New Jersey Geologic Survey
DGS07-1: Aquifer Recharge Potential for New Jersey Overview

County GWR Download


This information is provided to compliment the FGDC-compliant metadata prepared for and provided with each data set and is not intended to replace that metadata.


Contact:

Mark French
GIS Specialist
New Jersey Geological Survey
P.O. Box 427
29 Arctic Pkwy
Trenton, NJ 08625-0420
email: mark.french@dep.state.nj.us

Table of Contents

Abstract
Overview
Processing
Aquifer Rankings (table)
County Aquifer Rankings (table)
Composite Aquifer-Recharge Potential Ranks
Limitations
Provisos
References

Abstract:

Aquifer recharge potential was mapped by superimposing ground-water recharge maps over aquifer maps. A rankings system was developed to display the potential for aquifer recharge. Ground-water recharge areas were mapped and ground-water recharge  was calculated and ranked as described in "A method for evaluating ground-water-recharge areas in New Jersey" (E.G. Charles and others, 1993). Aquifer designations and delineations  from "Aquifers of New Jersey" (G. C. Herman and others, 1998), were used to produce a coverage of aquifer ranks.

Aquifers were ranked based on the median yield of selected non-domestic well yields. Yield was used as it was indicative of the capacity of the aquifer to supply water, which defines an aquifer. The prevalence of yield data made it possible to develop a ranking system over a regional area. The median yield was chosen as the ranking criterion as it more precisely indicated the central point of the data as opposed to the average. Large outlier values often found in the yield data can greatly influence the average. The median is the value at which half of the data values are above and half are below.

Well yield values varied over a range of  3,000 gallons per minute (gpm). Five ranks, A-E, were assigned: E, less than 25 gpm; D, 25 to 100 gpm; C, greater than 100 gpm to 250 gpm; B, greater than 250 gpm to 500 gpm; and A, greater than 500 gpm. Each county's yield data were analyzed and ranked based upon the above scale. Each watershed management area (WMA) aquifers were catagorized  using the statewide yield data as applied to the above scale.

Overview:

All geographic data were prepared using ESRI Arc/Infoor ArcView geographic information system software. Downloadable data were prepared using WinZip compression software and Adobe Illustratorsoftware (see Proviso below). Data CDs, available by request only, were prepared using the ISO-9660 CD file system standard and can be read by any computer and operating system with ISO-9660 compatibility.

Watershed management area is indicated by the two numbers after the initial "w" of the filename which corresponds to the number of the watershed management area. County is indicated by the first three letters of the file name corresponding to the first 3 letters of the County. Each shapefile was converted or exported from a corresponding Arc/Info coverage of the same name. The "shapefiles" are composed of three constituent files: SHP file containing the geographic elements (lines, points or polygons), the SHX file containing the geographic coordinate information and the DBF file containing the data attached to each geographic element.

Processing:

Aquifer coverages were created by clipping the Aquifers of New Jersey (G. C. Herman and others, 1998) coverage using the boundary of the area of interest (county or WMA).

Aquifer rank coverages were created by applying aquifer ranks for each aquifer based upon county/WMA well-yield data or statewide rankings to those aquifers which had no county/WMA well-yield data, then dissolving the coverage against that rank.

To create a system to rank these aquifers the NJGS analyzed statewide aquifer and well data that included well yield, hydraulic conductivity, specific capacity, transmissivity, and storativity. Well-yield data from a high-yield subset of non-domestic wells were used because they provided the most comprehensive data and were the most representative of the potential water-yielding ability of the aquifer (Sloto and others, 1990). Well-yield data were obtained from NJGS project databases and from the USGS Ground Water Site Index (GWSI) database (Vowinkel and others,1982). Statistical analysis showed that the median (a value, in an ordered set of values, below and above which there is an equal number of values) of the well yield could be used to adequately assess the aquifer. The ranges of yields for the rankings are selected based upon natural breaks in the data. These ranges were further refined after discussions with NJGS hydrogeologic staff. The five statewide rankings are as follows:

Aquifer Rank Range of Median Yields (gpm)
A > 500
B 250 to 500
C 100 to 250
D 25 to 100
E < 25

Once these ranges were established, statewide rankings were determined for each aquifer using median yield. If well-yield data were not available for an aquifer, it was ranked based upon its lithologic characteristics compared to the ranked aquifers, and the combined professional judgment of the NJGS geologic and hydrogeologic staff.

