Philip Harte


Extensive knowledge in ground-water flow and contaminant transport in natural and remedial settings. Studies include evaluation of remedial effectiveness, ground- and surface-water interactions, delineation of sources of water to wells, transport of natural and anthropogenic contaminants, geochemical processes, and ground-water flow and transport in various settings (unconsolidated sediments to fractured rock). Field experience in surface and borehole geophysics, geochemical sampling, and aquifer hydraulic testing. GIS and programming background.





Project Title: Review of contaminant transport and remediation efforts, Longhorn AFB, Tx

Description of Assignment:

Problem: Longhorn AFB, Karnack TX has multiple contaminantion sites that threaten nearby Caddo Lake.  Caddo Lake is a 25,400 acre (103 km²) lake and wetland located on the border between Texas and Louisiana. It is an internationally protected wetland and is the largest natural fresh water lake in the South, and the largest cypress forest in the world.

Objective: Provide technical support to USGS Central Region and U.S. Environmental Protection Agency (USEPA)  Region 6 on remedial efforts.    

My Research Focus: The discharge of contaminants to local streams threatens nearby Caddo Lake. I usesd a simple flow model to highlight several potential transport flow paths to streams.


Project Title: Framework for New York- New England crystalline-rock aquifers

Description of Assignment:

Problem: In Cycle II of the U.S. Geological Survey’s National Water-Quality Assessment (NAWQA) Program, a major focus is on regional assessments of ground-water quality conditions and trends. The assessments will increase our understanding of how natural features and human activities affect ground-water quality. This study serves to provide a blueprint in the regional analysis of ground-water quality data from a complex system.

Objective: Summarize regional ground-water quality issues in the NY-NE crystalline-rock aquifers, categorize some spatial patterns in regional ground-water quality that have been reported from regional and local studies within the aquifer system, and propose a methodology, called a framework, on how a multi-contaminant assessment of vulnerability of the aquifer to contamination can be evaluated on a regional scale.

My Research Focus:  To develop a framework approach for the regional analysis of ground-water quality of the crystalline rock by incorporating physical flow characteristics to describe the relation between the intrinsic nature of the rock and the water quality.


Project Title: Evaluation of Remediation Effectiveness, OK Tool Site, Milford, N.H.

Description of Assignment:

Problem: The OK Tool Site, a discontinued tool manufacturing facility, has been identified as the primary source of volatile organic contaminants (mostly tetrachloroethylene, PCE) that lead to contamination of a public supply well. The NHDES, in cooperation with the USEPA, in 1998 installed a low permeability barrier wall in the unconsolidated aquifer around the contaminant source area to prevent further spreading of the VOC plume. In addition, extraction and injection wells inside and outside the barrier wall are being used to capture VOC’s. As of 2007, inside the barrier wall, VOC concentrations are still high indicating source remediation has been ineffective whereas outside the barrier, concentrations are at remedial goals at over 75 percent of the wells.

Objective: To (1) evaluate the effectiveness of remediation efforts, (2) provide improved information on current and future rates of solute transport, and (3) help formulate improved monitoring strategies.

My Research Focus: I have used the findings of this study to (1) understand solute transport processes in a highly advective, relatively non-reactive VOC plume, (2) evaluate effectiveness of low permeability barriers to contain contaminants, and (3) develop new tools and methods (analytical and field based) to help characterize VOC spatial and temporal trends. Continuous monitoring of ground-water levels have shown that ground water in the bedrock quickly responds to remedial operations in the overburden and that significant bedrock upflow is induced into the barrier when extracting water from the overburden. Chemical monitoring results illustrate the importance of source area identification, stratigraphy, and understanding the vertical heterogeneity of contaminants. Vertical profiling with E-SASS proved effective in penetrating coarse resistive deposits, which were not penetrable with direct-push methods, and in the identification of potential source areas. Relatively small differences in stratigraphy contribute to large differences in vertical concentrations of VOCs. At several locations, recalcitrant PCE concentrations correlated with large changes in gamma signals, suggesting the presence of stratigraphic contacts. Lithologic data collected during test drilling corroborated that gamma signal changes are due to lithologic variation.  Extending the utility of borehole gamma as a mapping tool is a part of my research. Mineralogic variability and impact on gamma signals is being assessed with spectral gamma analysis so that lithologic and hydraulic controls can be better understood.


Project Title: I-93 Highway de-icing effects on ground-water quality, N.H.

Description of Assignment:

Problem: Understanding salt concentrations in ground water is important because ground-water discharge to surface water may provide a mechanism for time-delayed storage of salt input. Estimation of ground-water chloride loads and identification of point and non-point sources is necessary to mitigate chloride loads in streams.

