I just received this alert bulletin and thought it was of interest:

"As a result of the heavy rainfall over the last few weeks several contributing factors are coming together that is resulting in dangerous atmospheric conditions, particularly in below grade levels of dwellings.

The recent rainfalls have saturated the top layer of soil, down several feet. The water table also continues to rise toward the surface. As is always the case, Methane (natural gas) and Carbon Dioxide exist in soil as a result of the natural decomposition process.

The result of water pushing down and water pushing up is that the naturally occurring gases - Carbon Dioxide and Methane - are being squeezed out of the soil and pushed down (or up) the path of least resistance. This path has resulted in these gases making their way into sumps and other below grade accesses inside dwellings (they only present a hazard when confined, so although they are being pushed to the surface in other areas, they do not generally pose a threat.

MDE has reported several incidents across the region, and two incidents in Howard County, where Carbon Dioxide and Methane have created an unsafe atmoshpere in the basements of dwellings. What responders are being called for is residents experiencing shortness of breath, headaches or burning sensations of the mucous membranes. Responders typically find decreased levels of oxygen (caused by the presence of Carbon Dioxide in large quantities - >30,000 ppm in some instances) and positive LEL readings (caused by the presence of Methane) using a four gas meter.

Methane, under these circumstances, is colorless and odorless as it does not contain the additive mercaptan. Methane is lighter than air and is a flammable gas.

Carbon dioxide is also colorless and odorless. Carbon Dioxide is heavier than air and is non-flammable. Exposure to high levels of Carbon Dioxide can result in headache, dizziness, restlessness, paresthesia, dyspnea, sweating, malaise, as well as an increased heart rate and blood pressure.

During the next few weeks, while the water table remains high and the ground is saturated with water, if you respond to an incident where residents are exhibiting any of the symptoms listed in the absence of other medical explanations you should strongly consider the phenomenon described above. Particularly if the resident is in or has been in a below grade level.

Check below grade levels of the home with a four gas meter. If you detect LEL readings accompanied by decreased levels of oxygen you should evacuate the residence and request Special Operations for further investigation. A standard four gas meter cannot distinguish between methane and other flammable vapors."

Pete

Whoa! This is exactly the conditions in our area...great post, thanks.

Pete,

Any suggestions from your authorities on remediation? Should I crack open the Bilco door for the basement? Would a standard CO detecter be of use?

Of course my 135 year old house leaks air like a sieve anyway but cripes, another thing to worry about. But thanks for passing on that info.

I've live just across the MasonDixon line for you and we've got wet ground for sure.

Andy

I would and have done so for our basement and placed a fan to move/exhaust the air.


I always recommend at least one CO and smoke detector for every floor of the home including the basement.

Pete

Thats kinda what we've got here.

And I live in a basement!

Oh... so that's why...

(What? What do you mean I can't say that? He'll understand... Oh, all RIGHT!)

Ironraven, you'd best get one of those four-gas meter thingys. Get one with a good loud alarm. We've already lost one good member, and that's more than enough.

Sue

Hi Sue and All,

Those 4 gas meters are not something a consumer would go out and purchase for continuous monitoring like a standard CO or smoke detector. They are designed to check the atmospheric conditions as a result of some type of situation that would warrant such a device. Some of the situations include malfunctioning furnace/fire place/wood stove, CO or smoke detector activation, fire or any situation where occupants complain of headache, weakness, troubled breathing. The meters are somewhat expensive staring around $485 ( 4 Gas Meter ) and can go up to a couple of thousand dollars. They must first be calibrated to unaffected air and must be “bump’ tested before use (or at least daily). A bump test involves exposing the meter to a shot from a can of gases to which the meter will respond, not a cheap enterprise.

In most jurisdictions, the fire department will come out to your home as a good intent call with a meter and check the atmosphere if you suspect exposure.

Pete

LOL Thanks Sue. I think.

I've acutally already got a couple, both high and low, including one that sniffs for propane, since that is how we heat. There is a reason I have the roommate I do- we are both preppers and slightly paranoid. :P

So what's wrong with paranoia? They ARE after you, and it IS worse than you think!

Sue