Source Protection Zones (SPZs) have been invoked by the Environment Agency at Straitgate to safeguard the groundwater feeding private water supplies at Cadhay Barton. The EA has been made aware of the many water users and receptors around the site, and as a result of the new SPZs additional testing will now be required to model groundwater flows, to make sure that whatever Aggregate Industries does at Straitgate would not derogate or pollute water supplies. To this aim, four more boreholes will be drilled, piezometers installed and groundwater readings taken over 12 months.
Besides the zones indicated, the EA does in any case assume that "all sources intended for human consumption without a bespoke SPZ have at least a default SPZ1 of a 50-metre radius". The EA's Groundwater protection: Principles and practice (GP3) explains their purpose, but essentially "SPZs are an important tool for identifying highly sensitive groundwater areas and for focusing control or advice beyond the general groundwater protection measures applied to aquifers as a whole".
The map below indicates the new SPZs, together with the underlying geology: yellow for the pebble beds, orange for sandstone. AI has confirmed that the eastern part of Straitgate Farm with the overlying sandstone will (for geological, water and economic reasons) be left alone in perpetuity.
