environment impact assessment
All major new groundwater abstractions and those in sensitive areas require an environmental impact assessment as part of the licence application process. Rick Brassington has completed a large number of assessments that meet the requirements of the Water Resources (Environmental Impact Assessment)(England and Wales) Regulations 2003. Recent projects include investigations to estimate the potential environmental impact of proposed new quarries, landfills and new groundwater abstractions such as pumping from a coastal dune sand aquifer where there are rare amphibian habitats.
Environmental impact of abstractions in Delamere Forest
The Forestry Commission operates its Delamere Nursery to grow some 13million trees each year. The nursery is located at three sites in the Delamere Forest area, each with a water abstraction for irrigation. There are two major water-dependent Sites of Special Scientific Interest at Abbots Moss and at Oak Mere that are also candidate Special Areas of Conservation. The Habitats Regulations require the Forestry Commission to assess the potential impact of these groundwater abstractions and it appointed Rick Brassington to assess the areas of influence of the three abstractions and compare them with the location of the two SSSI wetlands. This assessment showed that the Forestry Commission abstractions have no potential impact on either the water environment in general or the two water dependent SSSI sites.
Environmental impact assessment of radioisotope production
The new Wolfson Molecular Imaging Centre at Manchester's Christie Hospital will employ Positron Emission Tomography and requires a supply of short-lived radioisotopes produced in the building's basement. There is a safety concern that neutrons may escape to activate elements within the sandstone below the site to produce radioactive isotopes, particularly Na24 with a half-life of 18 hours, and move into the environment through groundwater flow. Rick Brassington was appointed to undertake a hydrogeological investigation and environmental impact assessment. Chemical analysis of sandstone and groundwater samples taken from the site showed that environmental sodium to be relatively small and is mainly chemically bound within the rock-forming minerals. Groundwater flow rates were calculated to assess the potential impact on a minor watercourse that is the closest potential receptor. At the maximum groundwater flow velocity it will take more than 51 years for water flowing from the Christie Hospital site to reach the brook. This period is equal to some 25,000 half-lives of Na24 and consequently the proposal poses no risk
Environmental impact of a new water sources in a dune sands aquifer
Two golf clubs with courses in the sand dunes near Southport wished to increase the water supply to irrigate their courses. The coastal area contains a number of Sites of Special Scientific Interest including wet slacks, which are valleys between the dunes that are flooded seasonally by high groundwater levels. The potential environmental impact on SSSI areas was minimized by the selection of horizontal wellpoints as the new water sources. Horizontal wellpoints comprise a drainpipe installed at a depth of 5-6m. The groundwater flow pattern to the drain is parallel and laminar and as such causes significantly less drawdown than conventional borehole sources. As a result the water table is lowered by a negligible amount thereby minimizing the potential impact on the wetland areas. The projects involved the design of the horizontal wellpoint systems and management of their construction. The new sources were test pumped and the test data were used to assess the potential impacts as part of the abstraction licence application process.
Environmental impact of proposed new abstraction
A borehole has been constructed into a complex minor aquifer in an area where there is an increasing demand for irrigation water supplies for glasshouses. The project involved an initial evaluation of pumping test data including identifying the interference effects of existing abstractors and groundwater level fluctuations caused by changes in barometric pressure. After two years operation the impact assessment was reviewed using data from the source and from four Environment Agency observation boreholes to better establish the long-term impacts.