This article describes possible sources of methane gas that may be found in or around buildings including methane gas coming from a water well, from a septic system or plumbing drain problem, from gas leaks, or other sources.

We discuss different methane gas sources in buildings and how each contributes methane gas, what the problem is, and how to find and fix that methane gas leak source. We link to in-depth articles about the testing, detection, hazards, and correction of methane gas and sewer gas hazards and their sources in buildings.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

- Daniel Friedman, Publisher/Editor/Author - See WHO ARE WE?

Sources of Methane gas, LP gas, natural gas uses, sources, detection, hazards in & around buildings

Natural Gas & LP Gas fuels used in buildings or about Methane Gas (CH₄) production from sewers, septic systems, or other sources in or around buildings

Watch out: we warn in all sewer or septic gas odor articles that 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

See METHANE & SEWER GAS HAZARDS.

Question: what are the possible sources of methane gas in or around buildings?

I'm researching the possible sources of methane gas that might explain gas odors or leaks in or around buildings. Can you list the uses, properties, occurrence of and hazards of natural gas, LP gas, and methane gas that might be found in buildings. Can you refer me to LP, natural gas and methane gas information at InspectAPedia? - Anon.

Reply: Methane gas is widely used as a fuel in buildings and occurs in septic & sewer systems, in some wells, and in thawing permafrost

Sure. At InspectAPedia ou can find information on any of the gas topic names you list by using the search box found at the top or bottom of any InspectAPedia web page. It is worth noting that in addition to the widespread use of methane fuels as LP (liquid petroleum) gas or "bottled gas" and as piped in natural gas in buildings, there are a number of natural or manmade sources of methane gas (CH₄) that might be detected in or around buildings, including the biological production of methane by methanogens in septic and sewer systems and the occurrence of methane gas in soils, water wells, and even in lakes, and streams.

And in December 2011 the New York Times reported on significant levels of methane gas escaping from thawing permafrost.[1]

Here are some direct referrals to articles discussing LP, natural gas, methane gas uses & sources & hazards at buildings:

• BIO-FUEL PRODUCTION & USE - Bio-Gas Production: Large & Small-scale Sustainable Biogas Energy Projects
• DIAGNOSE & CORRECT SULPHUR ODORS - sometimes mistaken for methane odors in water supplies
• GAS PIPING, VALVES, CONTROLS - mistakes in gas piping can mean dangerous LP, natural gas or methane gas leaks in buildings
• METHANE GAS SOURCES - Sources of Methane gas in or around buildings
• MOLD ODORS, MUSTY SMELLS - MVOCs are sometimes reported by building occupants as or mistaken for methane gas odors and leaks. In December 2011 we investigated an LP gas leak complaint in San Miguel de Allende, Mexico.
  
  The building owner reported suspecting a "gas leak" at the entry to the home. LP Gas is widely used as a fuel for cooking and for heating (by open gas log fireplaces and by other gas heaters) in that city.
  
  We observed musty mold odors in the area of odor complaint, but (no surprise) using a combustible gas detector we did detect a significant LP gas leak at a wall-mounted gas heater in an upper floor of the same building. [2]
  
  Also see MVOCs & MOLDY MUSTY ODORS
• NATURAL GAS & PROPANE COMBUSTION PRODUCTS - what are the products of combustion of natural gas or LP gas (methane or CH₄) in building heating appliances.
  
  This article includes a FAQ discussion of can an electric water heater produce methane gas? that questions the possibility of methanogens in water heaters by the process of methanogenesis and the presence of organic contaminants.
• ODORS, Smells, Gases in Buildings - how to track down and cure odors and smells in and around buildings
• OUTHOUSE / LATRINE FIRE & EXPLOSION - case history of an outhouse fire attributed to a combination of toilet paper, methane gas, and kids playing with matches
• ROT, FUNGUS, TERMITES - termites may be a source of methane gas in nature
• METHANE & SEWER GAS HAZARDS - Methane Gas & Septic System Dangers
• SEWER GAS ODORS - Diagnosing and Curing Sewer Gas Smells and Septic Tank Odors. Methane or CH₄ is a principal ingredient in sewer gases such as gases produced in septic tanks and sewer systems.
• SEWER GAS ODORS in COLD / WET WEATHER - Wet Weather or Cold Weather Sewage or Septic Odors: Diagnosis and Repair Guide
• Methane gas in well water: in WATER POLLUTANT SOURCES from the U.S. EPA cites and we elaborate that methane gas or musty/earthy smell in water may be from decaying organic matter in water.
  
