Managing wastewater on your property
Many Kempsey Shire residents live in a house that’s not connected to the main sewer and have an on-site sewage management system on their property.
If you have such a system, it’s important to understand how it works and what you must do to maintain it.
On-site sewage management systems need regular checks and maintenance or they can adversely affect people's health and the local environment.
Your responsibilities
If you have an on-site sewage management system on your property, you are responsible for:
- ensuring the system is well maintained and regularly checked
- getting the tank pumped (desludged) when it’s full
- complying with Kempsey Shire Council’s requirements for installation, maintenance and operation of the system, and paying fees for inspections or maintenance.
Council’s role
Kempsey Shire Council will regularly inspect your on-site sewage management system and renew your approval to operate it.
The frequency of inspections will depend on what type of system you have and the risk that operating it poses to public health and the environment.
When your inspection is due, Council will send you a renewal letter that sets out the fees that apply to your system.
What is an on-site sewage management system?
An on-site sewage management system treats wastewater from a house within the boundary of that property.
Wastewater may be blackwater (toilet waste) or greywater (water from showers, sinks, kitchens and washing machines) or a combination of these. Greywater (sullage) can have a high percentage of the same pollutants as blackwater.
There are also partial on-site systems, such as pump out and common effluent systems (CES). Other systems or methods include chemical toilets, septic closets, composting toilets, cesspits and pans.
How does an on-site sewage management system work?
Complete on-site systems are designed to:
- treat wastewater to a certain standard
- apply the treated water to a dedicated area of land.
What can be done with the water depends on the quality of treatment. However, you should try to avoid contact with all wastewater, whether treated or untreated, and if you do come into contact thoroughly wash affected areas.
Treatment and application are carried out using various methods.
Septic tanks
Septic tanks treat both greywater and blackwater, but they provide only limited treatment through the settling of solids and the flotation of fats and greases. Bacteria in the tank break down the solids over time. Wastewater that has been treated in a septic tank can only be applied to land through a covered soil absorption system, as the effluent is still too contaminated for above-ground or near-surface irrigation.
Aerated wastewater treatment systems
Aerated wastewater treatment systems (AWTS) treat all household wastewater and have several treatment compartments. The first is like a septic tank but, in the second compartment, air is mixed with the wastewater to help the bacteria break down solids. A third compartment allows settling of more solids, and a final chlorination contact chamber allows disinfection. Some systems are constructed with all the compartments inside a single tank. The effluent produced may be surface or sub-surface irrigated in a dedicated area.
Composting toilets
Composting toilets collect and treat toilet waste only. Water from the shower, sinks and the washing machine needs to be treated separately – for example, in a septic tank or aerated wastewater treatment system. There are special requirements for the compost produced by this kind of toilet but usually it is buried on-site.
Other systems
Other treatment and application methods are available, such as sand filter beds, wetlands and amended earth mounds. NSW Health or Kempsey Shire Council can provide you with information on these systems.
Application of treated wastewater
Treated wastewater has the potential to negatively affect public health and the environment. For this reason, the application area must be chosen after a site evaluation, and approved landscaping must be carried out.
The system must allow even distribution of treated wastewater over the land application area. The area must be able to utilise the wastewater and treat any organic matter and wastes it may contain. The wastewater is rich in nutrients and can provide excellent nourishment for flower gardens, certain shrubs and trees. The vegetation should be suitably tolerant of high water and nutrient loads. Sandy and clay soils may present special problems.
Regulations and requirements
NSW Health sets the design and structural requirements for treatment systems for single households.
Councils are responsible for approving the installation of smaller domestic septic tank systems, composting toilets and aerated wastewater treatment systems. They are also responsible for approving land application areas.
The NSW Environment Protection Authority approves larger systems.
The design and installation of on-site sewage management systems, including plumbing and drainage, should only be carried out by suitably qualified people. Care is needed to ensure the treatment system and application area are the correct size. Approval to install and then operate a system is required.
Heavy fines may be imposed if wastewater is not managed properly.
How to keep your system operating well
What you put down your drains and toilets greatly affects how well your system performs. Poorly maintained sewage management systems are a serious source of water pollution and may present health risks, cause odours and attract vermin and insects.
Regular visual checks of the system will help you locate problems and fix them early. The signs of system failure include:
- surface ponding and run-off of treated wastewater
- soil quality deterioration
- poor vegetation growth
- unusual odours.
The following is a guide to the types of things you should and shouldn’t do with your system.
Do
- Learn how your sewage management system works and understand its operational and maintenance requirements.
- Learn the location and layout of your sewage management system.
- Keep a record of inspections and other maintenance.
- Have your septic tank or aerated wastewater treatment system desludged every three years to prevent sludge build-up, which may ‘clog’ the pipes.
- Conserve water. Limiting your water use will mean less water needs to be treated, reducing the chances of overloading your system. Overloading can result in wastewater backing up into your house or contamination of your yard, groundwater or nearby waterways.
- Spread your water use evenly throughout the day and week – for example, avoid doing several loads of washing in a short period.
- If you’re considering building an extension or increasing occupancy of your house, discuss with Council whether your sewage management system will be adequate.
Don’t
- Don’t let children or pets play on land application areas.
- Don’t water fruit trees, vegetables and lawn with effluent.
- Don’t extract untreated groundwater for cooking and drinking.
- Don’t put large quantities of bleaches, disinfectants, whiteners, nappy soakers and spot removers into your system through the sink, washing machine or toilet.
- Don’t allow foreign materials such as nappies, sanitary napkins or condoms to enter the system.
- Don’t dispose of food waste, including fats and oils, in your system.
- Don’t install or use a waste grinder or spa bath if your system is not designed for it.
By looking after your management system, you can do your part in helping to protect the environment and your community’s health.
For more information please contact the Environmental Health team at Kempsey Shire Council.