We recognize that water is an important resource for the oil and gas industry, our communities and the environment. We continually work to reduce our impacts on water resources. To monitor our impacts in sensitive groundwater areas, we frequently take groundwater samples before drilling.
Onshore, 93 percent (46.3 million barrels) of the water we used in 2016 was derived from public or private sources, meaning that we obtained agreements from government agencies and/or private water rights holders to use the water. No known water sources were significantly affected by water withdrawals related to our operations.
The remaining 7 percent (3.6 million barrels) of the total volume of water we used onshore was recycled or reused flowback and produced water. This reuse practice reduces both our freshwater consumption and our disposed water volumes. To maximize reuse in the Marcellus Shale, we share water between our operations and other operators in the basin, using a pipeline system to reduce truck trips. In 2016, we also improved and automated pressure monitoring on our water pipelines to reduce the likelihood of leaks.
In the DJ Basin, a change in our fracking process during 2016 increased total water consumption but reduced land disturbance and potential air emissions. The new approach allows for more reuse of water, which will be reflected in our 2017 data. A delay in implementing a new water recycling facility resulted in minimal reuse in 2016.
In our Texas business unit, we began planning and design of central gathering facilities in the Delaware area of the Permian Basin, with produced water recycling capabilities incorporated into the design. The first central gathering facility will be operational in mid-2017.
Monitoring and Mitigation
We take extra steps to mitigate the impact of our operations on local water resources.
In the DJ Basin, we are a member of the South Platte Water Related Activities Program, an organization that allows us to offset water consumption to address Endangered Species Act issues related to the Platte River. The program works by re-timing water flows to benefit federally listed endangered species.
In 2016, we continued a water monitoring protocol in a watershed within the Marcellus Shale known to contain federally threatened and endangered mussel populations. This process will also provide valuable population and viability data via multi-year surveys, which will help guide future development decisions.
In our recently added Texas operations in the Eagle Ford Shale and Permian Basin, we are focused on the environmental site screening process. We work to identify sensitive water bodies early in the planning process and, focusing on avoidance, integrate mitigation measures during the project development phase.
Onshore Water Disposal
We disposed of 19 million barrels of water in our onshore U.S. operations during 2016. None of this water was discharged to surface water bodies.
Offshore Water Consumption
In 2016, we used 29.4 million barrels of seawater in our offshore operations, and 244,000 barrels of freshwater (primarily for potable water needs). We discharged 15.2 million barrels of water offshore.
Finding a Better Way to Control Sediment
Noble Energy and West Virginia University are collaborating on a research project that may turn wood chips created when clearing well sites into filters to control sediment runoff into local streams. Drilling sites, like many other construction projects, use filter socks for erosion control. The filters allow water to flow at a controlled rate from the site. They also trap sediment and prevent the water from carrying harmful materials into streams.
Government standards require these socks to be filled with composted wood chips. As a result, fresh “woods-run” chips created during the clearing process are transported off the site, while filter socks filled with composted wood are transported on-site. The research is designed to test whether the woods-run chips could serve effectively as filter material.
Shawn Grushecky, coordinator of the energy land management program at West Virginia University’s Davis College of Agriculture, Natural Resources and Design, highlighted the potential benefits: “If we’re able to use the green (woods-run) chips on site, it’s going to save companies money, use a product that is being wasted and reduce truck traffic on these sites, which is a benefit to local communities.”
Stream-Stocking Teaches Environmental Lessons
More than 135 students spent a day outdoors for the second annual stream-stocking and clean-up event we hosted along Wheeling Creek and Bear Rock Lake in West Virginia. The students from Marshall and Ohio counties learned about fishing and wildlife management as they stocked a four-mile stretch of the creek with nearly 5,000 pounds of trout and picked up 2.5 tons of trash around the streams. They worked side-by-side with Noble Energy volunteers as well as participants from Cabela’s, the Fraternal Order of Police, the West Virginia Division of Natural Resources and West Virginia University. Woody Yoder, director of Curriculum and Instruction at Marshall County Schools, noted that the partnership teaches students the values of community service and environmental conservation, as well as supplementing classroom biology and physical science material with hands-on learning.