  [or from direct methane gas leaks into aquifers and water wells. We've had reports, especially from mining areas such as portions of Pennsylvania in the U.S. in which underground methane was seeping into the well through rock fissures.
  
  One client could on occasion light gas coming from their kitchen faucet! Be careful, such conditions are dangerous and risk explosion or fire--DF]
• Using the TIF 8800 Gas Detector - detection of LP gas, natural gas, Methane or CH₄ gas
• WATER ODORS, CAUSE CURE - How to Identify & Cure Odors in Drinking Water
• WATER TESTS for CONTAMINANTS and Well Pollution - methane gas occurs in some public and private wells and water supplies
• WELL WATER CONTAMINANT SOURCES - what are the common sources of water pollutants and contaminants?
  
  Watch out: Many serious problems (bacteria, heavy metals, nitrates, radon, and many chemicals) can only be found by laboratory testing of water.
• Also see additional citations atReferences or Citations

Reader Question: help tracing methane gas in a home

8/19/14 Meredith said:

We need help tracing a methane situation in our home. Starting in April we noticed a periodic strange smell in our son's bedroom. After much trial and error, we got an inspector to come and do an air test. Methane level was found to be 3.8ppm, not explosive but higher than usual for indoor air. Now we can't figure out where the methane is coming from!

-Our gas system was pressure-tested, no leak.

-Neighbor who shares our wall (it is a townhouse) pressure-tested her system, no leak.

-Gas lines do not even run in the walls of the room.

-Smell is limited to that one room, nowhere else in the house, and not above or below that room.

-No plumbing near the room, therefore don't suspect sewer gas.

-Smell has a 'mercaptan' odor similar to, but not exactly the same, as the odor added to natural gas

-Smell is there only at certain times of day! Strongest in the afternoon (which happens to be when that room is warmest as the sun hits in the afternoon, but that may be a coincidence), nonexistent in morning, variable at night time.

-Air was also tested for VOCs, came back negative.

Reply: track down the odor source in case it's not methane: visual inspection, possible odor sources

Meredith

Depending on just what testing was done, perhaps we should not be over-confident that we've really correctly identified the gas that makes the odor that you cite. Indeed most people are pretty good at spotting a mercaptan odor and indeed that's added to gas supplies for safety reasons.

But often odors are chemically complex, and many gas detectors and even some lab procedures may focus on methane and detect it and name it when in fact what's present is a more complex substance.

That's why your visual inspection and careful thinking make sense.

At ODORS GASES SMELLS, DIAGNOSIS & CURE we describe steps that might help you pinpoint the odor source, including keeping an odor log.

From your note my first guess would be a plastic building material such as siding, window, or window screen that off-gasses when heated by the sun.

Reader follow-up: Would the VOC test have detected any building materials offgassing?

Would the VOC test have detected any building materials offgassing? That test came back normal. But I see what you mean-- the methane could be a red herring, but the 3.8ppm level seemed usual to the inspector.

We had thought about the offgassing possibility before we got back the methane test.

The materials in the room are exactly the same as the materials in the other (non-smelling) bedroom which is right next door to it, shares a common wall, and also has the identical sun exposure. The house is brick, no siding.

We patch-tested the window and drywall (as per your recommendation), nothing. We've cut drywall open in several places and can't tell even which part of the room the smell is coming from-- it really fills the space.

We've removed all of the furniture, the cellular blind, the rug, etc. Checked outlets and light fixtures.

Obviously there is an explanation, but we are stymied. Who else can we call? The person we had out does specifically environmental testing. Is there another kind of specialist we can call in for help who might be familiar with solving these kinds of mysteries?

