What is an Overflow Relief Gully?

how to fix smelly drains

Today dad and I installed an overflow relief gully (ORG) to a house that had one installed in the wrong place.

What is an Overflow Relief Gully?

It’s a drain like fitting with a grate on top and has a bend at the bottom.

It is installed 150mm lower than the lowest drain point in the house.

We fixed the ORG on a house where it was originally installed higher than the floor grate inside the bathroom.

This meant meant when the council sewer backed up, the sewerage overflowed through the floor waste in the ground bathroom. Had an ORG been installed, it would have overflowed outside.

The floor waste was the deepest opening to the sewer main and it was unfortunately inside the house! It’s not the nicest sight (or smell!) to wake up to on an early Saturday morning.

Where should an ORG be installed?

An ORG is to be installed at the deepest part of the sewer drain OUTSIDE so that if the the sewer line backs up or blocks, the effluent will overflow outside.

It’s a plumbing by-law and council requirement that all houses and new dwellings have one to avoid this problem. It would pay to ensure if your house doesn’t have one that you call you local licensed plumber to install one.

The plumber will require a copy of the drainage plan to your house. You can purchase one from your local council.

It can be a relatively easy job to install providing the main sewer line into the house isn’t plumbed straight through the house.

In our case today, the sewer line ran alongside the house and we were able to locate it via the drainage plan and install the ORG.

Unfortunately some new houses have been built without an ORG. The home may have been built prior to the law coming into place. Or certification may have been missed.

If the house has been inspected by council, be assured an ORG has been installed onto your property.

How to maintain an ORG

To maintain an ORG, ensure that the trap bottom has a water seal to stop sewer smells. Also keep the grate clear from debris. Covering the ORG may force the overflow of sewerage back down to spill out elsewhere.