Sewage backup or spill cleanup in crawl spaces:

This article describes sewage backup or spill procedures for building crawl spaces or other hard-to-enter building areas.

We describe special safety procedures for crawl space entry, debris removal, sewage removal, and sewage-contaminated soil removal. We also describe steps to prevent future sewage contamination in the crawl area.

Hazards of & Best Response to a Sewage Spill in a Crawl Space

Reader question: I am writing in the hope of getting some information on a sewage spill that happened at the place we are renting. We are in a studio unit that is below the original plumbing of the main building.

There is a pump-up system to get rid of the sewage. It overflowed a couple of weeks ago because somebody previous to us had flushed tampons down the system and they had jammed the pump.

The effluent overflowed out of the top of the containment barrel and ran about 15'down the slope in the crawl space.

At that time the landlord removed a good bit of the contaminated soil and then put kitty litter over it to absorb the moisture.

Yesterday the tank overflowed again. This time, the plumber found a towel that had been flushed down the toilet, also by previous tenants.

Our landlords had said they noticed the towel missing in mid August. It is now mid Nov. The plumber thought that it had just been floating in the collection barrel and was only a matter of time before it got sucked up by the pump.

This all happened in the crawl space below the unit we are renting. We are in Whistler BC and the house is built on the side of the mountain, so the crawl space is not the traditional type one visualizes when we think of a crawl space.

Where the collection barrel is located, the space is just deep enough for the height of the barrel. By the entrance door of the crawl space, the ceiling to floor is well over 12'. Most of the are is mountain bedrock which is very jagged and sloping. As such, it is quite difficult to clean the area. This last spill has re-soaked the kitty litter from the previous spill.

My question to you is, are there health hazards due to the spill. My wife and I have somewhat compromised immune systems, so we have concerns about the consequences. The landlord had also stated that there was a continual problem with wet, damp soil in the crawl space.

Would this lead to a mold problem. What would you suggest to clean up the spill, if anything. Would putting kitty litter or some other absorbing material be a good enough solution?

Are there other steps that one could take to rectify the problem?

Can the bacteria be transferred by walking in the affected area and then tracked into our living space? Or is it of no concern? I thank you for your time and I look forward to your response in the near future.- R.P. 10/14/2012

Advice for Disinfecting & Drying Out a Sewage Contaminated Crawl Space

Reply: We can't reliably assess the extent of health hazards in your home due to a crawl space sewage backup from just your note, as there are other very important considerations that an onsite expert would consider, such as the ease with which air or dust can move from a contaminated crawl area into the occupied building space. But here are some thoughts that may help:

• At SEWAGE BACKUP, WHAT TO DO we give the first-response priorities & steps in a sewage spill or leak response.
• At SEWAGE CLEANUP PROCEDURES & STANDARDS we describe in more detail the steps in removing sewage & disinfecting & cleaning a building interior after a sewage backup or spill.
• At SEPTIC / SEWAGE SOIL CONTAMINATION HAZARDS we describe the hazards of sewage-contaminated soils and include suggestions for dealing with that soil, including removal, treatment with lime, or other measures.
• Just below in this article - CRAWL SPACE SEWAGE CLEANUP - we describe in detail the steps in removing sewage & disinfecting a building crawl space.

An appropriate response to sewage spills in a crawl space goes beyond dumping some kitty litter on the ground. Missing from your description of how the sewage spill was handled in the crawl space you describe are these additional steps or considerations:

1. An inspection for mold 
   
   or other contaminants in the same area, and further cleaning of surfaces as needed
   
   See CRAWLSPACE MOLD ADVICE
2. Inspector for and removal/replacement of contaminated materials
   
    (after surface cleaning) of any suspect or contaminated insulation or similar materials in the crawl area
3. Disinfection of the contaminated area.
   
   Professional cleaning companies use a variety of sanitizers and disinfectants beyond simple diluted bleach. The choice depends in part on just what surfaces and materials need treatment.
   
   Sanitizing a crawl space is described at CRAWL SPACE DRYOUT - home
4. Prevent cross-contamination:
   
   measures to assure that sewage contaminated soil was not tracked into the living area, or appropriate cleaning there if needed. This may mean a few surface tests for sewage contaminants in the living area, starting with the most-suspect areas of floors.
5. Check for contaminated mechanical equipment:
   
   If building water supply, fixtures, appliances etc. were contaminated they will need to be cleaned and disinfected or if necessary replaced. Any possible effect on the building HVAC systems - for example a warm air heat or air conditioning duct system exposed to contamination.
6. Check sewage or water ejecting systems & equipment:
   
   Examination of the sewage ejector pump to remove any other pending blockages and to assure that the proper type of sewage grinder pump, check valves, piping, etc. are installed.
   
