Philip T. Harte, P.G. (Former Employee)

We evaluated long-term trends and predictors of groundwater levels by month from two well-studied northern New England forested headwater glacial aquifers: Sleepers River, Vermont, 44 wells, 1992-2013; and Hubbard Brook, New Hampshire, 15 wells, 1979-2004. Based on Kendall Tau tests with Sen slope determination, a surprising number of well-month combinations had negative trends...

The distributional pattern of dissolved arsenic concentrations from landfill plumes can provide clues to the source of arsenic contamination. Under simple idealized conditions, arsenic concentrations along flow paths in aquifers proximal to a landfill will decrease under anthropogenic sources but potentially increase under in situ sources. This paper presents several conceptual...

Identifying hydraulically active fractures in low permeability, crystalline-bedrock aquifers requires a variety of geophysical and hydrogeophysical borehole tools and approaches. One such approach is Single Borehole Dilution Tests (SBDT), which in some low flow cases have been shown to provide greater resolution of borehole flow than other logging procedures, such as vertical...

Research on the hydrogeologic setting of Mirror Lake near West Thornton, New Hampshire (43° 56.5’ N, 71° 41.5’ W), includes the study of the physical, chemical, and isotopic characteristics of groundwater in the vicinity of the lake and nearby Hubbard Brook. Presented here are those physical, chemical, and isotopic data for the period 1983 to 1997. Data were collected from observation...

The Savage Municipal Well Superfund site consists of an eastward-directed plume of volatile organic compounds, principally tetrachloroethylene (PCE), in alluvium and glacial sand and gravel in the Souhegan River valley, just south of the river and about 4 kilometers west of the town of Milford, New Hampshire. Sampling of monitoring wells at the site has helped delineate the extent of the...

Leachate continues to be generated from landfills at the Auburn Road Landfill Superfund Site in Londonderry, New Hampshire. Impermeable caps on the three landfills at the site inhibit direct infiltration of precipitation; however, high water-table conditions allow groundwater to interact with landfill materials from below, creating leachate and ultimately reducing conditions in...

Tetrachloroethylene (PCE), a volatile organic compound, was detected in groundwater from deep (more than (>) 300 feet (ft) below land surface) fractures in monitoring wells tapping a crystalline-rock aquifer beneath operable unit 1 (OU1) of the Savage Municipal Well Superfund site (Weston, Inc., 2010). Operable units define remedial areas of contaminant concern. PCE contamination within...

Groundwater sampling from open boreholes in fractured-rock aquifers is particularly challenging because of mixing and dilution of fluid within the borehole from multiple fractures. This note presents an alternative to traditional sampling in open boreholes with packer assemblies. The alternative system called ZONFLO (zonal flow) is based on hydraulic control of borehole flow conditions...

Anthropogenic sources of carbon from landfill or waste leachate can promote reductive dissolution of in situ arsenic (As) and enhance the mobility of As in groundwater. Groundwater from residential-supply wells in a fractured crystalline-rock aquifer adjacent to a Superfund site in Raymond, New Hampshire, USA, showed evidence of locally enhanced As mobilization in relatively reducing...

The U.S. Geological Survey and the New Hampshire Department of Environmental Services entered into a cooperative agreement to assist in the evaluation of remedy simulations of the MSGD aquifer that are being performed by various parties to track the remedial progress of the PCE plume. This report summarizes findings from this evaluation. Topics covered include description of groundwater...

In situ chemical oxidation (ISCO) treatment with sodium permanganate, an electrically conductive oxidant, provides a strong electrical signal for tracking of injectate transport using time series geophysical surveys including direct current (DC) resistivity and electromagnetic (EM) methods. Effective remediation is dependent upon placing the oxidant in close contact with the contaminated...

A new tool called ESASS (Enhanced Screen Auger Sampling System) was developed by the U.S. Geological Survey. The use of ESASS, because of its unique U.S. patent design (U.S. patent no. 7,631,705 B1), allows for the collection of representative, depth-specific groundwater samples (vertical profiling) in a quick and efficient manner using a 0.305-m long screen auger during hollow-stem...