The Bush administration isn't about to let a few laws stand in its way of building a fence along the Mexican border.

Complying with the same laws applied to everyone else could slow down the 670 miles of fencing planned for this year. So, the Department of Homeland Security, using power approved by Congress, has waived compliance with more than 30 environmental and cultural laws to facilitate construction of two sections of the barrier. It had previously issued three waivers.

In the past, Homeland Security has done environmental studies called for by the National Environmental Policy Act, which allows for public input and comment.

The Secure Fence Act of 2006, though, stipulated that the fence be finished by the end of this year, and abiding by the environmental restrictions has made that difficult. With 309 miles of fencing erected, the required studies to assess risks to wildlife and the environment could not be done in time to complete the remaining 361 miles before the deadline.

The nature of the fencing varies, from metal barriers to concrete posts with all-weather roads, cameras and other infrastructure to police illegal immigrant crossings.

The waivers allow construction to go ahead before the assessments are completed. Homeland Security Secretary Michael Chertoff said the agency will continue to seek public input on the potential impact of the construction. By then, though, irreparable damage may be done for a project that has met intense opposition and the value of which remains questionable.