   See SEWAGE GRINDER PUMPS.
7. Sewage or flood warning systems:
   
   in low building floors, crawl spaces, basements, installation of a warning system that indicates if the sewage pump is not working, so that residents can stop using toilets and fixtures long enough to fix the problem and avoid future sewage spills in the structure.
   
   Also see SEWAGE BACKUP PREVENTION and
   
   see SEPTIC PUMP ALARM SYSTEMS
8. Building moisture control:
   
   in addition to removing contaminated soil (ok) in a flooded dirt floor basement or crawl area, typically we'd install a heavy plastic barrier to prevent soil moisture from continuing to enter the crawl area where it invites mold contamination.
   
   See CRAWL SPACE GROUND COVERS
   
   and CRAWL SPACE VAPOR BARRIER LOCATION
   
   Also see CRAWL SPACE DRYOUT - home to be sure there are not other sources of water entry into the crawl area.

Crawlspace Sewage Cleanup Research & References

• Berry, Michael A., Jeff Bishop, Claude Blackburn, Eugene C. Cole, William G. Ewald, Terry Smith, Nathan Suazo, Steve Swan, and Mr William G. Ewald. SUGGESTED GUIDELINES FOR REMEDIATION OF DAMAGE FROM SEWAGE BACKFLOW INTO BUILDINGS [PDF]  Journal of Environmental Health 57, no. 3 (1994): 9-15.
  
  Excerpt:
  Sewage poses a very significant threat to human health. However, the severity of the health threat depends on the content of the sewage and the degree and extent of penetration into the building environment. The degree of penetration is dependent on the porosity of contaminated materials, the quantity of sewage, and the amount of time the sewage remains in contact with materials.
• Boulder County SEWAGE BACKUPS AFTER A FLOOD [PDF] Boulder County DOH, 3450 Broadway, Boulder Colorado, Web: BoulderCountyWater.org Tel: 303-441-1564 - retrieved 2023-08-05 original source:-/bouldercounty.gov/disasters/flood/health/sewage-backup/
  
  Except:
  
  

  Contaminated Soil

  Plastic ground liners, surface contamination, and heavily contaminated soil should be removed from the impacted area if possible. Contaminated soil should be disposed of in an approved landfill, when removed.
  
  The remaining contaminated soil should be treated in place with a liberal application of garden lime to reduce odor and enhance degradation of the organic matter.

  If the contaminated area is in the open, it should either be covered with clean dirt or temporarily fenced off to prevent accidental contact with the lime and any remaining contamination. After a day or two, mix the lime in with a rake and use a sprinkler or hose to water the lime and any remaining residues into the soil.
  
  Prevent any water or soil from entering stormwater by containing it onsite or disposing of it in an approved landfill or approved wastewater dump station. Let the area dry in the sun if possible before allowing access.
  
  Excavated soils may be remediated onsite by treatment with garden lime and should be turned over frequently to provide oxygen to the naturally occurring microbes in the soil that degrade the organic material.
  
  If onsite treatment is not possible, or if it can’t be accomplished without creating a nuisance condition, contaminated soils and other materials removed from the impacted area may be disposed of at any landfill willing to accept them.

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Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2020-10-24 by (mod) - maggots and flies coming up from sewage spill under mobile home

Bobbie

That sewage spill and contamination does sound terrible.

If you are really finding maggots and flies entering the home through plumbing drains (as opposed to through various openings and cracks from below or through the heating or A/C system if you have ducts), then that sounds as if the plumbing drain traps are either missing or not working- an unsanitary condition that also allows potentially dangerous sewer gases into the building along with pathogens in sewage.

Sewage pathogens can also enter living space by being attached to soil or dust particles that can enter the home riding on air currents (dust) or by being tracked-in on feet.

The most-critical advice is to be guided by your doctor and to determine if there is indeed an immediate life-safety condition that means it's not safe to be in the home.

Here is my standard advice for this situation:

Personal health and questions about the safety of the environment in your home cannot properly be addressed by email or e-text. You need both

Advice from your doctor: what things in my environment should I look for and remove or reduce: things that would be likely to cause or aggravate my medical complaints

and

Advice from an onsite environmental and building expert: what evidence is there of an indoor environmental problem from mold (water leaks, stains, visible mold), or other common hazards such as mice, insects, use of chemicals, allergens, dust mites, etc.

It can be diagnostic, though very incomplete, to notice where you feel better or worse. In a home where there is an indoor environmental irritant sometimes people feel better when outside or when in another building.

However keep in mind that even this observation alone is not completely reliable, since complaint symptoms can be slow to diminish, or because other environments can contain their own irritants.

The object of these inquiries is the creation of a "to do" list: medical treatments, indoor environmental cleanup or repairs, etc. recommended by experts, in a priority order.

Finally, beware of wasting time and money hiring pseudo-experts who stop by to perform some test or other, like an "air test for mold".

