildings Water Quality Requirements Area WQV WQVLocation (Ac) I Rv (ft3) (gal)A. Milarepa Center Building 1 0.18 100 0.95 728 5,460 Building 2 0.11 100 0.95 455 3,413 Building 3 0.03 100 0.95 120 900 Building 4 0.04 100 0.95 153 1,148B. Bodhisattva 0.19 100 0.95 786 5,895The use of drywells and/or infiltrator chambers (Recharger 280 or Recharger 330 per Cultec,with a volume of 6.079 ft3/ft and 7.459 ft3/ft, respectively) was recommended. Page 13 of 17
  14. 14. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGEEROSION AND SEDIMENT CONTROLTEMPORARY EROSION AND SEDIMENT CONTROL FACILITIESLand disturbance at the proposed site will be carefully sequenced so that grading operations canbegin and end as quickly as possible, thus minimizing the exposed areas subject to erosion. Siteclearing, land grading, and installation of underground utilities (water, electric, telephone, etc.),will commence initially. All material from excavation will be stockpiled in-situ to concentratethe area of loose soil exposed to runoff. At the stock pile, silt fences will be installed andtemporary dikes/swales will be placed if necessary during construction.During this stage, soil in areas previously covered will be exposed to runoff. Erosion of theseareas will be controlled by establishing temporary seeding and mulch, and by placing straw baledikes and silt fences. The purpose of the temporary seeding and mulch is to reduce sedimentcarried by the runoff from the exposed areas and to control dust. Temporary seeding and mulchwill be placed as soon as the removal activity is completed. During development, areas whereconstruction has temporarily or permanently ceased will be stabilized within 14 days unlessconstruction will resume within 21 days.Construction of the buildings and their associated site improvements will commence once sitework has been substantially completed and stabilized. Prior to starting these activities, silt fenceswill be placed along the perimeter of the cleared areas and temporary seeding will be done asnecessary to install the silt fences.Structural Measures1. Straw Bale DikeStraw bale barriers will be provided downgradient of all construction activities. The purpose of abale barrier is to trap sediment from sheet erosion before it travels overland to downgradientproperties. The straw bale dikes will be placed as construction progresses on the site.2. Silt FenceSilt fence sediment barriers will be installed downslope of disturbed areas with minimal slope tofilter sediment runoff from sheet flow. Silt fences will also be provided around stockpile areasand between construction areas and property lines to reduce sediment laden runoff from travelingoff-site. Additional silt fences will be installed as required during construction activities.3. Anti-tracking Apron at Site EntranceA temporary stabilized construction entrance of gravel will be installed where the access areaintersects with Cragsmoor Road. During muddy conditions, drivers of construction vehicles willbe required to wash their wheels before exiting the site. Page 14 of 17
  15. 15. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGE4. Storm Drain Inlet ProtectionAll storm catchbasin inlets will be protected to prevent sediment laden runoff from clogging thedrain pipes during construction. Filter fabric inlet protection should be used on each inlet untilupland areas are stabilized.5. Diversion Dike/SwaleDiversion dikes/swales will be included in the erosion and sedimentation plan to control andreduce the amount of sediments leaving the site. These diversion dikes/swales will be placeddowngrade of disturbed areas, whenever these areas become larger than the areas allowed to becontrolled by only a straw bale or silt fence. The diversion dikes/swales will be placed followingthe existing topography and will be temporarily seeded with a fast-germinating grass, and riprapprotected at any discharge points.6. Check DamsCheck dams will be added to diversion swales/channels, as well as any temporary drainageswales to reduce the flow velocity in the channels. This will help to reduce erosion of thosetemporary drainage facilities.7. Water BarsWater bars will be provided across the proposed roads, particularly in areas where the grades arein excess of 5%. The water bars will limit the accumulation of erosive velocities of stormwaterrunoff by diverting the surface water to diversion or temporary drainage swales/channels.8. Temporary Sediment BasinsTemporary sediment