1. NWF 3/1/03, Blgs Facts about CBM and water 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.

2. Montana Wyoming North Dakota South Dakota Towns Powder River Basin Coal strip mines Areas prospective for CBM exploitation Areas of current CBM development Axis of Powder River Basin Powder Casper Gillette Sheridan Broadus Ashland Colstrip Miles City Forsyth Belle Fourche River North Platte River Decker Tongue Yellowstone River EPA Region 8 Courtesy of John Wheaton, MBMG

3. NWF 3/1/03, Blgs How much water? Average annual flow of Tongue River is ~ 320,000 acre feet Projected CBM product water volume is ~ 250,000 acre feet/year

4. NWF 3/1/03, Blgs Water Quantity and Quality Will Dictate Water Management Options Discharge to surface streams Ephemeral v. perennial Loosing v. gaining Surface discharge, spreading, irrigation Discharge to impoundments Evaporation v. infiltration Long term recharge v. abandonment Re-Injection – shallow v. deep

5. NWF 3/1/03, Blgs Options for Beneficial Use 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

6. NWF 3/1/03, Blgs Generalizations about CBM Product Water Quality Range in TDS of PRB CBM product water is 270-2,730 ppm, average is 740 ppm; median is 838 ppm Drinking water standard is 500 ppm Livestock water standard is 5,000-10,000 ppm SAR range of 5-68.7, median 8.8; threshold = 12 EC (SP) ranges from 10 dS/m across basin; threshold = 3.0 dS/m

7. NWF 3/1/03, Blgs The most looked-at water quality parameters ParameterUnitsTypical PRB CBM Water LivestockIrrigation Criteria Primary Drinking Secondary Drinking TDSmg/L, ppm 270- 2,730 5,000- 10,000 1,240- 1,920 500 EC, SC mmhos/ cm, dS/m 0.6- 3.8 7.8- 15.6 2.0-3.0, 8.0+ 0.8 SAR ~Na/Ca +Mg 5-35 40-50+ 7-12 varies Chloride mg/L, ppm 5-40250

8. NWF 3/1/03, Blgs The most looked-at water quality parameters ParameterUnitsTypical PRB CBM Water LivestockIrrigation Criteria Primary Drinking Secondary Drinking Barium ug/L100- 2,000 2,000 Boron ug/L70-1505,000750- 6,000 Fluoride ug/L200- 2,000 2,000- 3,000 4,000 Fe (diss)ug/L<30- 1,400 5,000300 Seleniumug/L< 550-1002050

9. NWF 3/1/03, Blgs What is saline water and what are the common problems or difficulties with the use of saline water for irrigation? 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.

10. NWF 3/1/03, Blgs Tolerant EC > 10 Semi- Tolerant EC = 4-10 Sensitive EC < 4 CropsBarley Sugarbeet Sunflower Wheat Oats Corn Safflower Potato Field Bean Peas Lentils Forages 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 Crop Tolerance to Saline Water

11. NWF 3/1/03, Blgs What is sodic water and what are the common difficulties with the use of sodic water for irrigation? 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.

12. NWF 3/1/03, Blgs

13. CBM product water in the Powder River Basin - knowns 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).

14. NWF 3/1/03, Blgs Additional knowns 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.

15. NWF 3/1/03, Blgs Courtesy of John Wheaton, MBMG

16. NWF 3/1/03, Blgs Saline and sodic conditions promote new plant communities Typically, encroachment by saline and sodic water promotes development of salt-tolerant, halophytic communities Commonly occurring species include: Prairie cordgrassCattail Baltic rushesAmerican bullrush Salt cedarAlkali grass

17. NWF 3/1/03, Blgs

19. 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 June/Service Berry Red Osier Dogwood Red Shoot Goose Berry Chokecherry Wild Plum Quaking Aspen Leafy Aster Red Raspberry Moderately Sensitive (EC 2-4 dS/m, SAR <8) Common Spikerush Field Horsetail Horsemint Sweet Medicine Sandbar Willow Snowberry Cattail Sweet Grass Saw Beak Sedge Stinging Nettle Western Yarrow

20. NWF 3/1/03, Blgs Change in CBM water chemistry over a 9 day time period following discharge subject to evapoconcentration. Initial pH Final pH Initial EC Final EC Initial SAR Final SAR % Change EC % Change SAR WQ6 7.48.13.073.753.74.4 22.15 18.92 WQ7 7.78.43.364.0112.51819.3544.00 WQ8 7.5 9.1 5.426.7120.733.823.8063.29 Average % Change 21.7742.07

21. NWF 3/1/03, Blgs Change from outfall to irrigation Aaron DeJoia Cascade Earth Sciences SourcepHSAREC mmhos/cm Outfall 7.520-263.8-4.2 Pump 8.227-302.6 Irrigation Nozzle 8.7322.9

22. NWF 3/1/03, Blgs

24. Summary Sustainable CBM product water management requires rigorous monitoring and coordinated management 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

25. NWF 3/1/03, Blgs A Strategy for CBM product water management Key elements to CBM product water management 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

26. NWF 3/1/03, Blgs MSU Water Quality Web Site http://waterquality.montana.edu/