Reply: typical in-home VOC testing does not cover all gas or odor sources, may not include methane, and may not be sufficiently diagnostic

"VOC" is short for Volatile Organic Compound (such as mold odors). In buildings VOCs are emitted by building materials or contaminants such as a mold odor (Mold VOCs or MVOCs) from moldy carpets.

Methane is not a off-gassed by a building material

In the atmosphere in general we see about 2.2 ppm of methane (CH₄).

Methane is a colourless gas. At low concentrations it is odourless, but it has a sweet smell at high concentrations. At mixtures more than about 5-15% in air, it is explosive.

It has a lifetime of around ten years because it is only very gradually destroyed by other chemicals in air. Methane is one of a group of chemicals known as the volatile organic compounds (VOCs). It is produced both naturally and from man's activities. - SEPA cited below.

Depending on the methane source and exactly where and how your consultant measured, the methane results would vary.

For example, since it's lighter than air, with no mixing fans running in a room, if methane were present I'd expect it to be at higher concentrations near the ceiling.

[Propane on the other hand is heavier than air - this is why we place propane gas detectors low in a room and methane gas detectors high]. While we're on it, CO (carbon monoxide) is also slightly lighter than air and will generally mix in air throughout a room.]

If the test was methane specific then there is a methane source - but keep in mind that there are plenty of common sources of methane including organic garbage and human flatulence.

• At low levels methane is not toxic and not a health threat.
• At concentrations in air between 5% and 15% methane is dangerously explosive.
• At high levels, because it can displace oxygen, methane can be an asphyxiant.

Methane (CH₄), which is a specific VOC and a GHG [GreenHouse Gas] naturally present in air, is often considered apart from the other VOCs, which are referred to as NMVOCs (non-methane volatile organic compounds). - CITEPA cited below.

Methane Gas Action Level

The EPA, in studying methane levels in homes near landfills defined this action level:

Methane: > 1.25% volume in air (12,500 ppm). The LEL for methane is 5% and 25% of the LEL is 1.25% - that's how EPA got that number. - "Lower Darby Creek Area - Clearvierw Landfill Site, Final Indoor Ambient Air Monitoring and Assessment Plan, April 2010, U.S. EPA, Tetra Tech EM, Inc., TDD No. #43-028-10-01-001

A "VOC" test, depending on how it is conducted, can be sensitive to a wide range of volatile organic compounds but I don't rule out other gases or smells not included in such a test.

While VOCs are chemicals that contain hydrogen H and carbon C and that evaporate easily, Methane, though it is a greenhouse gas, is not properly a VOC. Or as more-commonly stated,

Definition of VOC

Any chemical compound based on carbon chains or rings (and also containing hydrogen) with a vapour pressure greater than 2mm of mercury (0.27 kPa) at 25 deg C, excluding methane. Also excluded from "VOCs" are CO, CO2, carbonic acid and carbonate salts. - USEPA, AP-42 1996

Keep in mind that not everything that you smell is a "VOC".

See the additional Research and More Reading suggestions below.

Research on Methane Gas Sources in or at Buildings

• METHANE GAS SOURCES Start here with the list of methane gas or methane "odor" sources at buildings given above on this page.
• SEPA, METHANE GAS PROPERTIES, USES, SOURCES, HEALTH EFFECTS [PDF] Scottish Environmental Protection Agency, retrieved 2018/08/12, original source: http://apps.sepa.org.uk/SPRIPA/Pages/SubstanceInformation.aspx?pid=65
• CITEPA, Volatile Organic Compounds - VOCs [PDF] CITEPA, CITEPA - Centre Interprofessionnel Technique d'Etudes de la Pollution Atmospherique, 42, rue de Paradis, 75010 PARIS - FRANCE Tél: +33 (0)1 44 83 68 83 retrieved 2018/08/12, original source: https://www.citepa.org/en/air-and-climate/pollutants-and-ghg/aep/vocs
  Excerpt:
  
  Hydrocarbons are included in the VOC group and often mistakenly equated with it. This is probably because VOCs are often expressed as total methane- or propane-equivalent hydrocarbons. Methane (CH4), which is a specific VOC and a GHG naturally present in air, is often considered apart from the other VOCs, which are referred to as NMVOCs (non-methane volatile organic compounds).
  
