Aquifer Potential

							                                               AQUIFERS
Overview

An aquifer is a subsurface formation that stores or transmits water in recoverable quantities and
can be used as a source of well water for domestic and agricultural use.




One of our most valuable resources is the water beneath our feet - something you cannot see
and may not even know is there! Most of the void spaces in the rocks below the water table are
filled with water. However, rocks have different porosity and permeability characteristics, which
means that water does not move around the same way in all rocks.

Aquifer Potential

The Allentown Dolomite, the Beekmantown Group, the Jacksonburg Limestone, and the
Martinsburg Formation underlie the Township. The NJGS considers the Martinsburg Formation,
which is primarily shale and underlies about 70% of the Township, a poor aquifer. The other
bedrock formations, which being limestones and dolomites have greater permeability associated
with solution features, are considered fair aquifers (Herman, et al., 1998). These bedrock
formations have no primary porosity and ground water is transmitted through joints, fractures
and solution cavities within the rock. With respect to the overburden, glacial till is a poor aquifer,
although it does exceed 50 feet in thickness in some areas and provides small quantities of
ground water to domestic wells. The unconsolidated deposits along the Paulinskill valley are a
poor to fair aquifer, as discussed below.




                       Attribution: TRC Raviv Associates, Inc. Hydrogeologic Study: September 2003
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                                             AQUIFERS
Allentown Dolomite

The Allentown Dolomite has no primary porosity and ground water moves through joints,
fractures and solution cavities within the rock. Ground water is found under both water table
and semi-artesian conditions. The Allentown Dolomite occurs along the Paulinskill. The
hydraulic characteristics of the Allentown Dolomite are similar to the Beekmantown Group.

Beekmantown Group

Ground water in the Beekmantown Group is found under both water table and semi-artesian
conditions. Water table conditions exist near the ground surface and semi-artesian conditions
occur in some of the deeper solution channels, which are recharged through sinkholes or water
table aquifers. The solution channels are usually irregular, and two neighboring high-capacity
wells may tap the same solution channels and interfere with each other. Most successful wells
have intersected large openings and caverns at depths between 50 and 300 feet below grade.
Below 600 feet, the chances of obtaining a good supply well from this formation are generally
slight.

The reported yields from 17 domestic wells drilled into the Beekmantown Group in the Township
range from 3 to 35 gallons per minute (gpm) with an average of 13 gpm. The reported depths of
domestic wells range from 40 to 290 feet. Based on a hydrogeologic study conducted in
Sussex and Warren Counties in 1974, there are no industrial or water supply wells tapping the
Beekmantown Group in the Township, but reported yields from 32 industrial wells in the region
range from 18 to 815 gpm, with an average of 162 gpm and median of 100 gpm. Nine percent
of the wells yielded over 300 gpm (Miller, J.W., Jr., 1974).

The ground water in the Beekmantown Group rocks is fresh, slightly alkaline, non-corrosive, and
hard. Calcium-magnesium-bicarbonate waters dominate (Herman, G.C., and others, 1998).

Jacksonburg Formation

There are only a few wells in the Township penetrating the Jacksonburg Formation, because of
its limited extent. According to the ranking values for aquifers and confining units in New
Jersey, the median yields for water supply, irrigation and industrial water supply wells tapping
the Jacksonburg Formation in the regional area range from 100 to 500 gpm.

The ground water in the Jacksonburg Formation is fresh, slightly alkaline, non-corrosive, and
hard. Calcium-magnesium-bicarbonate type waters dominate (Herman, G.C., and others,
1998).

Martinsburg Formation

The Martinsburg Formation has no primary porosity or permeability. In the Township, the
fractures in this formation are relatively tight and it is, on the whole, a poor aquifer. Ground
water occurs under water-table conditions except in some of the deeper wells where water may
be semi-confined in a sandstone or limestone lens, a more permeable shale horizon, or a fault
shear zone.

