Cobb County GA Sewer & Septic | Two Utilities, One Code

The short answer

Who handles sewer and septic in Cobb County, GA?

Sewer comes from the Cobb County Water System in unincorporated Cobb, Kennesaw and Acworth, and from Marietta's own utility in Marietta. Septic permits come from Cobb & Douglas Public Health. County code makes owners responsible for the service line to the county lateral. We repair the owner's side of both systems.↗↗↗

Reviewed by Atlanta Water & Sewage Solutions · Last updated September 23, 2026

Local facts

Cobb County, by the records

Each row links to the agency, code or publisher it comes from. Tap a source to check it yourself.

Numbers that decide who fixes what, each linked to its source.
Topic	What it says	Source
Sewer customers (CCWS)	About 160,000, producing roughly 63 million gallons a day	Sewer \| Cobb County Water System
Septic systems, 2006	33,558 existing (up from 32,105 in 2001)	Georgia EPD — Total Maximum Daily Load Evaluation for Lake Allatoona (Chlorophyll a), April 2013, Table 9
Septic repairs, 2001–2006	1,417, against 1,453 new installs	Georgia EPD — Total Maximum Daily Load Evaluation for Lake Allatoona (Chlorophyll a), April 2013, Table 9
Median year built	1990; the 1980s left 74,972 homes	Census Reporter API — Cobb County, GA, ACS 2020-2024 5-year (B01003, B25035, B25034)
Population	775,208 (ACS 2020-2024)	Census Reporter API — Cobb County, GA, ACS 2020-2024 5-year (B01003, B25035, B25034)
Septic permits	Cobb & Douglas Public Health, 1650 County Services Parkway, Marietta; 770-435-7815	Cobb/Douglas Public Health District Office \| Georgia Department of Public Health

The Cobb County story

A county with two water utilities

Cobb was carved from Cherokee territory on December 3, 1832, and grew into the state's third most populous county. For water and sewer it effectively has two answers. The Cobb County Water System, a department of county government, has served unincorporated Cobb for more than 80 years and also serves customers in Acworth, Kennesaw, Mableton and Powder Springs. Marietta, the county seat, runs its own water and sewer through the Board of Lights & Water.↗↗

Both draw the owner's line in a way that surprises people. The county code says property owners build and maintain the service line from the house to the point where it meets the county service lateral. Marietta goes further in practice: its utility asks owners to clear service-line blockages even when the stoppage sits in the road right-of-way, and repairs that stretch itself only when broken pipe caused it.↗↗

Behind the pipes are four county treatment plants: R.L. Sutton, South Cobb in Austell, and Noonday and Northwest, both in Kennesaw. Together they turn a county of 775,000 people into a sewer market first and a septic market second.↗↗

On the record

Owners build and maintain the service line from the house to the county service lateral (Sec. 122-153).↗
CCWS plants: R.L. Sutton (up to 50 MGD), South Cobb (40), Noonday (20, since 1971), Northwest (12).↗

Sewer or septic?

Still tens of thousands of septic tanks

It's easy to assume a county this developed has no septic left. The state's numbers say otherwise. Georgia EPD's 2013 study of Lake Allatoona, using Public Health data, counted 33,558 existing septic systems in Cobb in 2006. Just as telling, Cobb logged 1,417 septic repairs between 2001 and 2006, nearly as many as new installations. These are aging systems, not new ones.↗

The county code explains why they persist. A home already on septic before sewer arrived may stay on it as long as the system works, and new septic tanks are allowed on residential lots of at least 80,000 square feet. The test for whether sewer is available is gravity: can the main floor drain to a sewer in a right-of-way or easement that borders, touches or crosses the lot?↗

How to tell which one you have

No sewer charge on the water bill usually means septic.
A tank lid or riser in the side or back yard.
A Cobb & Douglas Public Health permit on file for the address.

Permits · Cobb & Douglas Public Health — Cobb Environmental Health, 1650 County Services Parkway, Marietta (770-435-7815)

Septic permits in Cobb

Nothing gets installed, repaired or modified without a permit first.

01
Any installation, repair or modification of a septic system needs a Public Health permit before work begins.↗
02
County code adds the water system director's approval to construct, repair, alter or enlarge a tank.↗
03
New lots need a sewer non-availability letter from the Cobb County Water System or the serving city, and the county requires a street address first.↗
04
Each lot needs at least a Level 3 soil survey by a certified soil classifier.↗
05
If old field lines aren't in health records, a certified septic contractor documents their location and length.↗
06
Fees are quoted by phone and paid in advance; no schedule is posted online.↗

Georgia rule Cobb County Code Sec. 122-243

“shall be made to function in a sanitary manner within 30 days from the receipt of a written notification and order”

Read the rule

More about Cobb County

Rules Cobb septic owners run into

Lot size is the first. Cobb & Douglas Public Health wants at least 21,780 square feet of suitable soil on public water, or 43,560 on a private well, and roads, easements and buffers don't count toward it. One system may serve only one home or one commercial building.↗↗

The second is the clock. Under Sec. 122-243, a system the Board of Health finds unsanitary must be fixed within 30 days of a written order, which leaves little room for shopping around once the letter arrives.↗

The third is what happens at conversion. When sewer finally reaches the lot and the house connects, the old tank is pumped and filled with sand, gravel or dirt, or removed, and the connection is made upstream of the tank.↗

There has also been help with the bill. Cobb & Douglas Public Health's ARPA-funded project offered income-eligible owner-occupants up to $500 toward pumping and up to $15,000 toward a repair or sewer connection, scheduled in Cobb through September 30, 2026 or until the money runs out. Rentals and commercial properties weren't eligible.↗

Unsanitary systems must be corrected within 30 days of a Board of Health order.↗
Up to $500 for pumping and $15,000 for repair or connection for eligible owners, through Sept. 30, 2026 or until funds run out.↗

Lot size is the first.