basins will be constructed at the permanent detention basin locations tointercept sediment ladened runoff and to trap and retain the sediment. The size of the basin willbe in accordance with the New York State Standards and Specifications for Erosion andSediment Control for the area contributing to the basin during a particular construction phase.Vegetative Measures9. Temporary SeedingAll cleared areas which will not reach final grading for a period of more than 30 days will beseeded temporarily with fast germinating temporary grasses to reduce erosion potential,immediately following grading. Selection of the seed mixture will depend on the time of year itis applied, as recommended in Section 3 of the New York State Standards and Specifications forErosion and Sediment Control. Page 15 of 17
  16. 16. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGE10. Erosion Control Blankets or MulchNorth American Green biodegradable erosion control blankets will be installed to provideimmediate erosion protection and vegetation establishment on excavated or fill slopes or lowflow channels which have been brought to final grade and have been seeded to protect the slopesfrom rill and gully erosion and to allow the seeds to germinate properly. The erosion controlblankets will be double netting with degradable thread. This practice shall be applied especiallyat areas where slopes exceed 5 percent. Mulch (straw or fiber) will be used to control dustresulting from construction activity.Maintenance and Inspection of Temporary Control MeasuresIn general, all erosion and sediment control measures will be checked weekly and after eachsignificant rainfall of 0.5 inches or greater, unless otherwise specified. The following items willbe checked in particular: 1. Existing riprap protection outlets will be inspected to determine if high flows have caused scouring beneath the riprap or filter fabric. If repairs are needed, they should be done immediately. 2. Temporary dikes/swales shall be inspected for proper functioning or signs of erosion and shall be repaired as necessary. Sediment accumulated to an elevation one foot below the crest of the earth barrier shall be removed and placed in the stockpile. 3. Silt fence barriers shall be inspected for damage resulting from deterioration or undercutting and shall be repaired or replaced as necessary. Sediment shall be removed when the level of sediment deposition reaches halfway to the top of the barrier. 4. Catchbasins and drainage outlets will be checked for accumulation of sediment. 5. Straw bale dikes shall be inspected immediately after each rainfall. All damaged bales, end runs and undercutting beneath bales shall be replaced or repaired. Sediment deposits shall be removed after each rainfall or when the level of deposition reaches half the height of the barrier. 6. Sediment shall be removed from temporary sediment basins whenever their capacity has been reduced by fifty percent from the design capacity. 7. Construction entrance shall be inspected for evidence of off-site sediment tracking. The paved street adjacent to the site entrance will be swept daily to remove any excess mud, dirt or rock tracked from the site. Repair road and/or add stone as necessary. Dump trucks hauling material from the construction site will be covered with a tarp. 8. The paved street adjacent to the site entrance will be swept daily to remove any excess mud, dirt or rock tracked from the site. 9. Areas that have received final stabilization shall be inspected at least once per month until the entire site has been stabilized. 10. Disturbed areas and exposed areas used for storage/stockpiling that have not received final stabilization shall be inspected for their potential sediment contribution to stormwater. Page 16 of 17
  17. 17. STORMWATER MANAGEMENT PLAN MAHAMMUDRA BUDDHIST HERMITAGE 11. The seeded areas shall be inspected regularly to ensure that a good stand is maintained. Areas where vegetation is missing or damaged shall be fertilized and reseeded as needed. 12. Inspection schedule will be completed and maintained on-site and will contain the following information: date, name of person conduction inspection, areas inspected, problems/conditions encountered, actions taken to correct problem. 13. Employees will be trained to recognize any pollution source and report such immediately. Training will be provided before the construction activity begins. 