HiPAF® for up to 5,000 population equivalent (PE)

The HiPAF packaged treatment plant is an ideal solution for rural areas.  The three-stage process includes a primary settlement, biological treatment and final settlement.

Energy and cost savings are achieved with the patented HiPAF technology to the biozone. The patented technology employs a submerged moving-bed, fixed-film reactor which can treat wastewater with greater energy efficiency compared to traditional submerged SAFs, in a tighter site footprint whilst meeting environmental compliance.

Image: above and below ground HiPAF packaged treatment plant

Why choose the HiPAF solution:

Low maintenance

  • No internal mechanical or electrical moving parts within the tank
  • Emptying of the tank not required during maintenance – simply isolate and remove sections of the air distribution system
  • Large access lids therefore no requirement for confined space entry
  • Energy saving timer – pulse air from the blower(s) into the process
    The timer for the blower(s) provide intermittent pulses delivering effective aeration for reliable treatment, while consuming significantly less energy
  • Humus and primary sludge’s are stored in one place for simple tankering operation

Variable flows and loads

During low flow conditions the level in the primary tank is reduced utilising forward feed air lift pumps

This creates a buffering volume that reduces the impact during high flows

Low installation costs and flexibility on site

  • Off-site build significantly reduces installation time
  • Only a small excavation is required due to its compact modular design

Minimal visual impact

  • Does not impede views due to the below ground installation


  • Design criteria is as per the water utility asset standard
  • Peak flow treatment – custom design but generally 3-6 dry weather flow or formula A flows
  • Discharge standards – as specified
    HiPAF will attain typically: BOD 10mg/l: SS 10mg/l: Ammonia Nitrogen 2mg/l (with tertiary treatment), however higher standards are achievable
  • BS1509001 CDM regulations
  • Standard packaged treatment system is below ground with an acoustically lined kiosk housing Form 2 or Form 4 control panel and blower options
  • Custom designed options available
  • MK3 water utility specification lids with protective grate

Each packaged treatment plant can be designed to site-specific requirements. Our complete in-house design and specification service can include initial site survey, project liaison and commissioning


  • Standard below ground systems are manufactured in glass reinforced plastic (GRP) which is ultra violet (UV)  stabilised with an external gel coat finish to extend the asset life to 25 years.
  • UK manufacture in a quality-controlled environment

Image of WPL MK3 lids showing grates to walk on, part of the bespoke wastewater treatment system

Image: MK3 water utility specification lids with protective grate