SUEZ Water - Water Technologies & Water

Ice Pigging for Water Networks

Remove sediment and biofilm without damaging pipe walls

Ice Pigging is a patented process for cleaning the inside of pipes using an ice slurry. It is fast, effective and exceptionally low risk, using significantly less water than most other techniques.


Ice Pigging for drinking water pipe cleaning

ice pigging before and after Ice Pigging is based on harnessing the complex properties and unparalleled benefits of thick ice. Semi-solid ice can be applied uniquely because it is both pumpable like a liquid, but also takes on properties of a solid when a ‘pig’ of ice is formed within a pipe. The ice is pumped into the pipe and forced by pressure to remove sediment and built-up deposits to leave the pipe clear and obstruction free. As a relatively quick process, it leaves pipe walls undamaged.

Why clean pipes?

Over time, drinking water pipes can suffer from problems that can have an impact on water quality and cause consumer complaints. Ice Pigging is proven to effectively remove both sediment and biofilm without causing damage to the pipe wall.

Iron and manganese

Iron and manganese can accumulate as a result of poor filtering at the water treatment stage, or as a result  of deterioration of the drinking water network. Sediments can significantly affect the appearance of drinking water and can easily appear at customer taps when only the slightest changes to the operation of the system occur.


Biofilms are biological growths on the inside surface of the pipe. Typically, water with high manganese or aluminium content, or in any network where chlorination is not allowed can be susceptible to biofilm growth. In networks carrying water treated with  chlorine or chloramines, reactions with biofilms can  lead to the creation of TriHaloMethanes (THMs) which in turn have been associated with public health risks.

Ice Pigging Benefits

Benefits of Ice Pigging for drinking water pipes

Compared to water flushing, Ice Pigging requires at least 50% less water, takes around half the time, and is up to 1000 times more effective. Compared to foam swabbing, Ice Pigging is less expensive as typically no excavations are required and outages are factored in hours, not days. Ice Pigging is also faster and can be performed over larger diameters and greater lengths than air scour techniques.

  • Uses 50% less water than flushing or swabbing / standard pigging.
  • Is up to 1000 times more effective at removing sediment and biofilm than traditional flushing.
  • Flows through all diameters, fittings and bends of pipes.
  • Significantly reduces customer disruption.
  • Takes half the time that is normally required by other techniques.
  • Generally requires no excavation: a genuine ‘no-dig’ technique.
  • Lowest cost option when considering volume of sediment removed.
  • Exceptionally low risk – if ever the ice gets stuck, it will simply melt.
  • It produces quantifiable results – proof of the volume of sediment removed.
  • Ice is harmless to public health.

How It Works

How Ice Pigging works

Step 1: Isolate the main

The main isolated by closing  valves  upstream and downstream of the section to be cleaned.

Step 2: Insert the ice

The ice slurry is pumped into the pipe via a fire hydrant or similar fitting. The downstream pressure in the pipe is monitored and managed at the outlet point via a fire hydrant. A ‘pig’ of ice is formed.

Step 3: Open upstream valve

The ice is pushed along the pipe using the natural pressure in the network. To do this, the upstream valve is opened and flow at the outlet hydrant is used to control the speed of the ice. As the ice flows through the pipe it passes over every surface and collects sediment or wipes biofilm as it passes.

Step 4: Collect Ice Pig

Water in front of the pig is discharged normally. Temperature at the outlet point warns of the arrival of the ice, which allows the sediment laden ice to be collected separately in a tanker if desired.

Step 5: Flush and return to service

The pipe is then flushed to the appropriate standard and promptly returned to service. The process is efficient, rapid and exceptionally low risk.

Our Service

Our Service

We produce ice in our local ice factories and deliver to site using specially designed ice tanks. Ice loads of up to 35,000 litres are possible. All Ice Pigging operations are carefully monitored by our specialist engineers using our monitoring system.

Successful applications of Ice Pigging

SUEZ delivered an Ice Pigging trial on a stretch of sewerage pipe network providing the ideal solution to an expensive and inconvenient problem which may have otherwise led to pipe replacement.

Severn Trent Water, UK

Ice Pigging was used to clean a section of dairy rising main due to material build up on the pipe wall and the effects of this to the performance of the main.

Wessex Water, UK

After several pilot Ice Pigging trials in 2010, Oasen decided to use Ice Pigging to clean the water mains network in Zwijndrecht over a 3 month project.

Oasen Drinkwater, Holland

Ice Pigging was identified as the optimum method to remove sediments and other particles from drinking water pipes over a 3 year contract.

Gosford City Council, Australia

Northumbrian Water are carrying out a major programme of work to clean and upgrade their trunk water mains to reduce the likelihood of discoloured water. SUEZ have been awarded the 2 year contract to deliver this project.

Northumbrian Water, UK

Ice Pigging was used as solution to a build-up of manganese and iron in four lengths of water main. The technology was identified as the ideal solution due to its ability to adapt to changing pipe diameters, bends and fittings.

United Utilities, UK

Ice Pigging was chosen as a low risk pipe cleaning solution to remove sediment in parts of the water network as part of their water framework.

Dwr Cymru Welsh Water, Wales