# Rochester, NY — Drinking Water Quality (2024)

> Contaminant levels for the Rochester, NY public water system from its 2024 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ny/rochester/2024
- JSON API: https://www.thewatermap.com/api/water/ny/rochester/2024
- Source: the utility's annual Consumer Confidence Report (CCR)
- Verification: transcribed by a model, cross-checked by a second model, approved before publishing
- Reporting year: 2024
- Contaminants measured: 26
- Contaminants with a federal limit: 8
- Contaminants at or above the federal limit: 1
- Part of The Water Map — https://www.thewatermap.com

## Contaminants measured

| Contaminant | Category | Measured level | Sampling context | Federal limit | Status |
|---|---|---|---|---|---|
| Chlorine | Disinfectants | 0.96–1.23 mg/L (Average) | System-wide | 4 mg/L (MCLG) | Within the limit |
| HAA5 | Disinfection byproducts | 13 ug/L (Average) | System-wide | No federal limit | Within the limit |
| TTHM | Disinfection byproducts | 25 ug/L (Average) | System-wide | No federal limit | Within the limit |
| Chloride | Inorganic chemicals | 37 mg/L (Average) | Hemlock | No federal limit | Detected — no federal limit |
| Fluoride | Inorganic chemicals | 0.69–0.93 mg/L (Average) | Ontario | 4 mg/L (MCL) | Within the limit |
| Nitrate | Inorganic chemicals | 0.26–0.42 mg/L (Average) | Ontario | 10 mg/L (MCLG) | Within the limit |
| Sulfate | Inorganic chemicals | 26–26 mg/L (Average) | Ontario | No federal limit | Detected — no federal limit |
| Aluminum | Metals | 52–82 ug/L (Average) | Ontario | No federal limit | Detected — no federal limit |
| Barium | Metals | 0.022–0.024 mg/L (Average) | Ontario | 2 mg/L (MCLG) | Within the limit |
| Calcium | Metals | 35–38 mg/L (Average) | Ontario | No federal limit | Detected — no federal limit |
| Chromium, Total | Metals | 0–1.15 ug/L (Average) | Ontario | No federal limit | Within the limit |
| Copper | Metals | 290–4 ug/L (90th percentile) | At the tap | No federal limit | Within the limit |
| Lead | Metals | 0–107 ug/L (90th percentile) | At the tap | 0 ug/L (MCLG) | At or above the limit |
| Magnesium | Metals | 8.9–9.5 mg/L (Average) | Ontario | No federal limit | Detected — no federal limit |
| Potassium | Metals | 1.5–1.6 mg/L (Average) | Ontario | No federal limit | Detected — no federal limit |
| Silica | Metals | 0–0.7 mg/L (Average) | Ontario | No federal limit | Detected — no federal limit |
| Sodium | Metals | 20 mg/L (Average) | Hemlock | No federal limit | Detected — no federal limit |
| Total Coliform | Microbial | 1.2 % (Maximum) | System-wide | 0 % (MCLG) | Detected — no federal limit |
| PFOS | PFAS ("forever chemicals") | 0–2.2 ng/L (Average) | Ontario | 4 ng/L (MCL) | Within the limit |
| Alkalinity | Physical & aggregate | 91–91 mg/L (Average) | Ontario | No federal limit | Detected — no federal limit |
| Hardness | Physical & aggregate | 123–130 mg/L (Average) | Ontario | No federal limit | Detected — no federal limit |
| pH | Physical & aggregate | 7.8–8.1 (Average) | Hemlock | No federal limit | Detected — no federal limit |
| Specific Conductance | Physical & aggregate | 302–330 uS/cm (Average) | Ontario | No federal limit | Detected — no federal limit |
| TOC | Physical & aggregate | 2.4–2.46 mg/L (Average) | System-wide | No federal limit | Detected — no federal limit |
| Total Dissolved Solids | Physical & aggregate | 178–180 mg/L (Average) | Ontario | No federal limit | Detected — no federal limit |
| Combined Radium | Radionuclides | 1.11 pCi/L (Average) | Hemlock | 0 pCi/L (MCLG) | Within the limit |