  VOCs are released by:
  
  combustion
  
  the evaporation of solvents in paints, inks, glues
  
  stain removers
  
  cosmetics, etc
  
  the evaporation of organic compounds from petrol for example, biological reactions.
  
  There are a great many sources of VOC emissions. They are released by certain industrial processes involving the use of solvents (production of base and refined chemicals and parachemicals, metal cleaning, application of paints, printing, glues and adhesives, rubber, cleaning products, perfumes and cosmetics, etc.), and others not involving solvents (petroleum refining, production of alcoholic beverages, bread, etc.).
• [1] "Temperature Rising - As Permafrost Thaws, Scientists Study the Risks", Justin Gillis, The New York Times, 12/16/2011
• [2] San Miguel de Allende, Col. San Antonio, C.S. / DF Field investigation conducted by Daniel Friedman, 12/14/2011. Unpublished.
• [3] "Detailed Guide to Groundwater Pollution Sources of Drinking Water from Household Wells", EPA 816-K-02-003 January 2002.
• [4] "E.P.A. Links Tainted Water in Wyoming to Hydraulic Fracturing for Natural Gas", Kirk Johnson, The New York Times, 12/08/2011
• [5] "EPA Releases Draft Findings of Pavillion, Wyoming Ground Water Investigation for Public Comment and Independent Scientific Review", United States Environmental Protection Agency US EPA, Release Date: 12/08/2011, Contact Information: EPA HQ: Larry Jackson, 202-564-0236, jackson.larry@epa.gov; EPA Region 8: Richard Mylott, 303-312-6654, mylott.richard@epa.gov, Web searh 12/17/11, original source: http://yosemite.epa.gov/opa/admpress.nsf/0
  /EF35BD26A80D6CE3852579600065C94E

 

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Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2018-08-12 by Anonymous (no email)

Any chance you can connect me with the Melissa discussed here?

We are having the same off gassing problem in my daughters room and it is making us really nervous.

REPLY:

Sorry, Anon but no. Melissa chose to remain otherwise anonymous and did not share contact information.

However the article above suggests places to look by giving a series of more-detailed methane gas source diagnosis and repair articles.

The fact that you find the odor in only one room of your home is a helpful diagnostic. You can proceed then to relate that location to possible sources such as nearby plumbing, a dead animal in a wall, a spill, or some other odor source (it may not actually be methane).

To be clear, "Off-gassing" , the phrase you used, describes odors emitted by a substance or material, such as formaldehyde off-gassing from chipboard cabinets or some flooring products. You will not find methane off-gassing from a building product. Take a look again at the list of sources.

Understanding what a gas or odor *might* be and what it could *not* be can help track down the source.

At ODORS GASES SMELLS, DIAGNOSIS & CURE https://inspectapedia.com/odor_diagnosis/Odor-Diagnosis-Cure.php we describe steps that might help you pinpoint the odor source, including keeping an odor log. From your note my first guess would be a plastic building material such as siding, window, or window screen that off-gasses when heated by the sun.

Question: can an electric water heater produce methane gas?

Hello, I was reading your website about possible odors associated with systems in the home. Is it possible for an electric water heater to produce a methane gas? I have recently verified readings from a hot water line that had methane readings in the flammable ranges. Any input or information would be appreciated. Thanks, R.T.

Reply: an electric water heater does not naturally produce methane gas but there can be other methane gas sources in a building water supply and other odor sources in a water heater or in water supply

[OK so this is not a frequenly-asked-question about methane gas in buildings but it is a particularly interesting one that involves important safety hazards and an actual field report of a methane-gas in water-related building fire.- Ed.]

A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem with the water heater or with gas piping in the building, but none of these ought to involve methane induced into the water heater tank interior from the appliance or its fuel piping. And simply heating water does not innately produce methane gas.

An electric, or oil fired water heater does not produce methane gas (CH4). A gas fired water heater indeed uses a fuel gas that includes methane plus an odorant. However a gas-fired water heater might leak LP or natural gas into the air but as there is no under-water gas piping at a conventional water heater I'm doubtful that the fuel gas would be likely to leak directly into the water supply or hot water tank from the heater itself or its gas piping.

