There is a strong smell of gas near one of the external drains, would I be correct in saying it’s from the Sceptic Tank, there are no underground Gas Lines.

if this is the case how can I get rid off the smell ?

Cover the drain?

41 minutes ago, Vacuum said:

Cover the drain?

I can’t as it’s the drain for the Washing Machine and the rainwater off the roof.

The reason septic tanks and other underground sewage treatment plants are vented is to prevent the methane gas exploding.

 

The washing machine and rainwater however shouldnt be going anywhere near the septic tank, so really to resolve it may include diverting this drain into its own gulley/soakway chamber.

Your washing machine outlet is acting  as the vent....possibly

1 minute ago, eyecatcher said:

The reason septic tanks and other underground sewage treatment plants are vented is to prevent the methane gas exploding.

 

The washing machine and rainwater however shouldnt be going anywhere near the septic tank, so really to resolve it may include diverting this drain into its own gulley/soakway chamber.

Your washing machine outlet is acting  as the vent....possibly

The W.M. and the rainwater go into an open drain, the one I assume the smell comes from which might go into the Sceptic Tank, it’s obviously not visible where the drain actually goes.

i could let the W.M.water run onto the road, there are no surface water drains and block the drain so when it rains the water also runs straight onto the road.

The house is over 30 years old in a back lane of the main Soi, there are no visible manholes, drains for surface water although after heavy rains the water drains away quite quickly.

Change diet maybe ?

It may be that the balance of your septic system has been destroyed by using too much bleach to clean the toilets.

 

A septic system needs bacteria to digest the smelly stuff.

 

Try flushing a box of this down each toilet to revive the bacteria ...

https://shoponline.tescolotus.com/groceries/en-GB/products/6019837186

Not sure what you have been reading re bleach but thats completely untrue.

Bacteria and worms are present in all septics and to get those worms thriving it needs only two different people to take a dump.

 

Bleach and chemicals may destroy a handful of bacteria but thats all.

6 minutes ago, eyecatcher said:

Not sure what you have been reading re bleach but thats completely untrue.

Bacteria and worms are present in all septics and to get those worms thriving it needs only two different people to take a dump.

 

Bleach and chemicals may destroy a handful of bacteria but thats all.

Upon reflection I'm sure you are correct about the (non) effects of bleach. However, we find that the occasional dose of the Green Mate helps keep our system in good order.

From a recent post with info that suggests no chlorine based products in septic tanks.

 

 

 

Bleach is definitely not recommended for septic systems. Also, septic systems are vented to prevent back pressure to toilets and not to prevent explosions. An explosion would require an ignition source.

I don't know how your drain is configured but you can always install a trap. It may be the simplest and least costly solution. 

Get a couple of concrete rings place them in the ground and divert your WM water into it ,the ST is purely for the toilet nothing else and should have an air vent somewhere .

chemicals arent good for septic tank, only pee and poo.

Maybe your drain has no waterlock system, broke down or is very easy to drain, this waterlock prevents the smell going out.

I have the same problem at a hotel I stay at in Pattaya. They "treat" it by having a deodorant in the bathroom. ????

 

Anything I can do?

The septic tank will be independent to the smelly drain you are talking about. The water from the shower, sinks, kitchen etc will go out into the road drain, this then mixes with the rainwater when it rains. It is a stupid method but this is what is used. The drains are usually formed in concrete or cement and are pretty rough unlike glazed pipes, so the bits of food from the kitchen and soap mixture etc hang around in the drain and start to smell. Do you know anyone with a jet wash to blast down the drain? alternatively put a strong mixture of bleach in several buckets and was down the drain, do this over 2 days and you might just find it stops smelling till the next time.

 

THis is why they get the black shitty deoxygenated water pouring over the beaches in summer.

14 hours ago, eyecatcher said:

Bleach and chemicals may destroy a handful of bacteria but thats all.

99% of all known germs...... So the advert used to say!

1 hour ago, IssanMichael said:

The septic tank will be independent to the smelly drain you are talking about. The water from the shower, sinks, kitchen etc will go out into the road drain, this then mixes with the rainwater when it rains.

How do you know the OP's septic tank is independent to his smelly drain with showers and sinks connected to a street drain. There is no standard and not everyone has access to street drains.

 

Village houses often send everything from kitchen and bathroom to septic tanks then send a second leach tank overflow to the street. Our house and work buildings leach everything to the land nothing goes to the street.