Such testing, as a building screen for environmental hazards is incomplete, very unreliable, expensive, and worse: even if such tests indicate "a problem" they are not prescriptive: the "test" doesn't tell you where the problem is nor what to do about it.

As a result you end up having to pay expensive fees twice, hiring someone more-competent a second time to review the building and come up with an action plan for cleaning or modifications.

So what's needed on-site is a combination of interview, history-taking of both complaints and history of the building, and visual inspection. Tests are secondary in importance.
A useful expert understands building materials, construction, air movement, and common indoor environmental hazards.

She makes a thorough visual inspection of the property to look for likely trouble signs, for example: a history of leaks, visible mold, general cleanliness, history of infestations, chemical uses or pesticides, as well as immediate life safety hazards (loose railings, missing smoke detectors).

On 2020-10-24 by Bobbie in Phoenix

we have had a raw sewage leak under our rental trailor for close to a year final got fixed correctly a broken sewer pipe but my son keeps getting sick and breathing issues his brdroom right above where the break

was what test should i request from dr as i am taking the owners to court for not dealong with this issue for almost a year and did not have it cleaned up its still under his room nasty and hazourdous. The plumbers who finally fixed the pipe said it was so disguisting that there was

1000s of maggots worms and flies the flies were coming up the pipes in all the sinks and tubs in the house they were weird looking flies they were every where just is there a test my son can get to see if theres anything in his blood making him sick all the time

 

On 2018-12-12 by (mod) - onsite supervision by an expert is important at any cleanup job

Josie, companies offering flood damage restoration, mold contamination restoration, environmental damage restoration - there are national franchises such as ServPro - and also individual local firms.

Watch out: reputation is one thing to consider, but everything in the success of an actual sewage spill cleanup depends on the quality of work by the specific crew and the quality of its supervision.

On 2018-11-15 by Jpsie schug

what kind of specialist can clean sewage spill in dirt drawl space??

On 2016-10-17 by Francis McKenna

I have standing water in my crawl space and I believe it's sewer water smells like it.

On 2016-07-26 by (mod) - big sewage puddle under house

It may dry out but the area is likely to be unsanitary and thus unsafe; both fine droplets when wet and even pathogen-contaminated dust particles when dry could still enter the occupied space. I would check with the health department where you live, ask for cleanup advice.

Typically the topmost contaminated soil is removed, the area is sanitized, and a groundcover such as 6 mil poly or something heavier is installed.

On 2016-07-26 by Camille

We live in a rental house built in 1944 the main drain pipe had burst a leak and about a Large puddle or so of water and maybe sewage leaked out under the house. It's just a dirt crawl space whole length of house and tall enough to stand under there.

The landlord fixed the pipe but nothing was cleaned up whatsoever! We turned our air conditioner off opened Windows and aired house out all day. Plus the wood door to crawl space has been left open for couple days to air it out. Since it's just dirt and it's just a puddle size pool of water/? Will it just dry itself out? Or should there be bleach/lime poured out?

On 2016-02-11 6 - by (mod) -

Peter: I can't cite a law or guide or "should" about "who" but certainly if the cleaning person does not understand the very serious health risks involved s/he may be personally at risk, and if the cleanup is not properly conducted, serious health hazards could remain in the building.

A general rule of thumb derived from mold cleanup guidelines that pose similar health risks as sewage backups is that if more than 30 sq.ft. of surface area is contamianated, a professional cleanup is in order.

In some states or provinces sewage spill and mold remediation companies and similar water damage cleanup companies must be licensed.

On 2016-02-10 by Peter

Should sewer spill clean-up be conducted by a certified professional? or can any Maintenance employee or laborer conduct the clean-up?

On 2014-11-14 by (mod) - put down sand before laying the plastic polyethylene barrier in a crawl area

Thanks, Tom. Am I correct that your sand suggestion is to reduce the chances of poking a hole in the poly barrier while crawling around in the space?

On 2014-11-14 by Tom

This is all very good advice on how to handle sewage contamination issue in a crawl space.

The only thing that I would add to it is to add a layer of sand or absorbant over the disinfected soil before you put the poly down.

...

Continue reading  at SEWAGE CONTAMINATION in BUILDINGS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• SEWAGE & SEPTIC CONTAMINANTS
• SEPTIC / SEWAGE SOIL CONTAMINATION HAZARDS - persistence of contaminants & soil treatment or disinfection choices
• SEPTIC TANK / FIELD INSTALLATION HEALTH HAZARDS - health hazards when disturbing sewage-contaminated soil
• SEWAGE BACKUP, WHAT TO DO
• SEWAGE CONTAMINATION in BUILDINGS
• SEWAGE CONTAMINANTS in FRUIT / VEGETABLES
• SEWAGE NITROGEN CONTAMINANTS
• SEWAGE PATHOGENS in SEPTIC SLUDGE
• Step 6. FLOOD DAMAGED BUILDING CLEAN-UP if you need general guidance following a flood

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