                     Attribution: TRC Raviv Associates, Inc. Hydrogeologic Study: September 2003
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                                               AQUIFERS
The reported yields of 23 domestic wells drilled into the Martinsburg Formation in Blairstown
Township range from 1 to 20 gpm and the average yield was reported to be 10 gpm. The
reported depths of the domestic wells range from 50 to 345 feet (Miller, J.W., Jr., 1974).
According to NJDEP records, there are two public community water supply wells in the
Township; these wells tap the Martinsburg Formation. The reported yields for these two supply
wells are 70 and 135 gpm.

The ground water in the Martinsburg Formation is fresh, slightly alkaline, non-corrosive, and
moderately hard. Calcium-bicarbonate waters dominate (Herman, G.C., and others, 1998).

Surficial Deposits

Most of the surficial deposits in the Township consist of glacial till. These glacial deposits have
generally low permeability and are unimportant as aquifers in the area. Occasionally, a well
drilled into these sediments will provide sufficient water for domestic purposes; however, during
periods of drought, these wells can go dry. In the Township, these surficial deposits are usually
less than 10 feet thick, except in the north part of the Stony Brook area where these deposits
can locally attain thickness in excess of 50 feet.

Alluvial and glacial lake deposits along the Paulinskill consist of sand, gravel, silty sands, and
minor clay. These deposits are under water table conditions and reach a maximum thickness of
100 feet. In portions of Blairstown, the unconsolidated deposits in the Paulinskill valley are
sufficiently thick and permeable to form a significant potential aquifer (Herman, et al., 1998).

Sources of recharge of the surficial aquifers include precipitation, ground water discharge from
bedrock aquifers in the valleys, and flow from streams and bodies of water (lakes and ponds).
Wells drilled in stratified drift deposits near a lake or river may yield large, reliable quantities of
water by inducing recharge from these surface water bodies. The reported yields of 7 domestic
wells in the Township tapping the alluvial and glacial lake deposits range from 4 to 30 gpm and
the average yield is 18 gpm. The reported depths of these domestic wells range from 35 to 100
feet (Miller, J.W., Jr., 1974). These domestic wells are located along the Paulinskill valley.

The ground water in the glacial deposits varies with the sedimentary texture and mineral
content. Water is fresh, slightly alkaline, moderately hard to hard, and of the calcium
bicarbonate type (Herman, G.C., and others, 1998).




                       Attribution: TRC Raviv Associates, Inc. Hydrogeologic Study: September 2003
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                                                AQUIFERS

                            Sole Source Aquifer Designation Areas1
      Basin
     Aquifer     Counties                              Municipalities Served (Townships)
     System
Delawanna
                  Warren        Blairstown, Knowlton, Hope, & White and Town of Belvidere
Creek
                Warren and Andover, Blairstown, Frankford, Fredon, Frelinghuysen, Hampton, Hardwick,
Paulinskill                Hardyston, Knowlton, Lafayette, Pahaquarry, Sandyston, Sparta, Stillwater, and
                 Sussex Walpack, and Borough of Branchville, and Town of Newton

                Warren and Allamuchy, Andover, Blairstown, Byram, Fredon, Frelinghuysen, Green, Hope,
Pequest River                   Independence, Knowlton, Liberty, Mansfield, Oxford, Sparta, Washington, and White,
                  Sussex        the Borough of Andover, and Towns of Belvidere & Newton




                            Percentage of Basin Aquifer Systems In
                                Different Physiographic Provinces
                  Basin Aquifer System Piedmont Highlands Valley & Ridge
                  Delawanna Creek                       ----            ----                100
                  Paulinskill                           ----              4                  96
                  Pequest River                         ----             35                  65



                       Estimated Volume of Drinking Water Supplied
                                            Aquifer             Volume (gpd)2
                                     Delawanna Creek                      119,600
                                     Paulinskill                       2,162,900
                                     Pequest River                     2,444,600



 Please refer to Appendix ‘C’, Aquifers and Wellhead Protection Areas for additional
 information.




 1 New Jersey Department of Environmental Conservation. Available at
 http://www.epa.gov/region02/water/aquifer/basin/15bas-ta.htm
 2 Gallons per day (gpd).


                        Attribution: TRC Raviv Associates, Inc. Hydrogeologic Study: September 2003
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