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

Energy Advisory Board

Water Treatment

Rifle, Colorado - March 1, 2007

Agenda

■ Glossary

■ Water Process Review

■ EnCana Recycling Facilities

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

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

Reverse Osmosis (RO)

■ Removes TDS by passing the water through a semi-permeable cellophane-like membrane.

■ “microscopic filter”

Ultraviolet light (UV)

■ Sterilization technology

■ Ultraviolet lamps that produce short wave radiation lethal to bacteria, viruses and other microorganisms present in water.

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

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)

Distillation

■ Boiling water and condensing the purified water vapor

Artificial Wetlands

■ Constructed wetlands that utilize the biodegradation ability of plants.

■ Limited and specific TDS removal

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

Water Treatment■ Tested five different water treatment technologies

■ Looking at future up-coming processes