# Septic pumping interval estimator

Look up Penn State Extension Table 2 for a year-round home. Choose the tank capacity from your records in US gallons. This estimate is not a safe waiting period or a local service requirement.

Use the tool on the [web page](https://septics.fyi/tools/septic-pumping-interval). It works without JavaScript.

## How to use it

1. Choose tank size from records (us gallons).
2. Choose people living in the home.
3. Read the result.

## How it works

Source: Penn State Extension, Septic Tank Pumping, Table 2, fetched 2026-11-10: https://extension.psu.edu/septic-tank-pumping. The table is adapted from Mancl (1984), assumes year-round residence and 50 US gallons per person per day. We reproduce its cells without interpolation.

Columns are 900, 1000, 1250 and 1500 US gallons. Rows are household sizes 1 through 8. Larger or smaller households and other tank sizes are outside this tool. The default is an example, not a suggested household or tank size.

EPA SepticSmart, How to Care for Your Septic System, fetched 2026-11-10: https://www.epa.gov/septic/how-care-your-septic-system. EPA says typical household pumping is every three to five years and inspection at least every three years. Mechanical alternative systems generally need annual inspection.

A table result longer than EPA’s typical interval does not justify delaying service. A shorter result is also only an estimate. A professional must assess sludge, scum and system condition. Local instructions and manufacturer requirements take precedence. Not a model for commercial systems or aerobic unit service.

> Information only. This is a published table lookup, not a prescribed pumping interval. Do not delay service for symptoms, alarms, local requirements or inspection findings.

## Questions

### What if my tank size is unknown?

Do not choose a guessed size. Ask the local authority or service provider for the approved plan and tank records.

### Does a long result mean I can skip inspection?

No. The table estimates solids accumulation. It cannot detect defects or establish local requirements.