With limited oil supplies, natural gas formations like the Marcellus Shale formation in Southwestern Pennsylvania are seen as both tremendous opportunities and significant environmental challenges.
"The tragedy in the Gulf of Mexico is a reminder of the challenges we face in our development of oil and gas reserves that are deep under the earth," said Jeanne VanBriesen, professor of civil and environmental engineering at Carnegie Mellon University. "Engineering innovations like horizontal drilling and hydraulic fracturing have enabled us to access these reserves, but innovations in environmental protection and restoration have not always kept pace."
VanBriesen oversees a team of researchers taking a systems-approach to water resources in the Pittsburgh region.
"The water in the Monongahela River is many things to many people: we drink it, we play in it and on it, we use it for industry and for cooling our power plants, and we use it to move goods to distant markets. It is the home to fish and mussels and its banks are the home to picnickers and bikers," said VanBriesen. "The environment is our life-support system, and understanding how it works and how we can protect it during industrial activities, including oil and gas development, is critical to our future well-being."
VanBriesen says Marcellus Shale gas development requires lots of water and generates a highly salty wastewater that must be managed to prevent its discharge into our waterways.
"Salty water can kill fish and mussels, but it also affects our ability to treat the water for drinking and other industrial uses," she said. "Desalination is expensive, but if wastewater is not treated before it reaches our waterways, we will have to increase the cost to treat our drinking water."
Her team's research in this area underscores the need for companies and policymakers to look critically at the link that exists between drinking water and wastewater treatment.
One particular focus of their research is on bromide, which can be found in a variety of sources but is known to be a component of shale gas produced water.
"Bromide itself is not harmful, but when it enters a drinking water treatment plant it can be transformed to brominated organics that are harmful," she explained. "This transformation occurs during the disinfection of the water, which is critical to kill harmful microorganisms. So, the important disinfection process has an unintended consequence if the river water has bromide."
The research includes investigating ways to reduce the transformation in the drinking water plant as well as investigating the possible sources of bromide in the region including Marcellus-generated wastewater.
"It is important that while we develop domestic energy sources like shale gas, we also think about the potential consequences for our critical water resources, "said VanBriesen. "Anything we let go into rivers is something we may later have to pay to have taken out of the water. We need to start looking at the full cycle of water — everywhere it moves and what it carries from industry to our rivers and then to our drinking water."