Is water main renovation a more sustainable alternative to replacement?

Gareth Harris is an expert in no-dig technologies

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As we move toward the next AMP, it is anticipated that UK water companies will be looking for cost effective and more sustainable ways of upgrading their clean water distribution networks. And what could be better than through no-dig techniques.

Lining of water mains is not a new concept. In fact, water mains rehabilitation has been happening for over 50 years, but the development of the materials means that the process today is much quicker than it used to be, with some of the early epoxy coatings needing up to 16 hours to cure, whereas the materials available today mean that a water main can be brought back into service in a matter of hours.

But why do we need to rehabilitate water mains?

Many of our water mains were first built in the 19th century. Although there is no ideal measure of asset health available, the data suggests that the age of mains in the water industry in England and Wales is, on average, around 60 years old. Furthermore, there is a long tail of assets that are considerably older than this, with nearly 25% of assets being more than 80 years old; and over 13% of assets being more than 100 years old, and even up to 150 years old.

Historically, one of the primary reasons for water main rehabilitation was water quality, to remove discolouration from drinking water with a non-structural lining. However today, with water companies focusing is on preventing leakage, the semi-structural linings can increase an asset life by up to 50 years.

So how does it work?

The modern lining materials are 2 component polymeric resins, made up of a base and an activator, which are mixed on site and spray applied. The water main must firstly be cleaned before the lining can be applied. The DWI approve the linings and their Instructions For Use (IFU) which must be strictly complied with when applying the material. The material can then be applied at the desired thickness, and if necessary in more than one layer to achieve the design thickness.

So who can undertake in situ water main lining?

The operational requirements for the in-situ resin lining of water mains are set out in Water UK’s Water Industry Specification, WIS 4-02-01. The WIS requires that an Approved Contractor who has been certified by a Nominated Certifying Body, undertakes the lining.

WRc are Water UK’s Nominated Certifying Body for WIS 4-02-01. This means that any contractor wishing to become an Approved Contractor for the in-situ resin lining of water mains must go through the UKAS accredited process. This involves assessing the installation team’s knowledge, assessing the resin and rig combination, and completing lining trails.

Once approved the contractor will be subject to further lining rig performance audits to be conducted at the start of each lining programme to ensure the rig continues to apply the approved resin in accordance with the WIS

To find out more about WRc’s role as the NCB, please visit this page.

Created by potrace 1.16, written by Peter Selinger 2001-2019

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Created by potrace 1.16, written by Peter Selinger 2001-2019

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Gareth Harris

WRc Approved Manager

Gareth is responsible for the day to day management of the WRc Approved Scheme. Working with project managers and subject matter experts, Gareth will lead applicants through the Approval process. In addition, Gareth will work on promotion of the scheme to ensure that the WRc Approved name is the leading name for anyone looking for a product or service, or to get a product or service Approved for its fitness for purpose. In addition, Gareth will use his experience in Water Fittings Regulations to assist with other projects.

2024-03-12 15:02:00