Objective: Specific objectives include:  

1)       Map road salt concentrations in ground water adjacent to a highway,

2)       Establish a monitoring system that can be used for future ground-water assessments, and

3)       Estimate the salt load from ground-water discharge to an adjacent surface-water body.

My Research Focus: Evaluation of ground-water discharge patterns to streams and identification of solute processes, both physical and temporal, which affect discharge of chloride contaminated ground water. Design of improved methods and techniques in the identification of conductive ground-water discharge areas to streams. Results from the three EM tools showed good agreement and identified several reaches where high conductivity ground water may have been discharging. EM conductivity values ranged from 10 (typical background value for sand) to 300 mmhos/meter in the streambed. Based on the delineation of high EM values, seven streambed piezometers were installed to sample streambed pore water. Specific conductance in the pore water ranged from 0.64 to 26 mmhos/cm. Locations with high specific conductance in streambed pore water matched well with locations with high EM-conductivity values. Based on the good correlation between streambed pore water chloride levels and streambed EM values, a ground-water discharge chloride load estimate was computed from concentration, hydraulic gradients, and estimated streambed properties. This computed discharge load was 5 times greater than the residual chloride load measured in the streamwater and suggests that during extended baseflow recessions, chloride loads would increase from advective-dispersive chemical transport of chloride from the streambed. This hypothesis is supported by USEPA monitoring of streamwater chloride that shows increases in chloride during extended baseflow recessions. 


Project Title: Development and Documentation of Program ZONECONC

Description of Assignment:

PROBLEM: Spatial analysis of solute-transport simulation results is a powerful tool in understanding model results. Prior to this study, no quick and easy tool was available to efficiently post-process solute-transport concentration data from MODFLOW-GWT.  

OBJECTIVES: The primary objective of this study was to develop and document a computer program to help analyze solute-transport simulation results from MODFLOW-GWT.

My Research Focus: In my analysis of effectiveness of low-permeability barrier walls to contain contaminants, it became apparent that no easy tools were available to assess transport rates across barriers. ZONECONC is an outgrowth of this need to quantify rates of solute transport across barriers. At this time, ZONECONC works only on concentration data, however, it is my wish to expand the program to one day tabulate rates of solute mass flux.


Project Title: Geohydrologic characterization at a Former Chlor-alkali Plant, Berlin, NH

Description of Assignment:

Problem: During the early to mid 1900’s a chlor-alkali plant was used to produce chlorine gas for the papermaking industry in Berlin, New Hampshire. The facility, located between a river and canal, used mercury cells as cathodes in an electrolytic process that hydrolyzed a brine solution to produce chlorine. During operation of the plant, elemental mercury was spilled at various locations and times; contaminating the overburden and underlying fractured rock. Elemental mercury has been observed from bedrock fractures in at the riverbank of the adjacent Androscoggin River. The cell houses were removed and, in 1999, overburden at the site was capped and contained by a slurry wall keyed to the bedrock surface. However, ground water continues to flow from the capped area and elemental mercury is observed in bedrock fractures at the adjacent riverbank.

Objective: Provide a preliminary characterization of the ground-water flow system at the site by identifying crystalline bedrock and overburden aquifer head gradients, and assessing the influence of river stages on the ground-water-flow system.

My Research Focus: Ground and surface-water interaction at the site is a key to understanding ground-water flow and potential transport of contaminated water because of the proximity of the cell house to the Androscoggin River. Short term, transient hydrologic events were analyzed to assess hydraulic properties of the bedrock. An analytical model of stream-aquifer interactions was used in this effort. The magnitude of response of ground-water levels in the bedrock to changes in river stage varied spatially, indicating heterogeneity in the bedrock. The direction of maximum head gradient is similar to the fracture orientations found by the geophysical and geologic mapping. A simplified ground-water model of bulk fluid flow was constructed to test the conceptual model that fracture strike orientations impart a strong preferential anisotropy to the flow system. To replicate the observed direction of maximum head gradients, a horizontal anisotropy (100:1) was needed in the model.


Project Title: Impact of Transient Flow on Contributing Areas and Remediation Efforts, Savage Pre-Design Study, Milford, NH

Description of Assignment:

PROBLEM: The transient nature of ground-water flow and its effect on migration of contaminants in the subsurface can be significant in high-permeability environments. Furthermore, seasonal variations in ground-water recharge and discharge also affect sources of water to pumped wells and their zones of contri­bution. These processes will hinder remediation of contaminants unless information is acquired on transient advective transport. The feasibility of natural attenuation and other remedial alternatives requires a thorough investigation of physical flow processes under transient conditions.

