The volume of freshwater withdrawn by our unconventional gas operations was 3.7 million m3 in 2018, which represents 1.4% of the group total. We look at ways to reduce freshwater demand and support industry efforts to identify new water treatment technologies.
We design, operate and decommission our wells in a way that reduces the risk of water contamination. We install multiple layers of steel into each well and cement above and below any freshwater aquifers. We then test the integrity of each well before we begin the fracturing process and again at completion.
Hydraulic fracturing creates very small earth tremors that are rarely felt at the surface. Before we start work, we assess the likelihood of our operations causing such activity. For example, we work to identify natural faults in the rock. This analysis informs our development plans for drilling and hydraulic fracturing and we seek to mitigate this risk through the design of our operations.
The water and sand that make up 99.5% of the injection material used in hydraulic fracturing are mixed with chemicals that help reduce friction and bacterial growth in the well. We list the chemicals that we use at each site and, to the extent allowed by our suppliers who own the chemical formulas, submit data on the chemicals used in our hydraulically fractured wells at fracfocus.org or other state-designated websites.
We monitor the impact of new gas development and our operations on species. For example, in the San Juan Basin we monitor potential impacts on the population levels and movement patterns of species such as bald eagles and mule deer. This allows us to schedule our activities and to reduce any impacts.
Drilling and truck traffic can raise concerns over noise and disturbance to the local community. We seek to design facilities and plan road, pipeline and well pad locations to limit disturbances and mitigate noise and other impacts from drilling and truck traffic. To reduce the impacts from traffic, we aim to apply dust suppression techniques, install pipelines to transfer water where practical, and minimize the number of kilometres driven. We work with communities to manage traffic movements whenever possible.