Main Sewer Line Clog: What to Do Right Now
Stop water use, clear it the safe way
Do this now
- Confirm the pattern: one slow sink is a fixture clog, but every drain slow, gurgling toilets, or water appearing in the tub when the washer drains points at the main line.
- Stop adding water. Each shower or load of laundry raises the level in the pipe until it finds your lowest drain.
- Call the utility's emergency line first so they can rule the public main in or out before you spend money.
- Find your cleanout (a capped pipe at ground level outside, often near the foundation) and keep its cap on and intact; it's where any pro will start, and Gwinnett's lateral guidance tells owners to know where it is.
- Know the hidden risk before anyone clears the line: Atlanta Gas Light warns that gas lines bored underground can accidentally pass through a sewer pipe, a cross bore, and a cutting machine can slice that gas line. Their guidance is a camera inspection first and 811 before any clearing work.
Can you fix it yourself?
Main line work means a drain machine or jetter run from the cleanout, and the cross bore risk is exactly why Atlanta Gas Light says to hire a professional drain cleaning company or sewer contractor and get the line inspected by camera before mechanical clearing. If anyone, you included, ever finds a gas pipe crossing inside the sewer, all work stops and Atlanta Gas Light gets a call at 877.427.4321 to report it as a gas emergency.
When to call a pro
- Every main line clog, by the logic above
- Repeat clogs in the same line, which usually means roots, grease buildup, a belly or a break
- A camera shows roots at the joints or a collapsed section
- You're planning any digging to repair the line, which in Georgia means contacting 811 at least three business days before mechanized digging
We're a referral directory, not a contractor; this button opens our request form.
What to ask the plumber
- Will you camera the line before and after, and give me the footage?
- Did you check for cross bores, and will you call 811 before any excavation?
- Is this a cable, a jetting, or a repair conversation, and why?
- If you quote a replacement, what's the price difference between open trench and trenchless for my yard?
Questions we hear
What causes main line clogs here?
Grease leads: Cobb County's water system says 85 percent of its sewer blockages are grease-related, mostly residential. Tree roots hunting for water find pipe joints, and wipes snag on everything. The fixes are boring and cheap: scrape grease into the trash, flush only the three things, and plant deep-rooted trees away from the lateral.
Can I just rent a drain machine?
Atlanta Gas Light specifically discourages rooting out a blockage without locating utilities or camera-inspecting the sewer first, because of cross bores. A rental machine plus an unseen gas line is the bad version of this story. Let a pro with a camera own that risk.
Whose pipe is it?
From your house to the public main (or in Fulton's wording, to the property line and beyond in some cases) the lateral is the owner's responsibility in every city we cover. The utility owns the main. That's why the free utility check comes before the paid plumber.
Sources
Every number and local fact above comes from one of these, read 2026/10. Spot something out of date? Tell us.
- Gwinnett County Department of Water Resources: Sewer Service Lateral Repair and Cleaning Policy (homeowner handout)
- Gwinnett County Department of Water Resources: Sewer Lateral
- Atlanta Gas Light: Call 811 Before You Clear
- Atlanta Gas Light: Sewer Blockage Safety for Customers
- Georgia 811: Who We Are
- Cobb County Water System: Fat, Oil and Grease (FOG)
- Fulton County: Water and Sewer Service Laterals (flyer)