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Municipal Ground-Water Management: Pennsylvania Case Study using Water-Budget Approach or, All Hydrology is Local Hydrology by Dr. Amleto A. Pucci, Jr. PE CGWP, Ground-Water Management and Conservation, Inc. POB 78 Erwinna, PA 18920 610/294-9475
[email protected]
Prepared for the 1999 AWRA MID-ATLANTIC CONFERENCE "UNIFIED WATERSHED ASSESSMENT: WHERE DO WE GO FROM HERE?"
ABSTRACT This paper focuses on Tinicum Township, Bucks County Pennsylvania. Ground water is the only potable water source in the township, which is located on the fringe of urban sprawl. Ground-water withdrawals have increased with the population growth in the region. Most wells in the project area can support only low to moderate yields and, with increased frequency in the last few years, some domestic wells have periodically or permanently gon e dry which requiring attention to the management of the resource. Increased withdrawals may also have caused significant losses in stream flow. Because of their concern, the township undertook an investigation of the local hydrogeology with funding support from a foundation and cooperation from local environmental organizations. A ground-water flow model for the hydrogeologic region which contained the township was developed to help Tinicum Township quantify the water availability issues and to compute a water budget. The water budget approach simplifies and visualizes technical details of the complex local hydrologic system. The water budget analysis produced results which the municipal planning committee and environmental advisory council can use as a basis for recommending ordinances to the supervisory board. INTRODUCTION
General Tinicum Township and the municipalities in southeastern Pennsylvania are well within an area affected by urban sprawl (Figure 1). For decades, the management for environmental systems within areas undergoing such development pressure has usually been by hindsight. The causes of unrestricted development are broad, sometimes subtle, and deeply related to our cultural and legal outlook: “... the impulse that is driving the family of small means out upon the open road, there to build . . . regardless of discomfit and dangers to health, seems . . . to be a pretty common one. These people are in a vanguard of a general effort to get a little joy back into life. . . Its promises are illusory, since helter-skelter development such as is now going on in the countryside around our big cities promises only to spoil the landscape without permanently satisfying the hungry urbanites.” --The Lewis Mumford Reader Municipalities in the development fringe of suburban areas are often administratively unable to cope with rapid and unrestricted development pressure. Rapid development pressure often exceeds the capacity of natural settings, and systems. Or, to paraphrase Kirkpatrick Sales (1985), the stresses placed on an area which are caused by development can lead to a loss of the "carrying capacity" of the land.
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Regulatory framework The notion that limits to the development of ground-water in of southeastern Pennsylvania should include consideration of the "carrying capacity" of the environmental is not a radical idea but a progressive and timely one. In the Clean Water Act, the Federal Government has implicitly recognized that managing ground-water resources is difficult. Morandi (1989) points out that Congressional initiatives to protect ground water were hindered because regulations are limited by the "localized nature of ground water. . . and the reality of geographic differences in aquifer conditions and use, combined with land-use implications of ground-water regulation, which (sic) suggests a lead role for state and local governments". Perhaps in recognition that ground-water management can be so localized and is closely related to land-use management, the Commonwealth of Pennsylvania delegated much of the responsibility to manage ground-water resources to municipalities under the Municipal Planning Code (MPC) (1989). The language of the MPC recognizes that there are limits to the availability of water and authorizes that prudent municipal officials and planners to take that into account in zoning and sub-division ordinances which regulate water-resources. Land-use planning, zoning, and subdivisions are areas of primary municipal responsibility In 1998, the Delaware River Basin Commission (DRBC) promulgated regulations which are intended to establish the upper limits on water resources in sub-basins throughout Southeastern Pennsylvania. The method on which the withdrawal limits is based is best characterized as a gross estimate of flux components of a regional ground-water system. Previously the DRBC reviewed proposals for very large ground-water users with no overt estimate of the limitation on the "carrying capacity" of sub-basins within the region (Schreffler, 1996). This new focus was probably a response to a court decision concerning the limits of right of municipalities "to grant conditional use of water withdrawals where permission has been given by an interstate water authority or commonwealth authority" (State College Borough Water Authority v. Board of Supervisors of Half-Moon Township, Centre County, Pennsylvania, (659 A.2d 640 (Pa. Cmwlth, 1995))). A review of this case shows the Half-Moon Township did not place an expert hydrologic opinion in support of its position which could have warranted the municipal position. In this case appeal court might have remanded the decision to the lower court to determine the validity of the conditions. Judge Lord only cites expert testimony from a hydrologist of the Basin Commission who discussed why the Water Authority was given their approval. Or, if the Township had originally applied its conditions at that review stage in the hearing before the Basin Commission the municipality might have had support for their position from them. Well posed hydrologic impacts could have been considered in the hearing process which the Basin Commission followed.
