Septic Metrics

Signs of a failing septic system

Published by Muhammad Umar Shehzad. Updated . Based on the sources listed below. Expert review pending.

Short answer

The main signs are sewage backing up into the house, slow or gurgling drains, wet spots or standing water near the tank or leach field, sewage odors, and unusually green, spongy grass in dry weather. If sewage backs up indoors, avoid contact with it and call your local health department or a septic professional.

A house and a warning sign beside standing water and bright green grass

The EPA lists every sign below as a possible malfunction. None of them proves one on its own, since each can have more than one cause. Treat them as a reason to get the system checked, not as a diagnosis.

Sewage backing up indoors

This is the most urgent sign: water or sewage coming up through toilets, drains or sinks.

What to do first

  • Stay out of the affected area and keep children and pets away. Sewage can carry harmful pathogens.
  • Stop running water, so less reaches the system.
  • Call your local health department or regulatory agency for guidance, and a septic service provider.
  • Leave cleanup to people with protective gear, such as long rubber gloves and face splash shields.

Slow or gurgling drains

Slow tubs, showers and sinks, or gurgling in the plumbing, can mean the system isn't taking water as it should. Check how widespread it is. One slow fixture may just have a clog in that drain. A whole house draining slowly is the time to have the septic system checked.

Wet ground or standing water

Standing water or damp spots near or over the tank or leach field can mean the field is overloaded and wastewater is reaching the surface. Keep people and pets off it, because that wastewater may contain harmful pathogens.

Sewage odors

If you smell sewage around the tank or field, call a septic service provider or plumber.

Bright green, spongy grass

Grass over the tank or field that stays bright green and spongy, even in dry weather, can mean wastewater is close to the surface.

Signs beyond your yard

Some signs show up away from the house. The EPA also lists:

  • A straight pipe discharging untreated wastewater to the ground surface
  • Algae blooms in nearby lakes or other waterbodies
  • High levels of nitrates or coliform bacteria in surface water or drinking water wells

If your drinking water may be affected, contact your local health department about having it tested.

Rules vary by location

Who you need to call, and whether a repair needs a permit, depends on your county. Your local health department can tell you.

Quick answers

What should I do if sewage backs up?

Keep away from it, stop running water and call your local health department and a septic provider.

Sources