Septic Systems - What to Do after a Flood - Septic Flood Response, Safety, Health, Maintenance, Repair Advice InspectAPedia® -
How to evaluate a flooded septic tank and septic fields
Safety advice for flooded septic systems
How to get a flooded septic system working again, when to pump the septic tank, what to look for.
Questions & answers about flooded septic tanks and flooded drainfields or soakaway beds - what to do to restore the septic system to safe functional operation
Flooded septic tanks and drainfields - advice: if your septic system has been exposed to flooding, this document gives immediate safety and health advice and includes
other advice from the U.S. EPA and other septic system experts. We set priorities: safety, health, maintenance, and repair
for septic systems after flooding.
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The photo above shows red septic dye which appeared at the property surface when we tested a
recently flooded and still saturated, failed septic system close to a stream.
Citation of this article by reference to this website and brief quotation for the sole purpose of review are permitted.
Use of this information at other websites, in books or pamphlets for sale is reserved
to the author. Technical review by industry experts has been performed and is ongoing - reviewers welcomed and are listed at "References."
This article is part of our series: Inspecting, Testing, & Maintaining Residential Septic Systems an online book on septic systems.
The following text is not part of the original US EPA document but has been added by this website author.
Immediate Serious Safety Hazards: Property owners whose septic system has been flooded should be concerned first for immediate safety hazards
such as the increased risk of a dangerous collapse of a site-built septic tank, drywell, or cesspool. A site-built system, such as
a cesspool made of dry-laid stone or concrete blocks, may have been weakened by floodwaters. Rope off and prevent access to the area
where such systems are installed until you have made certain that there is no danger of collapse. Someone walking over a weakened
septic tank cover or cesspool or drywell could fall in - a possible fatal event. Never leave the cover off of a septic tank,
cesspool, or manhole. Someone can fall-in.
Electrical Hazards: if your septic system includes electrical components such as pumps, be sure that electrical power
has been turned off before attempting to examine the equipment.
Health Hazards: the EPA advice on this topic (below) refers to the high risk of sewage backup into homes during flooding. Sewage backup
into a home leaves a variety of pathogens and creates a serious risk of hidden mold in buildings.
Both of these can
create health hazards, particularly for people who are at extra risk: infants, the elderly, people who are immune-impaired,
people with asthma, etc. Further investigation, testing,
and cleaning are likely to be in order. A simple "pumpout" of a flooded basement, for example, may leave wet building materials and insulation
if the basement walls were finished with drywall or paneling. In these cases the wet materials should be removed promptly, the area dried,
cleaned if needed, and inspected for evidence of contamination before rebuilding.
Major Structural or System Damage: do not enter a flooded structure if there is evidence that the building may be unstable
or in danger of collapse. A building which has shifted off of its foundations, evidence of subsidence (depressions in the soil) over or near a septic system (or anywhere else),
or buckled foundation walls are examples of dangerous conditions that merit professional inspection and advice.
Manholes and Tank Covers may have shifted or may even have been lost during flooding. Falling into an open septic tank or sewer
is likely to be fatal. Watch for open, shifted, damaged, or otherwise unsafe covers or openings to these systems.
Property owners whose septic systems have been flooded should read the following articles as well as the advice offered
from the U.S. Environmental Protection Agency and re-printed below.
Contamination in buildings how to test buildings for bacterial contamination from Sewage and Septic backup, remediation, & references
Septic System Safety: Septic System, Septic Tank, & Cesspool Safety Warnings for Septic Inspectors, Septic Pumpers, and Homeowners
The information below is provided by the U.S. EPA. Additional comments or suggestions, where provided by the web author, will
be flagged as added text (such as the paragraphs preceding this section. I have re-ordered some of the original EPA text to put the
obvious and most important information first. [DJF]
What do I do with my septic system after the flood?
Once floodwaters have receded, there are several things homeowners should remember:
Be sure the septic tank's manhole cover is secure and that inspection ports have not been blocked or damaged. Otherwise someone could fall into the septic tank - a fatal hazard.
Do not use the sewage system until the water level in the soil absorption field is lower than the water level around the house.
Have your septic tank professionally inspected and serviced if you suspect damage. Signs of damage include settling or an inability to accept water.