This court ruling has probably led to an awareness on the part of the Delaware River Basin Commission that along with its newly redefined primacy role in administering water use, the involvement of municipalities, volunteer interest groups, and concerned individuals can be, and will become, a great asset as it manages the water resources of our regional basin.
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Tinicum Township anticipated the need for well posed scientific basis for management of its ground-water as early as 1989 (Pucci, 1984). It set about with the cooperation of its neighboring communities to undertake a hydrogeologic assessment of its water resources. The intention was to establish a database which could be used to address the concern for water availability. A water budget is a satisfactory approach to meet this goal. And, because hydrogeologic systems are complex, the quantitative approach used for analysis of water resources in Tinicum Township is a quantitatively rigorous approach which employed a groundwater flow model. Purpose and Scope Effective management of ground-water supplies requires an accurate understanding of the ground-water flow system. The ground-water flow system in Tinicum Township is part of the Newark Mesozoic-basin, which has been poorly understood because it is hydrogeologically complex. This report describes a computer model developed for the general project area in order to analyze flow for this complex hydrologic system in Tinicum Township and the scientific basis of the water-budget approach. The model was calibrated using a water-level maps made from measurements in 517 wells in the study area, measurements of flow duration, seepage runs, and published hydrogeologic properties. This paper presents an overview of the approach and the results (Ground-Water Management and Conservation, Inc, 1998). Average-annual water budgets are reported for several watershed areas. Some examples of the use of the water-budget to predict the effects of development on the hydrologic processes are also presented. . Description of Project Area Tinicum Township is the primary project area within a larger region which has natural groundwater flow boundaries. This hydrogeologic region includes all the area of the Townships of Tinicum, Bridgeton, and Nockamixon in northeastern Bucks County, Pennsylvania (McManus and others, 1994). The general project area, approximately 59 square miles, coincides with this hydrogeologic region (Figure 2). Tinicum Township lies totally within the Triassic Lowlands Physiographic Province and is within a structural-depositional feature known as the Newark-Gettysburg Basin. The topography consists of ridges and broad valleys. Relief is greatest in the north where there is rocky and rough terrain, along the east where there are steep cliffs of the Palisades along the Delaware River, and in the south where a gorge borders Tohicon Creek. Altitudes range from 826 feet above mean sea level (MSL) at Coffman Hill in Nockamixon Township, to less than 100 feet MSL along the Delaware River at Point Pleasant, Tinicum Township (Figure 2). Geologic Setting The rocks within the basin belong to a geologic classification known as the Newark Supergroup of Late Triassic and Early Jurassic age. The main formations within the project area are the Brunswick Group and the Lockatong Formation (Figure 3). Over geologic time Jurassicage diabase rocks intruded these formations. As a result of tilting, the units dip about 10 to 15 degrees toward the northwest (Willard, 1950). The Brunswick Group has been subdivided into a number of formations but in this report it is simply referred to as Brunswick Formation.
