Cranston is served by two water utilities, and they don't carry the same things

Cranston is one of the few places in Rhode Island where your neighbor's tap water can come from a different system than yours. Part of the city is served by Providence Water, off the Scituate Reservoir. Part is served by Kent County Water Authority. Both utilities list Cranston among the towns they supply.^[1]

They don't deliver the same water. One side carries a trihalomethane level above both of the cancer thresholds in the published research. The other side carries ten PFAS compounds. Neither list is a copy of the other, and neither utility is breaking a law.

So the first job is finding out which one you're on. Look at your water bill and see whose name is on it. If your address is near a boundary and the bill doesn't settle it, call the utility named on it and ask which system feeds your street. We check it as part of the free in-home test, because the answer changes what we're testing for.

Is Cranston tap water safe to drink?

Both supplies meet the federal limits that apply to them. What's in them is a different question, and the honest answer for Cranston is that it depends on your address.

Here's the side-by-side. Every substance in this table has no federal limit at all, on either supply.^[2]

EPA has never written a Maximum Contaminant Level for any of them, which means a utility could report any figure at all for these six and still meet every federal drinking water standard in existence. Against the health guidelines the Environmental Working Group publishes, the Providence-side HAA9 reads 324 times its guideline and the Kent County figure 273 times.^[3][4]

Both sets come from the same chemistry. Chlorine kills what's living in the water and reacts with the organic material suspended in it, and these are what come out of that reaction.

Where do the two supplies actually differ?

Three places, and they matter.

Trihalomethanes. Providence Water reads 55.2 ppb. Kent County reads 49.9 ppb.^[3:1][4:1] A January 2025 dose-response meta-analysis in Environmental Health Perspectives found bladder cancer risk statistically significant above 41 µg/L, and concluded that US and EU regulatory limits "fail to protect against cancer in the general population."^[5] A Spanish case-control study of 1,219 cases and 1,271 controls put households averaging above 49 µg/L at an odds ratio of 2.10 for bladder cancer against households at or below 8 (95% CI 1.09 to 4.02).^[6] The Providence side clears both marks. The Kent County side clears the first and sits just over the second. Micrograms per liter and parts per billion are the same unit, and the federal ceiling for both is 80 ppb, written in 1998.^[7]

PFAS. Ten distinct PFAS compounds were detected in the Kent County system, four of them above health guidelines, with PFOA at 3.89 parts per trillion against a federal limit of 4.0.^[4:2] On the Providence Water side, federal UCMR5 sampling found no PFAS above the new limits and no PFAS compound appears among its flagged substances.^[3:2] That's a real difference between two halves of one city.

Lead history. Providence Water's 90th-percentile lead result came in above the federal action level of 0.015 mg/L three years running: 0.022 in 2018, 0.016 in 2019 and 0.0168 in 2020, falling to 0.0016 by 2025 after service line replacement work.^[1:1] Kent County has never crossed that action level on record and read 0.0014 mg/L in 2025. Neither figure describes your house, for reasons the next section gets into.

Which substances are on the Kent County side only?

The PFAS group, and it's the one where the regulatory situation is strangest.

Kent County's detections include PFHxS, PFOA, PFOS and 6:2 fluorotelomer sulfonic acid above health guidelines, plus six more compounds below them.^[4:3] When EPA finalized its PFAS rule in April 2024 it published two numbers for PFOA and PFOS: an enforceable limit of 4.0 ppt, and a health goal of zero.^[8] EPA defines that health goal as the level below which there's no known or expected risk to health.^[2:1] It set that level at nothing at all, then set the enforceable figure at what it judged achievable for utilities. The 4.0 is an engineering and cost judgment, not a safe dose.

Then the deadline moved. Utilities now have until April 2031 to comply.^[9] That's a five-year wait for anyone hoping the utility handles it.

ATSDR links PFAS exposure to kidney and testicular cancer, low birth weight, accelerated puberty, higher cholesterol, and reduced immune response including diminished vaccine effectiveness.^[10] On that last point, the Boston Birth Cohort measured PFAS in the plasma of 748 mothers and tracked their children's antibody responses after MMR vaccination. Maternal PFHxS was among the compounds significantly associated with lower measles antibody response, and PFHxS was a leading contributor when the whole PFAS mixture was analyzed together.^[11] The effect was more pronounced in Black children and in children born preterm, no association appeared for rubella, and the authors describe the evidence as suggestive. PFAS were detected in 90% to 100% of the mothers tested.

PFHxS is on the Kent County list.

What about lead, on either side of Cranston?

Lead is the substance that ignores which utility you're on, because it doesn't come from either one. It dissolves out of the service line running into your house, out of solder in copper joints, and out of brass fittings. Congress banned lead solder and lead pipe in plumbing connected to public water systems in 1986, so anything plumbed before then may contain it.^[12]

Both published figures are 90th percentiles taken from a sample of homes, which means one in ten of those homes read higher than the number, and your house is almost certainly not in the sample.

On lead, the CDC's finding is that no safe blood lead level in children has been identified, with even low levels tied to reduced IQ, weaker attention and lower academic achievement.^[13] The pooled analysis behind that, covering 1,333 children across seven birth cohorts, found IQ falling as blood lead rose and the steepest losses per unit at the lowest exposures, with measurable deficits in children whose maximum reading stayed under 7.5 µg/dL.^[14] That work measured lead in blood rather than in water. EPA's own health goal for lead is zero.^[2:2]

Providence Water's 2018 to 2020 stretch is the clearest local demonstration. Nothing changed about the Scituate Reservoir in those years. The number moved because of pipes.