OBJECTIVES: The primary objective of this study was to research and demonstrate the use of models of ground-water flow to (1) characterize the temporal variability of surface- and ground-water interactions at contaminated sites, (2) characterize the effects of transient conditions on the ground-water flow system, flowpaths to wells, and advective transport of contaminants in a highly transmissive aquifer system, and (3) evaluate potential remedial designs.

 My Research Focus: The results of transient-flow analysis have been used to understand the spreading of a contaminant plume from advective processes. These data are important in improving estimates of solute transport and determining apparent dispersivity. The results of the transient-flow analysis also helped under­stand variations in simulated capture zones of wells. For wells with large withdrawals, such as public supply wells, estimates of steady state and transient long-term capture zones are comparable. However, for wells with small withdrawals, such as wells used to extract contaminants, transient capture zones varied by more than 25 percent from steady state capture zones. The source area to small withdrawal wells are affected by directional variations in ground-water flow from local boundaries. This variation in capture reduces the seasonal efficiency of extraction.


Position title: Environmental Specialist

Organization: U.S. Naval Reserve

Locations: Keflavik, Iceland, Norfolk, Virg.., Kittery, Maine, Brunswick, Maine, Pentagon

Description of Position: Member of a environmental engineering unit tasked with facilities  decontamination. Specific work tasks include an (1) assessment of SWMU sites and their potential impact on ground- and surface-water resources, NAS Keflavik, (2) construction of a environmental data base for Chesapeake Bay Initiative Program, COMNAVBASE Nor­folk, and (3) evaluation of remedial investigations at PNSY.








Harte, Philip T., and Flanagan, Sarah M., 2011, Application of a New Vertical Profiling Tool (ESASS) for Sampling Groundwater Quality During Hollow-Stem Auger Drilling; Ground Water Monitoring & Remediation, vol. 31, no. 1, pp. 86-98. [Link]


Harte, P.T., Sargent, B.P., and Vowinkel, E.F., 1986, Description and results of test-drilling program at Picatinny Arsenal, New Jersey, 1982-1984; U.S. Geological Survey Open-File Report 86-0316, 54 p.


Lacombe, Pierre, Sargent, B.P., Harte, P.T., and Vowinkel, E.F., 1986, Determination of geohydrologic framework and extent of ground-water contamination using surface geophysical techniques at Picatinny Arsenal, New Jersey; U.S. Geological Survey Water Resources Report 86-4051, 31 p. [I helped collect the geophysical data and wrote the hydrogeologic sections of the report]


Sargent, B.P., Green, J.W., Harte, P.T., and Vowinkel, E.F., 1986, Ground-water-quality data for Picatinny Arsenal, New Jersey, 1958-1985; U.S. Geological Survey Open-File Report 86- 0058, 66 p. [I helped summarize water-quality data and wrote the hydrogeologic sections of the report]


Smith, J.A., Harte, P.T., and Hardy, M.A., 1987, Trace-metal and organochlorine residues in sediments of the Upper Rockaway River, New Jersey; Bulletin of Environmental Contamination and Toxicology, vol. 39, p465-473. [I helped summarize water-quality data and wrote the hydrogeologic sections of the report]


Harte, P.T., and Mack, T.J., 1992, Geohydrology of, and simulation of ground-water flow in, the Milford-Souhegan Aquifer, Milford, New Hampshire; United States Geological Survey, Water-Resources Report 91-4177, 75 p.


Mack, T.J., and Harte, P.T., 1992, Documentation of input and output files for a ground-water flow model of the Milford-Souhegan Glacial-Drift Aquifer, Milford, New Hampshire (supplement to Water-Resources Report 91-4177); United States Geological Survey, Open- file Report 92-60, 4 p. [I created the model-input data files and output files]


Schaefer, F.L., Harte, P.T., Smith, J.A., and Kurtz, B.A., 1993, Hydrologic conditions in the upper Rockaway River Basin, 1984-1986; U.S. Geological Survey Water Resources Report 91-4169, 103 p. [I wrote the first draft of the report before moving to New Hampshire]


Harte, P.T., 1994, Comparison of vertical discretization techniques in finite-difference models: example from a hypothetical New England setting: U.S. Geological Survey Open-File Report 94-343, 25p.


Harte, P.T., and Johnson, William, 1995, Geohydrology and water quality of the stratified-drift aquifers in the Contoocook River Basin, south-central, New Hampshire; U.S. Geological Survey Water Resources Report 92-4154, 162 p.


Harte, P.T., and Winter, T.C., 1995, Simulations of flow in fractured crystalline rock and recharge from overburden in a hypothetical New England Setting: Ground Water, v.33, no. 6, p. 953- 964.


