U.S. Department of the Interior

U.S. Geological Survey

USGS Fact Sheet FS-129-02

March 2003

A network of 15 observation wells that transmit ground-water-level data on a real-time basis through satellite 

telemetry is operating (started May 2001) in New Jersey through a cooperative effort of the U.S. Geological Survey 

(USGS) and the New Jersey Department of Environmental Protection (NJDEP). The water-level data from these 

observation wells are transmitted every 4 hours and then are immediately posted for viewing on the Internet. This fact 

sheet describes the rationale for real-time monitoring of ground-water levels, the design of the network, and the equipment 

used to measure water levels and transmit the data to the Internet. Instructions for viewing the data are included.

REAL-TIME GROUND-WATER-LEVEL MONITORING IN NEW JERSEY, 2002

Background

This network was created to provide data to indicate 

water-level trends in shallow ground-water systems within 

the State of New Jersey and to make the data available in 

the shortest time possible. The wells in this network are 

located throughout New Jersey (fig. 1) and were chosen 

because they are completed in shallow aquifers (table 1). 

The monitoring of shallow aquifers is important because 

these aquifers are relied on for water supply and irrigation. 

Additionally, the natural discharge from shallow aquifers 

provides base flow to streams. Water levels in these 

aquifers respond relatively quickly to precipitation and 

dry periods, so the rapid reporting of water-level data is 

necessary to follow trends. This network, for example, 

provides data that allow observation of the onset of drought 

conditions in ground water. Also, the data from this 

network can be used to estimate the most recent water-level 

trend in surficial-aquifer wells not outfitted with satellite 

telemetry.

Description of the Network

Six of the wells are completed in the unconfined parts 

of the sand and gravel aquifers of the New Jersey Coastal 

Plain, namely the Kirkwood-Cohansey aquifer system, the 

Englishtown aquifer system, and the Holly Beach waterbearing zone. Additional information about the aquifers of 

the Coastal Plain can be found in Zapecza (1989). Eight 

of the wells are in northern New Jersey and are completed 

in bedrock formations, namely the Passaic Formation, 

the Stockton Formation, the Allentown Dolomite, and 

the Bossardsville Limestone, or in Precambrian Rocks 

(table 1). Although these wells are deeper, the fractures in 

the bedrock are connected to the land surface; therefore, 

water levels respond quickly to precipitation. One well 

is completed in a stratified-drift aquifer in northern New 

Jersey. Water levels have been collected at these 15 sites for 

periods that range from 11 to 80 years. Herman and others 

(1998) summarize the important aquifers of New Jersey.

Figure 1. Location of the 15 observation wells transmitting real-time data and 

New Jersey Department of Environmental Protection Drought Regions.

REAL-TIME OBSERVATION

WELL

CENTRAL

COASTAL, NORTH

COASTAL, SOUTH

NORTHEAST

NORTHWEST

SOUTHWEST

DROUGHT REGION

EXPLANATION

Taylor

Green Pond 5

Readington

School 11

Morrell 1

Cranston

Farms 15

Lebanon SF 23-D

Vocational

School 2

0 10 20 30 MILES

0 10 20 30 KILOMETERS

41°

40°

39°

75° 74°

LNAS-EC

Winslow 5

Corsalo Rd

Environmental

Center 1

Union County Park

Swartswood

Park 5

Black River 10

Pump Pond N
Well locations were selected to obtain an even 

distribution of sites throughout New Jersey and to attempt 

to locate wells within each of the six Drought Regions 

established by NJDEP (Hoffman, 2001). The areas 

represented by each Drought Region (fig. 1) are based 

on large-scale watersheds and similarity of water-supply 

characteristics, and are defined “so as to match municipal 

boundaries in order to assist enforcement of mandated 

water cutbacks during drought emergencies” (Hoffman 

2001, p. 1).

Description of Data Collection and Reporting System 

Water levels in each well in the network are 

automatically measured at hourly intervals and stored by 

a Data Collection Platform (DCP) located on site (fig. 2). 

Every 4 hours, a burst of data is broadcast from the site 

to the GOES satellite and relayed to a ground station. 

The data are retransmitted by the DOMSAT satellite to a 

USGS ground station, decoded, and automatically posted 

to the New Jersey District USGS Internet web page for 

viewing (fig. 3). To ensure the accuracy of the data, each 

well is visited every 6 to 8 weeks by a USGS technician 

who makes a manual water-level measurement to check 

the automated system and to perform maintenance on the 

equipment.

Where to View Data 

The ground-water level data from this network can be 

viewed by following these instructions:

1. Attach to the Internet web page, 

http://waterdata.usgs.gov/nj/nwis/current/?type=gw. This 

page lists each well in the network and indicates the latest 

water-level measurement.

2. Choose an observation well by clicking on its 

station number. This leads to a page that summarizes 

the characteristics of the well, lists the monthly waterlevel statistics, and shows a hydrograph of the hourly 

measurements for the latest 7 days (fig. 4). 

3. The output format can be modified to produce a 

table of water-level values or a hydrograph. The timeframe 

for the table or hydrograph can be modified from the past 

7 days up to the past 31 days by changing the value for 

“Days” in the box located above the hydrograph and then 

clicking on the “get data” button. A new hydrograph will 

then be drawn. Note that clicking on the indicated text 

will produce a presentation-quality hydrograph that can be 

downloaded easily and printed by the viewer.

GOES DOMSAT

Wallops, Virginia,

Command and

Data Acquistion Center

Internet

USGS

data system

Observation well

and instrument

shelter

Figure 2. Typical equipment at a real-time ground-water-level network site, 

including the observation well, equipment shelter, data collection platform, solar 

power panel, and satellite antenna.

