Septic or sewer? How to tell, and what your town actually has
The fastest answer is your bill: nobody charges you to use your own septic tank. Below that, five checks that settle it for your property, and then the part nobody else publishes, which is what public water and sewer actually reach in all 85 municipalities of Sussex, Warren, Morris County, from the state's own maps. 30 of them, about 35 percent, have effectively neither.
Five ways to tell, for your own house
- Read your bill. A sewer or wastewater charge from a town, an MUA or a sewerage authority means public sewer. There is no such thing as a bill for using your own septic tank. This settles it more often than anything else on this list.
- Look for the lid. A septic tank sits roughly eight to fifteen feet from the house, and there is normally a lid or an inspection port at grade or just under it. A metal detector or a probe finds it quickly if the yard has grown over.
- Watch the lawn. A drain field behaves differently from the rest of the yard. It greens up sooner, dries first after rain, and in a hard frost it is often the strip that thaws early. If part of your lawn has always been odd, that is frequently why.
- Find the cleanout. A sewered house usually has a capped cleanout near where the lateral heads toward the street. A septic house has its access on the tank side instead.
- Ask the town. The municipal construction or health department holds the septic permit if one was ever issued, and the sewer connection record if there is one. Your closing documents often name the system too.
If you have just been told there is a problem with the line either way, our post on what a failed sewer scope really means covers which camera findings are serious and which get oversold.
What your town has
New Jersey publishes both halves of this and never puts them together. NJDEP maps where public water is actually delivered, and separately maps where sewer service is planned. Joined against municipal boundaries, the two of them sort every town into one of four situations.
Note the last box. Not one municipality here is well country with public sewer, and that is the most useful single fact on this page. Public water arrives first and sewer follows the places that already have it, so if you are on a well you should expect to be on septic.
| Town | County | Public water | Sewer area | Situation | Main plant |
|---|---|---|---|---|---|
| Andover Borough | Sussex | 65.8% | 35.7% | Mixed, depends where you are | Sussex Properties Inc Andover Twp WTP |
| Andover Township | Sussex | 5.2% | 1.2% | Wells and septic | none mapped |
| Branchville | Sussex | 99.4% | 79% | Public water and sewer | Branchville Borough WTP aka SCMUA Paulins Kill STP |
| Byram | Sussex | 8.8% | 1.6% | Wells and septic | none mapped |
| Frankford | Sussex | 0.1% | 1.1% | Wells and septic | none mapped |
| Franklin Borough | Sussex | 30.4% | 45.3% | Mixed, depends where you are | Sussex County MUA Upper Wallkill WPCF |
| Fredon | Sussex | 2.8% | 1.4% | Wells and septic | none mapped |
| Green | Sussex | 5.5% | 0.7% | Wells and septic | none mapped |
| Hamburg | Sussex | 99.9% | 74.8% | Public water and sewer | Sussex County MUA Upper Wallkill WPCF |
| Hampton Township | Sussex | 1% | 2.7% | Wells and septic | none mapped |
| Hardyston | Sussex | 3.1% | 8.5% | Wells and septic | Sussex County MUA Upper Wallkill WPCF |
| Hopatcong | Sussex | 24.1% | 31.5% | Mixed, depends where you are | Musconetcong STP |
| Lafayette | Sussex | 1.4% | 2.3% | Wells and septic | none mapped |
| Montague | Sussex | 2.1% | 0.6% | Wells and septic | none mapped |
| Newton | Sussex | 88.4% | 72.8% | Public water and sewer | Newton WWTP |
| Ogdensburg | Sussex | 99.5% | none | Public water, septic | none mapped |
| Sandyston | Sussex | none | none | Wells and septic | none mapped |
| Sparta | Sussex | 34.7% | 2.5% | Mixed, depends where you are | none mapped |
| Stanhope | Sussex | 63.1% | 50.1% | Mixed, depends where you are | Musconetcong STP |
