Negotiations with Washington Redskins owner Daniel Snyder are delaying an environmental assessment launched in 2007 to determine the impacts of repairing a failed retaining wall on his River Road property, a Chesapeake and Ohio Canal National Historical Park official said Monday.

National Park Service and Maryland National Capital Park and Planning officials are waiting on a fix to the retaining wall problem before Snyder plants more trees to replace the 130 he improperly removed from his property in 2004.

"Nobody wants to replace the trees until all of the issues have been resolved so the trees have a better chance of surviving," said Brian Carlstrom, deputy superintendent of the C&O Canal Park. Bringing in equipment to repair the wall might pose a threat to newly planted trees, he said.

The National Park Service required Snyder to re-plant some trees after the initial cutting, Carlstrom said. Residents have raised concerns that those trees are dying.

Snyder, who drew a firestorm of controversy from Potomac area environmentalists in 2004 when he cut 130 trees in a federally protected scenic easement on his property near the canal, agreed in 2007 to pay for a federal environmental assessment for the retaining wall project. The retaining wall, within 200 feet of the canal, also is located in the easement — an area in which construction is prohibited to protect the views from the towpath. It is situated near the top of land that slopes toward the canal, and pressure from eroding soil caused the collapse, according to park officials.

"The [environmental assessment] has been 80 percent done for over a year," Carlstrom said. A draft of the assessment, required by the National Environmental Protection Act, was slated to be released to the public for further comment in 2008.

Carlstrom said the park is negotiating an "exchange of interests" with the Snyders, in which the park would permit construction in the easement in exchange for additional actions from the Snyders — such as helping to repair historic features in the park. The assessment looks at the impacts of replacing a portion of the wall that failed in 2005 or replacing the entire wall, Carlstrom said.

"We've been working with the Snyders to try and develop an exchange of interests, and we're at a point now where we can't resolve it," Carlstrom said. "We presented them with two different options and currently they haven't accepted."

Karl Swanson, a spokesman for Snyder, declined to comment.

In a settlement, Snyder paid $37,000 to the Maryland-National Capital Park and Planning Commission after being cited for violating forest conservation laws when the trees were removed. The settlement also required he re-plant the trees, said Mark Pfefferle, Park and Planning forest conservation program manager. However, Park and Planning won't require the trees to be re-planted until the retaining wall issue is resolved, Pfefferle said.

"Six years later — six years after the cutting — and this still has not been resolved," said Ginny Barnes, environmental chairwoman of the West Montgomery County Citizens Association.

Barnes called for more communication between Park and Planning and the national park to work toward a solution. Barnes said she doubted whether the condition of the slope would allow for replanting at all.

"The slopes are eroding, the soil won't be there to hold the trees, the trees aren't there to hold the soil — it's a mess, and nothing has been resolved."