Watch out: in some public and private well water supplies methane gas from mining, natural gas drilling and removal from the earth, or other sources may result in high levels of methane gas entering well water.

How to distinguish between naturally occurring methane gas odors and LP or natural gas odors

It might be helpful to note that you can and should distinguish between LP gas or natural gas (perhaps by odors) and methane from more natural sources because LP and natural gas fuels contain an odorant additive with a distinctive smell (mercaptan).

Methane is a common ingredient in sewer gases, and it might also be found in some soils and even wells into which it may enter from either natural or manmade sources.

And there have been reports of methane entering the water supply from those sources, especially in areas where there has been mining, or more recently, gas exploration and drilling that disturbs soils and rock formations.

Watch out: If you do have methane gas in your water supply it could be dangerous, presenting a possible explosion hazard. But if methane is in your water supply, it ought to be present in both hot and cold water, though due to the temperature differences it might be more obvious in one than the other.

The gas test instrument described at GAS DETECTION INSTRUMENTS may help you track down gas odors.

You may also to take a look at METHANE & SEWER GAS HAZARDS

Properly identify the odor or gas you are observing

Are you sure you are smelling methane and not some other odor. For example a water heater with a bad sacrificial anode or a water heater whose tank and water contain certain (naturally occurring) bacteria can produce a sulphur smell.

See SULPHUR & SEWER GAS SMELL SOURCES for details. And for a review of odors occurring in the water supply to a building

see WATER ODORS, CAUSE CURE.

We would much appreciate hearing any comments, critique, suggestions, or further questions that you may have after you've taken a look at that article. We are dedicated to making our information as accurate, complete, useful, and unbiased as possible: we very much welcome critique, questions, or content suggestions for our web articles. Working together and exchanging information makes us better informed than any individual can be working alone.

Please keep me posted on how things progress, and send along photos of yoru gas equipment if you have some, or any tests or reports you obtain if you can. Such added details can help us understand what's happening and often permit some useful further comment. What we both learn may help me help someone else.

More about water heaters and water heater odors is found at WATER HEATERS

and ELECTRIC WATER HEATERS and for checking the water heater sacrificial anode

also see Water Heater Anode & Dip Tube Check.

Also see ODORS GASES SMELLS, DIAGNOSIS & CURE for help in tracking down odor sources in buildings.

Follow-up discussion: details of detection of methane gas in an electric water heater

Thank you for the response. I should add that I am a firefighter and ran into this after a copper water line caused a flash fire in a room while the occupant was cutting the water line with a sawzall.

• There were two hot water heaters in the building running off the same water source.
• I monitored all the water lines in the building with a 4 gas meter (with included Ch4) and found the methane only in the one line that had caught fire.
• This line with the Ch4 contained about 200ppm after it had been cut and the fire had occurred. I then traced this line to the water heater and found readings around 6000ppm.
• There have been no other reports of methane leaks or contaminated water supply. The methane production seemed to originate in the water heater.

Any other ideas. Thanks - Ryan

Discussion: methane gas inside a water heater tank?

Your comment " I then traced this line to the water heater and found readings around 6000ppm." is the most critically diagnostic, I agree.

I'm looking for explanations of how we might get methane out of a water heater when methane is not in the water supply itself. (Earlier I warned about other gas production due to a corroding sacrificial anode or perhaps due to bacterial contamination). It might be possible to obtain methane by a biological process (methanogens, or the process of methanogenesis produce methane gas by the breakdown of organic materials) but I have not yet found a source that cites the types of bacteria that might be present in a water heater as a source of methaneogenesis. The Wikipedia entry on Methane clathrate is also interesting but seems even more remote.

