WASHINGTON (AP) — The Environmental Protection Agency again is raising objections to the proposed Keystone XL pipeline that would carry oil from western Canada to the Texas Gulf Coast.

Despite more than four years of study, the State Department's analysis of the project's environmental impact is "insufficient," the EPA said Monday.

In a letter to the State Department, the EPA urged State to conduct a more thorough analysis of oil spill risks and alternative pipeline routes, as well as greenhouse gas emissions associated with the $7 billion pipeline.

The concerns are similar to objections the EPA raised about the project in 2011. The State Department has authority over the pipeline because it crosses a U.S. border. A draft report in March said the project would not create significant environmental impacts.

The State Department said late Monday that officials have long planned to conduct additional analysis and will incorporate comments from the public and other federal agencies into a final environmental report expected this summer.

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  • <em>From Getty:</em> SAN FRANCISCO, CA - OCTOBER 25: Protestors against the construction of the Keystone XL oil pipeline hold signs and stand on a Keith Haring sculpture as they demonstrate outside of the W Hotel before the arrival of U.S. President Barack Obama on October 25, 2011 in San Francisco, California. Hundreds of protestors from a wide variety of activist groups staged protests outside of the W Hotel where President Obama was holding a $7,500 per person fundraiser. (Photo by Justin Sullivan/Getty Images)

  • <em>From Getty:</em> SAN FRANCISCO, CA - OCTOBER 25: A protestor against the construction of the Keystone XL oil pipeline climbs on a Keith Haring sculpture as he demonstrates outside of the W Hotel where U.S. President Barack Obama was holding a fundraiser on October 25, 2011 in San Francisco, California. Hundreds of protestors from a wide variety of activist groups staged protests outside of the W Hotel where President Obama was holding a $7,500 per person fundraiser. (Photo by Justin Sullivan/Getty Images)

  • <em>From Getty:</em> Demonstrators listen to speakers in Lafayette Park across from the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline. (Photo credit should read KAREN BLEIER/AFP/Getty Images)

  • <em>From Getty:</em> Demonstrators listen to speakers in Lafayette Park across from the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline. (Photo credit should read KAREN BLEIER/AFP/Getty Images)

  • <em>From Getty:</em> A demonstrator waves signs in Lafayette Park across from the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> A demonstrator dressed as an oil soaked bird in Lafayette Park across from the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> Demonstrators listen to speakers in Lafayette Park across from the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> A demonstrator holds signs in front of the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> A demonstrator holds a magazine open to an article concerning tanker routes for the proposed Keystone XL Pipeline in front of the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> Children demonstrate in front of the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline. AFP PHOTO / Karen BLEIER

  • <em>From Getty:</em> Demonstrators hold up a banner in front of the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline. AFP PHOTO / Karen BLEIER

  • <em>From Getty:</em> Demonstrators begin to line up around the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> Demonstrators in front of the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> Demonstrators line up in front of the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> A sign is seen in Lafayette Park across from the White House in Washington, DC November 6, 2011 during a protest. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6320235175/in/set-72157628079975942" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6320925438/in/set-72157628079975942" target="_hplink">Emma Cassidy and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6320975886/in/set-72157628079975942" target="_hplink">Shadia Fayne Wood and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6320307073/in/set-72157628079975942" target="_hplink">Amy Dewan and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6320919878/in/set-72157628079975942" target="_hplink">Emma Cassidy and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6320760272/in/set-72157628079975942" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6321050482/in/set-72157628079975942/" target="_hplink">Clayton Conn and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/mothernature/6306631974/" target="_hplink">mothernature photography</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>