Septic answers you can check for yourself
More than 1 in 5 US households depend on a septic system. Size it, price it, look after it and work out what’s wrong, with the method and source behind every number.
What size tank do you need?
- 7Free tools
- 24Guides with sources
- 50State contacts
Tools with their working shown
Each tool explains its formula and links to the rule or study behind it.
- Tank size calculatorCompare minimum tank sizes in four published state rules.
- Drain field size calculatorEstimate absorption area from bedrooms and soil type.
- Septic cost estimatorSee published price ranges for each system type.
- Pumping calculatorEstimate the years between pumpings for your household.
- Symptom checkerFind out how urgent a septic problem may be.
- Home buyer checklistKnow what to ask before you buy a home on septic.
- State contacts finderFind the agency that runs septic rules in your state.
Something seems wrong?
Start with what you can see or smell. Tick each sign, and we’ll show how urgent it may be and what to do first.
Browse by topic
Septic basics
What each part does, where it sits on your property and how to find it.
Leach fields
How the drain field works, how long it lasts and what makes it fail.
Septic maintenance
Pumping schedules, inspections and everyday habits that protect the system.
Warning signs
What smells, slow drains and wet spots can mean, and what to do first.
Septic costs
What installation, replacement, pumping and inspection cost, and why it varies.
Septic-safe products
What is and is not safe to put down the drain, by product type.
Why you can check our work
Every source is listed
We start with government and university guidance, and link to it from each page.
Formulas stay visible
Each calculator shows how it works and what it can’t tell you.
Nothing to sell you
We don’t sell septic services or take contractor leads. Read how we check facts
Common septic questions
How often should a septic tank be pumped?
The EPA says household tanks are typically pumped every three to five years. Your schedule depends on tank size and household use.
What is a leach field?
It’s the buried part of a septic system that releases liquid from the tank into the soil for treatment. It’s also called a drain field.
How much does a septic system cost?
Published guides put a conventional system at about $3,000 to $8,500. Other systems can cost far more. These are third-party, unverified estimates.