14. A maintenance schedule will be kept on-site to record and describe any discharge incidents occurring during construction activity, including actions taken to correct the problem, date, name of person conducting the maintenance.PERMANENT EROSION AND SEDIMENT CONTROL FACILITIESLand grading of the existing surface will be required in and around the proposed buildings androadway areas. Runoff from rooftops will be conveyed to drywells overflowing to cisterns forreuse and as a means to reduce the quantity of runoff and an initial treatment for stormwaterquality. Surface runoff from roads, paths, and landscaped areas will be directed to drainageswales and channels, and where appropriate catchbasins for ultimate connection to thestormwater quality basins and detention basins. Drainage swale and channels will bepermanently stabilized with vegetative material or rip-rap to prevent erosion and control runoffvelocities.The preformed scour holes at the detention inlets and the culvert apron at the STA 24+00 weredesigned according to the Federal Highway Administration (FHWA) –RD-75-508. A riprap witha minimum median diameter (D50) of 0.42 feet is recommended to protect all the outlets againstscour.In order to disperse or “spread” the concentrated flow from the detention basins outlets thinlyover the existing undisturbed vegetated ground, Level Spreaders were provided. Its purpose is tospread the concentrated outflow over a wide area so that the erosion does not occur. The levelspreader will also remove other pollutants from runoff by filtration, infiltration, adsorption anddecomposition. Page 17 of 17
  18. 18. APPENDIX SMP-1PRE-DEVELOPMENT DRAINAGE ANALYSIS
  19. 19. APPENDIX SMP-2POST-DEVELOPMENT DRAINAGE ANALYSIS
  20. 20. APPENDIX SMP-3SOIL TEST RESULTS
  21. 21. Results of Percolation Tests Percolation Test HoleTest Hole Rate Depth Soil Profile No. (min./inch) (inches) Reddish brown, sandy silt loam, with tracesML-1A 18 11 of clay/shaleML-1B 18 Reddish brown, sandy silt loam 8 Reddish brown, sandy silt loam, with tracesML-1C 18 11 of clay/shaleML-2A 18 Reddish brown, sandy silt loam 10ML-2B 20 Reddish brown, sandy silt loam 8ML-2C 18 Reddish brown, sandy silt loam 10 Reddish brown, sandy silt loam, with tracesNR-1A 18 8 of clay/shaleNR-1B 18 Reddish brown, sandy silt loam 12NR-1C 18 Reddish brown silty loam 15NR-2A 18 Reddish brown silty loam 15NR-2B 18 Reddish brown, sandy silt loam 15SR-1A 18 Reddish brown, sandy silt loam 20 Reddish brown, sandy silt loam, with tracesSR-1B 18 10 of clay/shaleSR-1C 18 Reddish brown, sandy silt loam 9SR-2A 18 Reddish brown, sandy silt loam 22SR-2B 18 Reddish brown, sandy silt loam 11BH-1A 18 Reddish brown, sandy silt loam 22BH-1B 18 Reddish brown, sandy silt loam 10BH-1C 18 Reddish brown, sandy silt loam 8TH-1A 18 Sandy silty loam 12TH-1B 18 Reddish brown, sandy silt loam 9TH-1C 18 Reddish brown, sandy silt loam 15TH-1D 21 Reddish brown, sandy silt loam 15MAHAMUDRA BUDDHIST HERMITAGE 1
  22. 22. Results of Deep Test PitsAREA/ DEPTHTEST HOLE SOIL DESCRIPTION DEPTH TO: (IN.)NO.GR-1 0" - 8" Top Soil Mottling @ 17"#1 8" - 17" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 17" - 50" Mottling Water @ 68" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)GR-1 0" - 8" Top Soil Mottling @ 20" Water Seepage @#2 8" - 20" Yellowish Brown Sandy Silt Loam 42" 20" - 54" Mottling Hardpan @ 54" Dark Brown Silty Loam w/ Traces of 54" - 84" Clay (~20% shale)GR-1 0" - 8" Top Soil Mottling @ 18"#3 8" - 18" Yellowish Brown Sandy Silt Loam Hardpan @ 54" 18" - 54" Mottling No Water Dark Brown Silty Loam w/ Traces of 54" - 84" Clay (~20% shale)GR-1 0" - 8" Top Soil Mottling @ 32"#4 8" - 32" Yellowish Brown Sandy Silt Loam Hardpan @ 54" 32" - 54" Mottling Water @ 59" Dark Brown Silty Loam w/ Traces of 54" - 72" Clay (~20% shale)GR-1 0" - 8" Top Soil Mottling @ 24"#6 8" - 24" Yellowish Brown Sandy Silt Loam Hardpan @ 54" 24" - 54" Mottling Water @ 72" Dark Brown Silty Loam w/ Traces of 54" - 84" Clay (~20% shale)ML-1 0" - 8" Top Soil Mottling @ 20"#1 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 42" 20" - 42" Mottling No Water Dark Brown Silty Loam w/ Traces of 42" - 84" Clay (~20% shale)ML-1 0" - 8" Top Soil Mottling @ 22"#2 8" - 22" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 22" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)MAHAMUDRA BUDDHIST HERMITAGE 1
