Septic and on-site sewage systems in Byron Shire

Unsewered properties in Byron Shire treat their own wastewater through a septic tank, an aerated wastewater treatment system (AWTS) or another on-site sewage management system (OSMS), and every one of them must hold an Approval to Operate from Byron Shire Council. Installing a new system or changing an existing one also needs Council approval first. If you send an enquiry here, it is passed to an independent local plumber or wastewater provider, and that business assesses the system, quotes and carries out the work.

Which properties use on-site sewage systems?

Council’s sewer network serves the Shire’s towns, but rural and rural-residential land outside the sewered areas has to manage its own wastewater. Byron Shire Council states that around 4,000 systems are on its register. Many sit on acreage around Bangalow, behind Mullumbimby and on farm blocks across the Shire, so check your own property records rather than assuming a street is sewered.

The common system types are:

System	How it works	Typical upkeep
Septic tank with absorption trenches or beds	Solids settle in the tank, liquid soaks into the soil through trenches	Periodic desludging, keeping the trench area clear of cars and structures
Aerated wastewater treatment system (AWTS)	Air is pumped through the wastewater to treat it, then it is disinfected and irrigated	Regular servicing by a qualified agent, power to the blower and pumps
Composting toilet	Toilet waste breaks down in a chamber, with greywater treated separately	Emptying and handling compost as the maker directs
Sand filter or mound systems	Effluent is filtered through a built bed of sand before it reaches the soil	Checks on pumps, distribution pipes and the bed surface

The right system for a block depends on soil, slope, lot size, distance to creeks and bores, and how much wastewater the household produces. Council says the system type should be decided by an experienced wastewater consultant or licensed plumber who has assessed the site.

What are the signs a septic system is failing?

Byron Shire Council lists leaks, soggy ground and unpleasant odours as the common signs. On site, those show up as:

• wet, green or spongy patches over the trenches or irrigation area when it has not rained
• sewage smells near the tank, the house vents or the land application area
• toilets and drains that empty slowly across the whole house at once
• an AWTS alarm light or buzzer, or a blower that has gone quiet
• effluent pooling at the surface or running towards a creek or the boundary

Slow drains in a single basin are more often a pipe blockage than a system failure, so a plumber may clear the line first. The blocked drains service deals with that side. After heavy rain, many trench systems struggle because the soil is already saturated, which is common in the Northern Rivers wet season.

What approvals apply to septic work in Byron Shire?

Byron Shire Council’s on-site sewage management page sets out the process:

1. Installing or altering a system needs Council approval under section 68 of the Local Government Act 1993, applied for through the NSW Planning Portal.
2. A site and soil assessment and design come first, prepared by someone with the right training, so the system suits the block.
3. Installation is plumbing and drainage work that needs a NSW licensed plumber and drainer. Any wiring for pumps or blowers needs a licensed electrician.
4. A final inspection by Council follows. Council issues the Approval to Operate for a new or altered system once that inspection is satisfactory.
5. Ongoing operation stays the owner’s job, including servicing and repairs.

Someone who buys a property with an existing system has three months to apply for an Approval to Operate in their own name. The checklist for buying a property in Byron Shire covers what to request from the seller.

Council also keeps a voluntary list of people it treats as suitably qualified to do site and soil assessments, design systems or service AWTS units. Asking whether a provider is on that list is a reasonable first question. A licence is needed for plumbing and drainage work in NSW at any job value, and the about page explains how to look up a provider’s licence class.

Council’s example designs tell designers and installers to consult AS/NZS 1547, the Australian and New Zealand standard for on-site domestic wastewater management.

What does an owner have to know about their system?

Council expects owners to know which type of system they have, what servicing it needs, and where the tank and the land application area are on the block. In practice, that means keeping:

• the Approval to Operate and any conditions on it
• the original approval plans showing the tank and trench or irrigation layout
• service reports for an AWTS, kept in date order
• notes of any pump-outs, repairs or alarm faults

Unapproved changes can reduce how well a system works and shorten its life, so avoid adding a bedroom, a second dwelling or a spa that feeds into the system without asking Council first.

What will a careful provider check or refuse to do?

A careful plumber or wastewater provider will check the approval status before quoting on changes, since altering a system without approval creates a problem for the owner. They will want to locate the tank lids and trench lines, check that the inlet and outlet baffles are intact, look at sludge and scum levels, and test any pumps and alarms. On an AWTS they look at the blower, the chlorinator or disinfection unit and the irrigation lines.

They will refuse to connect a new building to an existing system without approval, refuse to run irrigation lines into a creek buffer, and refuse to bury a tank lid so deep that it cannot be opened for pump-outs. Electrical work on the system will be referred to an electrician.

What does a new treatment system cost?

Oneflare’s national septic cost guide, last updated in January 2023, gives $15,000 to $20,000 to supply and install an aerated wastewater treatment system. That figure is several years old and is a national guide, so treat it as a starting point only. Soil testing, design, excavation on a slope, rock, access for machinery, the distance from the house and the size of the irrigation area all change the total a lot. Repairs, inspections and fault finding on an existing system are usually charged by the hour, at around $84 to $210 per hour for standard hours locally. Council application and inspection fees are separate and set by Council. The Byron Bay plumbing cost guide lists this figure with others for comparison.

What about Lennox Head and the Ballina hinterland?

Lennox Head and Ballina sit in Ballina Shire, which runs its own program. Ballina Shire Council’s on-site wastewater page says over 4,000 systems are installed in that Shire, and it has an on-site wastewater management strategy and its own guidelines from 2017. Approvals, forms and timeframes there are Ballina’s, not Byron’s, so mention the council area in an enquiry from Lennox Head or the Ballina hinterland.

Floods change everything about how a septic system behaves, and a system that has been under water needs checking before it is used again. The guide to plumbing after a flood in the Northern Rivers covers that recovery.

Next step

To send a septic system enquiry, say what type of system you have if you know it (septic tank, AWTS or composting toilet), your Approval to Operate number or a copy of the approval letter, roughly how old the system is, the symptoms you have noticed, the date and contents of the last service report, and the distance from the house to the tank. If you are planning a new system, say whether a site and soil assessment has already been done.

Send a job enquiry