Figure 3. Schematic drawing showing data transmission from an observation 

well through satellite telemetry to users on the Internet. Satellite

antenna

Data

collection

platform

Observation

well

Solar

power

panel

Equipment

shelter

Satellite

antenna

Data

collection

platform

Observation

well

Solar

power

panel

Equipment

shelter
25 percent, respectively, of all daily mean depths to water 

during the month. The latest water-level value (obtained 

from the table or from the line above the hydrograph) can 

be compared to the monthly statistics.

Because the water-level data are shown automatically, 

the message “Provisional data subject to revision” is 

incorporated into the graphs and charts on the web page. If 

problems with the measurement, communication, or storage 

systems are found, revisions will be made to the USGS 

database at a later time to provide the corrected values. For 

more information about this issue, click on the “Provisional 

data subject to revision” heading. 

For these 15 sites, daily mean depths to water 

below land surface also are available for the last 550 

days (approximately 18 months). A location map, waterquality data, and a database of monthly water levels can be 

accessed from the home page for each well. 

USGS, in cooperation with NJDEP and other 

agencies, regularly monitors water levels in about 175 other 

wells in New Jersey. The data from these wells, although 

not posted on a real-time basis, are available on the web 

site http://nj.usgs.gov/gw/gw_hydrographs.html. Groundwater data for all wells routinely monitored by USGS, 

including those of the real-time network, are summarized in 

an annually published report (for example, Jones, 2002). Figure 4. Example of an actual ground-water hydrograph that can be viewed and 

printed from the real-time network web page.

Table 1. Characteristics of ground-water monitoring wells with realtime data.

[USGS, U.S. Geological Survey; ID, identification; a.s., aquifer system; w.b.z., water-bearing zone]

Well name County

USGS site ID 

number

Start of 

record Aquifer or formation

Well 

Depth 

(feet)

Lebanon State Forest 23-D Burlington 395150074284201 1955 Kirkwood-Cohansey a.s. 33

Winslow 5 Camden 394440074593101 1972 Kirkwood-Cohansey a.s. 76

Pump Pond N Cape May 390156074533401 1992 Holly Beach w.b.z 43

Vocational School 2 Cumberland 392731075092401 1972 Kirkwood-Cohansey a.s. 47

Corsalo Rd Hunterdon 402151074525301 1989 Passaic Formation 299

Readington School 11 Hunterdon 403517074452501 1990 Passaic Formation 101

Environmental Center 1 Hunterdon 403455074514801 1991 Stockton Formation 175

Cranston Farms 15 Mercer 401804074432601 1990 Stockton Formation 200

Morrell 1 Middlesex 402143074185201 1923 Englishtown a.s. 11

Green Pond 5 Morris 410207074270001 1981 Stratified drift 120

Black River 10 Morris 404934074400501 1991 Precambrian Erathem 200

LNAS-EC Ocean 400232074213201 1992 Kirkwood-Cohansey a.s. 38

Taylor Sussex 410914074540401 1988 Bossardville Limestone 95

Swartswood Park 5 Sussex 410449074483301 1991 Allentown Dolomite 148

Union County Park Union 404106074171901 1943 Passaic Formation 290

The monthly statistics and historical data are provided 

on the web page to put the current water level in context. 

The number of years of data used to calculate the statistics 

is provided first. Statistics on the water levels are provided 

in terms of the depth to water below land surface. The 

minimum depth to water for a well actually describes the 

highest water level measured in that well for the month, 

and the maximum depth to water describes the lowest water 

level for the month. The 75 and 25 percent exceedance 

values are the water levels that were surpassed by 75 and 
Future Sites

The ultimate goal of this joint effor of the USGS and 

the NJDEP is to establish a network of about 21 wells that 

will provide an even geographic and hydrologic distribution 

of real-time monitoring wells in order to characterize 

shallow-ground-water conditions statewide.

—Walter D. Jones, Anthony S. Navoy, and Daryll A. Pope

References Cited

Herman, G.C., Canace, R.J., Stanford, S.D., Pristas, R.S., 

Sugarman, P.J., French, M.A., Hoffman, J.L., Serfes, 

M.S., and Mennel, W.J., 1998, Aquifers of New Jersey: 

New Jersey Geological Survey, Open-File Map, OFM24, 1 sheet.

Hoffman, J. L., 2001, Development of New Jersey drought 

regions: New Jersey Geological Survey Technical 

Memorandum 01-1, 18 p.

Jones, W. D., 2002, Water Resources Data, New Jersey, 

Water Year 2001, Volume 2. Ground-Water Data: U. S. 

Geological Survey Water-Data Report NJ-01-2, 232 p.

Zapecza, O.S., 1989, Hydrogeologic framework of the New 

Jersey Coastal Plain: U. S. Geological Survey Professional Paper 1404-B, 49 p., 24 pl.

For more information

District Chief

U.S. Geological Survey

810 Bear Tavern Road, Suite 206

West Trenton, New Jersey 08628

email: dc_nj@usgs.gov

On the web: <http://nj.usgs.gov/>

Related Internet Links

The home page for the NJDEP is 

http://www.state.nj.us/dep/.

The NJDEP drought information web page is 

http://www.njdrought.org/.

The home page for the NJDEP New Jersey Geological 

Survey, which has information on aquifers and related data, 

is http://www.state.nj.us/dep/njgs/.

The home page for the NJDEP Water Supply 

Administration, which has information 

related to drought policy and declaration is 

http://www.state.nj.us/dep/watersupply/.

The home page for USGS water-resources information for 

New Jersey is http://nj.usgs.gov/.

The boundaries of the drought regions, as defined 

by NJDEP, are available as N.J. Geological 

Survey Digital Geodata Series data set DGS00-

1, “Drought Regions in New Jersey” at 

http://www.state.nj.us/dep/njgs/geodata/dgs00-1.htm.