The county aquifer rank was created by retrieving well-yield data for each aquifer in that county. Medians were calculated for well-yield for data containing three or more values. The statewide ranking scale was then applied to the results. Aquifers which did not have county well data were assigned their corresponding statewide rank.The following table contains county well yield data, in gpm, used to rank county aquifers, the aquifer's cooresponding county and statewide rank, and the aquifers which were assigned only their statewide rank:

AtlanticCo.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank
Rank
Surficial Sediments of Coastal Plain sscp 274 150 70 603 3 C C
Kirkwood-Cohansey,
Lower KirkwoodSand (800ft. Sand)
kcas 450 300 10 3,600 262 B B
                 
Bergen Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Glacial Lake Sediment l             E
Stratified Drift sg 506 353 20 1,750 51 B B
Basalt bs 122 42 25 300 3 D D
Brunswick ba 201 178 5 759 173 C C
Lockatong lf             D
Precambrian imr 11 11 8 14 4 E D
                 
Burlington Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Holocene (unknown),
Piney Point
sscp 92 75 50 150 3 D C
Kirkwood-Cohansey kcas 707 308 6 4,560 28 B B
Red Bank ccu/ccua             C
Mt. Laurel-Wenonah mlwa 227 240 15 503 32 C C
Englishtown eas 103 100 10 311 15 D B
Upper PRM (OldBridge),
Middle PRM (Sayreville),
Lower PRM(Farrington),
Potomac-Raritan-Magothy
prma 597 549 10 1,987 218 A A
Wissahickon Gniess imr              D
                 
Camden Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Piney Point sscp             C
Kirkwood-Cohansey kcas 264 100 10 1,012 43 D B
Manasquan,
Manasquan-Vincentown
ccu/ccua 218 185 110 360 3 C D/C
Mt. Laurel-Wenonah mlwa 261 257 50 535 29 B C
Englishtown eas 449 507 250 533 4 A B
Upper PRM (OldBridge),
Middle PRM (Sayreville),
Lower PRM(Farrington),
Potomac-Raritan-Magothy
prma 850 950 15 3,000 241 A A
                 
Cape May Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Estuarine Sand sscp 360 250 60 1,007 12 C C
Holly Beach hb 110 100 15 302 10 D C
Cohansey,
Kirkwood-Cohansey,
Upper Kirkwood Sand (Rio Grande),
Lower KirkwoodSand (800ft. Sand)
kcas 539 517 10 1,500 95 A B
                 
Cumberland Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Piney Point sscp             C
Kirkwood-Cohansey kcas 457 375 8 1,639 231 B B
Englishtown eas             B
                 
Essex Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Stratified Drift sg 657 700 15 1,670 49 A B
Basalt bs 125 100 2 400 31 D D
Brunswick ba 270 216 3 1,404 104 C C
                 
Gloucester Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Quaternary sediments sscp 142 12 1 632 5 E C
Kirkwood-Cohansey kcas 247 100 13 1,016 52 D B
Vincentown ccu/ccua             D
Mt. Laurel-Wenonah mlwa 365 380 60 603 8 B C
Upper PRM (OldBridge),
Middle PRM (Sayreville),
Lower PRM(Farrington),
Potomac-Raritan-Magothy
prma 626 608 10 1,515 179 A A
                 
Hudson Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Brunswick ba 190 200 170 200 3 C C
Stockton sf             C
                 
