As part of the Portfolio Collaborative Research Programme, WRc has taken on the management of the sewer lining infiltration test procedure that Thames Water started to develop in 2004

Can cured-in-place linings reduce infiltration into sewers? As part of it's Portfolio Collaborative Research Programme, WRc plc has taken on the management of the sewer lining infiltration test procedure that Thames Water started to develop in 2004 with input from Industry end users and Practitioners. As part of the project (CP308 'Infiltration Reduction Capabilities of Cured-In-Place Linings'), WRc is able to offer manufacturers free witnessing of such tests, though these opportunities are limited to a first come, first served basis.

The test quantifies the amount of groundwater that can infiltrate after lining with cured-in-place pipe (CIPP) systems.

Such infiltration can occur either by water peculating through defects within the lining material or by water tracking between the lining and host pipe, and exiting either at the ends of the lining into a manhole or into the sewer at lateral connections.

The test requires a full length CIPP lining to be installed within an assembly (comprising five clayware pipe sections including a 45degree tee) against water infiltrating at 3m water pressure.

Valves at each of the collar joints allow water pressure to be applied to the lining.

After resin cure, the water pressure is increased to 5m head and any infiltration is collected and measured at the ends of the lined section.

The pass/fail infiltration rate has been set the same as for a new sewer.

To date 14 CIPP systems have been tested and 6 have passed.

The WRc Portfolio project CP308 is being sponsored by 4 water and sewerage companies.

As part of the work programme WRc will witness infiltration tests and provide a test letter certificate to those system/installers which are successful.

There is no fee to the installer for WRc witnessing the infiltration test during the project, but the number of witnessing visits is limited.

There are 8 visits remaining on a first to be tested, first to be served basis.

The number of tests witnessed for a particular CIPP system and supplier is limited to a maximum of two.

After the remaining 8 visits have been undertaken witnessing by a suitably qualified experienced independent company is likely to incur a charge.

Further information on the infiltration test procedure, CP308 project details and test letters for the CIPP systems who have passed to date can be found on the project web site.

To register for a witnessing slot contact Andy Russell.

Project CP308 is part of the WRc GBP1.5M programme of collaborative research called Portfolio.

The Portfolio research programme addresses topical problems in the water industry through promoting innovation, sharing research costs and leveraging budgets/experience.