NJ Water Hardness by Town: Real Utility Numbers for 20 Towns

The table lists NJ water hardness for each town we serve, sorted by the top of each published range. Hardness appears in two units because utilities and equipment do not speak the same one. Water systems report milligrams per liter as calcium carbonate, sometimes labeled ppm. Water softeners are sized in grains per gallon. The last column applies the USGS scale to the published mg/L range.

Six notes on the table, because the fine print is where most town-level hardness claims go wrong.

• Scotch Plains has the widest published spread. New Jersey American Water's Raritan System 3 sheet lists 90 to 600 mg/L and prints the conversion as 3 to 35 grains per gallon. The arithmetic on 90 mg/L gives 5.3, so we show 5.3 to 35.1.
• Springfield sits on its own zone sheet, and it is the hardest one the utility publishes for this area. New Jersey American Water posts a separate Short Hills sheet naming Springfield alone, fed by three wells in the Brunswick aquifer, at 240 to 293 mg/L, or 14.0 to 17.1 grains per gallon. It is easy to miss, because the Summit zone sheet is often quoted as if it covered the whole Short Hills system. It does not.
• Millburn and Short Hills have no zone sheet of their own. We could not find a typical water quality sheet naming Millburn, so that row uses the Short Hills system's 2025 annual water quality report instead, which lists total hardness of 52 to 342 ppm from 2024 sampling across the whole system.
• Watchung appears on two different sheets. It is named on the Short Hills Berkeley Heights sheet at 90 to 222 mg/L and on the Raritan System 3 sheet at 90 to 600 mg/L. We list the narrower figure, but a Watchung homeowner should treat the wider range as possible until a lab result says otherwise.
• Chatham is two water supplies under one name. Chatham Borough runs its own three wells, and its annual report does not contain the word hardness anywhere. New Jersey American Water's Chatham zone sheet, which names both the Borough and the Township, publishes 92 to 160 mg/L for the purchased surface water it delivers. For a Borough well customer, the published number simply does not exist, and a certified lab test is the only way to get one.
• Florham Park publishes no hardness figure at all. The borough runs four of its own wells and its annual report never states total hardness, so the table says so rather than borrowing a number from a neighbour. The Southeast Morris County MUA, which also lists Florham Park among the municipalities it serves, publishes 33 to 430 mg/L in its own sources, and Madison next door averages 346 mg/L on the same buried valley groundwater. Both suggest hard to very hard water, but neither is a measurement of what comes out of a Florham Park tap. A certified lab test is.

One more caveat on where these NJ water hardness figures come from. The typical water quality sheets are useful but old. The copies on the utility's site were posted in 2020 and carry no sampling year, so treat them as typical rather than current. The annual water quality reports are the fresher documents.

Every NJ water hardness category in the table above comes from one scale. The USGS classifies hardness in milligrams per liter of calcium carbonate, and its bands read: 0 to 60 mg/L is soft, 61 to 120 mg/L is moderately hard, 121 to 180 mg/L is hard, and more than 180 mg/L is very hard. That is what the last column of the table applies.

Softener equipment does not use those units. It is sized in grains per gallon, where one grain per gallon equals about 17.1 mg/L. You do not have to take our word for that conversion, because New Jersey utilities print both units themselves. The Summit zone sheet lists 80 to 240 mg/L on one line and 4.7 to 14.0 grains per gallon on the next. Livingston's report prints the state's 250 ppm recommended upper limit for hardness as 14.6 grains per gallon. Both land right around 17.

Run the USGS scale through that conversion and the softener-side version looks like this:

• Under 3.5 grains per gallon: soft
• 3.5 to 7 grains per gallon: moderately hard
• 7 to 10.5 grains per gallon: hard
• Above 10.5 grains per gallon: very hard

Most homes in our service area land in the upper two bands. One more number is worth knowing. New Jersey's recommended upper limit for hardness is 250 mg/L, set at N.J.A.C. 7:10-7.2 among the state's secondary drinking water regulations, which address taste, odor and appearance rather than safety. That is 14.6 grains per gallon. Livingston's report lists hardness against that limit and marks the result as not achieved. Madison's report shows a 346 ppm average from 2023 sampling against the same 250 ppm limit.