Most septic tanks are not damaged by flooding since they are below ground and completely covered. However, septic tanks and pump chambers can fill with silt and debris, and must be professionally cleaned.
If the soil absorption field is clogged with silt, a new system may have to be installed. [DF: check the area of the drain field for piping which has become exposed (soil loss) or piping which has become clogged with mud and silt.]
Only trained specialists should clean or repair septic tanks because tanks may contain dangerous gases. Contact your health department for a list of septic system contractors who work in your area.
If sewage has backed up into the basement, clean the area and disinfect the floor. Use a chlorine solution of a half cup of chlorine bleach to each gallon of water to disinfect the area thoroughly.
Pump the septic system as soon as possible after the flood. Be sure to pump both the tank and lift station. This will remove silt and debris that may have washed into the system. Do not pump the tank during flooded or saturated drainfield conditions. At best, pumping the tank is only a temporary solution. Under worst conditions, pumping it out could cause the tank to try to float out of the ground and may damage the inlet and outlet pipes.
Do not compact the soil over the soil absorption field by driving or operating equipment in the area. Saturated soil is especially susceptible to compaction, which can reduce the soil absorption field's ability to treat wastewater and lead to system failure.
Examine all electrical connections for damage before restoring electricity. This includes electrical connections for pumps that may be used in your septic system: a septic grinder pump, effluent pump, or ejector pump.
Check the vegetation over your septic tank and soil absorption field. Repair erosion damage and sod or reseed areas as necessary to provide turf grass cover.
[DF: if your septic system uses special equipment such as a packaged aerobic treatment unit or other packaged wastewater treatment systems,
check with the system manufacturer. Some manufacturers will void the system warranty if sealed components are opened by the homeowner.]
Remember: Whenever the water table is high or your sewage system is threatened by flooding there is a risk that sewage
will back up into your home. The only way to prevent this backup is to relieve pressure on the system by using it less.
Where can I find information on my septic system?
Please contact your local health department for additional advice and assistance.
For more information on onsite/decentralized wastewater systems, call the National Environmental Services Center at
(800) 624-8301 or visit their website at www.nesc.wvu.edu.Exit EPA Disclaimer
How to Find The Septic Tank - (added by web author)
Septic Tank Location - How to Find the Septic Tank, how deep will the cover be, how to document its location
Do I pump my tank during flooded or saturated drainfield conditions?
No! At best, pumping the tank is only a temporary solution.
Under worst conditions, pumping it out could cause the tank to try to float out of the ground and may damage the
inlet and outlet pipes. The best solution is to plug all drains in the basement and drastically reduce water use in the house.
[DF NOTE: As the EPA says above, however, pump and inspect the septic system (including the piping)
as soon as possible after the flood, just not so
soon that there is risk of floating the septic tank.
If a septic system is not going to be used for months and wet weather or high
ground water conditions are expected to continue, I would not pump a fiberglass or plastic septic tank as there is risk
that the tank will float up out of the ground.
This is not much of a risk with concrete septic tanks.
Be sure to pump both the tank and lift station. Further inspection for safety as well as the overall
condition of the system is needed.]
When to Pump a Septic Tank - (added by web author)
Septic Tank Pumping Frequency Guide for Septic Tanks: When, How, What to Watch For when pumping or cleaning septic tanks
What if my septic system has been used to dispose wastewater from my business (either a home-based or small business)?
In addition to raw sewage, small businesses may use their septic system to dispose of wastewater containing chemicals.
If your septic system that receives chemicals backs up into a basement or drain field take extra precautions to prevent skin,
eye and inhalation contact.
The proper clean-up depends of what chemicals are found in the wastewater.
Contact your State or EPA for specific clean-up information.
What are some suggestions offered by experts for homeowners with flooded septic systems?
Use common sense. If possible, don't use the system if the soil is saturated and flooded. The wastewater will not be treated and will become a source of pollution. Conserve water as much as possible while the system restores itself and the water table fails.
Prevent silt from entering septic systems that have pump chambers. When the pump chambers are flooded, silt has a tendency to settle in the chambers and will clog the drainfield if it is not removed.
Do not open the septic tank for pumping while the soil is still saturated. Mud and silt may enter the tank and end up in the drainfield. Furthermore, pumping out a tank that is in saturated soil may cause it to "pop out" of the ground. (Likewise, recently installed systems may "pop out" of the ground more readily than older systems because the soil has not had enough time to settle and compact.)
