Drinking water quality · 2024
· Verified
What's in Rockville, MD tap water
17 contaminants were measured in the Rockville, MD water system's 2024 annual report. Each is shown below against its federal limit.
- Reporting year
- 2024
- Contaminants measured
- 17
- Over federal limit
- 0
- Approaching the limit
- 1
- Service area
- MD
PFAS — EPA UCMR5 (2023–2025)
4 PFAS compounds detected in Rockville, MD
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFBS
● Detected (no federal limit)below national p90 (13.909999999999979 ng/L across detecting U.S. systems)
PFPeA
● Detected (no federal limit)below national p90 (15.95999999999999 ng/L across detecting U.S. systems)
PFHxA
● Detected (no federal limit)below national p90 (12.190000000000003 ng/L across detecting U.S. systems)
PFBA
● Detected (no federal limit)below national p90 (18 ng/L across detecting U.S. systems)
Where your water comes from · EPA SDWIS
Rockville, MD's drinking water comes from surface water, drawn from 1 source.
Source
- POTOMAC RIVER
Treatment
- POTOMAC FILTER PLANT
Distribution
Also buys water from WASHINGTON SUBURBAN SANITARY COMMISSION.
Historical readings · EPA Six-Year Review (2012–2019)
2 contaminants historically over EPA limits in Rockville, MD
Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.
| Contaminant | Worst detection | EPA limit | Years (2012–2019) |
|---|---|---|---|
TTHM worst: 2015 | 0.131 mg/L 1.6× | 0.08 mg/L | '12'13'14'15'16'17'18'19 |
HAA5 worst: 2015 | 0.0626 mg/L 1.0× | 0.06 mg/L | '12'13'14'15'16'17'18'19 |
DEHP worst: 2013 | 0.0024 mg/L within | 0.006 mg/L | '13 |
NITRATE NITRITE worst: 2018 | 2.04 mg/L within | 10 mg/L | '18 |
BARIUM worst: 2015 | 0.36 mg/L within above national p90 | 2 mg/L | '12'13'14'15'16'17'18 |
FLUORIDE worst: 2015 | 0.72 mg/L within | 4 mg/L | '12'13'14'15'16'17'18 |
NITRATE worst: 2014 | 1.8 mg/L within | 10 mg/L | '12'13'14'16'17'18 |
ATRAZINE worst: 2017 | 0.00022 mg/L within below national p90 | 0.003 mg/L | '14'17 |
CHROMIUM worst: 2012 | 0.0028 mg/L within below national p90 | 0.1 mg/L | '12'14 |
DBAA worst: 2012 | 0.0017 mg/L | — | '12'13'14'15 |
DCAA worst: 2012 | 0.0215 mg/L | — | '12'13'14'15 |
MCAA worst: 2012 | 0.0038 mg/L | — | '12'13'14 |
TCAA worst: 2012 | 0.0194 mg/L | — | '12'13'14'15 |
BROMODICHLOROMETHANE worst: 2012 | 0.031 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMOFORM worst: 2012 | 0.00075 mg/L | — | '12'13 |
CHLOROFORM worst: 2012 | 0.0797 mg/L | — | '12'13'14'15'16'17'18'19 |
DIBROMOCHLOROMETHANE worst: 2012 | 0.0097 mg/L | — | '12'13'14'15'17'18'19 |
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PFOAPerfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. | 2.07AverageSystem-wide | 4MCL | Within the limit |
| PFOSPerfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. | 2AverageSystem-wide | 4MCL | Within the limit |
| Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.' | 1.13AverageSystem-wide | 10MCL | Within the limit |
| Perfluorononanoic acidPerfluorononanoic acid, a PFAS 'forever chemical.' | 0.27AverageSystem-wide | 10MCL | Within the limit |
| Hexafluoropropylene oxide dimer acidHFPO-DA ('GenX chemicals'), a newer-generation PFAS replacement compound. | 0MinimumSystem-wide | 10MCL | None detected |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 1.32 mg/LMaximumSystem-wide | 4 mg/LMCLG | Within the limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| CopperA metal that enters water from corroding household plumbing. | 0.1 mg/L90th percentileAt the tap | 1.3 mg/LMCLG | Within the limit |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | Not detected ug/L90th percentileAt the tap | 0 ug/LMCLG | Detected — no federal limit |
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Escherichia coli (E. coli)Escherichia coli — bacteria found in the gut of humans and animals. | 3MaximumSystem-wide | 0MCLG | Detected — no federal limit |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.26 NTUMaximumSystem-wide | None set | Detected — no federal limit |
People also ask about Rockville, MD's water
+Is Rockville, MD tap water safe to drink in 2024?
Every one of the 17 contaminants measured in Rockville, MD's 2024 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in Rockville, MD tap water?
17 contaminants were measured in Rockville, MD's 2024 Consumer Confidence Report, spanning pfas ("forever chemicals"), metals, and disinfection byproducts. 16 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Are any contaminants in Rockville, MD tap water approaching the federal limit?
One contaminant is between 80% and 100% of the federal limit in this report: TTHM. Approaching means measured but not in violation — a margin that can close quickly if conditions change.
+Where does the data on this page come from?
Every value is transcribed from Rockville, MD's 2024 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Rockville, MD's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2024 report; a new report will replace it once the utility publishes its next annual update.