Photograph of  a seepage pit collection at the factoryDetermine the Age of a Cesspool

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

This document suggests methods for estimating the age of a cesspool.

The age of a cesspool can assist an owner in evaluating its condition and planning for its maintenance or replacement.

This material is a chapter of our Septic Systems Online Book: That document explains septic system inspection procedures, defects in onsite waste disposal systems, septic tank problems, septic drainfield problems, checklists of system components and things to ask. Septic system maintenance and pumping schedules. Citation of this article by reference to this website and brief quotation for the sole purpose of review are permitted.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Green links show where you are. © Copyright 2017, All Rights Reserved.

CESSPOOLS for WASTEWATER - How to Estimate the Age of a Cesspool

A cesspool combines the septic treatment tank and absorption system into a single component.

Several readers have written to ask if it is possible to determine the age of a cesspool A cesspool is pit into which sewage is discharged. Solids remain in the pit, effluent is absorbed into soil around the cesspool. Cesspools have a limited life and capacity, but they have been in use since the late 1400's (the beginning of the Renaissance).

While cesspools have been used for a long time, since the development of the more modern septic system (tank and drain field) cesspools may still be in use at old properties or even at newer ones (where permitted by local health departments) if there is not enough room for a conventional leach field.

Estimating the age and condition of anything which is buried is tricky, but not completely impossible. An estimate of the age of a cesspool may assist the building owner in planning for its maintenance, repair, or replacement.

Recently a reader asked if one could estimate the age and usage of a building by evaluating its cesspool. I was somewhat doubtful of this approach as cesspools have been in use for such a long time and have used such a variety of materials. But it's a very interesting idea, and certainly bounds can be put on the age of a cesspool by noting how it was constructed. The following details suggest other means for estimating the age and perhaps indirectly the condition of a residential property cesspool.

Four Steps in Estimating and Evaluating the Age and Condition of a Cesspool

Here are a few suggestions about estimating cesspool age, all of which can be answered only by collecting historical information about the home and perhaps by excavating to inspect the cesspool system.

  1. Inspecting Details Inside the Building: in the house: is there evidence of multiple generations of waste line in or leaving the building- various materials and locations?
  2. History of the Property and Septic Service Records: in the history of the house: is there record of septic system service - if so, call the contractors to ask them what they did when, and what they found to be installed and what they could see of its construction materials and location.
  3. Outside Visual Inspection for Cesspool Clues: is there visual evidence of a history of cesspools, additions, modifications. Eg. often when a cesspool fails people would leave it in place, leave the house waste line connected to it, and just build an additional cesspool "downstream" from and connected to the old one.

    A property from the 1930's in continuous use, depending on soil characteristics, level of occupancy, and cesspool size and construction, might have a chain of 3 to 5 cesspools strung out in a line from the original, or might have filled in some or some might have collapsed, leading to sewer line rerouting to new cesspools. We might observe a series of depressions extending away from the home where these systems were chained together. **SAFETY** watch out for collapsing cesspools - falling in can be a quick death.
  4. Cesspool Information by Excavating: locate and excavate the cesspool to see of what it is constructed. We might be able to recognize old building materials, e.g. concrete blocks made in the 1930's using the Sears masonry block kit that was in wide use. Also one could examine the materials used to construct the waste line itself. Orangeburg clay pipe, for example, was in common use in the 1920's and has most likely not been used since the 1950's.

    Hand made cesspools of stone, brick, or something else could be of any vintage unless we can recognize the probable age of the materials themselves. Same for cesspool covers.

    Pre-cast concrete cesspools: Finding a "new" pre-cast concrete (and safer) cesspool does not mean there was not an older one there previously, but the new unit is likely to be less than 20 years old.

Cesspool Inspection & Testing Safety Warnings

*** SAFETY WARNING *** digging up or poking into old septic systems or cesspools risks discovering a collapsing and very dangerous system. Dig and poke and excavate with great care and using a professional and not with anyone working alone - falling into a collapsing cesspool can be a quick and ugly death.

In Summary: watch out for cave-ins, keep away: cesspools, particularly older site-built cesspools present a very high risk of collapse from an unsafe cover or following some types of service involving pumping, aeration, or hydro-jetting.

Watch out: Adults or children should not walk over or even near cesspools because of the risk of falling-in followed by collapse, a virtually certain cause of death. If the presence of a cesspool is known or suspected at a property its location should be roped off to prevent access and it should be investigated by a professional.


Continue reading at CESSPOOL SAFETY WARNINGS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see CESSPOOLS which explains what a cesspool is, gives important safety and maintenance advice for cesspools, and defines the criteria for cesspool failure.


Or see these

Key Drywell & Cesspool Articles

Suggested citation for this web page

CESSPOOL AGE ESTIMATES at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia


Frequently Asked Questions (FAQs)

Click to Show or Hide FAQs

Ask a Question or Search InspectApedia

Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

Comment Box is loading comments...

Technical Reviewers & References

Click to Show or Hide Citations & References

Publisher's Google+ Page by Daniel Friedman