Some comments questions might help sort things out - in no particular order except how I've thought of them:

• What is the building water supply source? Is this a private well water supply or municipal water supply. A private well water source could contain methane while it would be highly unlikely in a municipal water supply (except for a freak accident). Methane gas is found in well water.
  • Here is a nice article from the Alberta Canada Govt http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex10840 - from a well source the methane would not be expected to be present in just one water heater
  • Here is a similar resource from Minnesota http://www.health.state.mn.us/divs/eh/wells/waterquality/methanemn.html
• Compare hot and cold water supply when testing for methane gas. Did you check cold water supply as well or just the hot water tanks? Heat indeed can cause dissolved gases of any kind to begin to appear in the water as gas bubbles.
• Were the other water heaters on or off at the time of your testing for methande gas? Because water temperature might change the ease of detection of dissolved methane in a water supply, if the other tanks were cold that could have made a difference.
• What is the fuel supply in the building: you note that the water heater is an electric one. But regarding any nearby piping for LP or Natural Gas; did you look over gas piping for defets, misconnections, damage, etc. ? Are we dead sure that the only pipe that was cut was a water line - not also an LP or NG pipe line?
• What do you make of finding CH₄ only at one water line? That argues against a water supply source of methane, right?
• What test instrument were you using? I find that some, such as the widely used TIF 8800 will respond not only to methane but to an extremely wide range of gases mixed in air - I can set off a TIF set to a sensitive reading level just by breathing on it (and that is not to say my breath contains alcohol)
• We need to rule in or out of consideration these other possible sources of methane gas in the water tank:
  • any plumbing cross connection that could have sent sewer gases into the water supply piping
  • any uncertainty about what the test instrument was seeing (for sure Ch4?)
  • any contribution from bacterial contamination or sacrificial anode contamination of the water heater producing H2S and any possible chemical reaction that converted that to methane and other gases

Here are some avenues of further exploration of the question of how methane gas appeared in this building's water supply but only at one water heater, an electric unit

Noting the Wikipedia entry on methane hydrate (http://simple.wikipedia.org/wiki/Methane_hydrate) the article notes that thermal recovery of methane is peformed using hot water (or steam) (in a natural gas well); Methane hydrate is decomposed by the hot water to form methane gas mixed in with hot water. But I can't see how methane hydrate would be formed inside of a hot water tank.

Working from the temporary assumption that your instrument really focuses specifically on CH4 and was not confused by anything else in the water heater (such as more likely hydrogen sulfide), I find this themochemistry lecture interesting. At (http://itl.chem.ufl.edu/2045/lectures/lec_8.html) the author gives a chemical reaction for the heat formation of methane C(s, graphite) + 2 H2(gas) = CH4(gas) - note the presence of that H₂?

Until we talk with a chemist this is all very speculative, but I'm thinking along the lines of an older water heater with a bacterial H₂S(hydrogen sulfide) or electrochemical (deteriorating sacrificial anode) source of hydrogen sulfude that somehow led to a reaction producing methane.

For example there may be organic contaminants in a water heater or water supply, or the presence of sulphur of sulfates in the water heater tank; Anerobic bacteria or possibly archaea methanogens found in a water heater tank may play a role in converting sulfates or H₂S (hydrogen sulfide or sulfates in the water heater tank may be from a bacterial source or from deterioration of the the sacrificial anode) into various components including methane. we cannot be at all confident of this without more research.

I also wanted to read http://www1.eere.energy.gov/femp/pdfs/bamf_wastewater.pdf but from my location I can't load that page

Comments or suggestions from other readers are invited to help sort out this question: how and why would methane gas appear just in a single electric water heater at a building?

Methane Gas in Well Water - Evidence of possibly unsafe methane gas & gas drilling chemicals in water wells

In December 2011 the U.S. EPA reported on a study of the Pavillion gas fields in Wyoming that at least in some areas of natural gas drilling experts have found compelling evidence of the seepage of natural gas (as well as chemicals used in natural gas drilling and fracking procedures) into drinking water wells. Quoting from the New York Times:

The study, which was prompted by complaints from local residents about the smell and taste of their water, stressed that local conditions were unusual at the site, called the Pavillion field, in that the gas wells were far shallower than in many other drilling areas around the country. The shallow depth means that natural gas itself can seep upward naturally through the rock, and perhaps into aquifers.