| Stillwater | Sussex | 1.8% | 0.3% | Wells and septic | none mapped |
| Sussex | Sussex | 94% | 84.6% | Public water and sewer | Sussex County MUA Upper Wallkill WPCF |
| Vernon | Sussex | 3.1% | 3.4% | Wells and septic | none mapped |
| Walpack | Sussex | none | none | Wells and septic | none mapped |
| Wantage | Sussex | 2.2% | 0.7% | Wells and septic | none mapped |
| Allamuchy | Warren | 7.9% | 14.6% | Wells and septic | Pequest Sewer Company |
| Alpha | Warren | 93.7% | 61.1% | Public water and sewer | Phillipsburg STP |
| Belvidere | Warren | 99.2% | 79.2% | Public water and sewer | Belvidere Area WWTF |
| Blairstown | Warren | 1.4% | none | Wells and septic | none mapped |
| Franklin Township | Warren | 99.4% | 1.5% | Public water, septic | none mapped |
| Frelinghuysen | Warren | 0.1% | 5.6% | Wells and septic | none mapped |
| Greenwich | Warren | 20.2% | 25.7% | Mixed, depends where you are | Phillipsburg STP |
| Hackettstown | Warren | 95% | 57.7% | Public water and sewer | Hackettstown WPCF |
| Hardwick | Warren | none | none | Wells and septic | none mapped |
| Harmony | Warren | 0.2% | 0.5% | Wells and septic | none mapped |
| Hope | Warren | none | none | Wells and septic | none mapped |
| Independence | Warren | 14.8% | 2.7% | Wells and septic | none mapped |
| Knowlton | Warren | none | 1% | Wells and septic | none mapped |
| Liberty | Warren | none | none | Wells and septic | none mapped |
| Lopatcong | Warren | 49.6% | 30.9% | Mixed, depends where you are | Phillipsburg STP |
| Mansfield | Warren | 12.6% | 6% | Wells and septic | Hackettstown WPCF |
| Oxford | Warren | 99.9% | 40.9% | Mixed, depends where you are | Oxford Service Area |
| Phillipsburg | Warren | 81.9% | 94% | Public water and sewer | Phillipsburg STP |
| Pohatcong | Warren | 8.7% | 7% | Wells and septic | Phillipsburg STP |
| Washington Borough | Warren | 100% | 77.8% | Public water and sewer | Boro of Washington WTF |
| Washington Township | Warren | 99.7% | 7% | Public water, septic | none mapped |
| White | Warren | 99.5% | 8.1% | Public water, septic | Belvidere Area WWTF |
| Boonton Town | Morris | 84.3% | 87.9% | Public water and sewer | Rockaway Valley Regional SA |
| Boonton Township | Morris | 6.4% | 14.7% | Wells and septic | Rockaway Valley Regional SA |
| Butler | Morris | 100% | 94.1% | Public water and sewer | Two Bridges SA |
| Chatham Borough | Morris | 100% | 79.7% | Public water and sewer | Molitor WPCF Madison Chatham Joint Meeting STP |
| Chatham Township | Morris | 99.9% | 73.5% | Public water and sewer | Chatham Twp WPCP 1 |
| Chester Borough | Morris | 99.6% | none | Public water, septic | none mapped |
| Chester Township | Morris | 4.7% | none | Wells and septic | none mapped |
| Denville | Morris | 98.8% | 62.6% | Public water and sewer | Rockaway Valley Regional SA |
| Dover | Morris | 100% | 84.7% | Public water and sewer | Rockaway Valley Regional SA |
| East Hanover | Morris | 97.3% | 68.5% | Public water and sewer | Parsippany Troy Hills STP |
| Florham Park | Morris | 91.3% | 76.5% | Public water and sewer | Florham Park Sewer Utility STP |
| Hanover | Morris | 100% | 80.1% | Public water and sewer | Hanover SA WWTP |
| Harding | Morris | 16.2% | 1.8% | Wells and septic | none mapped |
| Jefferson | Morris | 14.9% | 7.9% | Wells and septic | Musconetcong STP |
| Kinnelon | Morris | 17.7% | 1.6% | Wells and septic | none mapped |
| Lincoln Park | Morris | 56.5% | 43.7% | Mixed, depends where you are | Two Bridges SA |
| Long Hill | Morris | 100% | 34.4% | Mixed, depends where you are | Long Hill Twp STP |
| Madison | Morris | 100% | 95.4% | Public water and sewer | Molitor WPCF Madison Chatham Joint Meeting STP |
| Mendham Borough | Morris | 100% | 37.8% | Mixed, depends where you are | Mendham Borough STP |
| Mendham Township | Morris | 44.7% | 3.9% | Mixed, depends where you are | none mapped |
