Transcript Slide 1

Facts about CBM and water
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Extraction of CBM requires
withdrawal of water from coal
seams containing methane.
Projections call for disposal or
management of one quarter million
acre-feet of product water annually
in the Powder River Basin.
Common signature of CBM product
water is salinity, sodicity, ammonia,
bicarb, minor other constituents.
NWF 3/1/03, Blgs
EPA Region 8
Towns
Forsyth
Miles City
North
Dakota
Powder River Basin
Colstrip
Ashland
Broadus
South
Dakota
Coal strip mines
Montana
Decker
Wyoming
Areas prospective for
CBM exploitation
Sheridan
Gillette
Areas of current CBM
development
Axis of Powder River
Basin
Casper
Courtesy of John Wheaton, MBMG
How much water?
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Average annual flow of Tongue River is
~ 320,000 acre feet
Projected CBM product water volume is
~ 250,000 acre feet/year
NWF 3/1/03, Blgs
Water Quantity and Quality Will
Dictate Water Management Options
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Discharge to surface streams
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Surface discharge, spreading, irrigation
Discharge to impoundments
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Ephemeral v. perennial
Loosing v. gaining
Evaporation v. infiltration
Long term recharge v. abandonment
Re-Injection – shallow v. deep
NWF 3/1/03, Blgs
Options for Beneficial Use
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Livestock – watering, dispersals,
enhancement of forage utilization
Fish and wildlife –flow augmentation and
salinity modification-quality dependent
Industrial – dust, fire, extraction, new uses
Irrigation and added rainfall effects-???
Aquifer recharge, water storage
Recreation
Augmentation of domestic supplies – wells
NWF 3/1/03, Blgs
Generalizations about CBM
Product Water Quality
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Range in TDS of PRB CBM product water is 270-2,730
ppm, average is 740 ppm; median is 838 ppm
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Drinking water standard is 500 ppm
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Livestock water standard is 5,000-10,000 ppm
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SAR range of 5-68.7, median 8.8; threshold = 12
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EC (SP) ranges from < 0.5 to > 10 dS/m across basin;
threshold = 3.0 dS/m
NWF 3/1/03, Blgs
The most looked-at water
quality parameters
Parameter
Units
Typical
PRB CBM
Water
TDS
mg/L,
ppm
2702,730
0.63.8
EC, SC
mmhos/
cm,
dS/m
SAR
~Na/Ca
+Mg
5-35
40-50+
Chloride
mg/L,
ppm
5-40
Livestock
Irrigation
Criteria
Primary
Drinking
Secondary
Drinking
5,00010,000
7.815.6
1,2401,920
500
2.0-3.0,
8.0+
0.8
7-12
varies
250
NWF 3/1/03, Blgs
The most looked-at water
quality parameters
Parameter
Units
Typical
PRB CBM
Water
Livestock
Barium
ug/L
1002,000
Boron
ug/L
70-150
5,000
Fluoride ug/L
2002,000
2,0003,000
ug/L
<301,400
Fe (diss)
Selenium ug/L
<5
Irrigation
Criteria
Primary
Drinking
Secondary
Drinking
2,000
7506,000
4,000
5,000
50-100
20
NWF 3/1/03, Blgs
300
50
What is saline water and what are the
common problems or difficulties with the
use of saline water for irrigation?
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Saline water has a relatively high concentration
of dissolved salts (sodium, calcium, magnesium,
sulfates, chlorides, bicarbonates).
Plant growth becomes a problem as salts
accumulate in the root zone high enough to
negatively affect plant growth.
Excess soluble salts in the root zone restrict plant
roots from withdrawing water from the
surrounding soil.
NWF 3/1/03, Blgs
Crop Tolerance to Saline Water
Crops
Forages
Tolerant
EC > 10
SemiTolerant
EC = 4-10
Sensitive
EC < 4
Barley
Sugarbeet
Sunflower
Wheat
Oats
Corn
Safflower
Potato
Field Bean
Peas
Lentils
Tall wheatgrass
Beardless wildrye
Altai wildrye
Slender
wheatgrass
Western
Wheatgrass
Russian wildrye
Barley
Sweetclover
Alfalfa
Tall Fescue
Wheat (hay)
Orchardgrass
Cicer
milkvetch
White
clover
Red clover
Ladino
clover
Alsike
clover
Meadow
foxtail
NWF 3/1/03, Blgs
What is sodic water and what are the
common difficulties with the use of sodic
water for irrigation?
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The sodicity of water is expressed as the Sodium
Adsorption Ratio (SAR) which is:
 The relative amount of sodium compared to calcium
and magnesium; SAR greater than 12.
