Page 403 - Fundamentals of Gas Shale Reservoirs

THE DISPOSAL AND REUSE OF FRACKING WASTEWATER 383
in storage, accidental spills and mismanagement can cause The amount of wastewater being disposed of in Texas
releases to the environment that could contaminate nearby wells has skyrocketed with the spread of fracking, to nearly
waters and soils. 3.5 billion barrels in 2011 from 46 million barrels in 2005,
In November 2010, the Pennsylvania Department of according to data from the TRC. On average, companies in
Environmental Protection (PADEP) discovered a discharge Texas dispose of 290 million barrels of wastewater—
during an inspection of the Penn Township facility, where equivalent to about 18,500 Olympic‐size swimming pools
a PADEP inspector observed wastewater spilling from an every month, The Colorado Oil and Gas Conservation
open valve from a series of interconnected tanks. At the Commission, charged with both promoting and regulating
time, XTO Energy Inc., a subsidiary of Exxon Mobil the oil and gas industry, has issued over 3000 permits letting
Corporation, stored wastewater generated from energy companies dispose of liquid waste in evaporative ponds,
extraction activities conducted throughout Pennsylvania at shallow pits, and in 300 plus super‐deep injection wells.
its Penn Township facility and, at the time of the release, In states like Pennsylvania where, according to PADEP
stored produced fluid from its operations in the area. data, over 8418 Marcellus wells have been permitted as of
Pollutants from the release were found in a tributary of the August 2013, there are few Class 2 wells. New York State
Susquehanna River basin. has no disposal wells. The lack of injection wells has led to
EPA, in consultation with PADEP, conducted an investi- a significant increase in the amount of wastewater trucked to
gation and determined that wastewater stored in the tanks at Ohio for disposal via underground injection, from roughly
the Penn Township facility contained the same variety of pol- 26 million gallons in 2010 to 106 million gallons in 2011. In
lutants, including chlorides, barium, strontium, and total dis- 2012, Ohio injection wells handled 588 million gallons of
solved solids, that were observed in those surface waters wastewater, the majority of which was received from
(EPA, 2013a). The federal settlement between parties Pennsylvania (Ohio and Fracking, 2013). After a series of
required that XTO implement a comprehensive plan to small earthquakes near Ohio disposal sites in 2011, Ohio
improve wastewater management practices to recycle, prop- regulators now require far lengthier and more thorough
erly dispose of, and prevent spills of wastewater generated review of geological records which will make underground
from natural gas exploration and production activities in disposal there much more expensive.
Pennsylvania and West Virginia (XTO Energy, 2013). According to a study by researchers at Kent State and
Historically, the practice of disposing of waste in deep Duke University, despite producing less wastewater per unit
injection wells has not gotten much attention. However, in of gas produced than a conventional gas well, developing the
many regions of the country, injection wells have become Marcellus shale has increased the total wastewater generated
the preferred method for disposing of the liquid waste (pri- in the region by about 570% since 2004, overwhelming
marily oil‐field brine) produced during the hydraulic frac- existing wastewater disposal infrastructure capacity (Lutz
turing process. In the Southwest United States, producers et al., 2013). Wastewater was initially shipped to publicly
reinject the wastewater into abandoned wells. Injection owned wastewater treatment plants. These treatment plants
wells are not impacted by waste type or contaminants dur- were designed to treat municipal or county wastewater, and
ing disposal. The 1974 Clean Water Act, among other things, can remove biological contaminants and some heavy metals
requires EPA to protect underground sources of drinking but are far less capable of removing radioactive contami-
water and granted EPA the power to regulate injection wells. nants. When wastewater is sent to municipal sewage facil-
Injection wells are classified into six classes according to ities, harmful chemicals and other pollutants are merely
the type of fluid they inject and where the fluid is injected. diluted, rather than removed, and then released into the
Class 2 wells inject fluids associated with oil and natural gas state’s rivers, lakes and streams potentially affecting drinking
production operations (EPA Classes of Injection Wells). In water supplies.
the United States, there are more than 151,000 waste‐Class On April 19, 2011, the PADEP asked all Marcellus Shale
2 injection wells. More than 2 billion gallons of waste, natural gas drilling operators to stop delivering wastewater
mostly brine, from oil and gas drilling and production are from shale gas extraction to 15 different wastewater treatment
injected into those wells every day. plants around the Pittsburgh region by May 19. This request
States like Texas have many deep underground injection was greatly influenced by research conducted by a Carnegie
wells where companies dispose of the salty and chemical‐ Mellon river monitoring project that showed elevated levels
and mineral‐laden shale wastewater. The state has more than of bromide in the Monongahela River, a source of drinking
8000 active disposal wells, about 850 of which are large water for over 800,000 people in southwestern Pennsylvania.
commercial operations, according to the Texas Railroad Carnegie Mellon University Professor Jeanne VanBreisen
Commission (TRC), the regulator of oil and gas production. was first to discover high levels of bromides in drinking
Texas has another 25,000 wells that accept waste fluids and water sourced from rivers that have received treated fracking
use them to retrieve additional oil and gas (Texas Railroad wastewater (VanBriesen, 2012). Bromide itself is nontoxic,
Commission, 2013). except when it reacts with the chlorine that is used during