Is Marietta, GA tap water safe?
Supplied by Cobb County Water System · serves 695,000 people (183,518 connections) · Purchased surface water · EPA ID GA0670003
Data: U.S. EPA · How we read the data · How we check it
Most of Marietta gets its water from Cobb County Water System. Parts of the city are served by a smaller system: Marietta Board of Lights and Water (60,100 people). Your water bill names your system.
Buys water from Cobb County – Marietta Water Authority. Treated water bought from another system can carry that system's contaminants.
Summary
No limits exceeded in the data EPA has, but the record is incomplete: no lead results since 2003.
- PFAS
- Detected, below limit3 of 29 PFAS found at least once. All averages below the federal limits.
- Lead
- Out of dateEPA's national database has no lead results for this system since 2003 (then 2.6 ppb, 90th percentile). Systems this size normally test every one to three years, so this most likely means newer results were not reported to EPA, not that testing stopped. Ask the utility for its latest results.
- Violations
- None health-basedNo health-based violations since 2016.
- Built before 1986, or not sure what your service line is made of? Check your service line and test your tap. Utility data can't show your pipes.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read Cobb County Water System's 2026 water quality report (Consumer Confidence Report, from the utility). It lists every regulated contaminant tested, including ones not on this page. Questions: (770) 528-3300.
PFAS (“forever chemicals”)
EPA UCMR 5: 1 entry point tested Aug 2023 to May 2024. "Average" is the highest entry-point average (non-detects counted as zero), the way EPA compares UCMR 5 results to the limits. ppt = parts per trillion. These results do not determine compliance.
| Contaminant | Highest average |
|---|---|
| PFOA Not detected Limit 4 ppt | – |
| PFOS Not detected Limit 4 ppt | – |
| PFHxS Not detected Limit 10 ppt | – |
| PFNA Not detected Limit 10 ppt | – |
| HFPO-DA (GenX) Not detected Limit 10 ppt | – |
| Hazard Index (a combined score for PFHxS, PFNA, GenX and PFBS, where above 1 is over the limit) Detected, below limit Limit 1 | 0.0018 |
| PFBS Detected, below limit Guideline 2,000 ppt | 3.58 ppt |
| PFBA Detected, below limit Guideline 6,000 ppt | 1.63 ppt |
| PFHxA Detected, below limit Guideline 3,000 ppt | 0.8 ppt |
29 PFAS tested, 3 detected at least once. "Not detected" means below EPA's reporting limit (about 2 to 20 ppt depending on the chemical), not proven zero. PFAS not listed were not detected. The limits for PFHxS, PFNA, GenX and the Hazard Index were proposed for rescission in May 2026. That proposal is not final. Systems have until 2029 to meet the limits.
Lithium
Not detected in 4 samples (reporting limit 9 ppb). About lithium.
Lead and copper
Latest 90th percentile: 2.6 ppb lead (Jan 2003 – Dec 2003). No results since 2003
This is the newest lead result in EPA's national database. Utilities report lead results to their state, and states pass them to EPA. Gaps like this usually mean the newer results did not reach EPA's database, not that the utility stopped testing. Results this old may not reflect the water today. Ask the utility or your state drinking water program for the latest lead monitoring.
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2003 – Dec 2003 | 2.6 ppb |
| Jan 2002 – Dec 2002 | 13.7 ppb |
| Jan 2001 – Dec 2001 | 10 ppb |
Earlier results (1)
| Jan 2000 – Dec 2000 | 12 ppb |
Lead comes from pipes and fixtures, not the source water, so it varies home to home. The 90th percentile means 9 in 10 sampled homes were at or below it. More on lead.
Violations
Health-based violations mean a contaminant exceeded a limit or a required treatment step was missed. Monitoring and reporting violations mean required tests or reports were late or missing, so the water's quality during that time is unknown. The total includes every violation in EPA's records, most of them paperwork.
Earlier EPA testing (2013–2020)
| Contaminant | Highest | Guideline |
|---|---|---|
| Manganese | 46 ppb | 300 ppb |
| Chromium-6 | 0.14 ppb | – |
| Vanadium | 0.2 ppb | 21 ppb |
| Strontium | 0.035 ppm | 1.5 ppm |
| Chlorate | 430 ppb | 210 ppb |
Where it serves
Marietta, Roswell, Mableton, Smyrna, Woodstock, Kennesaw, Austell, Vinings
ZIP codes the system reported serving: 30008, 30060, 30062, 30064, 30066, 30067, 30068, 30075, 30080, 30082, 30101, 30102, 30106, 30126, 30127, 30141, 30144, 30152, 30168, 30188, 30339
Nearby utilities
- Marietta Board of Lights and Water Marietta · same area
- Woodstock Water System Woodstock · 10 mi · PFAS above limit
- City of Atlanta Department of Watershed Management Atlanta · 15 mi
- Paulding County Water System Dallas · 17 mi
- North Fulton County Water System Alpharetta · 17 mi
- Douglasville-Douglas County Water & Sewer Authority Douglasville · 17 mi
Questions
Is Marietta tap water safe to drink?
Most of Marietta gets its water from Cobb County Water System. Cobb County Water System has no health-based violations since 2016. EPA testing found no PFAS above the federal limits. Federal data can't tell you about your own pipes: lead comes from service lines and plumbing, so test your tap if your home was built before 1986. For the official word, read the utility's annual Consumer Confidence Report.
Does Marietta water have PFAS?
Yes. EPA's 2023–2025 testing of Cobb County Water System found 3 PFAS at least once. None of the averages were above the federal limits.
What is the lead level in Marietta water?
The most recent 90th-percentile lead result for Cobb County Water System is 2.6 ppb, for the period ending Dec 2003, which is more than five years old. The federal action level is 15 ppb, falling to 10 ppb in November 2027. The 90th percentile means 9 in 10 homes sampled were at or below this number. Individual homes can be higher.
Check these numbers yourself
Every figure on this page comes from public EPA records. You don't have to take our word for it:
- EPA's own report for GA0670003: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID GA0670003).
- EPA SDWIS download: the lead results, population and violation records we use.
- Cobb County Water System's 2026 water quality report: the utility's own annual report, including contaminants EPA's national database doesn't carry (link checked Nov 14, 2026). Phone: (770) 528-3300.
- Cobb County Water System website
Found something that doesn't match? Tell us and we'll check it against EPA's records. How we check our data.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.