Olimpio, J.R., and Harte, P.T., 1995, Reassessment of hydrogeologic data and refinement of a regional ground-water-flow model of the Milford-Souhegan Glacial-Drift Aquifer, Milford, New Hampshire; U.S. Geological Survey Water Resources Investigative Report 95-281, 40 p. [I rewrote the report after the first draft and performed numerical model simulations]


Harte, P.T., and Winter, T.C., 1996, Factors affecting recharge to crystalline rock in the Mirror Lake area, Grafton County, New Hampshire, in Morganwalp, D.W., ed., U.S. Geological Survey Toxics Substances Program: Proceedings of the technical meeting, Colorado Springs, Colorado, September 1993: U.S. Geological Survey Water Resources Investigations Report 94-4015, 12p.


Mack, T.J., and Harte, P.T., 1996, Results of aquifer tests to determine hydraulic and water- quality conditions in stratified-drift and streambed sediments near a former municipal well, Milford, New Hampshire; U.S. Geological Survey Water-resources Investigations Report 96- 4019, 77p. [I designed the field data-collection program, helped analyze data, and wrote sections on river-aquifer interactions and streambed properties]


Harte, P.T., and Mack, T.J., 1996, Effects of model discretization on zones of contribution to low- pumping rate wells in a hypothetical river-valley aquifer; in Hydrology and Hydrogeology of Urban and Urbanizing Areas, American Institute of Hydrology, April 1996, Annual meeting, Boston, Massachusetts, p.GWQE42-GWQE56


Harte, P.T.,1997, Lithologic and hydraulic properties of the glacial drift and shallow bedrock in the Mirror Lake area, Grafton County, New Hampshire: U.S. Geological Survey Open-File Report 96-654A, 56p.


Harte, P.T.,and Willey, Richard E., 1997, Effects of historical withdrawals on advective transport of contaminated ground waters in a glacial-drift aquifer, Milford, New Hampshire; U.S. Geological Survey Factsheet 162-97, 6p.


Harte, P.T.,Flynn, R.H., Kiah, R.G., Severance, Timothy, and Coakley, M.F., 1997, Information on hydrologic and physical properties of water to assess transient hydrology of the Milford- Souhegan Glacial-Drift Aquifer, Milford, New Hampshire; U.S. Geological Survey Open- File Report 97-414, 96p.


Johnston, C.M. and Harte, P.T.,1998, Documentation and application of a method to compute maximum slope and aspect of hydraulic gradients; U.S. Geological Survey Water-Resources- Investigation Report 98-402, 25p. [ Developed concept, assisted in programming]


Harte, P.T., Flynn, R.J., and Mack, T.J., 1999, Construction and calibration of numerical ground-water- flow models of the western half of the Milford-Souhegan glacial-drift aquifer, Milford, New Hampshire: U.S. Geological Survey Open-File Report 99-462, 76 p


Harte, P.T., Brayton, M.J., and Ives, Wayne, 2000, Use of passive diffusion samplers for monitoring volatile-organic compounds in ground water: U.S. Geological Survey Factsheet 088-00, 4p.


Harte, P.T., Brayton, M.J., Ives, Wayne, Perkins, Sharon, and Brown, Carroll, 2001, Testing and application of water-diffusion samplers to identify temporal trends in volatile-organic compounds: U.S. Geological Survey Open-File Report 00-196, 91p.


Konikow, L.F., Harte, P.T., and Honberger, G.Z., 2001, Simulating solute transport across horizontal-flow barriers: Proceedings from MODFLOW 2001 and Other Modeling Odysseys, Sept. 11-14, 2001, Golden Co., vol. 2, p. 510-516 [Helped developed concepts, assisted in analysis]


Brayton, M.J., and Harte, P.T., 2001, Results of a monitoring program of continuous water levels, specific conductance, and water temperature at the OK Tool facility of the Savage Municipal Well Superfund site, Milford, New Hampshire: U.S. Geological Survey Open-File Report 01-338, 50 p. [Established objectives and scope, assisted in analysis]


Hornberger, G.Z., Konikow, L.F., and Harte, P.T., 2002, Simulating solute transport across horizontal-flow barriers using the MODFLOW Ground-Water Transport Process: U.S. Geological Survey Open-File Report 02-52, 28 p. [Helped developed concepts , assisted in analysis]


Harte, P.T., 2002, Comparison of temporal trends in VOCs as measured with PDB samplers and low-flow sampling methods: Ground Water Monitoring and Remediation, v.33, no. 6, p. 45-47.


