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ODORS GASES SMELLS, DIAGNOSIS & CURE
AIR POLLUTANTS, COMMON INDOOR
AIR QUALITY IMPROVEMENT STRATEGIES
ALLERGEN TESTS for BUILDINGS
ANIMAL or URINE ODOR SOURCE DETECTION
BACKDRAFTING HEATING EQUIPMENT AQ
BIOGAS PRODUCTION & USE
BOOKSTORE - ENVIRONMENTAL
CARPETING & INDOOR AIR QUALITY
CHINESE DRYWALL HAZARDS
CHEMICAL CONTAMINANTS in WATER
COMBUSTION GASES & PARTICLE HAZARDS
DIRECTORY of MOLD / ENVIRONMENTAL EXPERTS
DISINFECTING BUILDINGS with BLEACH
DRYWALL MOLD TESTING
DUCT SYSTEM & DUCT DEFECTS
DUST SAMPLING PROCEDURE
EMERGENCY RESPONSE, IAQ, GAS, MOLD
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
GASES, EXPOSURE, TESTING
GAS DETECTION INSTRUMENTS
GAS EXPOSURE LIMITS & STANDARDS
INDOOR AIR QUALITY & HOUSE TIGHTNESS
INDOOR AIR QUALITY IMPROVEMENT GUIDE
INDOOR AIR QUALITY METHODS COMPARED
LIGHT, GUIDE to FORENSIC USE
GAS LP & NATURAL GAS SAFETY HAZARDS
Legionella Legionnaires' Disease
METHANE GAS SOURCES
MILDEW in BUILDINGS ?
MOISTURE CONTROL in BUILDINGS
MOLD: A COMPLETE GUIDE to TEST CLEAN PREVENT
MOLD ACTION GUIDE - WHAT TO DO ABOUT MOLD
MOLD EXPERT, WHEN TO HIRE
MOLD or INDOOR AIR EMERGENCY RESPONSE
TEST KITS for DUST, MOLD, PARTICLE TESTS
MVOCs & MOLDY MUSTY ODORS
ODORS GASES SMELLS, DIAGNOSIS & CURE
OUTHOUSES & LATRINES
OZONE for MOLD OR ODORS
PLUMBING SYSTEM ODORS
SEPTIC & CESSPOOL SAFETY
SEPTIC SYSTEM ODORS
SEPTIC TREATMENTS & CHEMICALS
SEWAGE & SEPTIC CONTAMINANTS
SEWAGE CONTAMINATION in BUILDINGS
SEWAGE EJECTOR / GRINDER PUMPS
SEWAGE PATHOGENS in SEPTIC SLUDGE
SEWAGE BACKUP, WHAT TO DO
SEWAGE BACKUP TEST & CLEANUP
SEWER GAS ODORS
SEWER LINE REPLACEMENT
SMELL PATCH TEST to Track Down Odors
STAIN & BIODETERIORATION AGENT CATALOG
STAINS on & in BUILDINGS, CAUSES & CURES
SULPHUR & SEWER GAS SMELL SOURCES
THERMAL IMAGING MOLD SCANS
UV LIGHT BLACK LIGHT USES
VENTILATION in BUILDINGS
VOCs VOLATILE ORGANIC COMPOUNDS
WASTEWATER TREATMENT BASICS
WATER ODORS, CAUSE CURE
WATER TESTS, CONTAMINANTS, TREATMENT
WATER TEST CHOICES & WATER TEST FEES
WATER TREATMENT EQUIPMENT CHOICES
WATER, WELLS, WATER TANKS: TESTING GUIDE
WETLAND SEPTIC SYSTEMS
Sewer or septic gases and odors traced to building drain or vent piping defects: this article describes how to diagnose, find, and cure odors in buildings caused by leaks or other defects in the building drains or sewer line - leaks that make sewage smells or sewer gas smells or "gas odors" in buildings with a focus on homes with a private onsite septic tank but including tips for owners whose home is connected to a sewer system as well.
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Watch out: Because sewer gas contains methane gas (CH4) there is a risk of an explosion hazard or even fatal asphyxiation. Sewer gases also probably contain hydrogen sulfide gas (H2S) In addition some writers opine that there are possible health hazards from sewer gas exposure, such as a bacterial infection of the sinuses (which can occur due to any sinus irritation).
At left is a sewer line leak in a building crawl area.
[Click to enlarge any image]
Sewer gas source: check for a cap left off of a sewer line cleanout:
In the page top photograph our client is pointing out an open sewer line in the basement of a home she was purchasing. The cap had been left off of a cleanout port where main waste line exited the building.
See Building drain odor source for more details about odors coming from plumbing drains - clues that may be more likely to appear in cool or cold weather. Also see our broad-scope article on diagnosis and cure of sewer gas and septic odors: Sewer Gas Odors diagnosing, finding, and curing septic tank and sewer line smells.
Also see ODORS GASES SMELLS, DIAGNOSIS & CURE for procedures to diagnose and cure all kinds of odors in and around buildings.
What makes the smell in sewer gas? Sewer gases are more than an obnoxious odor. They are also explosive and they may carry bacterial or pathogenic hazards too. Depending on the sewer gas source and other factors such as humidity and building and weather conditions, mold spores may also be present in sewer gases.
We discuss plumbing vents as sources of sewer gas odors separately at Plumbing Vent Defects.
We discuss plumbing fixtures, such as loose toilets, as sources of sewer gas odors separately at PLUMBING FIXTURE TRAPS.
Sewer Gas Source: inspect the building drains and gas lines for leaks:
Plumbing drains and traps may smell regardless, as they are usually a reservoir for organic debris.
Remember that a building drain can be leaking inside of a wall or ceiling cavity without showing up as a wet spot or mold.
If the plumbing fixture or drain "gurgles" or makes funny noises when it is draining, or if you hear gurgling noises at some fixtures, say a sink or tub when nearby fixtures are draining, we would certainly suspect that the fixture is not well vented or may not be vented at all.
If you suspect that odors are due to a problem with the building drains but you cannot find a drain line leak nor an open drain cleanout cover, take a look at CLOGGED DRAIN DIAGNOSIS & REPAIR.
The sewer gas odor may be coming not from a wet building drain (discussed just above) but from the dry or vent portion of a building's drain-waste-vent system. We discuss plumbing vents as sources of sewer gas odors separately at Plumbing Vent Defects.
CHINESE DRYWALL HAZARDS discusses Chinese drywall odors, sulphur smells, and corrosive outgassing hazards in buildings. Major costs to remove this product, repair or replace electrical wiring, plumbing, and HVAC components may be involved, and there may be immediate safety hazards due to damaged smoke detectors or carbon monoxide detectors in buildings where Chinese drywall outgassing has caused damage.
But on occasion we trace a sewer or septic gas odor to a hidden leak in a drain or vent line passing through building walls or ceilings.
At left our photo illustrates how hidden vent piping leaks may be lurking in an old building, a new building, or in one that has been renovated.
When the installer needed to extend the plumbing vent and drain line to an upper floor of this 1920's home, s/he simply broke open a cast iron vent pipe that was in a lower floor bathroom. There the "plumber" jammed a plastic ABS drain line into the open cast iron waste or vent pipe.
Our pen points out that this connection was certainly not sealed, and that sewer gases or septic gases were readily passing up the vent and/or drain line, into the building walls, and into the occupied spaces.
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Frequently Asked Questions (FAQs) about plumbing drain odors
Questions & answers or comments about diagnosing and curing septic or sewage odors at building drains
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