But the suite of chemicals found in two test wells drilled at the site, the report said, could not be explained entirely by natural processes. The agency’s analysis of samples taken from deep monitoring wells in the aquifer indicated the presence of synthetic chemicals, like glycols and alcohols consistent with gas production and hydraulic fracturing fluids, benzene concentrations well above standards in the Federal Safe Drinking Water Act standards, and high methane levels. [4]

And from the US EPA "methane in drinking water wells" study itself, the agency found gas production chemicals well above [the "bad" or "undersirable" direction] Safe Drinking Water Act standards:

Two Deep Water Monitoring wells: EPA’s analysis of samples taken from the Agency’s deep monitoring wells in the aquifer indicates detection of synthetic chemicals, like glycols and alcohols consistent with gas production and hydraulic fracturing fluids, benzene concentrations well above Safe Drinking Water Act standards and high methane levels. Given the area’s complex geology and the proximity of drinking water wells to ground water contamination, EPA is concerned about the movement of contaminants within the aquifer and the safety of drinking water wells over time.

Findings in the Private and Public Drinking Water Wells: EPA also updated its sampling of Pavillion area drinking water wells. Chemicals detected in the most recent samples are consistent with those identified in earlier EPA samples and include methane, other petroleum hydrocarbons and other chemical compounds. The presence of these compounds is consistent with migration from areas of gas production.

Detections in drinking water wells are generally below established health and safety standards. In the fall of 2010, the U.S. Department of Health and Human Services’ Agency for Toxic Substances and Disease Registry reviewed EPA’s data and recommended that affected well owners take several precautionary steps, including using alternate sources of water for drinking and cooking, and ventilation when showering. Those recommendations remain in place and Encana has been funding the provision of alternate water supplies. - U.S. EPA [5]

Question: distance from electric substation to wastewater treatment plant

(Mar 4, 2013) carlos w said:

Is there a minimum distance to keep from an electric substation when building a wastewater treatment plant?

Reply:

Don't know Carlos, I'm looking for a standard. Meanwhile check with our local electric utility and building department.

Question: tracking down an odd methane gas source

Meredith said:

We need help tracing a methane situation in our home. Starting in April we noticed a periodic strange smell in our son's bedroom. After much trial and error, we got an inspector to come and do an air test. Methane level was found to be 3.8ppm, not explosive but higher than usual for indoor air. Now we can't figure out where the methane is coming from!

-Our gas system was pressure-tested, no leak.

-Neighbor who shares our wall (it is a townhouse) pressure-tested her system, no leak.

-Gas lines do not even run in the walls of the room.

-Smell is limited to that one room, nowhere else in the house, and not above or below that room.

-No plumbing near the room, therefore don't suspect sewer gas.

-Smell has a 'mercaptan' odor similar to, but not exactly the same, as the odor added to natural gas

-Smell is there only at certain times of day! Strongest in the afternoon (which happens to be when that room is warmest as the sun hits in the afternoon, but that may be a coincidence), nonexistent in morning, variable at night time.

-Air was also tested for VOCs, came back negative.

Reply:

Meredith

Depending on just what testing was done, perhaps we should not be over-confident that we've really correctly identified the gas that makes the odor that you cite. Indeed most people are pretty good at spotting a mercaptan odor and indeed that's added to gas supplies for safety reasons.

But often odors are chemically complex, and many gas detectors and even some lab procedures may focus on methane and detect it and name it when in fact what's present is a more complex substance.

That's why your visual inspection and careful thinking make sense.

At ODORS GASES SMELLS, DIAGNOSIS & CURE

we describe steps that might help you pinpoint the odor source, including keeping an odor log. From your note my first guess would be a plastic building material such as siding, window, or window screen that off-gasses when heated by the sun.

...

Continue reading  at GAS DETECTION INSTRUMENTS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see

METHANE & SEWER GAS HAZARDS

METHANE GAS EXPOSURE LIMITS

MVOCs & MOLDY MUSTY ODORS

ODORS GASES SMELLS, DIAGNOSIS & CURE we describe steps that might help you pinpoint the odor source, including keeping an odor log.

PLUMBING S-TRAP CODES & HAZARDS

SEWER GAS ODORS

TESTS for SEWER GAS INDOORS

VOCs VOLATILE ORGANIC COMPOUNDS

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METHANE GAS SOURCES at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to GAS HAZARDS in BUILDINGS

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Citations & References

In addition to any citations in the article above, a full list is available on request.

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