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Your Land & Water for October 2024

jhansen49

Updated: Oct 16, 2024




What's in this issue? Where does your drinking water come from? What is an aquifer? A new name for a new property thanks to the support of people like you!

Also a chance to help us know what you want to know about!


 

South Jersey Drinking Water: Groundwater  Resources and Issues


If you live in South Jersey, your drinking water comes all or in part from the ground, through  domestic or public supply wells. Depending on your location, it is either entirely groundwater or  it is a combination of groundwater and treated Delaware River water that is sent to your  community through miles of pipes. Most of us know little about our drinking water sources but  it’s a bit easier to understand in South Jersey than the complex systems of North Jersey, which  depend on several rivers and large reservoirs and/or on many smaller aquifers. 


All of South Jersey lies on the Coastal Plain of New Jersey (figure 1). The geological dividing line  between North and South Jersey is approximately at Route 1, running diagonally across the state.


The geology of the New Jersey Coastal Plain generally can be visualized as a tilted layer cake, with  its “layers” or strata formed of gravels, sands, silts, and clays (Figure 2) that were deposited as  river deltas, seafloor, and beaches starting from the time of the dinosaurs and continuing to the  present day. The saturated gravel and sand layers, with their large pore spaces, are called  aquifers. Wells draw water from the aquifers. The silt and clay layers, which impede the  movement of water, are called confining beds. Confining beds can isolate aquifers from sources  of contamination. 



A cross section across southern New Jersey from west to east would show that the layers are not horizontal but tilt downward toward the southeast, getting deeper as they cross the state toward the Atlantic Ocean. Because of this tilting, each layer formation emerges on the land surface in a sequential manner. The deepest formations emerge on the surface near the Delaware River. Where a formation emerges is its “outcrop” area. Figure 3 shows a map of Gloucester County as an example of the outcrops of each major aquifer as they are located on the surface. These aquifer outcrops extend north and south across Camden, Burlington, and Salem Counties.


Water enters each aquifer from rainfall directly on the outcrop, referred to as the recharge area. Local recharge from rainfall and infiltration from streams are the primary sources of water to the Coastal Plain aquifers.









THE AQUIFERS OF SOUTH JERSEY 

The Potomac-Raritan-Magothy (PRM) formation, the deepest and most abundant aquifer, is a  major water source for Inner Coastal Plain communities. The PRM exists from the Delaware River  and underlies the entire region.  


Other aquifers on top of the PRM are the Englishtown, the Wenonah-Mount Laurel, and the  Kirkwood-Cohansey. The Mt. Laurel-Wenonah underlies about two-thirds of the southwestern NJ  counties. The Kirkwood-Cohansey is a formation composed of two thick layers, the Kirkwood  (lower) and the Cohansey (upper) that overlie the older formations. It begins east of the  inner/outer coastal plain divide and underlies about half of South Jersey.  


WATER SUPPLY ISSUES 

Potomac-Raritan-Magothy Aquifer System (PRM): The PRM is a major source of drinking water  to New Jersey residents from Burlington to Salem counties, and regionally in the Camden  metropolitan area. The PRM yields the most water of the aquifers in South Jersey. It has a  relatively wide recharge area that includes direct contact with the Delaware River.  


Because of high usage, PRM aquifer water levels declined dramatically, beginning in the1930s.  The water level drop became so serious that the New Jersey Department of Environmental  Protection (NJ DEP) established Water Supply Critical Area #2 in 1986 (figure 4). All water supply  companies within Critical Area #2 were given annual limits on water withdrawals in the PRM.  Usage from the PRM was cut back by 22% and no increases in pumping were allowed.  



To fill the gap, piping of treated Delaware River water via the NJ American Water Company’s  treatment plant in Delran and a 40-mile pipeline were developed. Nearly all municipalities within  the Critical Area #2 now utilize a combination of aquifer water and treated river water during a  year. Only those communities that have good local access to the Cohansey-Kirkwood aquifer are  unconnected to the pipeline. 


OTHER THREATS TO THE AQUIFERS 

Potomac-Raritan-Magothy Aquifer 

The Delaware Riverfront of Camden and Gloucester Counties is home to many industries and  businesses. This same area also sits on the outcrop of the PRM aquifer. Contamination of the  aquifer from the land use, notably volatile organic compounds (VOCs), has occurred, making nearby parts of the aquifer nondrinkable. A further concern in this area is that during drought  and low flow periods, the reach of the Delaware River along the riverfront can be salty. If future  pumpage were to concentrate near the river, saltwater could invade the aquifer.  


Mt. Laurel Wenonah Aquifer: The Mt. Laurel-Wenonah is tapped by public water supplies and  individual domestic wells in the center of western South Jersey. The Mt. Laurel-Wenonah aquifer  has a narrower recharge area with more limited sources of rainwater recharge than the PRM. Its  permeability by rainwater is also lower. Therefore, its yield of drinkable water is much lower than  the PRM. With the implementation of Critical Area #2 for the PRM, pumpage from the Mt. Laurel  has increased as it is being used as an alternative supply. Consequently, water levels in the  aquifer have been declining. The iron content of water from the aquifer can also be high in some  places, making treatment necessary prior to use. 


