Question to the Department for Environment, Food and Rural Affairs:

To ask His Majesty's Government what assessment they have made of the level of pollution caused by surface water runoff from highways into the sewers; and what plans they have to hold the highways authorities responsible for the pollution caused in this way and to eliminate the contribution of these sewage overflows in future.

We have not made an assessment of surface water runoff from highways into sewers. The amount of surface water entering our combined sewers network is dependent on the spread and intensity of rainfall. This is incredibly variable and therefore it is not possible to determine the relative contribution towards pollution from storm overflows from highway drains alone. As outlined in the Storm Overflow Discharge Reduction Plan HM Government will work with water companies and relevant stakeholders to better manage rainwater and assess the role of highway drainage as a rainwater drainage system.