Landfill Leachate treatment and recycling by the Natural Biological System (NBS)

System Design

  • Operating since 2006, the NBS receives wastewater from the landfill leachate, the visitor’s center, and the dump truck washing station. It is designed to treat 40 m3 per
  • The wastewater flows gravitationally through five subsurface ponds, each with different aggregates and plants essential for purification.
  • The retention time (RT) of the sewage in the system is three days on average.
  • From the wetland system, the reclaimed water flows into an ornamental pond near the visitor’s center. This water is used for irrigation around the site.

Entrance to settling tank

This tank collects the wastewater from 4 sources:

  • Leachate from raw garbage,
  • Leachate from the landfill,
  • garbage truck rinsewater,
  • and water from garbage separation

View of surface water in septic tank

A: The Visitor’s Center. The Ayala System is in the foreground
B: Partial view of the Visitor’s Center. Treated water (outflow) in a pond.
Water from septic tank and outflow from NBS
Water entering the NBS (starting to settle), and outflow from NBS
Outflow from NBS near final polishing and ornamental pond
Suspended particles from wastewater settle in the first pond, and create some sludge. The plants grow over the sludge, and break it down

A beautiful and low-cost system

  • Construction cost of NBS ponds is approximately 150,000$. In the case of Hiriya, the local design also included some complex concrete work and infrastructure, which cost an additional 130,000$. It is important to note that this is case-specific and is not a necessity in all sites.
  • Operation and maintenance costs of NBS are composed mainly of landscaping and general supervision and amount to approximately 2500$ a month.