Safeguarding water supplies - a frack too far?
Water is the latest natural resource under threat from fracking and unless the risks are properly assessed, certain areas could face real shortfalls in supply. Maxine Perella reports
Calls are growing to involve water companies more deeply in the planning process for shale gas extraction in the UK amid concerns that fracking poses a real risk to water supplies, especially in water-stressed regions across southern England.
A briefing paper released this month from Water UK, which represents water and wastewater utility firms, emphasises that while there is a strong argument for shale gas extraction given the country's growing dependence on imported gas, the process of fracking could have serious implications for its members in terms of maintaining water quality, water quantity and waste water management.
It notes that water quality - particularly groundwater - is at risk, most notably from three sources. These are: the surface spillages of chemicals, diesel and other materials at a drilling site; poor well design and construction with subsequent failure; and the hydraulic fracturing process, including the use of biocides and chemical friction reducers in fracturing fluid.
The use of pressurised water during the shale gas extraction process will likely place a high demand on water supplies which could in turn have an impact on local water resources. Water UK points out that while this demand may be met from a number of sources including public water supplies or from recycling/reuse of treated water, shale gas companies need to engage with water companies as early as possible to ensure their needs can be met without reducing the security of supply to existing customers.
In addition, wastewater firms may be asked to accept discharge of effluents recovered from the fracking process for treatment at wastewater treatment works. This flowback water can contain minerals, high concentrations of salinity and low amounts of naturally occurring radioactive material (NORMs). The feasibility of treating this water at a wastewater treatment works will depend on the volume and concentration of the flowback in relation to the size of the treatment works and the concentrations of NORMs present.
In order to enable water and wastewater service providers to make informed decisions about these issues, a platform for dialogue needs to be established with shale gas companies. According to water UK, these discussions will be key to understanding water and wastewater services requirements and in short and longer term as well is helping to identify resolve potential problems.
Specifically, key areas of interest include: the extent of baseline monitoring being proposed to assess impacts on the quality and quantity of local water resources; plans relating to site water management, especially in relation to water reuse to improve understanding of local impacts; shale gas company development plans including scenarios for expansion within a local area and what this means for short and longer term demand for water at specific locations; the expected volumes and chemical and biological composition of waste water as well as preferred disposal routes.
Water UK is now calling on the Government to consider introducing legislation to ensure that water companies are consulted by law during the planning process for shale gas exploration and development. It argues that this would ensure its members receive information about proposed extraction sites, allowing them time to engage with regulators and gas licence holders to ensure that such plans are fully understood and that the associated risks are addressed.