During end of May and early June, we had more than 2 weeks of continuous heavy rain. Late Friday afternoon on 6/6 when I walked past my front fence on my way home, I heard some bubbling sound and smelled some gas but couldn't work out where it came from. I thought it was from the neighbours and didn't pay much attention.
Next morning (7/6) we have some furniture delivered and the driver also mentioned about the heavy smell of gas. We quickly contacted AGL and I took a short video as below. In the video, after around the 20th second you can hear the bubbling sound from underground quite clearly.
This nice "Alinta" van arrived about 30min later and a guy called Luke started working on the problem.
First he surrounded the area and use this little machine (shown on the floor in photo below) to check and confirmed there was some gas leak. Then he asked what has been changed in past few days? When was the brick wall and foot path completed? ...etc. We got all the information prepared and told him the gas pipe was connected on 8/3 by AGL, the concrete slab for foot path/drive way completed on 6/5, and the brick wall was completed on 18/5. Nothing happened in past 2-3 weeks as we were waiting for the blocks from Boral (which just arrived a few days earlier).
He dig and dig for about 30min, tried very hard not to cause any damage to my new brick fence and foot path, but still couldn't find the gas pipe. I then remembered I got this pipe location chart (as below) as suggested by our landscaper Joe when he dig the brick fence footing and quickly printed it out. It saved him lots of effort. He located the pipe quite quickly but surprisingly the first thing he did was to check when will his backup arrive.
Luke explained this is their standard procedure before start working just in case something goes wrong he might be poisoned by the gas and lost conscious. Having a second person on site would also make it faster as digging holes and tracing pipes for leaks is quite a labour intensive job. Soon the second van arrived, they started digging more holes, tracing the pipes, and as shown below they even brought out the fire distinguisher for safety reason.
We then went shopping and when we returned after lunch, surprisingly they were still there, and working on a huge hole on the other side of the road...
After a few hours of hard work, they finally found the root cause of the problem. The previous AGL contractors who connected our pipe in early March didn't wait for the glue on the connector that connects to the main pipe (on the neighbour side of the road) to be completely dried before started working on the pipes. As shown below, the section marked in red is where the leak happened.
Which means, the whole thing has been leaking since early March, for 3 months!! As our side is higher, most of the gas actually traveled through the large pipe surrounding it over to our side. Luckily everything was covered by the soil and it was the continuous heavy rain that soften the soil and allowed the gas to travel to the surface. They will certainly track down those contractors and make them pay for all their work today!
This was the hole in front of our neighbour's house while they waited for the glue on the replaced connectors to dry, it took more than 1.5 hour!
Quickly drew a diagram in Visio as below to explain everything...
If you want to look at my previous post in March when the gas pipes were connected, here it is. If you see AGL sent the same contractor to your area for gas pipe connection, tell them what happened to my house and make sure they wait long enough before rushing to the next job! These Alinta guys are certainly much more professional...