| Mine Hill | Morris | 72.8% | 33.1% | Mixed, depends where you are | Rockaway Valley Regional SA |
| Montville | Morris | 37.7% | 55.7% | Mixed, depends where you are | Parsippany Troy Hills STP |
| Morris | Morris | 99.9% | 78.3% | Public water and sewer | Woodland STP |
| Morris Plains | Morris | 100% | 93.7% | Public water and sewer | Butterworth STP |
| Morristown | Morris | 100% | 95.7% | Public water and sewer | Morristown STP |
| Mount Arlington | Morris | 77.6% | 58.3% | Public water and sewer | Musconetcong STP |
| Mount Olive | Morris | 31.7% | 22.3% | Mixed, depends where you are | Musconetcong STP |
| Mountain Lakes | Morris | 97.8% | 71.5% | Public water and sewer | Parsippany Troy Hills STP |
| Netcong | Morris | 86.6% | 86.3% | Public water and sewer | Musconetcong STP |
| Parsippany-Troy Hills | Morris | 88.9% | 83.8% | Public water and sewer | Parsippany Troy Hills STP |
| Pequannock | Morris | 63.9% | 69.3% | Public water and sewer | Two Bridges SA |
| Randolph | Morris | 99.5% | 57.7% | Public water and sewer | Rockaway Valley Regional SA |
| Riverdale | Morris | 62.1% | 82.5% | Public water and sewer | Two Bridges SA |
| Rockaway Borough | Morris | 100% | 84.3% | Public water and sewer | Rockaway Valley Regional SA |
| Rockaway Township | Morris | 33.5% | 29.2% | Mixed, depends where you are | Rockaway Valley Regional SA |
| Roxbury | Morris | 49.8% | 51.2% | Mixed, depends where you are | Ajax Terrace WPCP |
| Victory Gardens | Morris | 100% | 100% | Public water and sewer | Rockaway Valley Regional SA |
| Washington Township | Morris | 22.7% | 8.2% | Mixed, depends where you are | none mapped |
| Wharton | Morris | 99.6% | 98.3% | Public water and sewer | Rockaway Valley Regional SA |
How to read this without getting it wrong
Both numbers are shares of the town's land area, not of its homes. A dense borough centre can hold most of a town's houses on a small share of its acreage, so a town reading low can still have most residents served. Expect the wells and the septic systems to be the outlying properties on the bigger lots.
And a sewer service area is a planning designation. It marks where a county wastewater management plan says sewer service is planned and permitted. It does not say a main runs past any particular house, and plenty of properties sit inside one on septic for decades. Proposed treatment facilities are excluded from these numbers entirely, because counting a plant that does not exist as service would simply be false.
6 municipalities have no mapped public water delivery area at all: Sandyston, Walpack, Hardwick, Hope, Knowlton, Liberty. That does not mean every property there stands alone. A system serving fewer than fifteen year-round connections falls below the threshold the state maps, so shared wells and small association systems exist without appearing anywhere. 9 have no mapped sewer service area at all: Ogdensburg, Sandyston, Walpack, Blairstown, Hardwick, Hope, Liberty, Chester Borough, Chester Township.
Why it changes what work costs
On sewer, you own the lateral, in most New Jersey towns all the way to the main under the street. A repair that stays in the lawn and a repair that reaches the road are different jobs with different bills, because the road brings an opening permit and municipal restoration with it. On septic, the tank, the distribution box and the drain field are all things that must not be driven over, built on or trenched through, and the system is regulated locally under N.J.A.C. 7:9A by your municipal or county health department rather than by NJDEP directly.
There is one more thing worth knowing before any machine arrives. New Jersey's One Call rules define an underground facility in a way that expressly excludes gravity sewers and storm drains, so your sewer lateral is never marked out. Water is marked, sewer is not, and somebody has to find it another way. That is covered in how a line actually gets replaced.
Questions people ask
How do I know if I have septic or sewer?
