The Supreme Court appeared likely Tuesday to somewhat narrow the scope of environmental reviews required for major infrastructure projects nationwide as it weighed the construction of a Utah rail line that would carry billions of gallons of oil.

The Supreme Court appears likely to weaken one of the nation’s bedrock environmental laws, after justices heard a key case on Tuesday. During oral arguments, several of the court’s conservative justices signaled that they could support at least some limits on the scope of which environmental impacts need to be considered in government decision-making.