Do not dig into the tank or drainfield area while the soil is still wet or flooded. Try to avoid any work on or around the disposal field with heavy machinery while the soil is still wet. These activities will ruin the soil conductivity.
Flooding of the septic tank will have lifted the floating crust of fats and grease in the septic tank. Some of this scum may have floated and/or partially plugged the outlet tee. If the septic system backs up into the house check the tank first for outlet blockage. Clean up any floodwater in the house without dumping it into the sink or toilet and allow enough time for the water to recede. Floodwaters from the house that are passed through or pumped through the septic tank will cause higher flows through the system. This may cause solids to transfer from the septic tank to the drainfield and will cause clogging.
Locate any electrical or mechanical devices the system may have that could be flooded to avoid contact with them until they are dry and clean.
AEROBIC Septic systems, septic plants, upflow filters, trickling filters, and other media filters have a tendency to clog due to mud and sediment. These systems will need to be washed and raked.
End of edited, supplemented US EPA text
Questions & Answers regarding this article
Questions & answers about flooded septic tanks and flooded drainfields or soakaway beds - what to do to restore the septic system to safe functional operation
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Additional technical contributors & reference sources for this article are listed below.
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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
Technical reviewers are invited to comment or ask questions - contact us
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.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 2010, $69.00 U.S., is available from Carson Dunlop. The Home Reference Book is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. InspectAPedia.com ® editor Daniel Friedman is a contributing author. Field inspection worksheets are included at the back of the volume.
Advanced Onsite Wastewater Systems Technologies, Anish R. Jantrania, Mark A. Gross. Anish Jantrania, Ph.D., P.E., M.B.A., is a Consulting Engineer, in Mechanicsville VA, 804-550-0389
(2006), Advanced Onsite Wastewater Systems Technologies.
Outstanding technical reference especially on alternative septic system design alternatives. Written for designers and engineers, this book is not at all easy going
for homeowners but is a text we recommend for professionals--DF.
AEROBIC SEPTIC SYSTEMS
Builder's Guide to Wells and Septic Systems, Woodson, R. Dodge: $ 24.95; MCGRAW HILL B; TP;
Quoting from Amazon's description: For the homebuilder, one mistake in estimating or installing wells and septic systems can cost thousands of dollars. This comprehensive guide filled with case studies can prevent that. Master plumber R. Dodge Woodson packs this reader-friendly guide with guidance and information, including details on new techniques and materials that can economize and expedite jobs and advice on how to avoid mistakes in both estimating and construction. Chapters cover virtually every aspect of wells and septic systems, including on-site evaluations; site limitations; bidding; soil studies, septic designs, and code-related issues; drilled and dug wells, gravel and pipe, chamber-type, and gravity septic systems; pump stations; common problems with well installation; and remedies for poor septic situations. Woodson also discusses ways to increase profits by avoiding cost overruns.
Country Plumbing: Living with a Septic System, Hartigan, Gerry: $ 9.95; ALAN C HOOD & TP;
Quoting an Amazon reviewer's comment, with which we agree--DF:This book is informative as far as it goes and might be most useful for someone with an older system. But it was written in the early 1980s. A lot has changed since then. In particular, the book doesn't cover any of the newer systems that are used more and more nowadays in some parts of the country -- sand mounds, aeration systems, lagoons, etc.
Septic & Sewage Pathogens and Contaminants, References & Research Articles
Amahmid, O., Asmama, S., & Bouhoum, K. (1999). The effect of waste water reuse in irrigation on the contamination level of food crops by Giardia cysts and Ascaris eggs. International Journal of Food Microbiology, 49(1-2), 19-26.
Barak, J.D., Whitehand, L.C., & Charkowski, A.O. (2002). Differences in attachment of Salmonella enterica serovars and Escherichia coli O157:H7 to alfalfa sprouts. Applied and Environmental Microbiology, 68(10), 4758-4763.
Beuchat, L.R. (1996). Pathogenic microorganisms associated with fresh produce. Journal of Food Protection, 59(2), 204-216.
Castro-Rosas, J., & Escartin, E.F. (2000). Survival and growth of Vibrio cholerae O1, Salmonella typhi, and Escherichia coli O157:H7 in alfalfa sprouts. Journal of Food Science, 65(1), 162-165.