  23. 23. ML-1 0" - 8" Top Soil Mottling @ 22" Water Seepage @#3 8" - 22" Yellowish Brown Sandy Silt Loam 38" 22" - 50" Mottling Hardpan @ 50" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)ML-1 0" - 8" Top Soil Mottling @ 18"#4 8" - 18" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 18" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)ML-1 0" - 8" Top Soil Mottling @ 22"#5 8" - 22" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 22" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)ML-1 0" - 8" Top Soil Mottling @ 22"#6 8" - 22" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 22" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)ML-1 0" - 8" Top Soil Mottling @ 24"#7 8" - 24" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 24" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)ML-1 0" - 8" Top Soil Mottling @ 24"#8 8" - 24" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 24" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)ML-1 0" - 8" Top Soil Mottling @ 20"#9 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 46" 20" - 46" Mottling No Water Dark Brown Silty Loam w/ Traces of 46" - 84" Clay (~20% shale)ML-1 0" - 8" Top Soil Mottling @ 18"#10 8" - 18" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 18" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)MAHAMUDRA BUDDHIST HERMITAGE 2
  24. 24. ML-1 0" - 8" Top Soil Mottling @ 17"#11 8" - 17" Yellowish Brown Sandy Silt Loam Hardpan @ 30" 17" - 30" Mottling No Water Dark Brown Silty Loam w/ Traces of 30" - 84" Clay (~20% shale)ML-1 0" - 8" Top Soil Mottling @ 19"#12 8" - 19" Yellowish Brown Sandy Silt Loam Hardpan @ 48" 19" - 48" Mottling Water @ 80" Dark Brown Silty Loam w/ Traces of 48" - 84" Clay (~20% shale)ML-1 0" - 8" Top Soil Mottling @ 20"#13 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 20" - 50" Mottling Water @ 66" Dark Brown Silty Loam w/ Traces of 50" - 70" Clay (~20% shale)ML-1 0" - 8" Top Soil Mottling @ 20"#14 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 20" - 50" Mottling Water @ 66" Dark Brown Silty Loam w/ Traces of 50" - 70" Clay (~20% shale)ML-2 0" - 8" Top Soil Mottling @ 20"#1 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 20" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)ML-2 0" - 8" Top Soil Mottling @ 20"#2 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 20" - 50" Mottling Water @ 74" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)SR-1 0" - 8" Top Soil Mottling @ 22"#1 8" - 22" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 22" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)SR-1 0" - 8" Top Soil Mottling @ 28"#2 8" - 28" Yellowish Brown Sandy Silt Loam No Hardpan 28" - 84" Mottling No WaterMAHAMUDRA BUDDHIST HERMITAGE 3
  25. 25. SR-1 0" - 8" Top Soil Mottling @ 19"#3 8" - 19" Yellowish Brown Sandy Silt Loam No Hardpan 19" - 38" Mottling No WaterSR-1 0" - 8" Top Soil Mottling @ 20"#4 8" - 20" Yellowish Brown Sandy Silt Loam No Hardpan 20" - 60" Mottling No WaterSR-1 0" - 8" Top Soil Mottling @ 16"#5 8" - 16" Yellowish Brown Sandy Silt Loam Hardpan @ 48" 16" - 48" Mottling No Water Dark Brown Silty Loam w/ Traces of 48" - 84" Clay (~20% shale)SR-1 0" - 8" Top Soil Mottling @ 19"#6 8" - 19" Yellowish Brown Sandy Silt Loam Hardpan @ 48" 19" - 48" Mottling Water @ 72" Dark Brown Silty Loam w/ Traces of 48" - 84" Clay (~20% shale)SR-2 0" - 8" Top Soil Mottling @ 14"#1 8" - 14" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 14" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)SR-2 0" - 8" Top Soil Mottling @ 22"#2 8" - 22" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 22" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)SR-2 0" - 8" Top Soil Mottling @ 14"#3 8" - 14" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 14" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)SR-2 0" - 8" Top Soil Mottling @ 36"#4 8" - 36" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 36" - 50" Mottling Water @ 84" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)MAHAMUDRA BUDDHIST HERMITAGE 4
