Transcript Research - Soil and Water Lab

Fate of Natural Gas Brine Constituents Released to Roads and Soils
Christopher Guerrero, Steven Pacenka, Tammo Steenhuis
Department of Biological and Environmental Engineering, Cornell University (Summer 2011)
Materials and Methods
Background
Wastewater from the hydraulic fracturing of natural gas
wells is currently being discharged into the surface
environment. Releases include the intentional spreading
of brine on roads for ice/dust control and the accidental
spilling of fracturing water. Depending on the location and
rock type, the formations from which the natural gas is
derived can contain high concentrations of salt and
metals. These brine constituents are potentially harmful
to not only human health, but also ecosystems.
Moreover, as upstate New York lays on the verge of
intensive gas well development, the production and
handling of brine and fracturing wastes is expected to
expand tremendously over the next few years. The object
of this research project is to examine the environmental
fate of natural gas brine constituents. By determining the
concentrations of salts and metals in the brine and
roadside sediment, one can assess the effects of
accidental spills and brine spreading by comparing these
results to current quality standards.
Analyzed using Inductively Coupled Plasma Atomic
Emission Spectroscopy (ICP-AES).
Results of Sediment Analyses
Discussion
14
 Brine Analysis
12
10




Brine Analysis
Collected in Cherry Creek and South Dayton, NY.
Diluted 25, 50, 100, 500 and 1000 times.
For the 25 times dilution, 2 mL of filtered brine was
added to 48 mL of 5% (v/v) Nitric Acid.





Sediment Analysis
Collected in Boutwell Hill State Forest, NY.
Sampled at three sites at the top and slope of the hill.
Sampled a strata at 3, 5, 7, 12 in. below the surface.
Background samples were taken 20 ft. into the forest
next to each roadside.
 After air-drying and sieving, samples were digested
with 4 M Nitric Acid in a hot water bath for an hour.
8
B/b
BA/b
L/b
6
4
 Roadside Strata Analysis
2
0
Ca
Mg
Na
Sr
Figure 1. Division of salt concentrations in roadside ditch
samples averaged at each of the three sites (B, BA, L)
by the background sample (b)
 Together
3
2.5
B/b
L/b
BA/b
1.5
1
0.5
0
Ba
Parameter
mg/L
Medina Brine
Composite
Medina Brine
Individual Well
Sodium (Na)
58800
66800
Calcium (Ca)
Magnesium
(Mg)
21000
23200
Cu
Ni
Pb
Figure 2. Division of trace metal concentrations in
roadside ditch samples averaged at each of the three
sites (B, BA, L) by the background sample (b)
1760
1780
Potassium (K)
1080
1040
Iron (Fe)
130
129
Manganese (Mn)
70
85
Calcium, strontium, magnesium and sodium are highest
to lowest salts and barium, copper, nickel and lead are
highest to lowest trace metals.
Lead concentrations were consistently lower than the
background in both the strata and roadside ditch
results.
Future work
9
3360
Strontium (Sr)
The roadside ditches and strata had higher calcium,
magnesium, sodium, strontium, barium, copper and
nickel values that the background soil.
10
8
3000
The salt and trace metal results for the strata showed a
downward trend in their salt content with the sample at
three inches below the surface (BH3) being the highest
and the sample at twelve inches below the surface
(BH12) being the lowest.
3.5
2
Table 1. Chemical characteristics of brine from traditional
Medina wells analyzed by the New York Department of
Environmental Conservation
While lead may not be present in our brine samples,
one possible explanation as to why lead was not
detected in the brine is because at low dilutions, high
salt concentrations interfere and at high dilutions, the
lead concentration fails to surpass its detection limit.
7
6
BH3/b
BH5/b
BH7/b
BH12/b
5
4
Results of Brine Analyses
3
2
Parameter
mg/L
NYDEC
Deep Gas
Brine
Cherry
Creek
Brine
South
Dayton
Brine
Nickel (Ni)
3.6
3.1
Lead (Pb)
2.5
2.2
Zinc (Zn)
1.2
0.6
Sodium (Na)
61003
36100
44200
Copper (Cu)
0.6
0.6
Calcium (Ca)
29880
34500
34200
Strontium (Sr)
1400
1200
1230
0
Mg
Na
 Develop a method to isolate any lead present in the
brine for analysis.
 Research history of roadside strata analyzed to
determine types of soil present and composition of
brine spread.
1
Ca
While this preliminary work gives some insights into the
environmental fate of natural gas brine constituents, we
are considering several possible next steps:
Sr
Figure 3. Division of salt concentrations in the strata
samples averaged at each of the four heights (BH3,
BH5, BH7, BH12) by the background sample (b)
5
4.5
 Research salt and metal concentration differences in
brine from newly drilled Marcellus Shale wells.
 Compare effects of brine and commercial road salt on
roadside ditch salt and metal concentrations.
4
Magnesium (Mg)
4240
3270
3200
3.5
3
Objectives
Barium (Ba)
89
145
144
BH3/b
BH5/b
BH7/b
BH12/b
2.5
2
Locate towns in Western NY where brine is used in the
summer for dust control.
Test production brine from the towns’ holding tanks.
Sample roadside ditches and backgrounds on roads
where brine is currently applied in these towns to gather
data on short-term effects of brine application.
Sample strata in a roadside ditch to gather data on
long-term effects of brine application.
Lead (Pb)
2.68
ND
ND
1.5
1
Copper (Cu)
2.4
0.39
0.5
2.66
0.23
0.23
Table 2. Comparison of chemical characteristics from
New York reports to the Cherry Creek and South Dayton
brines used in this study.
 Funding from Engineering Learning Initiatives
 Shree Giri, Tigist Tebebu, Carla Ferreira from the BEE
Soil and Water Lab
0.5
0
Nickel (Ni)
Acknowledgments
Ba
Cu
Ni
Pb
Figure 4. Division of trace metal concentrations in the
strata samples averaged at each of the four heights
(BH3, BH5, BH7, BH12) by the background sample
(b)
 David Orr and Lynne Irwin from Cornell Local Roads
Program
 George Spanos, Director, Chautauqua County
Department of Public Facilities