Private Wells in Cape May County, NJ: Saltwater Intrusion

Cape May County sits on a peninsula with five distinct aquifers, and salt water has been creeping into several of them for over sixty years -- forcing the abandonment of public, industrial, and more than a hundred domestic wells countywide. For anyone planning a new well on inland or bayshore land here, that history is not optional background reading.

This page covers what's specific to Cape May County. For the general explanation, see the national guide.

A documented, decades-long problem -- not a hypothetical risk

The U.S. Geological Survey's own hydrogeologic study of Cape May County found that during 1960-1990 alone, saltwater intrusion forced the abandonment of at least 10 public-supply wells, 3 industrial-supply wells, and more than 100 domestic-supply wells across the county. That's not an isolated historical event -- more recent secondary reporting (WHYY, NJ Spotlight News) documents salt water continuing to creep into private wells and some deeper aquifers on the Cape May peninsula as of recent years, driven primarily by freshwater withdrawal drawing down aquifer levels and worsened by ongoing sea-level rise. Lower Township has responded in some affected areas by extending municipal water lines specifically to serve properties with documented saltwater intrusion and VOC contamination issues -- itself a sign of how localized and persistent the problem is in specific parts of the county.

Cape May County draws its groundwater from five distinct aquifers -- the Holly Beach water-bearing zone, the estuarine sand aquifer, the Cohansey aquifer, the Rio Grande water-bearing zone, and the Atlantic City 800-foot sand -- and they are not equally vulnerable. Historically, shallower aquifers nearer the coast and heavily-pumped areas have been hit hardest, which is part of why deeper wells drawing from the Atlantic City 800-foot sand or similarly protected zones have become a more common target for new construction in vulnerable areas, though depth alone is not a guarantee against future intrusion as withdrawal patterns and sea levels continue to shift.

Monitoring, and why "still below the limit" is not the same as "safe long-term"

New Jersey's Department of Environmental Protection tracks salinity through a network of "sentinel" wells specifically designed to give early warning of saltwater intrusion before it reaches drinking-water wells. As of recent public reporting, salinity levels in roughly two dozen of these Cape May County sentinel wells remain below the state's regulatory limits -- but the same reporting is explicit that coastal communities are being urged to consider their long-term water-supply options given the trend, not treated as a solved problem. A buyer should read "currently below the limit" as a snapshot in an ongoing, documented trend, not as a permanent assurance for a specific well site over a multi-decade ownership horizon.

New Jersey's statewide well construction and permitting rules (N.J.A.C. 7:9D) apply here as everywhere -- all permit applications, well records, and decommissioning reports go through NJDEP's e-Permitting portal, and only licensed well drillers and pump installers (per N.J.S.A. 58:4A-11) may perform the work, with as-built well records due within 90 days of completion. Cape May County does not appear to layer additional county-specific well-siting restrictions on top of the state process based on available research, but a buyer should confirm directly with NJDEP's Bureau of Water Allocation and Well Permitting (wellpermitting@dep.nj.gov) whether any county- or municipality-specific siting guidance applies to a given parcel, especially one near the coast or in a documented intrusion-affected area.

What to actually check before relying on a well for inland Cape May County land

Before assuming a new well is a safe, permanent water source on a specific Cape May County parcel, ask NJDEP directly (or a local licensed well driller with Cape May County-specific experience) which aquifer realistically serves that location and whether it has a documented history of salinity issues -- proximity to the bay or ocean is a reasonable first flag, but intrusion has also affected wells further inland than a buyer might assume, since the mechanism is aquifer-level drawdown, not simple surface distance from salt water. If you're buying an existing property with an established well, request its full water-quality testing history, not just a single point-of-sale test: under New Jersey's Private Well Testing Act, a potable well must be tested at every property transaction (up to 43 parameters, including mercury, which is specifically required for Cape May County among other counties), but a one-time test at closing won't show a slow-developing salinity trend the way a testing history would.

Finally, ask whether municipal water is available or planned for the specific area -- Lower Township's own history of extending water lines to intrusion-affected neighborhoods shows this is a real, active mitigation path in parts of the county, and a parcel near the edge of an existing water-line extension may have a materially better long-term water-supply outlook than one relying solely on a new private well in a documented-risk area.

Private Wells in Cape May County: Saltwater Intrusion and What to Check

A documented, decades-long problem -- not a hypothetical risk

Monitoring, and why "still below the limit" is not the same as "safe long-term"

What to actually check before relying on a well for inland Cape May County land

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