2. Energy Advisory Board Water Treatment Rifle, Colorado - March 1, 2007

3. Agenda ■ Glossary ■ Water Process Review ■ EnCana Recycling Facilities

4. Water Terminology ■ Salt – A dissolved solid in water. Eg. Calcium, magnesium, “Table Salt” NaCl ■ Suspended solids – particles or materials in the water that do not dissolve ■ Total Dissolved Solids (TDS) – a measure of the total concentration of salt in a solution

5. Freeze-Thaw Evaporation ■ Difference in freezing points of pure water (32°F) and water containing salts (< 32 °F) ■ Water freezes while higher TDS water stays liquid

6. Reverse Osmosis (RO) ■ Removes TDS by passing the water through a semi- permeable cellophane-like membrane. ■ “microscopic filter”

7. Ultraviolet light (UV) ■ Sterilization technology ■ Ultraviolet lamps that produce short wave radiation lethal to bacteria, viruses and other microorganisms present in water.

8. Chemical Treatment ■ Chlorination – Chlorine addition to water removes bacteria, viruses, protozoa and other organisms along with oxidizing iron, manganese and hydrogen sulfide to a filterable form. ■ Iodine – another chemical used to disinfect water ■ Precipitation – polymers and other chemicals are used to bind solids in the water together and then settled out

9. Ion Exchange ■ A process that removes specific dissolved salts from water by exchanging them with other salts on a medium ■ Medium is regenerated by washing with a concentrated mixture of the exchanged salts ■ Typically used as residential water softeners (removes calcium and magnesium)

10. Distillation ■ Boiling water and condensing the purified water vapor

11. Artificial Wetlands ■ Constructed wetlands that utilize the biodegradation ability of plants. ■ Limited and specific TDS removal

12. EnCana Produced Water Use ■ Water Disposition − Recycling water in drilling and fracturing operations 2006 recycled ~3,600,000 bbl (465 acre·ft) ~90% of total water produced − Storage and evaporation 500,000 bbl (64 acre·ft) of storage

13. Water Treatment ■ Tested five different water treatment technologies ■ Looking at future up-coming processes