Hardness is calcium and magnesium that water picked up from rock. So the question of why NJ water hardness swings from 6 grains per gallon to 35 within a few miles is really a question about geology and plumbing.

Surface water is the softer end. The Raritan system draws from seven intakes on the Raritan River, the Millstone River and the Delaware and Raritan Canal. River water spends far less time in contact with mineral-bearing rock than groundwater does, and it shows. The Raritan System 1 sheet covering Westfield and Cranford lists those intakes as the only source, with no wells, and gives a tight 104 to 130 mg/L. That is the most predictable water on this list, and it is the only pure surface-water zone on it.

Groundwater is the harder end. Madison's five wells and Chatham Borough's three wells draw from the Buried Valley Aquifer system. Livingston's fourteen wells draw from the same aquifer system. Water sitting in those formations dissolves calcium and magnesium for years before anyone pumps it, which is why Madison reports 320 to 380 mg/L and Livingston reports an average of 332 mg/L with 2024 samples reaching 505. Springfield tells the same story from a different formation: three wells in the Brunswick aquifer, 240 to 293 mg/L, very hard from end to end.

Blended systems are why the ranges get so wide. The Summit zone of the Short Hills system mixes surface water from two Canoe Brook plants on the Passaic River, water purchased from the Raritan system and from the Passaic Valley Water Commission, and twelve wells in the Brunswick aquifer. Raritan System 3, which serves Scotch Plains and names Watchung, blends those same river intakes with roughly 98 wells across the Brunswick, Passaic, Stockton, Glacial Drift and Basalt aquifers. When the mix reaching your street shifts with season and demand, your hardness shifts with it.

You can see that in the sampling data. The Short Hills system's 2025 annual report measured total hardness across 2024 at 52 to 342 ppm. The low end of that range is soft on the USGS scale. The high end is very hard. Same system, same year.

Homeowners often assume that if NJ water hardness were a real problem, the utility would deal with it. New Jersey utilities generally do not, and the reasons are on the record.

New Jersey American Water's own water quality FAQ treats hardness as a customer matter rather than a treatment step. It explains that hardness is a term used to describe the high level of calcium and magnesium in the water, and that excessive hardness can cause scale (white spots) to be deposited in boilers, pipelines, faucet aerators and shower heads. On equipment, the company's stated position is that the decision to purchase a home water softener is therefore one of personal preference. Nowhere does it say the utility softens the water before delivering it.

There is a regulatory reason behind that. Hardness has no maximum contaminant level in New Jersey, and it does not appear at all in the EPA's national secondary drinking water regulations, because calcium and magnesium are not treated as health contaminants. New Jersey's 250 mg/L figure is a recommended upper limit under N.J.A.C. 7:10-7, the state's secondary drinking water rules. Those rules are not toothless, since NJDEP may require treatment at an existing system if an exceedance causes adverse effects on customers, but exceeding a recommended upper limit is not the same as violating a drinking water standard. Livingston's report shows a system reporting hardness well above the limit and marking it as not achieved.

New Jersey does contemplate municipal softening, and regulates it when it happens. Under N.J.A.C. 7:10-11.15, a public community water supply may not be softened to zero hardness, and softened water must be blended so that what reaches distribution keeps a minimum hardness of 50 mg/L as calcium carbonate. Even where a system softens, in other words, it is required to leave some hardness in.

The practical result for a New Jersey homeowner is simple. Whatever hardness the aquifer or the river hands your utility is close to what arrives at your tap. If you want it removed, that happens inside your house or it does not happen.

No rule triggers a softener at a set hardness, so the useful way to read your NJ water hardness number is to ask what it costs you.

