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INNOVATIVE RESEARCH FOR A SUSTAINABLE FUTURE

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EPA's Study of Potential Impacts of Hydraulic Fracturing on Drinking Water
Resources:

Wastewater Source Apportionment Project

In 2010, the US Congress
recognized growing public concern
about drinking water in areas with
hydraulic fracturing (I-IF) activity. In
response to these concerns. Congress
requested that EPA conduct a study
examining the potential relationship
between I-IF and drinking water
resources.

EPA's Study of Potential Impacts of
Hydraulic Fracturing on Drinking
Water Resources will provide new
information and help to answer
questions for decision makers at
local, state, tribal and federal levels.

What is the research?

The HF Wastewater Source
Apportionment Project is a
component of EPA's study of the
potential impact of HF on drinking
water resources. The goal of the
project is to evaluate the
relationship, if any, between
disposal of treated HF wastewater
and river pollution. More
specifically, the study lias been
designed to assess the potential
impacts of HF on river systems that
serve as sources for public drinking
water systems.

produced water are collectively
referred to as "HF wastewaters" in
this study. In addition to the
chemicals used during fracturing,
these wastewaters may contain salts,
crustal elements and radioactivity.
The wastewaters are typically stored
on-site in tanks or pits before being
transported for treatment, disposal,
land application, and/or discharge.
In some cases, flowback and
produced waters are treated to
enable the recycling of these fluids
for reuse in other HF operations.

Concerns have been raised that the
discharge of treated HF wastewater
to rivers may be contributing to
increased levels of pollutants,
including salts or brines, in rivers.
However, there are other potential
sources of these materials, including
acid mine drainage, storm water
runoff from road de-icing materials,
and discharges from power plants,
among others. This research aims to
characterize the relative impacts of
HF wastewater river discharges and
other possible sources of pollutants
observed at downstream public
drinking water plants.

The HF process uses large amounts
of water mixed with chemical
additives to enhance the production
of oil and gas from underground
reservoirs. After fracturing, the fluid
that returns to the surface can be
referred to as either "flowback" or
"produced water," and may contain
both HF fluid and natural formation
water. For this study, EPA considers
"flowback" to be the fluid returned
to the surface after HF lias occurred,
but before the well is placed into
production. The flowback and

How will the research be
conducted?

In the spring, summer and fall of
2012. EPA scientists, in
collaboration with Pennsylvania's
Department of Environmental
Protection will collect wastewater
samples in two river systems in
Pennsylvania. Samples will be
collected from wastewater treatment
plant outlets where they discharge
into rivers, and from downstream
river locations where public drinking
water plants draw in water. Samples

Continued on back...

Daily water samples will be drawn
from up to ten locations using
automated collection systems.

The photograph below illustrates the
Isco automated sampling system,
which will be used in this project.

The samples will be analyzed for
major ions, trace elements, and trace
metal isotopes by scientists from
EPA and the U.S. Geological
Survey.

will also be collected from the major
sources of wastewaters discharged
into the EPA study areas.

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U.S. Environmental Protection Agency

Office of Research and Development

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Researchers will use mathematical
models to compare "fingerprints" of
the chemicals with the river data
they collect in order to quantify
which sources contribute to
increased contaminant levels.

This project is designed to help
answer critical scientific questions,
including:

Which sources are contributing
to elevated levels of constituents
in rivers at intakes to drinking
water treatment plants?

What is the relative amount of
material associated with HF
wastewater found at intakes to
drinking water treatment plants?

What is the seasonal and daily
variability of levels of
constituents from HF
wastewaters?

How will the research benefit
the community?

Study results will help decision
makers, including federal, state, and
local governments, industry, non-
governmental organizations and the
public, better understand whether
there are any potential impacts from
HF on drinking water resources,
such as rivers used for drinking
water supplies.

Results from this work will be
published in a final draft report
expected to be released for public

comment and peer review in 2014.
For more information about EPA's
hydraulic fracturing research, see
www.epa. gov/hfstudy.

REFERENCES:

http://www.epa.gov/hfstudv/

CONTACT: Dayna Gibbons, Office of Research and
Development, 202-564-7983
g ibb ons. dayna@epa. gov

Publication number: 601R12009

2

U.S. Environmental Protection Agency

Office of Research and Development

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