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Hydrogeologic Units There are four hydrologic units in the general project area (Sloto and Schreffler, 1994). The Brunswick Formation, which crops out in the central and northern part of the project area, is composed of dull red shale interbedded with siltstone and interbedded siltstone and sandstone (Sloto and Schreffler, 1994). The Brunswick Formation (JTrbl) forms the major aquifer rock group and is considered moderately productive. The Lockatong Formation, the oldest unit, crops out in the southeastern comer of the project area. The Lockatong Formation (Trl) consists of a sequence argillite and shale with lesser interbedded red siltstones. Because of its hardness, the Lockatong Formation creates a surface which is relatively impermeable to water with little primary porosity. The Locatong Formation is less productive than the Brunswick Formation. An extensive diabase sill is a principal feature of hydrogeologic system in the northern central part of the project area. The diabase has no primary porosity, and ground-water moves through limited secondary network of fractures. Because of its pronounced resistance to erosion, the diabase forms the highest ridges in the study area. Schreffler (1996) describes the groundwater flow paths as short with nearly all ground-water storage in a shallow weathered zone. Local deposits of Quaternary unconsolidated sediments overly all this material. Unconsolidated sediments have primary porosity and ground-water easily moves through them. Valley deposits of cobbles, gravel, loose sand, and silt are extensive along the immediate boundary of the Delaware River (Drake and others, 1961). Where these sediments occur in close proximity to the Delaware River, they are in direct hydraulic with the river. Surface Water The entire project area is within the Delaware River Basin. Lake Nockamixon, which is a regional reservoir, is located along the northwest boundary of the project area. Lake Warren, a man-made lake, is located in the north central part of the project area. Figure 2 shows the subbasins within the general project area. The main sub-basins which will be discussed in this report are Tinicum Creek (11.44 mi2), and the east side of Tohicon Creek Watershed downstream of the Lake Nockamixon Dam (5.60 mi2). Direct drainage areas to the Delaware River are found in the northern part of the general project area, and in the southern area of Tinicum Township. Geohydrology Water Table aquifer McManus and others (1993) generally mapped the water table surface as controlled by the configuration of the land surface and the locations of streams, ponds, and lakes, but in a subdued fashion. They divided aquifer units in the northern part of the project area into an unconfined and confined aquifer. Where this distinction is made, the unconfined aquifer is referred to as the Upper Aquifer (Figure 4) (McManus and others, 1993). Where the water table aquifer extends into the rest of the project area and it is undivided, McManus and others (1993) called it the Lower Aquifer. For discussion purposes, this report refers to the unconfined part of the Lower Aquifer as the Regional aquifer (Figure 5).
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Confined aquifer McManus and others (1993) also mapped a confined aquifer area as part of the Lower Aquifer in the project area (Figure 5). The extent of the confined part of the Lower Aquifer is determined by where it occurs beneath the Upper Aquifer (Figure 4). This generally corresponds to the areas of the diabase and the northwest part of the project area. The mapping of this aquifer was based on an examination of well logs and water-level measurements. Together, the unconfined regional aquifer and the confined aquifer are referred to as the Lower Aquifer. GROUND-WATER FLOW The design of the digital ground-water flow model was based on the conceptual model of ground-water flow. A conceptual model of ground-water flow was developed on the basis of the hydrogeologic framework, measured water levels, hydrologic characteristics, and conclusions of previous investigations. The water-level maps of the project area were used to help conceptualize ground-water flow, identify recharge and discharge areas, assess the effects of geology on the water-level configuration, and calibrate the digital model. For purposes of this paper, only a brief summary of the digital model design and the results of ground-water flow simulation are presented. The details of the these procedures are extensively described elsewhere (GroundWater Management and Conservation, 1998) Simulation of Ground-Water Flow The digital computer ground-water flow model was used for evaluating the ground-water system and to predict how it would respond to future ground-water development. The model simulated present (1991-1992) ground-water conditions and was used to test calibration hypotheses concerning the features of the ground-water flow system in the project area. These features include the decrease in the density of fractures with depth, the anisotropy caused by dipping water-bearing rock strata, area variations of recharge, and the separation of the Upper Aquifer and the confined part of the Lower Aquifer. The model was developed with sufficient detail to simulate these features, but not all of the local complexities are simulated in the model. Consequently, the model was not designed as a tool for detailed quantification of flow at specific discrete points, but for overall development of water budgets for the entire project area, or large portions of the project area. In this project emphasis was placed on the regional flow system in the Upper Aquifer and Lower Aquifer. Very little information on the hydrogeology of the confined system is known. Some mathematical simplifications were based on current knowledge of the aquifer system; others were necessary to accommodate model-area boundaries, the scale of the investigation, and the availability of data. Major model assumptions are: * Flow is somewhat uniform over discrete distances of about 580 ft (cell dimension). Flows within the cells which make up the model layers have vertical and horizontal components. * Hydrogeologic properties were varied only in large-scale variations (or zones). * The hydraulic properties of the ground-water system are heterogeneous between model grid cells but homogeneous within each cell. Aquifer properties are anisotropic. "Long-term net ground-water recharge from net precipitation and evapotranspiration fluxes is to the upper most active model layer.