 

Some areas have rules governing what goes to the street. My wife has rooms for rent that cant sent anything except storm water directly into street without passing through some treatment.

 

Anything goes with Thai plumbing. Always be prepared for the worst.

47 minutes ago, uksmdh said:

99% of all known germs...... So the advert used to say!

you will discover the ad said "household germs"

worktops, bathroom surface  not the sewage dump

1 hour ago, elgenon said:

I have the same problem at a hotel I stay at in Pattaya. They "treat" it by having a deodorant in the bathroom. ????

 

Anything I can do?

Floor drains are often plumbed in without traps. Sewer gas can kill you. When I have encountered these stinky bathrooms, I find a plastic bag filled with water makes a great stopper.

On 12/12/2018 at 4:14 PM, Jumbo1968 said:

I can’t as it’s the drain for the Washing Machine and the rainwater off the roof.

Washing machine and rain water is not connected to the septic tank. 

If that’s what you think it is, just put some bleach in there it will help a lot. 

(Do not ad bleach if it ends up to the septic tank)

2 minutes ago, The Theory said:

Washing machine and rain water is not connected to the septic tank. 

If that’s what you think it is, just put some bleach in there it will help a lot. 

(Do not ad bleach if it ends up to the septic tank)

i have no idea where the waste water is routed, every thing is underground. My biggest concern is the manhole for emptying the sceptic tank is in the bedroom although the smell is outside.

i think possibly the smell could be seeeping through the ground not the drain. I have put Toilet Waste Digester in both toilets but that would bring an immediate result I think.

 

If it is a drain , Install a trap, the water in the trap will keep gas  from  escaping

If it is a vent , try extending it to above you roof line

7 minutes ago, sirineou said:

If it is a drain , Install a trap, the water in the trap will keep gas  from  escaping

If it is a vent , try extending it to above you roof line

Great idea but everything is buried beneath concrete and tiles.

Just now, Jumbo1968 said:

Great idea but everything is buried beneath concrete and tiles.

Sorry, I know it is a hustle , but it is the only viable long term solution. Get a small grinder with a diamond blade, cut the grout out if the surrounding tile/liles, remove the tile , break the cement.

The hard job is now done

Install , trap, replace cement  and install tile back. Or if vent extend pipe. 

Or better yet , pay your local builder/ handyman to do it, grab a beer and watch .????

There will be a lot of quick fix solutions suggested, but IMO , do it right and forget it.  

 

11 hours ago, whaleboneman said:

 An explosion would require an ignition source.

No it doesnt.....an explosion can be caused by a build up of pressure in the bubble.

Thats the reason septic tanks, and land fill sites have vent pipes.

2 hours ago, Jumbo1968 said:

 

At night when you are done with using water, 

Use shower drains (if you have more than one shower do it to all) and use a big can of bleach all into the drains. 

The day after check for result. 

It costs B80, before you do anything else. 

10 hours ago, eyecatcher said:

No it doesnt.....an explosion can be caused by a build up of pressure in the bubble.

Thats the reason septic tanks, and land fill sites have vent pipes.

I disagree. Without an ignition source there can be no explosion as the septic system cannot be overpressurized to that extent. The vents are there to prevent excess pressure from venting back through the toilets.

i had an improperly installed system in Issan and the toilets always bubbled away whenever we had a lot of rain as the tanks would fill and block the tank vents.

They had not installed vents at each toilet as required.

 

2 hours ago, whaleboneman said:

I disagree. Without an ignition source there can be no explosion as the septic system cannot be overpressurized to that extent. The vents are there to prevent excess pressure from venting back through the toilets.

i had an improperly installed system in Issan and the toilets always bubbled away whenever we had a lot of rain as the tanks would fill and block the tank vents.

They had not installed vents at each toilet as required.

 

Yep,I will go with that. I was stretching my point a bit into methane build up in landfill sites or even under melting glaciers which are now exploding.

Agree its highly unlikely that pressure can build up in pipes and manholes and a vented systems primary role is to prevent a vacuum and disabling the wc.

Didnt want to appear argumentative, we are all here to learn snippetts from each other when all said and done.

On 12/13/2018 at 1:52 PM, whaleboneman said:

Floor drains are often plumbed in without traps. Sewer gas can kill you. When I have encountered these stinky bathrooms, I find a plastic bag filled with water makes a great stopper.

Thanks!