Charkowski, A.O., Barak, J.D., Sarreal, C.Z., & Mandrell, R.E. (2002). Growth and colonization patterns of Salmonella enterica and Escherichia coli O157:H7 on alfalfa sprouts and the effects of sprouting temperature, iinoculum /in·oc·u·lum/ (-ok´u-lum) pl. inoc´ula material used in inoculation.
Evans, M.R., Ribeiro, C.D., & Salmon, R.L. (2003). Hazards of healthy living: Bottled water and salad vegetables as risk factors for Campylobacter infection. Emerging Infectious Disease, 9(10), 1219-1225.
Frost, J.A., McEvoy, M.B., Bentley, C.A., Andersson, Y., & Rowe, B. (1995). An outbreak of Shigella sonnei infection associated with consumption of iceberg. Emerging Infectious Disease, 1(1), 26-28.
Guo, X., Chen, J., Brackett, R.E., & Beuchat, L.R. (2001). Survival of Salmonellae on and in tomato plants from the time of inoculation at flowering and early stages of fruit development through fruit ripening,
said of meat. See curing. . Applied and Environmental Microbiology, 67(10), 4760-4764.
Guo, X., Chen, J., Brackett, R.E., & Beuchat, L.R. (2002). Survival of Salmonellae on tomatoes stored at high relative humidity, in soil, and on tomatoes in contact with soil. Journal of Food Protection, 65(2), 274-279.
Guo, X., Iersel, M.W.V., Chen, J., Brackett, R.E., & Beuchat, L.R. (2002). Evidence of association of salmonellae with tomato plants grown hydroponically in inoculated nutrient solution. Applied and Environmental Microbiology, 68(7), 3639-3643.
Itoh, Y., Sugita-Konishi, Y., Kasuga, E, Iwaki, M., Hara-Kudo, Y., Saito, N., Noguchi, Y, Konuma, H., & Kumagai, S. (1998) Enterohemorrhagic Escherichia colienterohemorrhagic Escherichia coli EHEC Any of the E coli serotypes–eg O29, O39, O145 that produces shiga-like toxins, causing bloody inflammatory diarrhea, evoking a HUS. See Escherichia coli O157:H7, Hemolytic uremic syndrome. O157:H7 present in radish sprouts. Applied and Environmental Microbiology, 64(4), 1532-1535.
Madden, J.M. (1992). Microbial pathogens in fresh produce--The regulatory perspective. Journal of Food Protection, 55, 821-823.
McMahon, M.A.S., & Wilson, I.G. (2001). The occurrence of enteric pathogens and Aeromonas species in organic vegetables. International Journal of Food Microbiology, 70(1-2),155-162.
Puohiniemi, R., Heiskanen, T., & Siitonen, A. (1997). Molecular epidemiology of two international sprout-borne Salmonella outbreaks. Journal of Clinical Microbiology
. 35(10), 2487-2491.
Shearer, A.E., Strapp, C.M., & Joerger, R.D. (2001). Evaluation of polymerase chain reaction-based system for detection of Salmonella enteritidis, Escherichia coli O157:H7, Listeria spp., and Listeria monocytogenes on fresh fruit and vegetables. Journal of Food Protection, 64(6), 788-795.
Takeuchi, K., Hassan, A.N., & Frank, J.F. (2001). Penetration of Escherichia coli O157:H7 into lettuce as influenced by modified atmosphere and temperature. Journal of Food Protection, 64(11), 1820-1823.
Wright, C., Kominos, S.D., & Yee, R.B. (1976). Enterobacteriaceae and Pseudomonas aeruginosa recovered from vegetable salads. Applied and Environmental Microbiology, 31(3), 453-454.
...
Onsite Wastewater Disposal Books
Onsite Wastewater Disposal, R. J. Perkins;
Quoting from Amazon: This practical book, co-published with the National Environmental Health Association,
describes the step-by-step procedures needed to avoid common pitfalls in septic system technology.
Valuable in matching the septic system to the site-specific conditions, this useful book will help you install a reliable system in
both suitable and difficult environments. Septic tank installers, planners, state and local regulators, civil and sanitary engineers,
consulting engineers, architects, homeowners, academics, and land developers will find this publication valuable.
