Question to the Department for Transport:

To ask His Majesty's Government what assessment they have made of the levels of chromium-6 found at HS2 sites across the Colne Valley; and whether these are related to cement used in construction works.

HS2 Ltd’s contractor Align JV collects water samples from groundwater, surface water and water associated with construction activities along the route of the Colne Valley Viaduct. The water samples are analysed for a number of substances, including chromium VI, and the data is assessed against environmental quality standards and drinking water standards. The data is then provided to the Environment Agency and Affinity Water on a monthly basis.

All the cement used in the construction of the Colne Valley Viaduct meets EU limits for chromium VI content. Chromium VI has been identified in some waters from the cement used in construction. Such water is collected and either treated at the Align water treatment plant at their South Portal site or at off-site commercial facilities.