What do these byproducts do over time?

The bladder cancer evidence is the deepest. A 2025 meta-analysis in the Journal of Hazardous Materials screened 433 publications and pooled 16, covering 8,126 cases against 13,843 controls plus three cohorts of 112,654 people. Long-term exposure to trihalomethanes carried an odds ratio of 1.59 against never or brief exposure (95% CI 1.40 to 1.81), and medium-term exposure 1.30.^[15] The authors state that their cohort data alone don't establish a causal link, and that the association held in men but not in women.

For the unregulated half of the list, toxicological assessment finds haloacetic acids more carcinogenic than trihalomethanes, and the National Toxicology Program's 15th Report on Carcinogens lists selected haloacetic acids found as water disinfection byproducts.^[16][17]

Children carry more of it. The same peer-reviewed analysis of US occurrence data estimated cumulative lifetime cancer risk at 7.0 × 10⁻⁵ using standard adult body weight and intake, and 2.9 × 10⁻⁴ once age sensitivity factors for infants and children were applied.^[16:1] Four times the risk, same water. And because trihalomethanes leave hot water as vapor, the Spanish study also found the highest quartile of shower and bath exposure carrying an odds ratio of 1.83 against the lowest (95% CI 1.17 to 2.87).^[6:1]

Why doesn't either published number describe your tap?

Because both are system-wide figures: averages or peaks from fixed sampling points, on a schedule set by regulation. Providence Water's covers 333,142 people across four municipalities. Kent County's covers 94,107 across eight towns.^[1:2] Cranston is a fraction of each, and your street is a fraction of that.

Your address has its own distance from the treatment plant, its own service line, its own plumbing age and its own hours when water sits still in the pipe. Byproducts keep forming while chlorinated water travels, so the far end of a run reads above the average it's folded into. Lead is decided inside your own walls.

In a town served by two utilities, the published numbers don't even agree with each other. Only a test at your kitchen sink tells you which one you're living with, and what it's doing by the time it reaches your glass.

Book your free in-home water test and we'll confirm which system feeds your address while we're there. Our systems run $3,995, $5,495 and $6,995, financing is available, and every price is published before we come out. A licensed plumber does the install, the equipment is yours outright with no rental and no monthly fee, and a 156-day money-back guarantee comes with it. If the water at your address doesn't warrant a system, we'll tell you that and leave.

Both supplies are documented in full: the Providence Water record in full and everything Kent County reports. For the same water in single-utility towns, see how this supply reads in Providence, Warwick, entirely on Kent County, and East Greenwich.

Cranston questions we get asked

Is Cranston tap water safe to drink? Both supplies serving Cranston meet the federal limits that apply to them, and what they carry differs by address. On the Providence Water side, 8 of 17 detected substances came in above published health guidelines, all disinfection byproducts, with trihalomethanes at 55.2 ppb. On the Kent County side, 17 of 39 came in above guidelines, with trihalomethanes at 49.9 ppb and ten PFAS compounds detected. Six substances have no federal limit at all on either supply.

How do I find out which utility serves my Cranston address? Check whose name is on your water bill. Providence Water and Kent County Water Authority both list Cranston among the towns they serve, so the bill is the fastest reliable answer. If the address sits near a boundary and the bill leaves it unclear, call the utility named on it and ask which system feeds your street.

Do the two Cranston supplies carry different substances? Yes, in three places. Trihalomethanes read 55.2 ppb on the Providence Water side and 49.9 on the Kent County side, so one clears both published cancer thresholds and the other clears one. Ten PFAS compounds were detected in the Kent County system, while no PFAS is flagged on the Providence Water side and UCMR5 sampling found none above the new federal limits there. Providence Water also has an action-level lead history from 2018 to 2020 that Kent County doesn't have.

Does the lead question change depending on which side I'm on? Not really. Lead comes out of the service line, the solder and the brass in your own house rather than from either utility, so the published 90th-percentile figures describe a sample of homes and not yours. Providence Water's readings were above the 0.015 mg/L action level in 2018, 2019 and 2020 and read 0.0016 by 2025; Kent County read 0.0014 in 2025 and has never crossed the action level. No safe blood lead level in children has been identified by CDC, and EPA's health goal for the substance is zero.

Is there PFAS in Cranston water? It depends on the supply. Ten distinct PFAS compounds were detected in the Kent County system, four above health guidelines, with PFOA at 3.89 parts per trillion against a federal limit of 4.0. On the Providence Water side, no PFAS compound is among the flagged substances and UCMR5 sampling found none above the new limits. EPA's health goal for PFOA and PFOS is zero, and the compliance deadline for the limits is April 2031.

Substance levels and health-guideline multiples: EWG Tap Water Database profiles for PWSID RI1592024 (state-reported testing 2013 to 2024) and PWSID RI1559511 (2014 to 2024). Lead 90th-percentile results, populations served and town lists: EPA ECHO Safe Drinking Water Act extract, 2026Q2. Pulled 2026-08-06.