Why is a new pressure reduction installation needed?
Pressure reduction installations (PRIs) help to control and regulate the flows of gas and need to be located at strategic points to ensure the country’s gas network operates efficiently and economically.
National Grid first applied for planning permission to build a new PRI on a site at Corse, immediately west of the existing Tirley above ground installation (AGI), in April 2006. The application was refused by Forest of Dean District Council.
The council’s decision was upheld following an appeal in 2007, but the Planning Inspectors and the Secretaries of State agreed that there is a need to connect a new PRI to the existing gas network at Tirley AGI.
Site selection process
Following this decision, we carried out an extensive evaluation of potential sites for the PRI within a 10km radius of Tirley AGI. We concluded that our preferred location is on land to the east of Flat Farm, off the B4213 just to the east of Tirley AGI. Using this site would also allow us to remove our above-ground equipment from Tirley AGI and return that site to its previous condition.
Consultation and planning permission
We began the site evaluation process in January 2008, and at every stage we consulted planning officers from the local planning authorities within 10km of Tirley AGI, along with representatives of the local action group CAPRI, to seek their views on the evaluation criteria, process and findings.
In late summer 2008 we held two public exhibitions to inform local people about the three-stage site selection process and to ask for their comments on our preferred locations for the PRI.
All feedback received was taken into account during the final stage of the site selection process, after which we submitted our planning application to Tewkesbury Borough Council.
Copies of the planning application, along with the site selection report and Environmental Statement, are available to view at Tewkesbury Borough Council's offices and at Newent Library. The Environmental Statement contains the results of our Environmental Impact Assessment, a study of the likely effect of the PRI on local wildlife, landscape and cultural heritage.
Construction
The methods used to construct the PRI are based on best industry practice, which includes plans to manage the effects of noise, dust and construction traffic on local communities and roads. The early creation of earth bunding will help to minimise noise from the site for nearby properties and passers-by. Additional measures to protect the environment are put in place, such as works to manage groundwater run-off from the temporary construction site.
The design for the proposed new Tirley PRI includes integrating existing above-ground equipment from the neighbouring Tirley AGI. Following the commissioning of the new PRI, the redundant valves at the AGI will be removed and the area returned to a green field site.
Construction of the PRI will take approximately 15 months.
Safety
Safety is a top priority for National Grid and we have an exemplary safety record. Great Britain’s high-pressure National Gas Transmission System has been in operation for more than 35 years, and has never experienced a serious incident affecting life or property – the means by which safety performance is normally defined.
PRIs and their associated pipelines are designed, constructed and operated to the most exacting safety standards set out by the Institute of Gas Engineers and Managers and approved by the Health and Safety Executive. Pressure vessels and pipes are constructed using high grade steel, and undergo rigorous testing before commissioning.
Once constructed, the PRI is an extremely safe and secure installation, protected from interference by a series of fences and security systems.
Minimising our impact on the community
National Grid takes its responsibilities to local communities seriously. We are committed to working with local people to minimise the impact of our works wherever possible.