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Cobb County: tap water results

Georgia · about 695,000 people · purchased surface water

Detected, below the 2024 limit

PFBS was found in 4 of 28 samples taken between Aug 2023 and May 2024. Every value was below the 2024 federal limits.

Research monitoring by EPA (UCMR 5), samples Aug 2023 – May 2024 · read 2026-10-31 · next check: Your utility's yearly water quality report is due by 1 July each year. EPA's next national monitoring round (UCMR 6) is planned for 2028–2030.

What this page is: a plain-language restatement of public test results that the US EPA published for the water system named above, with the dates of the samples and the date we read them. It describes the system, not the water at your tap, which also depends on the pipes in your building. It is not a safety verdict, not medical advice and not a recommendation to buy anything: "buy nothing" is one of the outcomes in the cost section below. We earn nothing from any link on this page.

What EPA measured here (research monitoring, UCMR 5)

SubstanceFound inHighest2024 limit
PFOA0 of 4below 4 ng/L4 ng/L
PFOS0 of 4below 4 ng/L4 ng/L
PFHxS0 of 4below 3 ng/L10 ng/L
PFNA0 of 4below 4 ng/L10 ng/L
HFPO-DA (GenX)0 of 4below 5 ng/L10 ng/L
PFBS4 of 44.2 ng/Lnone
lithium0 of 4below 9 µg/Lnone

"Found in" counts samples above the laboratory reporting level. ng/L = nanograms per litre (parts per trillion); lithium is shown in µg/L as EPA reports it. "Highest" is the single highest sample at any entry point or tap, not an average. "Below the reporting level" means the laboratory did not find the substance above its minimum reporting level (MRL), the smallest amount the EPA method reports. It is a laboratory threshold, not a health threshold, and it is not the same as zero.

UCMR 5 was a one-time national monitoring programme (2023–2025). The results are a snapshot at the system's entry points or taps on the sample dates, not a continuous measurement and not a compliance record.

What the 2024 limits are

In April 2024 EPA set the first national limits for PFAS in drinking water: 4.0 ng/L for PFOA and PFOS; 10 ng/L for PFHxS, PFNA and HFPO-DA (GenX); plus a hazard index for mixtures. PFBS has no limit of its own. Lithium has no federal limit; UCMR 5 measured it for information. On 20 May 2026 EPA proposed removing the limits for PFHxS, PFNA and HFPO-DA and the hazard index; that proposal was not final when we last checked (5 Nov 2026). The PFOA and PFOS limits are not affected by it. We show the 2024 numbers as written; check EPA's PFAS rule page for the current state. EPA PFAS rule page.

Compliance record and lead (regulatory data, SDWIS)

Not yet on this page: the system's compliance record (violations) and its lead sampling results from EPA's SDWIS database. We will add them with their own dates and wording. Until then, the two closer sources are the utility's yearly report and EPA's public databases, linked below.

The utility

EPA system nameCobb County
EPA ID (PWSID)GA0670003
People served695,000
Service connections183,518
Main sourcepurchased surface water
StateGeorgia

Phone and website: on your water bill, or through EPA's CCR finder above. We list no contact details we have not verified.

What would a filter cost in your home?

Types, not brands. Yearly cost of the replaceable filters at average use (about 0.23 gallons of drinking and cooking water per person per day, EPA Exposure Factors Handbook). Figures from our cost page, prices read 27–30 October 2026. Your numbers stay in your browser.

3 people
Buy nothing
one of the outcomes: your utility's report and your own tap decide
$0 a year
Faucet-type filter
cartridge listed for 100 gallons, about $14
$35
Pitcher filter
cartridge listed for 120 gallons, about $17.50, six-month limit
$37
Under-sink reverse osmosis
filters, power and drain water; mostly time-limited
$178

Which type fits depends on what, if anything, your own water report shows; filters certified to NSF/ANSI 53 or 58 carry a tested claim for the substance named on the listing. Our list by type: filters certified for lead and PFAS.

Questions people ask

Who runs the water system for Cobb County?

Cobb County (EPA ID GA0670003) serves about 695,000 people through about 183,518 service connections, mainly from purchased surface water. The name on your water bill is the one that counts; a ZIP code can be served by more than one system.

Were forever chemicals (PFAS) found in Cobb County's water?

PFBS was found in 4 of 28 samples taken between Aug 2023 and May 2024. Every value was below the 2024 federal limits. "Below the reporting level" means the laboratory did not find the substance above its minimum reporting level (MRL), the smallest amount the EPA method reports. It is a laboratory threshold, not a health threshold, and it is not the same as zero.

Does this page say whether the water is safe to drink?

No. We publish the public test results with their dates and explain what they do and do not cover. What reaches your glass also depends on the pipes in your building, and anyone with a health condition should ask their clinician about their water. The two closer sources are the utility's yearly report and a test at your own tap.

Is a value above the 2024 limit a violation?

A single sample above a 2024 limit is a measurement, not a violation. Compliance is judged on running yearly averages, and water systems have until 2029 to meet the limits. On 20 May 2026 EPA proposed giving qualifying systems until 2031 for PFOA and PFOS and removing the limits for PFHxS, PFNA and HFPO-DA; those proposals were not final when we last checked (5 Nov 2026).

Where do I find the yearly water quality report for Cobb County?

Every community water system must deliver a Consumer Confidence Report to its customers by 1 July each year. Use EPA's CCR finder or the utility's own website; the report covers more substances than this page.

What would a filter cost for a household in Cobb County?

It depends on the number of people and the filter type, not on the brand. For 3 people at average use, a faucet-type filter costs about $35 a year in cartridges and a pitcher about $37; an under-sink reverse-osmosis unit about $178 a year in filters. Buying nothing costs $0 and is one of the outcomes.

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