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*
* * *
* * * *
Layers may de-water during the simulation. Present day rates of ground-water withdrawals are at constant average annual rates. This water is essentially recycled to the ground-water system by including it “net recharge” for model cells. In model simulations where wells are designated, the well is screened in one model cell and they are completely efficient. Surface water-bodies in the unconfined aquifer area act as areas of recharge to, or discharge from, the ground-water system. Intermittent streams may only act as drains. In wetland areas, recharge to the unconfined ground-water system is from head-dependent flow. Steady state conditions are approximated by running simulations for a period of 10,000 years, well beyond a period in which head changes were observed. Steady ground-water-flow conditions represent conditions measured by the U.S. Geological Survey (1993). It is assumed all the flow is through primary porosity although almost all the flow is through fractures. This assumption is reasonable for regional scale aquifers. There is continuity in Model layer 1 between the Upper Aquifer and the unconfined area of the Lower Aquifer (or the Regional Aquifer). The extent of the Upper Aquifer was not pre-determined by limiting the extent of layer 1. The extent of Upper Aquifer is the limit of those model cells in which the simulated heads were at or above 400 ft MSL, as mapped by the U.S. Geological Survey (McMahon and others, 1993).
Description of Digital Model The ground-water-flow system was simulated by use of a three-dimensional finite-difference ground-water-flow model (MODFLOW) (McDonald and Harbaugh, 1988). The model is a numerical finite-difference approximation of the partial-differential equation for three-dimensional ground-water flow. A three-dimensional approach is used to simulate flow. Other features of the numerical code that are used to represent hydrologic features such as streams, lakes, and recharge conditions are described in the McDonald and Harbaugh (1988). The code was revised to allow for variable ansotropy ratios within each model layer (Chiang and Kinzelback, 1993). The anisotropy ratio is the hydraulic conductivity along model columns (the dip direction) divided by the hydraulic conductivity along model rows (the strike direction). The model also accounts for the dipping of the hydrogeologic units. A wetting factor of -1.5, with a wetting iteration interval set equal to 5 was used for computing the variation in saturation thickness caused by changes in the water levels. Vertical discretization The continuous decrease in fractures and water availability with depth as described in the simplified conceptual model was represented by a three layer computer model (Figure 6). The continuous decrease in fractures and fissures and water bearing zones with depth was approximated by adjustments to porosity, hydraulic conductivity, etc., in the second layer and third layer. The approximate depth for the upper layer is set to 150 feet because this approximates the median depth of the Upper Aquifer wells which is 158 feet. In areas where landsurface elevation decreases abruptly, the bottom of model layer 1 is deeper than 150 ft below land surface. These areas are found along the edges of diabase sill, especially along the northern and northeastern edges of the sill. The bottom of the second model layer is 250 ft below land surface throughout most the model area. The second and third layers are entirely within bedrock and extend to a depth limit for
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more than 90 percent of the wells screened in the region, or about 575 feet. The bottom of layer 3 reaches its maximum depth below land surface in model cells located near Coffman Hill within the diabase area. Grid orientation and area discretization The model grid (Figure 7) was oriented so that the model rows mostly coincided with a) stream-flow channels and the topographic and trends in the primary project area, and b) the strike of the geologic units to allow simulation of the difference in horizontal hydraulic conductivity in the strike and dip directions. The model was discretized into 102 rows, 73 columns, and 3 layers. Of the 22,338 model cells, 14,454 are active, 4818 active cells in each layer. The inactive cells are outside the general project area. Each model cell is 580 ft long and 580 ft wide. Lateral boundaries Lateral model boundaries coincide with the general project area (Figures 9). Natural surface-water hydraulic boundaries are defined a) in the north and east along the Delaware River, b) along the south west and south by Tohicon Creek, and c) along the west by Lake Nockamixon and Haycock Creek. In layers 2 and 3 along model boundaries a), b), and c), flow lines are assumed to be vertical and represent stream-line (no-flow) boundaries since these boundaries represent major discharge or recharge and flow is expected to nearly vertical. Upper boundary The upper boundary was simulated as a free surface (water table) with specified flux applied to represent area recharge (Figure 6). Surface water boundary Surface water was simulated in five ways. 1) The major permanent streams were simulated as head dependent-flux boundaries by using the "River module" of MODFLOW. 