Sodic water is not necessarily saline.
 leads to poor drainage and crusting, which can affect
establishment, growth and yield.
 irrigation with sodic water on sandy soils does not
cause crusting and poor drainage. However, if the
water is saline-sodic, it may affect crop growth and
yield.
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NWF 3/1/03, Blgs
CBM product water in the
Powder River Basin - knowns
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Trend of increasing sodium adsorption
ratio (SAR), electrical conductivity (EC)
and total dissolved solids (TDS)
progressing north and west through the
basin (Rice et al., 2000).
NWF 3/1/03, Blgs
Additional knowns
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Most wells in southern portion are
within the irrigation standards;
Most wells in the northern section are
above the limits for salinity and sodicity
(Rice et al., 2002).
Soils are generally high in clays and can
be saline-sodic.
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Saline and sodic conditions promote
new plant communities
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Typically, encroachment by saline and
sodic water promotes development of
salt-tolerant, halophytic communities
Commonly occurring species include:
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Prairie cordgrass Cattail
Baltic rushes
American bullrush
Salt cedar
Alkali grass
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Tolerance and/or sensitivity of culturally significant plant
species on the Northern Cheyenne Reservation to
salinity, sodicity, and flooding 
Sensitive (EC < 2 dS/m,
SAR 1.6 - 8
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Moderately Sensitive
(EC 2-4 dS/m, SAR <8)
June/Service Berry
Red Osier Dogwood
Red Shoot Goose
Berry
Chokecherry
Wild Plum
Quaking Aspen
Leafy Aster
Red Raspberry
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NWF 3/1/03, Blgs
Common Spikerush
Field Horsetail
Horsemint
Sweet Medicine
Sandbar Willow
Snowberry
Cattail
Sweet Grass
Saw Beak Sedge
Stinging Nettle
Western Yarrow
Change in CBM water chemistry over a 9
day time period following discharge
subject to evapoconcentration.
WQ6
WQ7
WQ8
Initial
pH
Final
pH
Initial
EC
Final
EC
Initial
SAR
Final
SAR
%
Change
EC
%
Change
SAR
7.4
8.1
3.07
3.75
3.7
4.4
22.15
18.92
7.7
8.4
3.36
4.01
12.5
18
19.35
44.00
5.42
6.71
20.7
33.8
23.80
63.29
Average
%
Change
21.77
42.07
7.5
9.1
NWF 3/1/03, Blgs
Change from outfall to
irrigation
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Aaron DeJoia
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Source
Cascade Earth
Outfall
Sciences
pH
SAR
EC
mmhos/cm
7.5
20-26
3.8-4.2
Pump
8.2
27-30
2.6
Irrigation
Nozzle
8.7
32
2.9
NWF 3/1/03, Blgs
Soil solution saturated paste extract (EC sa t ) versus percent clay of soil m aterial prior to
treatm ent (baseline) and follow ing treatm ent w ith various w ater quality x w etting regim es
12
Ba s e lin e
1 X W e t /Dr y - P .R.
1 X W e t /Dr y - C BM
5 X W e t /Dr y - P .R.
EC (dS/m) (Saturate d Paste Extract)
10
5 X W e t /Dr y - P .R.+d is t ille d
5 X W e t /Dr y - C BM
5 X W e t /Dr y - C BM + d is t ille d
8
6
4
C BM T r e a t m e n t EC
2
P .R. T r e a t m e n t EC
0
4
6
7
8
T e x tu r a l C la s s 1
9
15
17
18
19
21
21
22
23
26
T e x tu r a l C la s s 2
28
29
30
T e x tu r a l C la s s 3
R a n k e d C la y %
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33
33
34
37
44
45
52
56
T e x tu r a l C la s s 4
C o p y r ig h t: K . M . R o b in s o n , M S U - B o z e m a n
L a n d R e s o u r c e s En v ir o n m e n ta l S c ie n c e - 2 0 0 2
NWF 3/1/03, Blgs
Summary
Sustainable CBM product water management
requires rigorous monitoring and
coordinated management
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Essential requirements –
Soil, water, and plant baseline information
Amount and quality of CBM product water
Rigorous monitoring at all points
Coordinated water management with multiple
strategies
NWF 3/1/03, Blgs
A Strategy for CBM product
water management
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Key elements to CBM product water
management
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Watershed based water management
Surface and ground water in concert
Maximize beneficial uses – infrequent
water spreading
Maximize plant consumptive use –
reducing water volumes with wetlands
Minimize deep drainage
NWF 3/1/03, Blgs
MSU Water Quality Web Site
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http://waterquality.montana.edu/
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