Hunteredon Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Stratified Drift sg             B
Brunswick,
Triassic
ba/bac 232 157 4 900 33 C C
Lockatong lf 41 50 8 75 9 D D
Stockton sf 123 134 34 200 3 C C
Ordovician gpkm             D
Kittatinny,
Leithsville
jkh 677 500 30 1,500 3 B C
Precambrian imr 122 118 35 219 7 C D
                 
Mercer Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Holocene (unknown),
Pennsauken
sscp             C
Upper PRM (Old Bridge),
Old Bridge,
Middle PRM (Sayreville)
Farrington,
Potomac-Raritan-Magothy
prma 437 386 15 1,209 64 B A
Diabase db 15 20 5 20 3 E E
Brunswick ba 75 39 3 412 72 D C
Lockatong lf 26 19 0 100 15 E D
Stockton sf 207 200 4 700 26 C C
Wissahickon Gniess imr 90 60 7 230 7 D D
                 
Middlesex Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Old Bridge,
Farrington,
Potomac-Raritan-Magothy
prma 545 520 1 1,840 223 A A
Brunswick ba 220 200 2 850 43 C C
Lockatong lf 131 100 35 257 3 D D
Stockton sf 224 115 2 608 8 C C
                 
Monmouth Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Kirkwood-Cohansey kcas 510 401 94 1,200 22 B B
Manasquan
Navesink
Vincentown
Red Bank
ccu/ccua 190 83 10 900 12 D D/C
Mt. Laurel-Wenonah mlwa 176 124 8 750 38 C C
Englishtown eas 303 300 10 1,486 85 B B
Upper PRM (Old Bridge),
OldBridge,
Farrington,
Potomac-Raritan-Magothy
prma 737 712 40 1,800 132 A A
                 
Morris Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Stratified Drift sg 563 500 2 2200 226 A B
Basalt bs 77 60 2 350 15 D D
Brunswick ba 135 87 4 800 64 D C
Leithsville jkh 394 167 10 2035 25 C C
Precambrian imr 106 85 8 402 50 D D
                 
Ocean Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Piney Point sscp 435 372 150 800 16 B C
Kirkwood-Cohansey,
Upper Kirkwood Sand (Rio Grande),
Lower KirkwoodSand (800ft. Sand)
kcas 375 275 4 1,245 273 B B
Vincentown,
Manasquan
ccu/ccua 198 160 4 524 7 C D/C
Mt. Laurel-Wenonah mlwa 118 104 40 240 10 C C
Englishtown eas 346 375 70 520 26 B B
Upper PRM (Old Bridge),
Middle PRM (Sayreville),
Lower PRM(Farrington),
Potomac-Raritan-Magothy
prma 1,199 1,001 35 2,461 29 A A
                 
Passaic Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Stratified Drift sg 332 125 10 1,280 19   B
Basalt bs 63 45 1 225 18   D
Brunswick ba 177 151 3 560 48   C
Precambrian imr 52 40 10 140 9   D
                 
Salem Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Kirkwood-Cohansey kcas 369 200 20 1,227 41 C B
Vincentown
Manasquan
ccu/ccua 118 40 10 270 5 D D/C
Mt. Laurel-Wenonah mlwa 165 112 10 600 36 C C
Englishtown eas             B
Upper PRM (Old Bridge),
Middle PRM (Sayreville),
Lower PRM(Farrington),
Potomac-Raritan-Magothy
prma 471 483 40 1,500 81 B A
                 
Somerset Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Old Bridge prma             A
Basalt bs 31 30 6 70 7 D D
Jurassic,
Brunswick
ba 188 150 20 460 28 C C
Stockton sf             C
Precambrian imr             D
                 
Sussex Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Stratified Drift sg 403 250 100 942 9 B B
High Falls gpkm             D
Martinsburg mfjs 44 35 20 75 5 D D
Kittatinny,
Allentown
jkh 291 200 3 800 10 C C
Franklin,
Precambrian
imr 123 94 9 425 18 D D
                 
