Waste stabilisation ponds - Nutrient neutrality private mitigations

There are several variants of waste stabilisation ponds with different levels of operation and systems dependent on their primary removal role. They are simple to operate but in general are recommended for warm-climate areas as they require high temperatures to remove pathogens.

The ponds are often shallow, open basins lined to make them impermeable. Some can be used to remove pathogens such as the pictured maturation pond, which uses algal populations to remove organisms. Other ponds can be used to remove ammonia, nitrogen, and phosphorus.

These ponds can be used as primary and secondary treatment options with waste water treatment plants often having several different types of ponds each capable of offering a different removal service.

Other ponds that are available: Facultative ponds, anaerobic facultative ponds, facultative aerated ponds, complete mix aerated sedimentation ponds, anaerobic facultative maturation ponds.

• Reuses water
• Capable of handling high flows

• Could produce large quantities of cyanobacteria that could be ecologically damaging to receiving waters
• High energy requirements for algae systems
• Potential mosquito habitat
• Emits odours

1. Phosphorus
2. Ammonia
3. Nitrogen
4. Coliforms
5. BOD/COD
6. Suspended solids
7. Heavy metals

• Short term energy requirements for construction
• Ongoing energy usage especially if using aeration and algae ponds

• Requires bacterial community to become established for removal

• Removal of nutrients and sediment is required not to cause capacity issues

• Performance can be easily affected by climate conditions and harvesting technology factors, these can be mitigated but
• Performance can be kept at optimum with well a well-established maintenance schedule
• Removal of nutrients and sediment is required not to cause capacity issues

The size and type of ponds is defined by the load of nutrient removal and nutrients needed to be removed. Design criteria to meet:

• Monitoring required of the separate ponds
• Ongoing monitoring of oxygen levels and level of water
• Must take into account climate factors and climate change, such as droughts and dry weather, or water gains from rainfall, etc. As well as effect of wind and low sunlight
• Mass loading will directly impact sizing and pond types
• Must take into account seasonal efficiency tied to plant growth
• Other requirements; pond specific

ICRA. (n.d.). Facultative Ponds. 

ICRA. (n.d.). Maturation Ponds.

University of Bristol. (2022). Algae farms to offer a cheaper, renewable solution to cleaning wastewater. Retrieved from https://www.bath.ac.uk/case-studies/algae-farms-to-offer-a-cheaper-renewable-solution-to-cleaning-wastewater/

Von Sperling, M. . (2007). Biological Wastewater Treatment Series- Volume 3: Waste Stabilisation Ponds. . Water Intelligence Online. London: Iwa Publishing.

Xu, L., Weathers, P.J., Xiong, X.-R. and Liu, C.-Z. . (2009). Microalgal bioreactors: Challenges and opportunities. . Engineering in Life Sciences, 9(3), pp.178–189.