Site Monitoring and Remediation

As with any energy delivery system with many years of operations, historic leak sites exist along our energy transportation and distribution systems. We carry out voluntary inspections and assessments on our systems to identify and measure environmental risk from past spills, leaks and other activities. We use a risk-based approach to identify and rank sites for environmental impacts, remediation and monitoring.

Since the early 1990s, Enbridge has reviewed about 110 historic leak sites on the Lakehead System. By reviewing files, interviewing company personnel, visiting sites and contacting regulatory agencies, we have ensured that past cleanup efforts meet today's standards and, in some cases, we have taken corrective measures. In 2003, we successfully completed this effort, with the exception of two sites at Elgin, Illinois, and Pinewood, Minnesota, where we are conducting further remediation to recover residual crude oil in soil and groundwater.

In our U.S. Natural Gas Business, we carry out a risk-ranking process to evaluate contamination from past operations and reduce the risk of environmental liabilities in our operations. In 2003, for example, we conducted soil sampling and contamination tests, focusing on recently acquired gas gathering pipeline systems in Texas.

Other highlights of Enbridge's site monitoring and remediation work:

1. We installed groundwater monitoring wells at four pump stations along our Lakehead System in upper Michigan. Wells were also installed at four pump stations along our Liquids Pipeline System in Alberta, Saskatchewan and Manitoba. These sites will be incorporated into our regular groundwater monitoring program;
2. We worked alongside regulators to develop a remediation plan for our pump station at Metiskow, Alberta, where we discovered crude oil in groundwater after installing monitoring wells in 2002; and
3. We restored land after decommissioning an oil gathering line at Tecumseh Gas Storage Operations near Sarnia, Ontario. We removed 560 tonnes of oil-and brine-contaminated soil. The land will be returned to agricultural use in 2004.

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