Environmental Issues Related to Brine Disposal from Oil and Gas Development in Pennsylvania

Tao Wen, Pennsylvania State University-Main Campus

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Introduction

One environmental concern regarding shale gas development is disposal of the salt water that is produced with the gas. Each well may return 5-10% of the injected fracturing fluids initially before the well is put into production, which is known as flowback with a volume ranging from approximately 0.25-1 million gallons. This salty water, also called brine, can contain residual fracking compounds, especially during the first few weeks that gas is recovered. After the well is put into production, brine is produced along with the gas and known as "production water", which generates 100s to 1,000s of gallons of brine per day per well. We explore three aspects of these production waters: 1) why the waters cannot be discharged directly into rivers; 2) how disposal can be sometimes associated with earthquakes; 3) how Pennsylvania tries to find ways to dispose of brines safely. We use different online services to find publicly available data.

Intended Audience

mid-level undergraduates in hydrology

Conceptual Learning Outcomes

Students will learn critical thinking skills, data analysis skills, and synthesis of ideas skills
Student will learn how disposed brine might impact the environmental regarding surface water chemistry and seismicity

Practical Learning Outcomes

Students will be able to use HydroClient, PA DEP Oil and Gas Mapping tool, and Google Earth

Student Time Required

2-3 hours

Supporting Reference Documents and Files

Instructions

There will be three steps in this unit. Students will first use Hydroclient to investigate the stream water chemistry upstream and downstream to brine water disposal site at multiple locations in Allegheny River system. Then students will learn what should be done after detecting and locating a new seismic event to determine the cause of the seismic event, in an attempt to tell if a seismic event in Pennsylvania is caused by mining activity, or if it is a natural earthquake or one induced by oil and gas activity. Subsequently, students will use PA DEP Oil and Gas Mapping tool to understand how Pennsylvania Disposes of Brines Safely.

Steps within this lesson

Assessment

Students will answer a few sets of questions as they move through the exercise.