InspectAPedia ®

Building & Environmental Inspection, Testing, Diagnosis, Repair, & Problem Prevention Advice
InspectAPedia
Home
| Air
Conditioning
| Electrical | Indoor
Environment
| Exteriors | Heating | Home
Inspection
| Insulate
Ventilate
| Interiors | Mold
Inspect/Test
| Plumbing
Water
Septic
| Roofing | Structure | Contact Us
Directory of Professionals to Inspect or Test a Building


PLUMBING TOPICS
SEPTIC SYSTEMS HOME
SEPTIC SYSTEMS ONLINE BOOK
SEPTIC SYSTEM DESIGN BASICS
SEPTIC DESIGN ALTERNATIVES
SEPTIC INSPECTIONS
SEPTIC & CESSPOOL SAFETY
  TANK, & CESSPOOL WARNINGS
  SPECIAL WARNINGS FOR HOME OWNERS
  SEPTIC METHANE GAS
SEPTIC SYSTEM FLOODING
SEWER GAS ODORS
  First Steps for Sewer Gas Odors
  Dangerous Conditions
  Building Drain & Sewer Line Odors
  Cure Odors in Septic Systems
  Other Causes of Odors from a Septic System
  Plumbing Fixtures or Traps
  Plumbing Vent Definitions, Types
  Plumbing Vent Defects
  Septic System or Sewer Piping
  Site, Weather, or Failing Neighbors
  Tests for Indoor Sewer Gas
  Tracking Odors to Source
SEWER GAS ODORS in COLD WEATHER
  Short Answer in Cold Weather
  Diagnosing Sewer Odors
  Cold Weather Plumbing Vent Blockage
  Trap Siphonage and Sewer Gases
  Building drain odor source
  Fixture versus system blockage
  Odors in Wet Weather
  Indoor Septic Odors Outdoor Causes
  Outdoor Odor Sources
  Sewer Odor Tracking
  Remedies for Sewer Odors
  Odors and Drain Lines
  Failed Drainfields and Odors

More Information
ODORS & SMELLS DIAGNOSIS & CURE

InspectAPedia® Home & Site Map
Air Conditioning & Heat Pumps
Bookstore
Electrical
Environment
Exteriors
Heating
Home Inspection
Insulate Ventilate
Interiors
Mold Inspect/Test
Plumbing Water Septic
Roofing
Structure
Accuracy & Privacy Policies
Contact Us



Photograph of sewer line break in a crawl space

How to Track the Source of Sewer Gas Smells and Septic Tank Odors
InspectAPedia®  -    

  • How to track septic odors or sewer gas odors to their source
  • What diagnostic questions to ask when finding the source of a septic or sewer gas smell
  • How to prevent or cure sewer gas odors from septic systems, building plumbing, & other causes
  • Sewer gas smell diagnosis - plumbing checklist
  • Septic gas smell diagnosis - septic system checklist
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/appointment.htm.

This page describes how to track down the source of septic or sewer gases as a step in the procedure to diagnose, find, and cure odors in buildings including septic or sewage 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. What makes the smell in sewer gas? Sewer gases are more than an obnoxious odor.

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). 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.

Also see Wet Weather or Cold Weather Septic Odors or Sewage Odor Diagnosis & Repair Guide for additional odor tracing and cure advice for odors occurring during wet or cold weather.

© Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links 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.

Guide to Tracking Sewer Odors to Their Source

Photograph of sewer line break in a crawl space
Track the septic odor strength to a source: The photo shows how this pays off. A family room over this crawl space had the strongest septic odors. An abandoned waste line was no longer connected to a bathroom but it had been left open in the crawl space, permitting gases from the septic system to enter that area.

Is the sewage odor stronger outside or indoors? If indoors, is the odor only at a specific bathroom or fixture? Perhaps there is simply a particular bathroom which is missing a plumbing vent.

If the sewage odor is strongest outside that suggests a septic or sewer gas problem in the septic or sewer system, but don't rule out unusual site or wind conditions discussed below. Track the septic or sewer odor source to its strongest point. Before tearing up your own property or drains or building, let's be sure the odor is coming from your property and not from a neighbor or other facility.

Before proceeding to the more detailed septic odor diagnostic articles listed below, see if you or other friends and family members can make these simple diagnostic observations. Each of these answers can point to some of the specific odor causes we list in our detailed articles below. Don't worry if you don't know the answer, just collect what data you can and then proceed to the detailed articles we list below.

  1. Where is the sewer or septic smell strongest? Indoors, or outdoors?
    1. Indoors odor tracking: on what floor of the building and in what room(s) is the odor strongest? This may lead to a specific drain, trap, plumbing fixture, or similar problem
    2. Outdoors odor tracking: on what side of the building is the odor strongest? Does the odor get stronger if you walk away from the building or towards it? Is the odor coming from your property, a storm drain, a neighbor's property?
  2. How does the septic or sewer gas odor strength vary? Is the variation associated with:
    1. Weather conditions: sun, sun shining on certain sides of the building or property; rain, freezing weather, snow cover, wind direction.
    2. Time of day: odors may be associated with periods of plumbing system usage; also temperature and wind conditions vary by time of day.
    3. Season of the year: snow cover and freezing weather can make odors appear or disappear.
  3. What plumbing or flooding or other events have happened that may relate to odors: such as septic flooding during area flooding, a burst sewer pipe, a sewage leak in a crawl space that was not cleaned up, a change, addition, modification, or repair of the septic system, sewer line piping, or other mechanical systems in the home.
  4. Does the building water supply smell funny? Hot water and cold water both or just hot water?
  5. When did someone first notice the septic odor or sewer gas odor? and How old is the building?
    1. Has the odor always been present or has it developed recently.
    2. What else happened? If the sewer gas or septic odor began recently, what changes in the building or events at the property can be placed at about the same time as when odors were first noticed? Have there activities such as remodeling, demolition, or plumbing repairs that may have disturbed or affected the building drain waste vent piping, chimneys, gas appliances, or use of chemicals? Dead animals?