Union Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Stratified Drift sg 359 353 180   16 B B
Potomac-Raritan-Magothy prma             A
Basalt bs             D
Jurassic,
Brunswick
ba 220 180 2 870 215 C C
                 
Warren Co.
Aquifer           County State
hydrogeology abbreviation Mean Median Min Max Count Rank Rank
Stratified Drift sg 490 415 151 927 6 B B
Allentown,
Epler,
HighFalls
gpkm 211 110 20 602 4 C D
Martinsburg mfjs 55 29 4 150 6 D D
Kittatinny,
Leithsville
jkh 419 470 68 800 6 B C
Precambrian imr 59 45 15 140 5 D D

CompositeAquifer Recharge Potential Ranks:

Aquifer-recharge potential coverages(*aqrp) were created through the combination of ground-water recharge coverage and the aquifer rank coverage in the area of interest (county/WMA). Aquifer recharge or recharge to water-bearing geologic units is defined by this study as the groundwater which reaches the water table in the uppermost geologic unit with a thickness of 50 feet or greater. After the combination of the two coverages, a composite ranking of 25 possible aquifer-recharge potentials was produced by combining the 5 possible ground-water recharge ranks with the 5 possible aquifer ranks.This composite, aquifer-recharge potential rank highlights the multiple relationships between the ground-water-recharge area ranks (indicative of the infiltration rate) and the underlying water-table aquifer ranks (indicative of the aquifer's capacity to absorb, transmit and supply water). The following table shows the composite rankings:

Aquifer
Rank
GWR*
Rank
Alphabetic
Composite Rank
Numeric
Composite Rank
A A AA 11
A B AB 12
A C AC 13
A D AD 14
A E AE 15
B A BA 21
B B BB 22
B C BC 23
B D BD 24
B E BE 25
C A CA 31
C B CB 32
C C CC 33
C D CD 34
C E CE 35
D A DA 41
D B DB 42
D C DC 43
D D DD 44
D E DE 45
E A EA 51
E B EB 52
E C EC 53
E D ED 54
E E EE 55
OtherRanks:
97: hydric soils
98: wetlands and open-water
99: no recharge calculated
(*GWR = ground-water recharge)

As can be seen, ground-water-recharge rates vary independently across the underlying aquifers. High-ranked ground-water-recharge areas can be found on low-ranked aquifers. This indicates infiltration or recharge at higher rates than the aquifer can absorb. This excess recharge provides water to wetlands and for stream baseflow. When high-rank, ground-water-recharge areas are located over high-ranked aquifers, this indicates an area where recharge rates are matched more closely to the aquifer's ability to absorb this water and are indicative of important aquifer-recharge areas.

This coverage incorporates additional assumptions besides those outlined in the ground-water-recharge methodology as presented by Charles and others (1993). These assumptions are: (1) Any lateral flow of ground water along boundaries of differing hydraulic conductivity has not been incorporated in this map. (2) The influence of topography on recharge is considered to have been addressed in the ground-water-recharge methodology as presented in Charles and others (1993). (3) Each constituent coverage may not have exactly matched in there geographic extent. This may have led to polygon slivers at the edges for which no recharge was calculated. In the interest of timely delivery, these polygons may not have been removed.

Limitations:

This data is subject to all limitations inherent in the NJGS ground-water recharge methodology as outlined in Part IV in GSR-32 and any other limitations noted above. Geographic data is reliable to 1:24,000 scale. Please refer to NJDEP GIS web site for further information on constituent coverages and metadata. (http://www.state.nj.us/dep/gis)

Provisos:

The data is supplied as is with no implied support or warranty by the NJGS. The end-user is responsible for any alterations to the original data. 

The mention of third party software products does not constitute an endorsement of these products by the NJGS. The NJGS does not support these products nor is the NJGS liable for any problems or damages arising from their download, use and/or misuse.

References


NJ Geologic map with Franklinite crystal