  26. 26. SR-2 0" - 8" Top Soil Mottling @ 16"#5 8" - 16" Yellowish Brown Sandy Silt Loam Hardpan @ 48" 16" - 48" Mottling No Water Dark Brown Silty Loam w/ Traces of 48" - 84" Clay (~20% shale)SR-2 0" - 8" Top Soil Mottling @ 20"#6 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 20" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)SR-2 0" - 8" Top Soil Mottling @ 16"#7 8" - 16" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 16" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)NR-1 0" - 8" Top Soil Mottling @ 16"#1 8" - 16" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 16" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 60" Clay (~20% shale)NR-1 0" - 8" Top Soil Mottling @ 20"#2 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 20" - 50" Mottling Water @ 60" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)NR-1 0" - 8" Top Soil Mottling @ 21"#3 8" - 21" Yellowish Brown Sandy Silt Loam Hardpan @ 42" 21" - 42" Mottling Water @ 72" Dark Brown Silty Loam w/ Traces of 42" - 84" Clay (~20% shale)NR-1 0" - 8" Top Soil Mottling @ 19"#4 8" - 19" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 19" - 50" Mottling Water @ 72" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)NR-2 0" - 8" Top Soil Mottling @ 22"#1 8" - 22" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 22" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)MAHAMUDRA BUDDHIST HERMITAGE 5
  27. 27. NR-2 0" - 8" Top Soil Mottling @ 22"#2 8" - 22" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 22" - 50" Mottling Water @ 72" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)NR-2 0" - 8" Top Soil Mottling @ 16"#3 8" - 16" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 16" - 50" Mottling Water @ 72" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)NR-2 0" - 8" Top Soil Mottling @ 36"#4 8" - 36" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 36" - 50" Mottling Water @ 84" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)NR-2 0" - 8" Top Soil#5 8" - 16" Yellowish Brown Sandy Silt Loam Mottling @ 16" 16" - 48" Mottling Hardpan @ 48" Dark Brown Silty Loam w/ Traces of 48" - 84" No Water Clay (~20% shale)NR-2 0" - 8" Top Soil Mottling @ 20"#6 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 20" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)NR-2 0" - 8" Top Soil Mottling @ 16"#7 8" - 16" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 16" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)BH-1 0" - 8" Top Soil Mottling @ 20"#1 8" - 17" Yellowish Brown Sandy Silt Loam 17" - 68" Mottling Water @ 68"BH-1 0" - 8" Top Soil Mottling @ 22"#2 8" - 22" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 22" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)MAHAMUDRA BUDDHIST HERMITAGE 6
  28. 28. BH-1 0" - 8" Top Soil Mottling @ 22"#3 8" - 22" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 22" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)BH-1 0" - 8" Top Soil Mottling @ 19"#4 8" - 19" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 19" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)BH-1 0" - 8" Top Soil Mottling @ 15"#5 8" - 15" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 15" - 50" Mottling Water @ 60" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)BH-1 0" - 8" Top Soil Mottling @ 17"#6 8" - 17" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 17" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)BH-2 0" - 8" Top Soil Mottling @ 20"#1 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 20" - 50" Mottling Water @ 84" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)BH-2 0" - 8" Top Soil Mottling @ 24"#2 8" - 24" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 24" - 50" Mottling Water @ 72" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)BH-2 0" - 8" Top Soil Mottling @ 20"#3 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 20" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)BH-2 0" - 8" Top Soil Mottling @ 20"#4 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 20" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)MAHAMUDRA BUDDHIST HERMITAGE 7
  29. 29. BH-2 0" - 8" Top Soil#5 8" - 19" Yellowish Brown Sandy Silt Loam Mottling @ 19" 19" - 50" Mottling Hardpan @ 50" Dark Brown Silty Loam w/ Traces of 50" - 84" Water @ 84" Clay (~20% shale)BH-2 0" - 8" Top Soil Mottling @ 20"#6 8" - 20" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 20" - 50" Mottling Water @ 84" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)BH-2 0" - 8" Top Soil Mottling @ 22"#7 8" - 22" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 22" - 50" Mottling No Water Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)BH-2 0" - 8" Top Soil Mottling @ 24"#8 8" - 24" Yellowish Brown Sandy Silt Loam Hardpan @ 50" 24" - 50" Mottling Water @ 72" Dark Brown Silty Loam w/ Traces of 50" - 84" Clay (~20% shale)MAHAMUDRA BUDDHIST HERMITAGE 8
  30. 30. STORMWATER MANAGEMENT PLANMAHAMMUDRA BUDDHIST HERMITAGE APPENDIX SMP-4 WATER QUALITITY COMPUTATIONS

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