The answers to these questions will help you make sense out of the diagnostic suggestions in the articles that follow. Contact Us if you have other diagnostic suggestions or if you simply cannot figure out the source of a problem odor at a building.

Share this Article      

...

Technical Reviewers & References

  • Daniel Friedman - principal author/editor of the InspectAPedia® Website
  • InspectAPedia Bookstore lists recommended books, organized by topic & available for purchase. Most of our articles also include a list of recommended books for the specific article topic as well as other references, and information sources.
  • 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.

MVOCs & MOLDY MUSTY ODORS
ODORS & SMELLS DIAGNOSIS & CURE
PLUMBING TOPICS
GAS MEASUREMENT TOOLS
SEPTIC SYSTEMS HOME
SEPTIC SYSTEMS ONLINE BOOK
SEPTIC SYSTEM DESIGN BASICS
SEPTIC DESIGN ALTERNATIVES
SEPTIC INSPECTIONS
SEPTIC & CESSPOOL SAFETY
SEWER GAS ODORS
  First Steps for Sewer Gas Odors
  Dangerous Conditions
  Building Drain & Sewer Line Odors
  Cure Odors in Septic Systems
  Other Causes of Odors from a Septic System
  Plumbing Fixtures or Traps
  Plumbing Vent Definitions, Types
  Plumbing Vent Defects
  Septic System or Sewer Piping
  Site, Weather, or Failing Neighbors
  Tests for Indoor Sewer Gas
  Tracking Odors to Source
SEWER GAS ODORS in COLD WEATHER
  Short Answer in Cold Weather
  Diagnosing Sewer Odors
  Cold Weather Plumbing Vent Blockage
  Trap Siphonage and Sewer Gases
  Building drain odor source
  Fixture versus system blockage
  Odors in Wet Weather
  Indoor Septic Odors Outdoor Causes
  Outdoor Odor Sources
  Sewer Odor Tracking
  Remedies for Sewer Odors
  Odors and Drain Lines
  Failed Drainfields and Odors
Toxic Gas Test Procedures

  • Thanks to Slade Franklin for the reminder that a leaky wax ring at a toilet can lead to septic odors in bathrooms. 11/2007
  • Thanks to J.V. (privacy protected) for the reminder to make a detailed inspection of the plumbing vent system when sewer gas odors are present. 07/2008
  • Thanks to Roger Hankey & Cheryll Brown, www.hankeyandbrown.com, ASHI home inspectors in Minnesota, for the deteriorated transite pipe gas flue vent photograph and comments. Mr. Hankey is a past chairman of the ASHI Technical Committee, serves as co-chairman of ASHI legislative committee, and has served in other ASHI professional and leadership roles. 7/2007
SEPTIC SYSTEMS HOME

More Information

InspectAPedia.comInspectAPedia ® Home & Site Map
InspectAPedia Blog - News Updates
Air Conditioning & Heat Pumps
Bookstore
Electrical
Environment
Exteriors
Heating
Home Inspection
Insulate Ventilate
Interiors
Mold Inspect/Test
Roofing
Plumbing Water Septic
Structure
Accuracy & Privacy Policies
Contact Us

More Information on Building Diagnostic Inspections and Repairs

InspectAPedia.comInspectAPedia® 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.
GO TO the MOLD and INDOOR ENVIRONMENT INFORMATION CENTER for in-depth advice on avoiding testing for or cleaning up mold and other indoor environmental hazards, odors, gases, contaminants
The Mold Information Center:
What to Do About Mold in Buildings, When and How to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems
GO TO MOLD TEST KITS: This expert-recommended mold test kit is cheap and yet top performing *IF* you use a competent analysis laboratory!
Use this simple, economical mold test kit
by following our instructions on how to collect and mail mold samples to our lab
GO TO IAQ/MOLD-TEST LAB SERVICES: Mold, Pollen, indoor air quality, field and laboratory services by an expert.Environmental Inspection, Testing, & Diagnosis 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.
GO TO our PRE PURCHASE BUILDING INSPECTION SERVICES: Authoritative information for home buyers and home owners is included with your inspection.
Building Inspection, Problem Diagnosis
, Forensic Investigation & Testing, Repair Consulting

CONTACT Daniel Friedman - Dan is a senior ASHI home inspector, nationally recognized expert on building inspection, building failures, and sick building investigation
Contact Daniel Friedman for website content suggestions or for fee-paid consulting

10/23/2009 - 08/26/2006 - InspectAPedia.com/septic/Septic_Odor_Tracking.htm - © 2009 - 1988 Copyright Daniel Friedman All Rights Reserved - InspectAPedia® is a Registered U.S. Trademark