Blackburn Sewer Improvement Project
We are inspecting the condition of some of our sewer pipes in Blackburn to ensure we have a reliable sewerage network.
Inspecting our sewer pipes in Blackburn
Yarra Valley Water is responsible for maintaining and improving the sewer network for two million Victorians. Our contractor,ADS Environmental Services, will be inspecting some pipes in Blackburn to ensure they are working efficiently, anytime on weekday between Monday 15 June until Monday 31 August.
Why are the inspections happening?
Sometimes, during heavy storms, rainwater can find its way into our sewer pipes, significantly increasing the flow within the pipes and creating a risk of sewage spilling into local creeks, parklands or even backyards.
The first phase of this project uses a technique called ‘smoke testing’ to quickly find the causes of rainwater entering our sewer pipes – usually pipes that are cracked or broken, or where stormwater pipes have incorrectly been connected to the sewer. This phase will be completed in late August, subject to good weather.
The second phase of the project involves repairing damaged sewer pipes, and ensuring incorrect stormwater connections are properly redirected to the nearest stormwater drain. This phase will begin in late 2020.
Once these phases have been completed, we will have reduced the likelihood of sewage spills occurring in local waterways or low-lying parklands, such as the Cootamundra Walk.
We are committed to maintaining our sewerage system, so we can all continue to enjoy a healthy and clean local environment.
How does rainwater get into sewer pipes?
Stormwater can enter the sewer from various sources, such as:
- tiny cracks in the pipe from ground movement and old age
- tree roots
- incorrect connections from private properties (e.g. plumbing on roof spouting and overflow pipes from rainwater tanks).
Is it bad if rainwater gets into sewer pipes?
Yes, sewers are designed to be a certain size that is appropriate for their catchment area. If stormwater enters the sewer and flows within the pipes become too big, there is a risk of sewage spilling into the environment. These spills usually occur from sewer maintenance holes, located at low points in the sewerage network. Maintenance holes are where we get access into the sewer. Once we get access to the sewer, we can inspect the pipe to ensure it is reliable.
Using smoke testing to check the condition of our pipes
What is smoke testing?
We’ll be blowing a small amount of harmless smoke into our underground sewer pipes, from maintenance holes, and looking to see where the smoke escapes from. Smoke will escape where there are cracks in the pipe, or if a property’s stormwater pipes are incorrectly connected to the sewer pipe. The smoke will disappear after a few minutes.
The ‘smoke’ we’re using is the same used at concerts and doesn’t involve any flames or fire. It’s whitish grey in colour, harmless, has no smell and is non-staining.
Smoke testing is the least intrusive way that we can check the condition of the pipes. It helps identify the specific damaged pipe sections and why they’re damaged.
Where will the smoke appear from?
When the smoke is blown into the sewer system, it will then escape through any cracks in the pipe or incorrect connections to show us where the problems are located. This smoke may be seen from coming out:
- of maintenance holes
- of the ground
- of drains
- of vents on roofs
- from under your dwelling, if it is built on stumps
- of downpipes in gutters and roofs.
The harmless smoke will disappear after a few minutes.
Is the smoke harmful or does it create a smoke hazard?
No, the ‘smoke’ we’re using is the same used at concerts and doesn’t involve any flames or fire. It’s whitish grey in colour, harmless, has no smell and is non-staining.
How is the smoke created?
We create the harmless ‘smoke’ by heating a clear, very pure oil. The same oil is also used in products such as make-up, massage oil, and food packaging
I have received a letter from Yarra Valley Water requesting access to my property. What do I need to do?
Do I need to be home when you may access my property?
We may need to access your driveway or front yard, but we will not enter any fenced areas. We don’t need to enter your house and you don’t need to be home during the inspection. If we need to access your property, we will only be there for a few minutes and your sewerage service won’t be affected. We really appreciate your cooperation.
Is my pet in danger during the smoke testing?
The smoke is not harmful to pets, people, food or material goods. The ‘smoke’ we’re using is the same as what is used at concerts and doesn’t involve any flames or fire. It’s whitish grey in colour, completely harmless, has no smell and is non-staining.
Is Yarra Valley Water permitted to enter my property?
We understand it’s unusual for us to come onto your property to do testing, however this project is important to help us to identify how rainwater is entering the sewer.
While we’d prefer to have your consent to come onto your land, you should be aware that under the Water Act 1989, Yarra Valley Water has the authority to enter private properties and conduct inspections to ensure our regulations and by-laws are being complied with.
Why can’t you tell me a specific day or time for when the testing will occur?
For us to see the smoke, the testing cannot be conducted on rainy or very windy days. If we don’t get a sunny or clear day, the testing may be delayed.
What happens with the findings of the inspection?
After we’ve finished inspecting all properties in the trial, we’ll review our findings and identify viable options to reduce stormwater flowing into our sewerage system.
If we find an incorrectly connected stormwater pipe, we will let the customer know. If you are in this situation, we will also give you information to help you understand the problem, and how it can be fixed.