Who owns what

Who owns which pipe in Cobb

Green = sewer (APWA uniform color code)Typical handoff here: Property line

Blue = potable water (APWA uniform color code)Typical handoff here: Meter

Cobb County Water Systemsewer lateral
Owner up to the county service lateral; pumps moving sewage to the county line are the owner's↗
Where the line sits: County lateral connection
Cobb County Water Systemwater service line
County from main to meter; owner from meter to house↗
Where the line sits: Meter
Marietta Power & Watersewer lateral
Owner clears blockages even in the right-of-way; city repairs pipe failure there↗
Where the line sits: Right-of-way / BLW easement

On the water side, the county guarantees at least 20 psi at the meter for customers at or below 1,140 feet; anything above that, including a reducing valve, is the customer's.↗

Soil & terrain

Eroded clay and two river basins

A ridge from Lost Mountain through Kennesaw Mountain to Sweat Mountain divides the county. Most of Cobb drains southeast to the Chattahoochee through creeks like Sope, Rottenwood, Nickajack and Sweetwater; the far north-northwest drains to the Etowah and Lake Allatoona by way of Noonday and Allatoona creeks.↗

The soil survey reads like a history of cotton farming. The largest map units are Gwinnett, Madison and Pacolet clay loams listed as severely eroded, meaning the topsoil is largely gone and trenches go straight into red clay subsoil. Stream bottoms carry frequently flooded Cartecay soils, where septic fields don't belong.↗

Gwinnett clay loam, 6–10%, severely eroded↗
Largest unit, about 13,445 of 220,700 acres.
Madison and Pacolet soils, 10–15%, severely eroded↗
About 13,380 acres.
Cartecay fine sandy loam, frequently flooded↗
About 9,845 acres of stream bottoms.
Soil series · USDA NRCS

Towns we serve

Cobb towns we serve

Three Cobb cities have their own pages; the rest are served from the same crews.

Also in the county

Smyrna
Mableton · Cobb's largest city; a CCWS customer city.
Powder Springs · Served by the county water system.
Austell · Home of the South Cobb reclamation plant.
Vinings, Fair Oaks and east Cobb's unincorporated neighborhoods

Services here

Services across Cobb

Also available:Septic Pumping Septic Inspection Sewer Camera Inspection

Certified on the septic side

Cobb & Douglas Public Health requires state-certified installers and pumpers. Atlanta Water & Sewage Solutions is on Georgia DPH's lists of certified septic tank installers and approved pumpers.

FAQ

Cobb County sewer and septic questions

Straight answers, with the rule or record behind them. Still unsure? Call and ask the crew that digs.

(678) 863-5620

Who issues septic permits in Cobb County?

Cobb & Douglas Public Health's Environmental Health staff. Any installation, repair or modification needs their permit before work starts; call 770-435-7815.

Source: Information For Homeowners — Septic Systems | Cobb & Douglas Public Health

Are there really still septic systems in Cobb?

Yes. State figures counted 33,558 in 2006, and 1,417 repairs were recorded between 2001 and 2006.

Source: Georgia EPD — Total Maximum Daily Load Evaluation for Lake Allatoona (Chlorophyll a), April 2013, Table 9

How big does a lot have to be for septic in Cobb?

County code allows new septic on residential lots of 80,000 square feet or more without gravity sewer; Public Health's own minimum is 21,780 square feet of suitable soil on public water.

Source: Cobb County Code Sec. 122-153 Wastewater system (Municode, Supp. 53)

What does a Cobb septic permit application need?

For a new lot: a sewer non-availability letter, a Level 3 soil survey by a certified classifier, a recorded plat and fees paid in advance.

Source: Cobb & Douglas Public Health — Lot Configuration Requirements for On-Site Sewage Management Systems (Cobb, rev. 10/12/2017)

Which part of the sewer line is mine?

Under county code, the service line from your house to the county service lateral. In Marietta, the city also expects owners to clear blockages in the right-of-way.

Source: Cobb County Code Sec. 122-153 Wastewater system (Municode, Supp. 53)

Who fixes a water leak on my side of the meter?

You do. The county owns the main-to-meter pipe; the owner owns meter to house.

Source: Pipe Ownership | Cobb County Water System

Is there financial help for septic repairs?

Cobb & Douglas Public Health's ARPA-funded project offered eligible owner-occupants up to $500 for pumping and up to $15,000 for repair or sewer connection, scheduled through September 30, 2026 or until funds run out.

Source: Cobb County — Cobb & Douglas Public Health launches Septic System Pumping & Repair Project for low-income homeowners

I got a Board of Health order about my septic. How long do I have?

Thirty days from the written order to make the system function in a sanitary manner, under Cobb County Code Sec. 122-243.

Source: Cobb County Code Ch. 122, Art. II, Div. 8 — Private Wastewater Disposal Facilities (Municode, Supp. 53)

Who do I call for a sewer backup in the street?

Cobb County Water System's emergency line, 770-419-6201, or Marietta's water and wastewater line, 770-794-5230, inside the city.

Source: Pipe Ownership | Cobb County Water System

Guides

Guides for Cobb owners

Sources

Where these facts come from

Rules, costs and local facts on this page link to the agency, code or publisher that states them. Cost figures are third-party market ranges, not our prices — estimates are free.

Reviewed by Atlanta Water & Sewage Solutions · Last updated September 23, 2026

Cobb County sewer and septic service under the county water system, Marietta's utility and Cobb & Douglas Public Health.

Who handles sewer and septic in Cobb County, GA?

Cobb County, by the records

A county with two water utilities