TransCanada Corp. (TRP) has attempted to appease Nebraska lawmakers by adding increased safety measures to a section of the controversial Keystone XL pipeline system that crosses the state's large underground water system.

The Canadian pipeline company made several guarantees to Nebraska lawmakers, including a $100 million bond to ensure adequate funds to clean up after any oil spills, as the state's legislature considered holding a special session to consider legislation to force the company to change Keystone's route.

TransCanada maintains that Keystone's route, which crosses the state's Ogallala Aquifer, causes the least environmental disturbance and that the pipeline is safe. Critics are worried an oil spill could damage the aquifer, which provides water for the state's people and agricultural economy.

In a letter to the Speaker of the Nebraska legislature, Sen. Mike Flood, TransCanada also offered to build a concrete containment ditch around the pipeline where it cross the environmentally sensitive Sand Hills area, to locate a rapid spill-response team in the Sand Hills, to encase the pipeline with an additional protective coating in certain areas, to provide free water testing to nearby land owners and to pay for state regulators to hire a special public liaison officer to handle concerns about the pipeline.

A TransCanada spokesman said company executives offered the concessions to Sen. Flood and other lawmakers in a meeting last week. It's still not clear whether the Nebraska legislature intends to hold a special session on the pipeline. Flood's office couldn't immediately be reached for comment late Tuesday.