Kirkwood-Cohansey Aquifer System: The Kirkwood-Cohansey is the primary source of water to  individual domestic wells, public water supplies, and irrigation wells from the central part of  Southern new Jersey to its southern border. This aquifer system is the uppermost, or surface  aquifer layer so it exists at land surface throughout the southern half of South Jersey. This  exposes the aquifer to a considerable amount of recharge from rainfall, but it also exposes it to  possible contamination from various land uses.  

Because of its surface position, the Kirkwood-Cohansey aquifer is connected to the streams of the  area. The baseflow of the streams (water not flowing directly from storm runoff) is groundwater  that enters (discharges to) the streams. This baseflow is the major part of the water of Coastal  Plain streams and sustains their flow during dry periods and drought.  



Any pumping from the aquifer will reduce the stream baseflow. If the well is too close to the  stream, its pumpage can dry up the stream. This situation results primarily from pumpage by  public water supply wells and tends to occur in late summer. 


There is also a net loss of water from the aquifer because of the subsequent exportation of the  resulting area sewage which is sent to treatment plants along the Delaware River and then  discharged into the river. Conversely, private home well pumpage uses less water and relies on waste disposal through septic tanks. This keeps the aquifer water nearer to its source and has less  of a depletion effect.  


The surface nature of the Kirkwood-Cohansey makes it vulnerable to contamination from various  land uses. Industrial chemicals (VOCs), agricultural chemicals used for crop production, and  residential landscaping, pesticides, and products of septic tank effluent have all been found in  water from the aquifer. Recently radium and mercury have been found in the water from the  aquifer. Where possible, care must be taken to site wells to avoid proximity to harmful land use  and contamination. Also, a high priority must be given to maintaining a routine water-quality  monitoring program for all wells, including private domestic wells, to ensure that contamination  would be detected before any harmful consequences are realized. 


Your South Jersey Land & Water Trust works to preserve land that is important for groundwater  recharge and also monitors surface water conditions – the flow and quality of streams and rivers.  We all must advocate for good land use practices and maintaining high water quality standards to  protect our drinking water and preserve surface water habitats.  





Sources:

-This article is derived principally from the Anthony S. Navoy article. 

-Canace, Robert J. and Jeffrey L. Hoffman. Potential Rate of Stream-Base-Flow Depletion from Groundwater Use in  New Jersey. NJ Geological Survey, Technical memorandum 09-1. Trenton, NJ, New Jersey Department of  Environmental Protection, 2009. 

-Forsman, Charles R. Compilation of records from Tri-County files and his personal experience on the Tri-County  Board. 

-McCarthy, Suzanne B. Compilation of the history of the Tri-County Water Management Area from Tri-County files  held by the Delaware Valley Regional Planning Commission, personal communication. 

-Navoy, Anthony S. “Gloucester County Ground-Water Resources and Issues.” Watershed News Early Spring 2001.  The Newsletter of the Federation of Gloucester County Watersheds and the South Jersey Land Trust, Gloucester  Co., April 2001.  

-Zapecza, Otto S. Hydrogeologic Framework of the New Jersey Coastal Plain. US Geological Survey Professional Paper  1404-B. Washington D.C.: United States Government Printing Office, 1989.


 

Schipani-Hallissey Property becomes the Franklin Indian Branch Preserve


The Schipani-Hallissey property, located at the intersection of Main and Tuckahoe Roads in Franklin Township, is now named the Franklin Indian Branch Preserve thanks to your votes! Several weeks ago we collected your answers to our poll of what the new name should be and we are proud to announce the official new name.



This is a lovely piece of land that is fully forested and was never farmed.  That makes it good habitat for wildlife, including birds that breed in our area or migrate through, especially in the fall, and crucial winter roosting sites for raptors.  It is 143.5 acres in size and is dominated by mixed pitch pine and oak trees. Interestingly, this property has one of the highest “recharge” rates in Franklin Township. That means that when it rains, as much as 11 – 14 inches of rain percolate each year through the forest into the groundwater and refill the aquifer below. This is an important feature because everyone in South Jersey relies to some extent on wells that tap our aquifers for their drinking water, as seen in the article above!


Like most forest preservation projects, this one was the work of many people and organizations, led by the South Jersey Land & Water Trust. The New Jersey Conservation Foundation was a key partner and the funding for the land came from New Jersey’s Green Acres Program and its Office of Natural Resource Restoration. Natural Lands of PA also partnered through providing funding towards the completion of the environmental assessment. Franklin Township contributed funds to cover all the “soft” costs – the appraisals, survey, and closing costs. The owners, William Hallissey and the estate of Louis Schipani, made a generous contribution of half the value of the property.


 

South Jersey Land & Water Trust Feedback Survey


As we approach the new year we want to know what you would like to know about and we need your help! We ask you to take this quick survey to let us know how best we can serve you in the upcoming year. We greatly value your opinion and appreciate your cooperation!





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South Jersey Land & Water Trust
21 Main Street/Auburn-Pointers Rd.,

Auburn, NJ 08085

Tel: 856-376-3622

cnolan@sjlandwater.org

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