Degnan, J.R., Clark, S.F., Jr., and Harte, P.T., 2004, Integration of geophysics, geologic mapping and water-level monitoring to characterize the hydrogeology of a fractured bedrock site in Berlin, New Hampshire, in Symposium on the application of geophysics to engineering and environmental problems, Colorado Springs, Colo., February 22-26, 2004: Environmental and Engineering Geophysical Society Annual Meeting, ENVO5, p. 759-769. [Evaluated framework and developed conceptual models of flow]


Harte, P.T., 2004, Simulation of solute transport of tetrachloroethylene in ground water of the glacial-drift aquifer at the Savage Municipal Well Superfund site, Milford, New Hampshire, 1960-2000:  U.S. Geological Survey Scientific Investigations Report 2004-5176, 84 p.


Harte, P.T., 2005a, Results of a monitoring program of continuous water levels and physical water properties at the OU1 area of the Savage Municipal Well Superfund site, water years 2000-03, Milford, New Hampshire:  U.S. Geological Survey Open-File Report 2005-1303, 44 p.


Harte, P.T., 2005b, A computer program (ZONECONC) for tabulating concentration statistics using results from the U.S. Geological Survey Three-Dimensional Ground-Water Flow and Transport Model:  U.S. Geological Survey Open-File Report 2005-1422, 24 p.


Degnan, J.R., Clark, S.F., Jr., Harte, P.T., and Mack, T.J., 2005, Geology and preliminary hydrogeologic characterization of the cell-house site, Berlin, New Hampshire, 2003-04: U.S. Geological Survey Scientific Investigations Report 2004-5282, 55 p. [Evaluated framework, estimated hydraulic properties, and developed conceptual models of flow]


Harte, P.T., 2006a, Effects of a remedial system and its operation on volatile organic compound-contaminated ground water, Operable Unit 1, Savage Municipal Well Superfund Site, Milford, New Hampshire, 1998-2004: U.S. Geological Survey Scientific Investigations Report 2006-5083, 73 p. [REPORT AVAILABLE ONLINE at].


Harte, P.T., Konikow, L.F., and Hornberger, G.Z., 2006, Simulation of solute transport across low-permeability barrier walls: Journal of Contaminant Hydrology, v. 85, p. 247-270 [REPORT AVAILABLE ONLINE at ]


Harte, P.T., 2006b, ZONECONC: A simple post-processor for tabulating concentration statistics from MODFLOW-GWT: in Proceedings for MODFLOW and More 2006 Managing Ground Water Systems, vol. 1, p. 33-37.


Winter, T.C., Buso, D.C., Shattuck, P.C., Harte, P.T., Vroblesky, D.A., and Goode, D.J., 2008, The Effect of Terrace Geology on Ground-water Movement and on the Interaction of Ground Water and Surface Water on a Mountainside Near Mirror Lake, New Hampshire, USA:  Hydrological Processes, vol. 22, p. 21-32  [Developed key concepts on ground-water flow processes along hillside terraces]


Harte, P.T., and Kiah, R.G., online, Measured river leakages using conventional streamflow techniques: Hydrogeology Journal <>


Harte, P.T., Robinson, G.R., Jr., Ayotte, J.D., and Flanagan, S.F., 2008, Framework for evaluating water quality of the New England crystalline rock aquifers: U.S. Geological Survey Open-File Report 2008–1282, 47 p., available only online at


Harte, P.T., and Kiah, R.G., 2009, Measured river leakages using conventional streamflow techniques: Hydrogeology Journal, vol. 17, no. 2, p. 409-424.


Harte, P.T., and Trowbridge, P.R., 2010, Mapping of road-salt contaminated groundwater discharge and estimation of chloride load to a small stream in southern New Hampshire, USA:Journal of Hydrological Processes. available only online at


Harte, P.T., 2010, Hydrostratigraphic mapping of the Milford-Souhegan Glacial Drift Aquifer for Operable Unit 1, Savage Superfund Site, Milford, New Hampshire: U.S. Geological Survey Open-File Report 2010–1047, 48 p. available only online at


Harte, P.T., and Flanagan, Sarah, 2011, A new vertical profiling tool (ESASS) for sampling ground -water quality while auger drilling: submitted to Ground Water Monitoring and Remediation, vol. 31, no. 1, p. 86-98.


Mack, T.J., Harte, P.T., Chornack, M.P., 2011, Challenges in the Development of Models for Regional Groundwater Resource Appraisal in Southern Afghanistan, in Proceedings of the conference MODFLOW and More 2011: Integrated Hydrologic Modeling, Volume1, p. xxx-xxx, International Ground Water Modeling Center, Colorado School of Mines, Golden, Colorado.