2) The steep reaches of several streams were modeled as specified-flux boundaries in 81 cells. This was done because water level in these stream reaches falls as much as 20 ft over the length of a model cell and an average stream reach elevation within a model cell is a poor representation of stream elevation at all points in the cell. 3) Lakes, ponds, swamps, were simulated as stream boundary condition. 4) Intermittent streams were simulated as drains. 5) General head boundary conditions were applied in 155 cells along Lake Nockamixon and the Delaware River. Lower boundary The lower boundary was simulated as a no-flow boundary. Calibration of Digital Model All values of hydraulic properties initially used in the model were estimates. During model calibration, the initial estimates of area recharge, horizontal hydraulic conductivity, vertical hydraulic conductivity, anisotropy, and stream-bed, drain, and general-head boundary
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conductances were adjusted until the model was an acceptable representation of the conceptual model and the measured head values for the aquifers. No adjustments were made to the no-flow boundaries. Determining the acceptability of the match between simulated and conceptual groundwater flow system is subjective, but generally judged to be good. Figures 4 and 5 show the measured and simulated heads in the Upper and Lower Aquifers. Comparisons were made both to the regional water level contour maps and the water levels in individual wells. Although an attempt was made to match measured water levels, an exact match was not possible because many of the small-scale complexities of the geologic framework are not represented in the model. For example hydraulic conductivity is constant over each outcropping geologic unit, whereas the actual conductivity probably varies because the spacing of interconnected fractures varies. A detailed description of the model calibration is beyond the scope of this paper. Water budgets The water budget for simulated ground-water flow regions was determined using the ZONEBUDGET computer program (Harbaugh, 1990). This program calculates water budgets for user-specified model areas from cell-by-cell flow results which are output from the MODFLOW model. Only the water budgets for the Tinicum Creek watershed, the major watersheds in the project area, is discussed in detail in this project report. Tinicum Creek Watershed The entire Tinicum Creek Watershed is comprised of the main stem of the Tinicum Creek Watershed, and the tributary Beaver Creek and Rapp Creek Watersheds (Figure 4). The total inflow and outflow budget for the entire Tinicum Creek Watershed calculated from the calibrated model simulation is 8.3 Million gallons per day (Mgal/d). The eight components of the flow budget, as listed in Figure 8, are (1) recharge, (2) creek leakage to ground-water, (3) groundwater discharge to creeks and drainage to intermittent streams, (4) net lateral ground-water flow to Gallows Run Watershed, (5) net flow of ground-water to Falls Creek and Delaware River Watersheds, (6) net ground-water flow to Cafferty Creek and Lodi Creek Watersheds, (7) net flow to Smithtown Creek Watershed, and (8) net ground-water flow from Tohicon Creek Watershed. Component “(2)” includes ground-water recharge from lakes and swamps with free standing water. "In-flow" budget components are presented as positive values; "outflow-budget" are presented as negative values from the Tinicum Creek Watershed. Under modern conditions, the major sources of water are area recharge from the upper model layer (5.18 Mgal/d, or 63 percent of total inflow), creek and surface-water leakage to ground-water (1.90 Mgal/d, or 23 percent of total inflow), and lateral ground-water flow from the Tohicon Creek Watershed (1.12 Mgal/d, or 14 percent of total inflow). Most of the ground water in the basin is discharged to streams (7.07 Mgal/d, or 86 percent of total outflow). The other significant ground-water discharge is to Gallows Run Watershed (0.8 Mgal/d, or 10 percent of outflow). The annual recharge computed from ground-water discharge to the surface water system based on annual daily flow and the contributing area yields net annual recharge of 7.45 in/yr for the entire basin.