## What these contaminants are

- **Chlorine** — A disinfectant added to drinking water to kill bacteria and viruses. Effective and necessary, but high residual levels can cause taste and odor issues; the EPA caps the residual disinfectant level.
- **HAA5** — Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. Long-term exposure above the federal limit is associated with an increased cancer risk.
- **TTHM** — Total trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. Long-term exposure above the federal limit is linked to liver, kidney, and central-nervous-system effects and increased cancer risk.
- **Chloride** — A naturally occurring salt compound. Regulated only as a secondary (cosmetic) standard; high levels cause a salty taste and can corrode pipes.
- **Fluoride** — A mineral often added to drinking water to help prevent tooth decay. Beneficial at low levels, but long-term exposure above the federal limit can cause bone disease and tooth mottling.
- **Nitrate** — A compound from fertilizer runoff, septic systems, and erosion of natural deposits. Levels above the federal limit can cause 'blue baby syndrome,' a serious oxygen-transport condition in infants.
- **Sulfate** — A naturally occurring mineral from rock and soil. No health-based federal limit; high levels can have a laxative effect and a bitter taste.
- **Aluminum** — A common element sometimes used as a treatment coagulant. Regulated only as a secondary (cosmetic) standard; high levels can discolor water.
- **Barium** — A metal from erosion of natural deposits and industrial discharge. Long-term exposure above the federal limit can raise blood pressure.
- **Calcium** — A naturally occurring mineral that contributes to water hardness. Not federally regulated for health; affects scaling and taste.
- **Chromium, Total** — Total chromium — the sum of all chromium forms, from natural deposits and industrial discharge. Long-term exposure above the federal limit can cause allergic dermatitis; includes hexavalent chromium.
- **Copper** — A metal that enters water from corroding household plumbing. Short-term exposure causes stomach distress; long-term exposure can damage the liver and kidneys.
- **Lead** — A toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. There is no safe level of lead; it harms brain development in children and raises blood pressure in adults. The EPA sets an action level, not a health goal above zero.
- **Magnesium** — A naturally occurring mineral that contributes to water hardness. Not federally regulated for health; affects scaling and taste.
- **Potassium** — A naturally occurring mineral from rock and soil. Not federally regulated for health.
- **Silica** — A naturally occurring compound from sand and rock. Not federally regulated for health; relevant mainly for industrial water use.
- **Sodium** — A naturally occurring salt component. Not federally regulated for health; relevant for people on sodium-restricted diets.
- **Total Coliform** — A group of bacteria used as an indicator of overall water-system sanitation. Coliforms themselves are usually harmless, but their presence signals that disease-causing organisms could enter the system.
- **PFOS** — Perfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. Linked to cancer, thyroid disease, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
- **Alkalinity** — A measure of the water's capacity to neutralize acids. Not federally regulated for health; relevant to corrosion control and treatment.
- **Hardness** — A measure of dissolved calcium and magnesium minerals. Not federally regulated for health; affects scaling, soap use, and taste.
- **pH** — A measure of how acidic or basic the water is. Regulated only as a secondary standard; very low or high pH can corrode pipes or affect taste.
- **Specific Conductance** — A measure of how well water conducts electricity, which tracks dissolved mineral content. Not federally regulated for health; used as a proxy for total dissolved solids.
- **TOC** — Total organic carbon — a measure of organic material dissolved in the water. Not harmful itself, but it is the raw material that forms disinfection byproducts; removal is a treatment requirement.
- **Total Dissolved Solids** — Total dissolved solids — the combined content of all dissolved minerals and salts. Regulated only as a secondary (cosmetic) standard; high levels affect taste and hardness.
- **Combined Radium** — Combined radium-226 and radium-228 — naturally occurring radioactive elements. Long-term exposure above the federal limit increases the risk of bone cancer.

## How to read this

- A water-quality report covers an entire service area, not a single address.
- 'Federal limit' is the EPA standard (MCL, action level, treatment technique, etc.) that the measured level is compared against.
- 'At or above the federal limit' means the utility's own reported figure met or exceeded that standard.

_Figures are the utility's own published numbers. Generated 2026-06-04 from thewatermap.com._