Onsite Wastewater Treatment Systems, Bennette D. Burks, Mary Margaret Minnis, Hogarth House 1994 - one of the best septic system books around, suffering a bit from small fonts and a weak index. While it contains some material more technical than needed by homeowners, Burks/Minnis book on onsite wastewater treatment systems a very useful reference for both property owners and septic system designers.
Septic Tank/Soil-Absorption Systems: How to Operate & Maintain [ copy on file as /septic/Septic_Operation_USDA.pdf ] - , Equipment Tips, U.S. Department of Agriculture, 8271 1302, 7100 Engineering, 2300 Recreation, September 1982, web search 08/28/2010, original source: http://www.fs.fed.us/t-d/pubs/pdfimage/82711302.pdf
Planting Over Septic System Component", Daniel Friedman (author/editor, InspectAPedia.com), The Innovator, Winter/Spring 2008, BCOSSA, British Columbia OnSite Sewage Association, 201-3542 Blansard St., Victoria BC V8X 1W3 Canada
Septic System Owner's Manual, Lloyd Kahn, Blair Allen, Julie Jones, Shelter Publications, 2000 $14.95 U.S. - easy to understand, well illustrated, one of the best practical references around on septic design basics including some advanced systems; a little short on safety and maintenance. Both new and used (low priced copies are available, and we think the authors are working on an updated edition--DF.
Quoting from one of several Amazon reviews: The basics of septic systems, from underground systems and failures to what the owner can do to promote and maintain a healthy system, is revealed in an excellent guide essential for any who reside on a septic system. Rural residents receive a primer on not only the basics; but how to conduct period inspections and what to do when things go wrong. History also figures into the fine coverage.
Test Pit Preparation for Onsite Sewage Evaluations, State of Oregon Department of Environmental Quality, Portland OR, 800 452-4011. PDF document. We recommend this excellent document that offers detail about soil perc tests, deep hole tests, safety, and septic design. Readers should also see Soil Percolation Tests and for testing an existing septic system, also see Dye Tests
Grass is Always Greener Over the Septic Tank, Bombeck, Erma: $ 5.99; FAWCETT; MM;
This septic system classic whose title helps avoid intimidating readers new to septic systems, is available new or used at very low prices.
It's more entertainment than a serious "how to" book on septic systems design, maintenance, or repair. Not recommended -- DF.
US EPA Onsite Wastewater Treatment Systems Manual Top Reference: US EPA's Design Manual for Onsite Wastewater Treatment and Disposal, 1980, available from the US EPA, the US GPO Superintendent of Documents (Pueblo CO), and from the National Small Flows Clearinghouse. Original source http://www.epa.gov/ORD/NRMRL/Pubs/625R00008/625R00008.htm
Water Wells and Septic Systems Handbook, R. Dodge Woodson. This book is in the upper price range, but is worth the cost for serious septic installers and designers.
Quoting Amazon: Each year, thousands upon thousands of Americans install water wells and septic systems on their properties. But with a maze of codes governing their use along with a host of design requirements that ensure their functionality where can someone turn for comprehensive, one-stop guidance? Enter the Water Wells and Septic Systems Handbook from McGraw-Hill.
Written in language any property owner can understand yet detailed enough for professionals and technical students this easy-to-use volume delivers the latest techniques and code requirements for designing, building, rehabilitating, and maintaining private water wells and septic systems. Bolstered by a wealth of informative charts, tables, and illustrations, this book delivers:
* Current construction, maintenance, and repair methods
* New International Private Sewage Disposal Code
* Up-to-date standards from the American Water Works Association
Wells and Septic Systems, Alth, Max and Charlet, Rev. by S. Blackwell Duncan, $ 18.95; Tab Books 1992. We have found this text very useful for conventional well and septic systems design and maintenance --DF.
Quoting an Amazon description:Here's all the information you need to build a well or septic system yourself - and save a lot of time, money, and frustration. S. Blackwell Duncan has thoroughly revised and updated this second edition of Wells and Septic Systems to conform to current codes and requirements. He also has expanded this national bestseller to include new material on well and septic installation, water storage and distribution, water treatment, ecological considerations, and septic systems for problem building sites.
The NSFC Products List has an excellent list of design manuals/modules available from their website or by telephone 800-624-8301
Submissions welcome. send us a suggested document link or request an exchange of website links