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A comparison of flow-budget components show that net recharge to the surface-water basin (component 1) is not sufficient to meet the amount of ground-water discharge to creeks (component 3). This deficit is offset by recharge from surface-water leakage, which includes leakage from lakes and wetlands (component 2), and lateral flow from Tohicon Creek (component 8). The magnitude of component 8, underscores the oversimplification which is made in computing area recharge for a surface-water shed area if the ground-water basin is very different, as it is in this project area. This factor is made more obvious for the budget of the watershed for the main stem portion of the Tinicum Creek. Main Stem Tinicum Creek Watershed A separate zone budget was done for the area of the main stem of Tinicum Creek. The main stem area does not include the contributing area of the two principal tributaries. The flow budget for this area is shown as a 3-D schematic chart in Figure 9. This budget shows the Tinicum Creek Watershed as a triangular area bounded by a) the Tohicon Creek Watershed to the west, b) the Delaware River and Smithtown Creek Watersheds to the east, and c) the Beaver, Rapp, and Cafferty Creek Watersheds to the north. This budget only shows stream-flow losses to the ground-water system and ground-water discharge to the surface-water system. Ground-water flow is further divided into flow components between model layers within the Tinicum Creek area, and for different levels of lateral flow boundaries. Net ground-water discharge to surface water in the main-stem basin is 8.2 in/yr (4.65-0.61 Mgal/d). Net recharge to ground-water system is much less, approximately 5 in/yr (this tends to be low because of large numbers of cells in this area contain surface-water cells). A relatively large ratio of ground-water discharge to recharge is sustained by lateral flow components into the main stem area flow from the Tohicon Creek boundary and the Beaver, Rapp, and Cafferty Creek boundary. The schematic shows that 57 percent of ground-water discharge in the mainstem area for the Tinicum Creek is accounted for by water which flows laterally into the mainstem area. The schematic also shows an increase in net vertical flow upward between layers 3&2, and 2&1 from the bottom to the top in the model. This is caused primarily by flow into the watershed from deeper model layers along the Tohicon boundary of the Watershed. Flow components from these deeper layers represent inter-basin regional flow. DISCUSSION One result of this model is that it shows in the case for the Tinicum Creek Watershed that estimating water availability based on recharge to the surface watershed area did not account for all the water that actual was supplied to the watershed. The ground-water flow model accounted for the extra water as lateral flow into the Tinicum Creek watershed. An advantage to the ground-water modeling approach is that it is able to delineate the true local and regional groundwater flow. If it was assumed that the areas for the ground-water basin and surface-water drainage area were the same deal significant interpretive error would have resulted. The results suggest many uses for a “water budget” for determining water availability in a
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municipal planning context. Among the many applications which can be suggested for local water-resources management is the delineation of the extent of the local and regional components of the regional flow systems. It naturally follows from the completion of such a calibrated model for a water budget that the model can thereby be used to estimate the effects of ground-water development on the hydrologic systems. References Bucks County Planning Commission, GIS Coverage, Watershed, Doylestown, PA, 1997. ----------------------------, GIS Coverage, Road Centerlines, Doylestown, PA, 1997. Chiang, W.H., Kinzelback, W., 1993, Processing Modflow, version 3.0. Commonwealth of Pennsylvania, 1989, Municipal Planning Code, Senate Bill 535. Drake, A.A., Jr., McLaughlin, D.B., and Davis, R.E., 1961, Geology of the Frenchtown