Start with your bill. A line item for sewer or wastewater from your town, a municipal utilities authority or a sewerage authority means you are on public sewer, because nobody bills you to use your own septic tank. Then look at the ground: a septic system leaves a tank lid and often an inspection port in the yard, usually eight to fifteen feet from the house, and the drain field is the area of lawn that greens up differently or dries first after rain. Inside, a septic house normally has a single main drain line leaving through the foundation toward the tank, while a sewered house has a cleanout near where the lateral heads to the street. Your town's construction or health department has the septic permit on file if one was ever issued, and the property deed and title work from your purchase often name the system. If you are on septic you will also have a pumping history, so ask the previous owner or the local pumping companies.
Which New Jersey towns are on wells and septic rather than public water and sewer?
Across the 85 municipalities in Sussex, Warren and Morris Counties, 30 of them, about 35 percent, are well and septic country: less than a fifth of the town's land area sits inside either a public water delivery area or a mapped sewer service area. 32 towns have both across most of their area. 5 have public water but no meaningful sewer service area, which is a real and often surprising combination. 6 municipalities have no mapped public water delivery area anywhere inside them at all.
Can a town have public sewer but no public water?
Not in this region. Across all 85 municipalities, none is well country with public sewer. Sewer coverage does exceed water coverage in 19 towns, but never by enough to change the category. That ordering is not a coincidence: sewering a neighbourhood only makes sense once density and water supply justify it, so public water arrives first and sewer follows the places that already have it. If you are on a well, you should expect to be on septic, and if somebody tells you otherwise it is worth confirming.
Does this page tell me whether my own house is on sewer?
No, and it is important that it does not pretend to. The percentages here are shares of a town's land area inside a mapped service area, not shares of homes, and a sewer service area is a planning designation that says service is planned and permitted there, not that a main runs past a particular property. A house can sit inside a sewer service area and still be on septic, sometimes for decades. Use this page to know what exists in your town and what is plausible for your address, then confirm your own property with the checks in the first answer.
Why does it matter whether I am on septic or sewer before I dig?
Because it changes what is in the ground and who is responsible for it. On sewer, you own the lateral, in most New Jersey towns all the way to the main under the street, so a repair that reaches the road brings a road opening permit and municipal restoration with it. On septic, you have a tank, a distribution box and a drain field that must not be driven over, built on or trenched through, and the system is governed locally under N.J.A.C. 7:9A by your municipal or county health department rather than by NJDEP directly. Either way the sewer lateral itself is worth knowing about before a machine arrives, because New Jersey's One Call rules exclude gravity sewers from the facilities that get marked out.
What does the percentage in the table actually measure?
The share of the municipality's land area inside a mapped service area, never the share of homes. A compact borough centre can hold most of a town's houses on a small slice of its acreage, so a town reading 24 percent by land area can still have most of its residents served. Read a low number as most of the ground being unserved and expect the well and septic properties to be the outlying ones on larger lots.
My town shows a treatment plant but almost no coverage. What does that mean?
It usually means the plant is not a municipal system at all. The NJDEP layer includes on-site treatment works serving a single school, diner, campground, shopping centre or nursing home, and those appear alongside real municipal plants. A town can list eight or ten facilities and still be septic country, which is why this page ranks by share of land area rather than by how many facilities are named. Anything under five percent is not shown as the town's plant here.
Sources
- NJDEP Purveyor Service Areas of New Jersey, NJDEP's mapped public community water purveyor delivery areas. NJDEP is explicit that these are delivery areas and that franchise areas are not depicted.
- NJDEP Sewer Service Areas, NJDEP's mapped sewer service areas, retrieved 2026-08-25.
- Both joined to US Census 2020 county subdivision boundaries to produce a share of each municipality's land area. Slivers below 0.08 percent are dropped as boundary noise.
- Septic systems of 2,000 gallons per day or less are governed by N.J.A.C. 7:9A and administered by the local health department, municipal in some towns and county in others, rather than by NJDEP directly.
State files lag reality, and we would rather say so than pretend otherwise. Reviewed 2026-08-28. This is general information and not a determination about your property. Your municipality, your utility and your local health department have the final say.
More on water specifically in who supplies water in your NJ town, and on septic capacity in septic density across Sussex County.
Not sure what is under your property?
Call 862-268-2510. We work on both sides of this, septic and sewer, and we would rather tell you what you have than sell you what you do not need.
Call 862-268-2510