Ice Pigging Information

Ice Pigging- What is it??

What is Ice Pigging? 

Ice Pigging is an award winning, innovative, low risk, advanced pipe cleaning technology to clean drinking water, raw water, sewer force mains and siphons.

Developed by the University of Bristol, England, SUEZ Advanced Solutions is the sole rights holder in North America.

Ice Pigging has been proven to be more effective at removing sediment and debris than water flushing alone. The ice slurry can be inserted and removed through hydrants, line taps, air valves, and other existing fittings, so expensive excavations are not required. Ice Pigging harnesses the characteristics of a semi-solid material that can be pumped like a liquid but behaves like a solid once the pig is formed in the pipe. Because Ice Pigging relies on the natural glacial effect of ice to pick up unwanted sediment, it uses approximately 50% less water than standard water flushing and takes significantly less time. Typically, the section of main being cleaned is out of service for no more than 30 minutes. Traditional cleaning methods do have operational limitations that Ice Pigging can overcome. A main feature of Ice Pigging is that it cannot get stuck and, if for some reason the pig would get stuck, we would allow the ice to melt and flush it from the main. Pipe bends, changes in diameter or butterfly valves can all pose problems for swabbing or pigging, yet ice pigs can easily negotiate these obstacles. To launch and receive traditional pigs, excavations have to be made to allow the installation of launch and reception stations. This can mean costly, extensive interruptions to water networks or force mains and siphons and require the installation of temporary bypass pumping or overland rider main.

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The Benefits

Sustainable, Simple, Innovative and Effective 

ICE PIGGING combines the operational advantages of flushing with the cleaning impact of soft pigging. The Ice Pig is a semisolid that is pumped like a liquid and flows through changes in diameter, bends and fittings without blockage. Ice Pigging has a minimum impact on customer supply or operations. The ice pig is simply pumped into and recovered from a hydrant at each end of the pipe section without excavation or modification to the hydrant.

Value of SUEZ Advanced Solutions Ice Pigging Program: 

• 1,000 times more effective removal of biofilm and sediment

• Produces quantifiable results

• Lowers disinfectant demand

• Requires no excavation

• Minimal downtime

• Requires only 1/2 the time of other techniques

• No requirement to disinfect post cleaning

• Less disruptive/expensive than solid/foam pigging

• Uses 50% less water than conventional flushing

• Environmentally sustainable

• Exceptional low risk

SUEZ Advanced Solutions Ice Pigging Program includes: 

• Combines operational advantages of flushing with cleaning impact of soft pigging

• Ice slurry injected and recovered through hydrants

• System pressure pumps slurry through complex pipe networks

• Pig behaves like a liquid, flows through changes in diameter, through bends and butterfly valves without blockage

• Efficient

Frequently Asked Questions 

Q: What is in the ice?

A: Making the ice is a specialist process carefully developed with the understanding of how ice crystals are formed and maintained. We use a freezing point suppressant to control the consistency of the ice. Normally the only chemical additive is food grade sodium chloride (salt) in small quantities. The ice is completely harmless.

 Q: How does ice get into the pipe, how is it removed?

A: Ice can be inserted, and extracted, through many points. In the past, we have used fire hydrants (preferable), air release valves, blow offs and even DMA / WWMD meters.

Q: What is required to be done to the pipe prior to cleansing?

A: Nothing, there is no pretreatment of the pipe required.

Q: How long is main out of service and are by-pass mains required as part of preparation work?

A: A typical operation will be less than 2 hours, this will include the isolation of the main, ice pigging operation, flushing and sampling and returning the main to service. There is no need for by-pass mains.

Q: How many passes does this technique need to cleanse the main?

A: Normally one pass is sufficient but in certain circumstances more may be required. This depends on many conditions: the type and amount of sediment, and the length, material and diameter of main are all considered.

Q: How long will the ice last?

A: Ice has a life of about 18 hours, this depends on ambient temperature. This means that if the ice needs to travel from the production site it can safely travel for several hours and still be in perfect condition.

Q: What flow conditions are required?

A: In most conditions, the normal system operating flow and pressure is all that is required. However, if the lines are experiencing very low flows, please tell us about it so we can make allowances for higher melt rates.

Q: What about waste disposal?

A: Waste has to be considered before any ice pigging operation. The preferred method of waste disposal is discharge to sewer or collect the ice pig in a tanker (provided by water authority), but flush to waste just before and after ice pigging. De-chlorination must be considered if discharging to watercourse.

Q: How much flush water is required afterwards?

A: Very little is normally required post ice pigging. The quality of the water is very good and returns to within limits very quickly, typically within ¼ - ½ pipe volumes.

Q: Will it affect the Waste Water Treatment Plant?

A: It is all about dilutions. What volume does the plant usually take in a day? How far is the discharge point from the WWTP?

Q: How much (length) can the ice pig clean in an operation?

A: The length cleaned is dependent on the pipe diameter and material. Typically; 2 ¼ miles of 6” PVC or 1500’ of 12” Cast Iron Unlined

Q: How do you deal with customer service connections?

A: Either, a) isolate all corporation taps prior to ice pigging operation, or b) leave service connections open. The ice passes the connections in a very short period of time, but if a customer does open their faucet as the ice passes, then ice could be drawn through the service pipe.

Q: Can the technique/existing equipment be used on cross-country pipelines? (Rough access)

A: Good ground is required for the delivery rig. We have hoses to pump over 100’ to the access point on the line.

Q: Are there any pipe materials the technique is not suitable for?

A: No although special care is required when dealing with unlined cast iron.

Q: What data is recorded during an ice pigging operation?

A: Water temperature, conductivity, flow, pressure and turbidity are all recorded. A post pigging report will be provided with the total volume of material removed. (Not sewers)

Q: Are customers normally notified prior to ice pigging operations?

A: We recommend that water authority notify customers in the same way as any other operation on the distribution network. Typically, this will be by means of letter, door hanger and /or via the local media.