What is a Wastewater Consultant?

A Wastewater Consultant is a qualified professional who designs on-site wastewater management systems, often required for homes not connected to mains sewer. They assess your site, recommend a suitable treatment solution (e.g., septic tank, AWTS, sand filter), and prepare plans and documentation for approval by council or a certifier.


This work is completed before construction begins, often as part of the pre-DA or pre-CDC documentation process.

What does a Wastewater Consultant do?

Your consultant will complete works according to your agreed scope.


Typically, they will:

  • Conduct a site and soil assessment to determine disposal suitability
  • Prepare a Wastewater Management Plan outlining system type, location, and treatment method
  • Complete the Wastewater System Design, including hydraulic layout and effluent disposal zones
  • Provide documentation to support DA/CDC approval
  • Liaise with council, certifiers, or hydraulic engineers where needed


Some consultants also assist with system selection and post-installation sign-offs.

Barry's Toolbox

Choose your wastewater system early — it affects your site layout, excavation sequence, and even landscaping design.


Make sure your proposed dwelling, tank, and effluent fields respect all required setbacks from water sources, driveways, and boundaries. Council will reject non-compliant designs!

What Makes a Good Wastewater Consultant?

When reviewing quotes and qualifications, look for someone who:

  • Is experienced with on-site wastewater design in your region
  • Understands local council and certifier requirements for your LGA
  • Has credentials in environmental engineering, soil science, or similar fields
  • Provides a clear scope of deliverables and approval pathway
  • Offers practical design solutions suited to site constraints like slope, soil type, or setbacks


Bonus: Consultants who can liaise directly with your certifier or assist in preparing DA documentation will save you time.

Before You Begin: What You’ll Need Ready

To get quotes from Wastewater Consultants, you’ll need:

  • A current site plan or survey (showing boundaries, contours, and structures)
  • Dwelling layout and total number of bedrooms (affects sizing)
  • Any DA or CDC checklists related to on-site wastewater
  • Geotech report (if available), or details on slope, soil, and vegetation
  • Preferred timeline for submission or approval

Average Timeframe

For this task, Pros typically provide quotes within 7-10 business days.

When Can I Expect Quotes?

Timeframes often vary based on demand and the type of Pro you're engaging (e.g. a plumber). If additional communication or clarification is needed is needed, the quoting process may take longer.

 

Don't be alarmed if you don't receive quotes or communication from any Build Buddy Pros straight away. Some work is more complex and the Pro may need time to comprehend your documents or scope of work. Depending on the job, there may even be some work required by the Pro before they are able to quote (e.g. a site visit might be required).

 

If the average timeframe indicated here has passed, and you have not received any messages or quotes, please feel free to contact the Build Buddy Expert Guidance and Support team for an update on quoting for this task.

Frequently Asked Questions

  • Do I need a Stormwater Engineer if I already have a builder?

    Yes — unless your builder includes stormwater design in their scope, this is often your responsibility and must be approved separately.

  • What happens if I skip this step?

    You won’t receive your DA/CDC approval or Occupation Certificate (OC). Proper drainage is mandatory.

  • What if my site slopes away from the street?

    You may need a charged system, pump, or onsite detention — your engineer will advise based on your survey.

How to Complete this Task?

STEP 1

Review and Adjust the Scope of Works

Timeframes may vary based on demand and the type of Pro you're engaging (e.g., a plumber). If additional communication or clarification is needed, the quoting process may take longer.

STEP 2

Confirm Required Documents Are Uploaded

Check that the following required document(s) are uploaded for this task. These are essential to proceed:

STEP 3

Update the Quality Assurance Checklist

Go to the Quality Assurance tab in this task and review the checklist. Edit any details to suit your project requirements. Being clear and upfront helps set expectations with the Pro. Updating the checklist before requesting quotes ensures everyone is aligned.

STEP 4

Request Quotes

Click the orange ‘Request Quotes’ button to start the quoting process.

STEP 5

Review the Quotes

Once you receive quotes:

  • Review each one carefully, including the payment schedule and any special terms
  • Download attached quote documents for detailed review
  • Check each Pro’s profile and read past client reviews

STEP 6

Communicate with the Pro

If needed, message or call the Pro to clarify details or negotiate terms.

STEP 7

Accept a Quote

Choose the quote that best suits your needs. Once you accept a quote, any other pending quotes will be automatically declined. An agreement will automatically be generated.

STEP 8

Complete the Tasks In Your App

New tasks will appear to guide you through this job — follow each step carefully. Make sure to use the Quality Assurance Checklist, and refer to your contract and final Scope of Works whenever needed.

NEED HELP?

Reach Out to Your Build Buddy Pro

If you have any questions or need a hand, your Build Buddy Pro is your best first contact. They’re a licensed expert in their field and can understand the ins and outs of your project. You can message them via the platform, or you can call them directly.


If you have already contacted your Build Buddy Pro and still need further assistance, the Build Buddy Expert Guidance and Support team are here to help. They will be able to guide you on your next steps or help you find answers to any questions you may have.