Water Use at Alberta Gas Ethylene

Abstract

Alberta Gas Ethylene Co. Ltd. (AGEC), a subsidiary of NOVA AN ALBERTA CORPORATION, operates a world-scale petrochemical plant at Joffre, Alberta, 20 km east of Red Deer. This plant withdraws an average of about 2500 dam3 of water per year from the Red Deer River, mainly for cooling purposes. Approximately 70 percent of this is consumed, mainly through evaporation and drift from the cooling tower. Waste water is discharged to the River on a batch basis after treatment.The consumption of Red Deer River water by Alberta Gas Ethylene averages about 0.06 m3/s, with a maximum monthly rate of 0.10 m3/s. Dickson Dam is to guarantee a minimum flow of about 16 m3/s in this area of petrochemical development. It is estimated that the maximum consumption of water from the Red Deer River by all petrochemical users will not exceed one m3/s in the year 2000. Other withdrawals from the river may total close to 10 m3/s, over half of which would be consumed. Alberta Government decisions regarding the amount of Red Deer River water that will be allocated to Saskatchewan could restrict further consumption in the basin shortly after the turn of the century.Alberta Gas Ethylene has engaged in several efforts to recycle water. It is estimated that water withdrawals have been reduced by as much as 20 percent, and wastewater discharges by 70 percent. Operational costs have thereby been reduced and the impact of the plant on the environment has been lowered. AGEC has shown that sewage and process wastewaters can be used as cooling water make-up without adversely affecting cooling tower operation. The net consumption of water from the Red Deer River has not, however, been affected.