Below about 3.5 grains per gallon, water is soft and a softener has nothing to do. No town in our area sits there. From roughly 3.5 to 7 grains per gallon the water is moderately hard, and the effects are the slow ones the utility itself describes: spotting on glassware and fixtures, scale in aerators and shower heads, more soap for the same result. Plenty of Westfield and Cranford homeowners live with that for years without acting, and it is a reasonable choice.

From about 7 to 10.5 grains per gallon, scale starts collecting where it costs you rather than where it annoys you, including inside the water heater and, on tankless units, inside the heat exchanger. Above 10.5 grains the water is very hard and the case gets straightforward. At Madison's 18.7 to 22.2 grains, Livingston's 19.4 average or Springfield's 14.0 to 17.1, a household burns through softening capacity two to three times faster than a home at 7 grains, so sizing stops being a formality and becomes the whole job.

If you decide to treat it, a cation exchange water softener is the equipment category that removes hardness, and NSF/ANSI 44 is the standard those units are certified to for reduction of hardness. Sizing is your grains per gallon multiplied by your household's daily water use, which is why the number in the table matters before anyone quotes equipment. A softener also trades calcium and magnesium for sodium, which New Jersey American Water notes in the same FAQ, and New Jersey's recommended upper limit for sodium in drinking water is 50 mg/L. That is one reason some households run potassium chloride instead, or pair a softener with a reverse osmosis unit certified to NSF/ANSI 58 at the kitchen tap.

Jersey Water Pros is based in Summit, and installs are performed by licensed NJ master plumbers. If you want the sizing math run for your own house, the free quote at /free-estimate covers it, with no water test used as a sales device.

Two documents carry NJ water hardness numbers, and knowing which one to open saves a lot of time.

The annual water quality report, sometimes called a consumer confidence report or CCR, is the one your utility mails or posts every year. Look for a table headed secondary substances, secondary compounds or secondary contaminants, then find the row labeled hardness or total hardness. Municipal utilities like Madison and Livingston list it there, with an average, a range, the sampling year and the 250 ppm recommended upper limit beside it. Livingston prints grains per gallon as its own row, which is unusually helpful.

Here is the catch that trips people up. Not every report includes hardness, because no rule requires a system to report it. The Raritan system's 2025 annual report does not list hardness anywhere, and neither does Chatham Borough's. If your report has no hardness row, that is not an oversight you can appeal. It is a document that was never going to answer the question.

For New Jersey American Water customers, a second document sometimes fills that gap. The company publishes a typical water quality sheet for individual service zones, listing hardness in both mg/L and grains per gallon alongside the source water and the disinfectant used. Zones are defined by town and ZIP code, so confirm your own town appears on the sheet you are reading. Westfield, Scotch Plains and Springfield sit on three different sheets with very different numbers, and not every town has a sheet at all.

When the published figure is missing, too wide to size equipment against, or simply not yours, the official answer comes from an NJDEP-certified laboratory testing your own tap. Jersey Water Pros does not test water. We help arrange testing through a certified lab and then work from the result. For a whole-house picture of what treatment would involve, the free in-home quote is the next step.

Reading about water quality is useful right up to the point where you need your own numbers. On city water, start with the annual water quality report your utility is required to publish. It lists what was detected and at what level, and it is free. On a private well, nothing is measured unless you order it, and only a laboratory certified by NJDEP produces results that count for a real estate transaction or a health decision. We help homeowners arrange that testing and read the results, and we do not run our own testing or use a countertop demonstration to sell equipment.

Once the numbers are in front of you, the treatment decision gets simple, because each problem has a proven fix and a certification that proves the equipment does what it claims. You can also check your town’s water profile for the utility serving your street and its published hardness, or size a system yourself with our softener size calculator.

Jersey Water Pros is based in Summit and serves Union, Essex & Morris County, NJ. Every system we install is performed by a licensed New Jersey master plumber, permitted and inspected the way the state requires, and quoted in writing before any work starts. If your water turns out not to need treatment, we will tell you that instead of selling you something.