You’ve just bought a new home, moved your family in and are getting settled when you discover that a few years back, the Water Corporation ran main line water and sewage past your property.  You’ve now been told that regulations require that you connect your property up to mains sewage within ten years of it becoming available, and de-commission your existing septic tank system at your own expense.

The problem is, this is not always such an easy task to accomplish.

Plumber Steve Neale, was kind enough to share his thoughts about the septic to main sewerage conversion process with us. Steve provides plumbing services in Perth and has performed hundreds of septic change overs for residents of Perth for more than a decade as the owner of Superior Plumbing Drainage & Gas.

If you have an older septic tank system or the installation onto your property was particularly complex, you could be looking at a pretty substantial project from a cost and time perspective to carry this work out.  There could be a requirement for significant excavations and your pipework will need to be examined and potentially replaced to bring it up to current standards depending on how long ago it was installed. 

It’s important that when you want to undertake the effort to convert your septic tank system into a mains system that you talk to a professional plumber service that has a long and successful track record of doing this kind of work in the Perth area.


The most critical part of the conversion process is that the regulations and guidelines set out by the Water Corporation must be adhered to.  There is no point in cutting corners or taking short cuts with something as critical as this, so the best and ultimately cheapest way to convert to the mains system is to do it right and do it to code the first time.

The first thing a plumber will do is to send plumbing experts to your site to do an inspection and figure out what they need to do to get your property hooked up and then what’s required to de-commission your septic tank.  Once they have that information they’ll be able to provide you with a no obligation quote for the cost to complete the project.  They’ll also give you an idea of how long it will take to complete the work because living without a functioning sewage system is not fun for families, so they hopefully will focus on making sure we minimise the disruption.

The next step the plumber will undertake on your behalf is to apply for approval to connect with the Water Corporation.  These applications are all done online using the BuilderNetsystem and they also submit the associated paperwork with the Plumbers Licensing Board at the same time. 

When the approvals have been granted, they will organise a time with you for them to kick off the project and get things underway.  Depending on what they discovered during our pre-work inspection, they’ll either connect you to the existing sewage junction for your property or they can install a new junction and connect your property to that.  This can be quite complicated because it involves excavating your existing piping to the septic tank and replacing it with new PVC pipework that’s connected to the mains junction.  Depending on the complexity, this can take a fair bit of time.

From there they’ll begin the process of decommissioning your existing septic tank which involves pumping out the contents, cleaning the inside and then filling it with sand and burying it.  Because of the sensitive environmental and health impacts, they need to take great care in doing this part correctly.  Occasionally plumbers will come across septic tanks that have not been dealt with properly, and these can pose a health hazard to anyone on the property. 

After these steps have been completed, and your property has been connected up to mains sewage, your plumber will then create and submit the required plumbing diagrams and submit them to the Building Commissions to round out the process.

You can view more information about septic to main sewerage at the Superior Plumbing website.

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