The Environment Agency and Northumbrian Water are working in partnership to identify the sources of   nitrate   contamination   to   the   Till   Fell   Sandstone   groundwater   body,   located   in   northern Northumberland, England. Currently nitrate concentrations in the recharge area of the aquifer exceed the drinking water supply. This puts public water supply abstractions at risk - concentrations of nitrate at the public water supply boreholes are currently below the drinking water standard. We are working together to reduce the infiltration of N from agricultural practices on this highly vulnerable aquifer.