WPL HiPAF® modular

Wastewater treatment system (up to 2,000 people equivalent)

The WPL HiPAF  modular packaged wastewater treatment solution (sewage or industrial trade effluent) is for properties of up to 2,000 population equivalent (PE) where mains drainage is unavailable.

Our plants can be configured to meet various population sizes and to meet demanding, individual site requirements. The WPL HiPAF range is regularly specified by the highly regulated UK water utilities, and the range meets stringent European environmental discharge consent standards.  This makes our products the preferred choice for sensitive locations such as Sites of Special Scientific Interest (SSSI).


Seasonal variations often experienced by hotels, caravan parks and cafés

Our discreet packaged plants can be design engineered to operate efficiently based on seasonal variations in loadings often experienced by hotels, caravan parks and cafés. Higher pollution loads and site expansion can be accommodated by adding WPL HiPAF modules.

Modular systems design for sewage treatment consist of a separate primary settlement, biological (submerged aerated filter) for biological treatment and final settlement modules. The unique design of the flow balancing in the primary tank means it can cope with variable flows and loads making it ideal for caravan sites and other seasonal venues. WPL Sand Filters/WPL Micro-screens can improve final effluent for strict consent requirements.


WPL support

All WPL HiPAF solutions are backed by our continued support for the life of the project. With unrivalled specialist capabilities, we supply technical information and drawings; offering any additional assistance if required. This is to ensure a wastewater treatment solution that works effectively and efficiently, with minimal impact on the day to day running of businesses.


Footage of a WPL HiPAF wastewater  treatment system (620 PE) in the Czech Republic which has cut costs, allowing for greater investment in site landscaping and design. The high environmental standards required included 22mg/l biological oxygen demand (BOD), 25mg/l suspended solids and 12mg/l ammonia. Phosphate removal was also specified by the environmental regulator.

The WPL HiPAF midi is UK manufactured in glass reinforced plastic (GRP) which is ultra violet (UV)  stabilised with an external gel coat finish which extends the asset life to 25 years.


Why you should choose the WPL HiPAF modular system:

Ease of installation

  • Modular plants enable access and installation at space restricted sites
  • Overall compact design minimises excavation required offering small footprint and lower installation costs

Low maintenance

  • No internal mechanical or electrical moving parts
  • The complete absence of mechanical and electrical components within the hostile environment provides safe and clean working conditions on site.
  • Optional low energy compressors with adjustable timers
  • Each diffuser (biological treatment) is capable of being isolated and removed individually without the need to shut down the plant or affect the air supply to the rest of the unit
  • Tankering made easier because primary sludge and humus are stored together

Ease of access for maintenance

  • Large access lids for safe, clean, accessible air diffuser system maintenance

Energy efficiency

  • Optional duty-standby blower arrangement is designed to provide process air; additional scour is provided by the secondary blower when required, reducing energy use
  • Variable speed drives can be used to optimise power use

Minimal visual impact

  • Below ground installation means the plant does not impede views of the landscape
  • Discreet for use in tourist and leisure applications

Variable flows and loads

  • The unique design of the flow balancing in the primary tank means it can cope with variable flows and loads making it ideal for caravan sites and other seasonal venues


  • Fully compliant with UK Building Regulations and Environment Agency (EA) guidelines
  • 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
  • WPL HiPAF treatment plants are CE marked where applicable


  • Proven WPL 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
  • Robust operation and stand-by facility
  • GRP is UV stabilised with an external gel coat finish which extends the asset life to 25 years
  • Quality controlled environment at the WPL factory (UK)
  • WPL tailor our robust and reliable wastewater treatment solutions to meet our clients’ demanding specifications and expectations


Standard commercial kiosk design comes with:

  • Weatherproof kiosk to house the control panel and air blowers on site
  • The kiosk is acoustically-lined, houses a control panel, which automatically manages the operation of the plant; the air distribution manifold and one or more air blowers as required.
  • Thermostatic cut-off controls and air filtering monitoring which can alert the operator to loss of air pressure.
  • Ten metres of high temperature resistant airline hose is supplied to connect blowers to the treatment plant – extra lengths can be supplied if the kiosk is sited further than 10m from the treatment unit.

Design options:

  • Inverts up to 1.5m with turret extensions
  • Pumped inlet flow control
  • Control panels are available to cater for single and three phase electrical supplies
  • Alarm beacon for mechanical failure and loss of air pressure
  • Duty/standby blowers with automatic changeover to ensure an uninterrupted air supply
  • Energy-saving options such as variable speed drive blowers
  • GSM telemetry for remote monitoring of the plant
  • WPL Sand Filters/WPL Micro-screens can improve final effluent for strict consent requirements

MK2 lids for commercial application:

The internal sections of the plant can be accessed from the top of the unit to make servicing, maintenance and de-sludging easier. Plants are fitted-as-standard with large, stainless steel, gas strut assisted lids to give full access to the relevant parts of the plant.

  • All lids are lockable
  • Large lids for easy access to each zone
  • Assisted lifting with gas struts
  • Fully serviceable due to easy access
  • Easily removable air diffusers
  • Optional safety grating when in place prevents risk of fall

WPL HiPAF sewage treatment plant showing gas strut open lids  Image showing the internal configuration of a WPL HiPAF sewage treatment plant

Typical commercial uses of the WPL HiPAF modular system include:

  • Animal waste options such as stables and kennels
  • Agricultural growers and garden centres
  • Camping and caravanning sites
  • Custodial establishments
  • Golf courses and fishing lodges
  • Hotels, restaurants and public houses
  • Housing developments
  • Motorway service stations
  • Manufacturing – industrial trade effluent
  • Care homes and retirement villages
  • Commercial buildings and offices
  • Schools, colleges and training centres
  • Stately homes and large country estates
  • Villages and rural communities
  • Visitor centres
  • Zoos, theme parks and leisure attractions and leisure centres

For water utilities requirement, please see WPL HiPAF® bespoke systems