WPL HiPAF® bespoke solution

Sewage treatment for the UK water utilities


The WPL HiPAF bespoke wastewater treatment plant is a solution for properties of up to 5,000 people equivalent where mains drainage is unavailable.

Image of WPL bespoke HiPAF solution for utilities

Each WPL HiPAF treatment plant includes a three-stage process – primary settlement, biological treatment (biozone) and final clarification.  The systems are installed below ground in GPR, though the range is adaptable to provide above-ground treatment (manufactured in steel, stainless steel) when required.


Why you should choose the WPL HiPAF bespoke sewage treatment system:

Low installation costs and flexibility on site

  • Only a small excavation is required due to its compact design allowing flexibility of positioning on site

Low running costs

  • Significant reduction in power consumption can be achieved using VSD’s, timers, instrumentation and control to deliver the lowest TOTEX solution
  • Energy saving options and chemical dosing packages can be configured to the HiPAF design for site specific requirements

Low maintenance

  • No internal mechanical or electrical moving parts within the tank therefore it requires minimal annual maintenance
  • Emptying of the tank is also not required during maintenance – the design can isolate and remove sections of the air distribution system
  • Large access lids therefore no requirement for confined space entry reducing health and safety risks
  • Access also offers ease of maintenance and process optimisation.
  • Humus and primary sludge’s are stored in one place for simple tankering operation

Minimal visual impact

  • Does not impede views due to the below ground installation

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


  • BS1509001 CDM regulations
  • Incorporating BIM workflow principle
  • Bespoke design to ensure that the plant meets each water specification
  • Can offer a complete in-house design and specification service including a turnkey service of initial site survey, commissioning and project liaison if required.


  • Designed using the British Water Code of Practice Flows and Loads, to ensure correct sized tanks
  • Designed to BS EN 12255 – 1/15 and manufactured using BS 4994


  • Proven WPL SAF technology based on over 25 years empirical data
  • Unique internal circulation system leads to increased process performance
  • Use of high quality blowers and pumps underpins reliability of plant
  • GRP is UV stabilised with an external gel coat finish which extends the asset life to 25 years
  • Plants and kiosks are produced in a quality controlled environment at the WPL factory

Bespoke design options can include:

    • Lid type, orientation and colour finish options are available
    • Single or three phase power supplies
    • Blower kiosk cooling fan
    • N-SAF tertiary treatment options
    • Inverts 0.5m as standard
    • Volt free telemetry contacts on control panel
    • Form  2 or form 4 control panel
    • Pumped inlet flow control
    • Duty/standby and duty standby assist blower upgrades
    • Blower and airline hose upgrades for long hours
    • Kiosk options including walk in kiosk
    • GRP or steel construction for transportable plants
    • Above ground or below ground solutions
    • Permanent or temporary solutions

MK3 lids for the UK Water Utilities specification:

  • Anti-slip pads on the lids
  • All lids are lockable
  • Two lids per width of the tank – lids less than 25 kilo’s to lift
  • Lockable stainless steel stays
  • Grating held in position under the lid when in the down position allows ease of access to all air distribution pipework
  • Grating when in place prevents risk of fall
  • Raised air distribution pipework allows for ease of maintenance

Image of WPL MK3 lids with grating showing air distribution pipework, part of the bespoke wastewater treatment system, the WPL HiPAF  Image of WPL MK3 lids showing grates to walk on, part of the bespoke wastewater treatment system

Ease of access is also a key feature of the WPL HiPAF sewage treatment range.

The internal sections of the plant are accessible from the top by opening the access lids, allowing for easy service, maintenance and de-sludging.

Standard Kiosk Design

Each WPL HiPAF comes complete with a weatherproof, acoustically lined GRP kiosk, situated above ground. This houses the blower(s), a Form 2 control panel and air distribution manifold.

Included as standard is 10m of airline, to connect the blowers to the tank. Blower and airline upgrades are available if the kiosk is sited further than 10m from the plant.

The Form 2 control panel, automatically controls the operation of the plant.  Form 4 is also available.

Kiosks upgrades available on request e.g. walk in kiosk.

About the WPL HiPAF®

The WPL HiPAF brand name refers to High Performance Aerated Filter, which is a unique hydrodynamic flow through the biological filter bed. This helps provide even distribution across the media that is housed in the tank; ensuring strong even growth of the bacteria used in the treatment process and providing a robust stable treatment.

Feeding the biological zone is WPL’s unique airlift forward feed, maintaining a stable and even food source that enhances bacterial performance to degrade contaminants.

WPL’s robust biological treatment process is guaranteed to meet specified discharges of BOD5, ammonia and suspended solids, underpinned by over 25 years of experience and empirical data.

News: at a glance – WPL wins three Scottish Water framework contracts
Package treatment plant specialist WPL has won three contracts with public utility Scottish Water after a competitive procurement process. The Hampshire-based company will supply submerged aeration filter (SAF) plants, conical settlement tanks and hire equipment. Read more