CESSPOOLS for onsite wastewater disposal - Cesspool Collapse Warnings and Cesspool Safety
Warnings about cesspool collapse and fatality hazards
Cesspool rejuvenation, agitating, jetting, or hydrojetting cesspools
Our site offers impartial, unbiased advice without conflicts of interest.
We will block advertisements which we discover or readers inform us are associated with bad business practices,
false-advertising, or junk science. Our contact info is at
InspectAPedia.com/Contact.htm.
This document explains and describes some critical safety concerns for people owning and maintaining cesspools for onsite waste treatment. Cesspools, depending on how they have been constructed and how they are serviced, can present particularly dangerous conditions and risk collapse and fatal injury. The hazards described here in discussing cesspools can also be present
at drywells and seepage pits.
Readers trying to diagnose and deal with sudden soil subsidence or yard collapses should see CESSPOOL SAFETY WARNINGS as those hazards can also apply to drywells and septic tanks, and also see SINKHOLES, WARNING SIGNS. Additional septic system safety warnings are at SEPTIC & CESSPOOL SAFETY. Quoting from our sink holes article:
The bare minimum that a property owner needs to know about sinkholes or any other sudden subsidence
of soils at a property is that these conditions might be very dangerous. Someone falling into a sink hole
or into a collapsing septic tank could be seriously injured or even die. If a suspicious hole, subsidence,
or depression appears at a property the owner should rope off and prevent access to the area to prevent
anyone from falling into the opening, and then should seek prompt assistance from a qualified expert,
geotechnical engineer, septic contractor, excavator, or the like.
This document is a subchapter of our online text about cesspool design, cesspool installation, cesspool maintenance and cesspool inspection. These pages explain what a cesspool is, gives important safety and maintenance advice for cesspool systems, and defines the
criteria for cesspool failure. We also provide critical safety warnings concerning cesspool systems as with some older and especially site-built cesspools there is a risk of dangerous collapse or cave-ins.
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. Use of this information in books or pamphlets for sale is reserved to the author.
Some technical review by industry experts has been completed-reviewers are listed at "References."
Review comments and content suggestions are invited. Home buyers should see the Home Buyer's Guide to Septic Systems.
Also see Septic & Cesspool Safety - Septic System, Septic Tank, & Cesspool Safety Warnings for Septic Inspectors, Septic Pumpers, and Homeowners.
Also see The Septic Systems Home Page.
Cesspool Safety Warnings and Cesspool Capacity Limitations
Very Important Cesspool Safety Warnings
Safety Warning: do not walk over the top of or close to the edges of a cesspool or any other onsite pit or excavation because
of the danger of fatal collapse. Keep pets and children away from such systems.
Our photo (left) shows a sudden back yard collapse that may have been due to an old drywell or cesspool, discussed in detail at Sinkholes in New York.
Safety Warning: there is a high risk of cesspool collapse, risking fatality if someone falls in to one of these
systems. This is particularly true for older site-built systems that were often made of dry-stacked stone or concrete block,
and more-so if such systems are not protected by a very secure cover.
Safety Warning: pumping cesspools is dangerous since older site-built systems may be more likely to collapse inwards
when relieved of their contents. Also, pumping a cesspool from the bottom, in an attempt to break up the sludge layer and "rejuvenate" the cesspool is likely to undermine the structure's walls and in the case of dry-laid concrete block or stone, as we warn just below, can lead to a dangerous and sudden collapse of the cesspool.
Experienced septic pumpers who attempt this "cesspool rejuvenation" method despite severe safety warnings not to do so, will still avoid pumping much waste out of the cesspool in hopes to avoid a collapse. Hydrojetting a pre-cast cesspool in good condition and standing on stable soil (not sand) may be less dangerous and is usually performed after a partial pumpout. Before taking any action, review your cesspool repair plan with your local health and building departments for both building code and site safety concerns can be grave when a cesspool is disturbed.
Safety Warning: hydrojetting a cesspool, aerating or agitating sludge at the bottom of a cesspool in an attempt to renew its function or extend its
life also risk system collapse - in particular if the cesspool is an older type of site-built structure, typically made of dry-stacked stone or concrete blocks, jetting the cesspool bottom, and even pumping out the cesspool can undermine the cesspool walls leading to collapse of the system. We are informed of a serious fatality involving a cesspool that was jetted and then collapsed, burying the owner. Don't do this.
Cesspools that are collapse-resistant pre-cast concrete structures are safer in this regard. However many municipalities define the end of life of a cesspool in terms of its static full level and do not provide for rejuvenation attempts. See CESSPOOL FAILURE CRITERIA.
Safety Warning: do not drive over cesspools (nor over septic tanks, septic piping, or drainfields) as there is risk of collapse or cave-in. The photographs of a collapsed
seepage pit (which could as well have been a cesspool collapse) at the top of
this page and just below show what happens when a heavy truck drove over a seepage pit which was not designed to carry such a heavy traffic load. See Driving or Parking over Septic Components?
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.
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.
Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
Additional technical contributors & reference sources for this article are listed below.
Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.
Thanks to Denise Cermola for permission to use the photo at page top (email 11/16/06 to 12/10/06). The contractor drove over this seepage pit connected to septic tank and caused total destruction of the system. Luckily there were no injuries in this event.
Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. (727) 595-4211 mark@BestTampaInspector.com 11/06
Hankey and Brown home inspectors, Eden Prairie, MN, technical review by Roger Hankey, prior chairman, Standards Committee, American Society of Home Inspectors - ASHI. 952 829-0044 - hankeyandbrown.com 11/06
Arlene Puentes, a licensed home inspector, educator, and building failures researcher in Kingston, NY. 11/29/06
More Reading about Cesspool, Drywell, and Seepage Pit Safety, and Septic System Maintenance and Repair:
Cesspool Safety - Specific Warnings about Cesspool Collapse Hazards (this document)
Septic & Cesspool Safety - septic system, septic tank, & cesspool safety warnings for septic inspectors, septic pumpers, and homeowners.
Septic D-BOX Inspection provides for help in finding and inspecting the septic system drainfield distribution box
Don't Flush these things into a septic system: a list of what's ok and what's not ok to put into septic tanks and building drains
Septic Safety: Septic System, Septic Tank, & Cesspool Safety Warnings for Septic Inspectors, Septic Pumpers, and Homeowners
Tank Location - How to Find the Septic Tank, how deep will the cover be, how to document its location - these methods also apply to locating a cesspool or drywell at a property.
Dye Tests: how to perform a Septic Loading and Dye Test - septic dye testing procedures in complete detail, a septic function test - a chapter in the above book.
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
More Information on Building Diagnostic Inspections and Repairs
The Septic System Information Website - Extensive, Detailed Consumer and Industry Information on Septic System Inspection, Testing, Maintenance, Alternatives for on-site waste disposal
InspectAPedia® Home & Site Map - Building & Environmental Inspection, Testing, Diagnosis, Repair, & Problem Prevention Advice: In-depth research & advice on diagnosing, testing, correcting, & preventing building defects & indoor environmental hazards. Unbiased information, no conflicts of interest.
Building & Indoor Air Quality Environmental Inspection, Testing, & Diagnosis Experts providing on-Site IAQ, Gas, Air Testing, Mold Investigation, Sick Building Diagnosis, Lab Services, & Remediation Plan Preparation - indoor air quality testing, problem source determination, supporting lab work, written remediation plan addressing removal of environmental and other hazards and prevention of their recurrence. Also see MOLD CLEANUP COMPANIES
InspectAPedia ® Home & Site Map
The Septic System Information Website
Building & Indoor Air Quality Environmental Inspection
