Odour Control In Australian Wastewater

Odour control in Australian wastewater ponds is a common problem throughout the country. Especially if the pond has neighbours that don’t appreciate the smell of rotten eggs.

A properly functioning wastewater pond is mostly free from odour. If a pond does have odour problems, the type of odour can give clues to what’s going wrong within the pond. 

Odour issues in Australian Wastewater Ponds. Pond appearance, odour, and possible cause:


If a wastewater pond is somewhat clear or slightly brown with no odour or a somewhat earthy odour then it’s likely be in good shape. In most cases when odour is present it’s due to too much organic load, algal blooms or both. These odour producing problems usually double up with high TSS and BOD which can create problems and challenges meeting discharge or water usage requirements. Then there’s the human factors with the odour potentially creating problems such as eye irritation, headaches or respiratory problems.

In short, no-one likes a stinky wastewater pond. 

In most cases the odour, algal blooms, increased TSS and BOD are symptoms not the actual problem.

The three most common odour causing issues in Australian wastewater ponds:

  • Overloading of the pond causing it exceed its capacity
  • Inadequate design or aeration equipment
  • Seasonal turnover

While overloading is an issue that must be addressed externally, seasonal turnover and issues with inadequate aeration can be rectified internally.

Seasonal Turnover In Wastewater Ponds

Seasonal turnover is when changes in water temperature force settled sludge to the upper layers of the pond causing odour and feeding algal blooms.

If your pond experiences these problems a few times a year then you can usually control the odour and algal blooms using biological water treatments, such as Biostim Powder, combined with odour control products such as Dazzel Eco-Plus.

This type of treatment is preferred over chemical treatment such as algaecides because algae treatments only tackle the symptom whereas biological treatments stimulate bacteria to increase in numbers and efficiency to tackle the excess nutrients which is the real problem. 

Inadequate Aeration In Your Wastewater Pond

If your pond is odourous for longer periods then you should look at the entire system and your aeration system in particular. If a pond has sufficient DO then it will allow the aerobic bacteria to break down the BOD maintaining a healthy system. Ongoing dosing with biological treatments will compliment aeration improving the overall result. 

In wastewater ponds mixing is just as important as aeration because there’s no point aerating water if the oxygen rich water isn’t well mixed within the pond. Poorly mixed ponds with dead spots will continue to cause sludge build up and odours so choosing the right aerator is important.

While aerating wastewater ponds deserves its own article, I will mention that nowadays there are several good aeration options that are equally good mixers with some operated from solar power.  Our preferred wastewater aeration systems are the Airolator Aquarian Commerical (surface aerator available in mains or dedicated solar power as well as as a hybrid system) or the MARS subsurface aeration system from TriplePoint Water Technologies.


Odour control is one of the biggest issues experienced within the Australian wastewater industry.

If you’re experiencing odour problems in your pond, consider it a warning sign of an underlying issue and be grateful for the opportunity to do something about it before it gets worse. 

If you require any assistance, please do not hesitate to get in touch via our contact page or give us a call on 1300 283 387.

No Comments
1300 283 387