Quadrangle, New Jersey-Pennsylvania: U.S. Geological Survey Map GQ-133, scale 1:24,000. Harbaugh, A.W., 1990, A computer program for calculating subregional water budgets using results from the U.S. Geological Survey Water-Supply Paper 2206, 24 p. Ground-Water Management and Conservation, Inc., 1998, Municipal Ground-Water Resources Management in Tinicum Township, Bucks County, Pennsylvania, using the Water Budget Approach: Final Report, 92 p. Lewis, J.C., 1992, Effect of An isotropy on ground-water discharge to streams in fractured Mesozoicbasin rocks, in Hotchkiss, W.R., and Johnson, A.I., eds., Regional aquifer systems of the United StatesAquifers of the southern and eastern states: Bethesda, Md.: American Water Resources Association Monograph Series No.17, p. 93-106. Lewis-Brown, J.C. and Jacobsen, E., 1995, Hydrogeology and Ground-Water Flow, Fractured Mesozoic Structural-Basin Rocks, Stony Brook, Beden Brook, and Jacobs Creek Drainage Basins, West-Central New Jersey, U.S. Geological Survey, Water Resources Investigations Report 94-4147, 83 p. Lyttle, P.T. and Epstein, J.B., 1987, Geologic Map of the Newark 1-degree x 2-degree Quadrangle, New Jersey, U. S Geological Survey Miscellaneous Investigations Map Series, Map I-1715, 2 Plates. McDonald, M.G., and Harbaugh, A.W., 1988, A modular three-dimensional finite-difference groundwater flow model: U.S. Geological Survey Techniques of Water-Resources Investigations, book 6, chapt. A1, 576 p. McManus, B.C., and Rowland, C.J., 1993, Altitude and configuration of the potentiometric surfaces of the upper and lower aquifer systems in Bridgeton, Nockamixon, and Tinicum Townships, Bucks County, Pennsylvania, April 1991 through April 1992: U.S. Geological Survey Water Resources Investigation Report 92-4194, scale 1:24,000. Morandi, Larry, 1989, State groundwater protection policies: A legislature's guide: National Association of State Legislatures, 80 p. Pucci, A.A., Jr., 1994, Cooperative ground-water resources management: a local perspective, ASCE J. of Water Resources Planning and Management v. 120, no. 6, pp. 984-991. Sales, Kirkpatrick, 1985, Dwellers in the land: The bioregional vision: Sierra Club Books, San Fran., CA. Schreffler, C.L., McManus, B.C., Rowland, C.J., and Sloto, R.A., 1994, Hydrologic data for northern Bucks County, Pennsylvania: U.S. Geological Survey Open-File Report 94-381. Sloto, R.A., and Davis, D.K., 1983, Effect of urbanization on the water resources of Warminster Township, Pennsylvania: U.S. Geological Survey Water Resources Investigation 82-4020, 72 p. Sloto, R.A., and Schreffler, C.I., 1994, Hydrogeology and Ground-Water Quality of Northern Bucks County, Pennsylvania, Water Resources Investigations Report, 94-4109, 85. p. U.S. Geological Survey, Riegelsville, PA topographic quadrangles, 1:24,000. ----------------------, Frenchtown, NJ topographic quadrangles, 1:24,000.
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----------------------, Lumberville, PA topographic quadrangles, 1:24,000. ----------------------, Bedminster, PA topographic quadrangles, 1:24,000. Willard, Bradford, and others, 1959, Geology and mineral resources of Bucks County, Pennsylvania: Pennsylvania Geological Survey, 4th ser., Bulletin C9.
Biography Dr. Amleto A. Pucci, Jr. PE is President of Ground-Water Management and Conservation, Inc. (GWMC), which specializes in consulting clients in areas where ground-water resources are undergoing rapid development or threatened by contamination. The firm provides clients with advice on current issues, future needs, and the understanding needed for meeting the challenges of complex environmental problems and regulations. GWMC supports the most effective and reasonable outcome for the client while protecting the environment. Dr. Pucci has an extensive career in water resources and environmental engineering. He is a PE in Pennsylvania and New Jersey, and a Certified Ground-Water Professional (CGWP). He worked for the U. S. Geological Survey, was a Civil and Environmental Engineering faculty member at Lafayette College, and is recognized as an expert in ground-water hydrology, ground-water chemistry, and contamination problems.
