Local tap report · checked August 12, 2026
Mountainside tap water: what the 2025 report says
Mountainside is served within New Jersey American Water’s Raritan System. This guide uses the current Raritan report—not Berkeley Heights’ Short Hills data—and adds the borough’s current water-main project record.
New Jersey American Water states the Raritan System met state and federal drinking-water requirements in 2025. The report also carries forward follow-up work from a 2024 coliform assessment. The report’s results and prior-year assessment apply at the system level; they do not describe one Mountainside street or faucet.
Scope: These are Raritan System results, not a test of your Mountainside home.
The rating
Why the public information scored 95/100
This score measures whether a resident can find, understand and act on public information. It does not score water quality or faucet safety, and higher contaminant readings do not automatically lower it.
The current official report is detailed about sources, treatment, household plumbing and customer help. Taste-and-scale context receives 15/20 because it reports sodium and manganese but no current hardness or scale range.
The supply
A large water system—not one neighborhood sample
- Utility
- New Jersey American Water
- Water system
- Raritan System
- Public system ID
- NJ2004002
- Report year
- 2025
The utility reports 92% surface water and 8% groundwater. Sources include the Millstone and Raritan rivers, the Delaware & Raritan Canal, 98 wells, seven surface-water intakes and one purchased surface-water source.
Groundwater supplies are disinfected with chlorine; surface water is treated with chloramines, according to the utility report.
Open the official 2025 Raritan System report ↗What the utility reported
Four results worth understanding
90th percentile; 54 homes were sampled and none were above the action level. The program was marked compliant.
Highest result; the report lists a range from not detected to 7 ppt and marks compliance achieved.
Highest result; the report lists a range from not detected to 6 ppt and marks compliance achieved.
The report treats sodium as an informational result and notes possible relevance for people on sodium-restricted diets.
The 2 ppb lead result is a system 90th-percentile statistic. The report explains that service lines and indoor plumbing are common lead sources, so one address can differ and only testing can answer the faucet-level question.
The follow-up record
A prior-year assessment still worth knowing
The 2025 report says total-coliform sampling was 0% positive and compliant. It also explains that 2024 findings triggered a Level 1 system assessment and nine corrective actions.
Eight actions were complete when the report was published. New Jersey’s environmental agency approved a schedule for the remaining action to be completed by the end of 2026.
This is system-level context. It is not a current Mountainside faucet result or a substitute for current utility alerts.
What is local to Mountainside
Five roads are in the current main-replacement plan
Mountainside’s 2026 project notice lists water-main replacement work on Short Drive, Ridge Road, Heckel Drive, Puddingstone Way and Sunnyview Drive.
A separate December 2024 Raritan-system taste-and-odor event included Mountainside. New Jersey American Water said no drinking-water advisory was in effect while the utility and state monitored the source. That historical event is context—not a statement about today’s water.
What it cannot tell you
Your faucet can be different
This report covers a large water system. Source mix, distribution conditions, a service line and indoor plumbing can all change what is present at one address. EPA says testing is the only sure way to know whether lead is present in the drinking water at your faucet.
Sources
Go straight to the record
- New Jersey American Water2025 Annual Water Quality Report — Raritan SystemOpen source ↗
- U.S. Environmental Protection AgencySafe Drinking Water Information System — NJ2004002Open source ↗
- U.S. Environmental Protection AgencyUnderstanding your annual water quality reportOpen source ↗
- U.S. Environmental Protection AgencyHow can I tell if my water contains lead?Open source ↗
- New Jersey American Water2026 foundational filing and service-area exhibitsOpen source ↗
- Borough of Mountainside2026 American Water main-replacement projectOpen source ↗
- New Jersey American WaterRaritan System taste-and-odor monitoring updateOpen source ↗
Sources checked August 12, 2026. System values describe the utility network, not a RatingWater sample.
Nearby refill option · Berkeley Heights
Prefer a large-bottle refill?
Purity Water refills 3-, 4- and 5-gallon bottles in Berkeley Heights. That may suit a household looking for a different taste, less mineral scale or a refill routine; it is not evidence that tap water is unsafe.
Purity’s service details come from its published website and are kept separate from this tap report. RatingWater has not tested Purity’s water or water from your faucet.