What is a land application area?

When it comes to treating the wastewater in your home, you'd be excused if you didn't really know much about it. Effluent? OSFs? LAAs? Sewage systems? Sounds pretty difficult to us!

That is why we thought we would put together a little information regarding some important aspects when it comes to wastewater treatment - in this case, land application areas.

Land application areas are a crucial component of an onsite sewage facility (OSF), so learn more about how they work below. If you would like some further assistance or information, give Express Wastewater a call at 1300 722 517 and we would be happy to help.

*Please note, this information is courtesy of the Sunshine Coast Regional Council. Your local council area may differ, so please ensure you speak to the relevant authority before any works are commenced.

What is a land application area?

A land application area, otherwise known as an LAA, is a section of land that is used to dispose of treated wastewater.

What factors must an LAA have?

An LAA must:

• Be capable of absorbing organic matter contained in the effluent (wastewater), which is rich in nutrients.
• The vegetation must be able to manage large amounts of water and nutrients.

How does a land application area work?

An LAA disposes or re-uses wastewater created on a property through soil absorption (disposal) or irrigation (usage).

What are the different kinds of LAA?

There are four major kinds of land application areas:

Soil absorption systems

• Do not need effluent that is highly treated - septic tank treated wastewater, with solids content is suitable.
• Release effluent into the ground at a depth that the roots of most small plants can not reach.
• No recommended in sensitive areas - may contaminate surface and/or groundwater.

Irrigation systems

• May provide surface or subsurface irrigation.
• Wastewater must be of good quality ie. produced by an aerated wastewater treatment system (AWTS)

Surface irrigation

• Effluent must be highly treated.
• Effluent must have had aeration and disinfection treatments to reduce the chance of bacterial and viral contamination.
• Introduced to the land area through drip, trickle, or spray points designed to stop airborne drift and run-off.

Subsurface irrigation

• Highly treated effluent is needed, as it is introduced into the soil at a shallow level.

Where should a land application area be located?

In order to ensure no negative effects result from an LAA, including both on public health and the environment, it must be located in accordance with the information from a site evaluation. Also, note that approved landscaping must occur and be complete before a building can be occupied.

One of the main aspects when it comes to LAA is the soil type - some soils, such as those that are sand-based, can let effluent through too quickly and can reach the water table without being treated properly. On the other side, soils that are much heavier (like clay soils) may not allow effluent to get through enough, which results in ponding.

Tip: Systems for on-site application are designed for the expected water use volume. Uncontrolled water use may lead to poorly treated effluent being released. LAAs can become waterlogged if the system is overloaded, or clogged with solids. - Sunshine Coast Regional Council

It is imperative that the system, once complete, allows even distribution across the LAA of treated effluent. An LAA must also be designed in accordance with AS/NZS 1547 On-site Domestic Wastewater Management.

Who can build a land application area?

Only people who are fully licenced professionals should be designing and installing LAAs. This can only occur after a proper site and soil evaluation by a licenced assessor is completed.

Correct buffer distances must be in place between the LAA and bores, waterways, buildings, and other properties.

Fines may apply if the effluent is not managed correctly.

If an irrigation system is being used in an area, LAAs must have up on display a minimum of 2 warning signs along the boundary. The signs should have 20mm high Series C lettering in black or white on a green background with the words “Reclaimed effluent. Not for drinking. Avoid contact” written on them.

No access should be granted to LAAs during and immediately after the application of effluent - the longer people stay away, the lower the public health risk is.

Maintaining an LAA

The following are some do's and don't's when it comes to your LAA - speak to a professional to find out more:

DO's

• Regularly check that equipment is operating correctly and the LAA is not overloaded.
• Depending on the type of system installed, you may need to enter into a service contract with a licenced service agent to ensure your system remains running effectively.
• Build and maintain drains to divert surface water away from the LAA.
• Fill in any depressions in the LAA with soil, not clay, to keep it level.
• Keep the grass mowed and plant shrubs on the land application area.
• Ensure that all roof and driveway run-off is sent away from the LAA.
• Ensure all irrigation areas are fenced.
• Ensure appropriate warning signs are visible at all times at the LAA.
• Arrange for a service agent to check all irrigation systems.

DONT's

• Build structures or paths over the land application area.
• Allow animals to graze on the LAA.
• Drive over the LAA.
• Plant large trees that shade the LAA as the area must have sunlight (for evaporation).
• Plant trees or shrubs over house drains.
• Allow stormwater to run into or near the LAA.
• Let your pets or children play on or around the land application area.
• Use effluent to water fruits or vegetables.
• Drink groundwater.

What happens if your LAA isn't maintained properly?

If your LAA isn't maintained properly, this can cause:

• Health risks.
• Pollution.
• Bad odours.
• Attract vermin and insects.

Maintaining your LAA properly protects the environment and health of your family and neighbours, as well as the wider public.

If your on-site sewerage facility fails and is not repaired you will be issued with an advisory notice outlining the action required. Failure to comply will result in enforcement action. - Sunshine Coast Regional Council

Signs that your LAA isn't being maintained properly include:

• Pooling of treated wastewater on the surface.
• Soil quality deterioration.
• Vegetation isn't growing well.
• Unusual odours.

If you would like further information, give Express Wastewater a call at 1300 722 517 and we can discuss your needs today.

Resources: Sunshine Coast Council (Land Application Areas): https://www.sunshinecoast.qld.gov.au/Development/Building-and-Plumbing/Onsite-Treatment-and-Greywater/Land-Application-Areas