Work on the $2.2-million wall that will prevent the waves of Thunder Bay and its winter ice from further eroding the huge pile of cement kiln dust on National Gypsum property begins Monday.

David Bassett, a public relations official for National Gypsum and consultant BBL Engineers, and Daniel O'Neill, vice president of BBL, were in Alpena Friday to explain the 16 weeks worth of work that lay ahead.

Completion is set for Dec. 1.

Bassett said permits were received from the Michigan Department of Environmental Quality and the U.S. Army Corps of Engineers and work will begin first with the access road which will take a couple of weeks before the 1,850 feet of wall construction begins.

This wall will be built into the lake bed starting with smaller stone and finishing with armor stone weighing between 3 and 6.5 tons apiece.

He said Lafarge Corp. is providing the funding for the stone, which will come from the Glawe Inc. quarry on Long Lake Avenue, and Glawe is performing the construction. The stone from this quarry is approved by the Corps of Engineers and is the same stone the corps is using on its project on the Alpena harbor breakwall.

O'Neill said the first phase of roads on the site will come off Ford Avenue.

"The new road will be constructed back to the eastern side of the pile at a wooded area," O'Neill said. "Then we'll lay a pad down and on that all the armor stone will driven back and placed at a staging area. So, we'll have all the stone that we need for construction placed out there first."

Another road will go down to the shoreline and follow in front of the bluff of cement kiln dust. Construction will begin on the west side and proceed eastward.

"Another leg of the road will be constructed up onto the pile and then back to the stone where the staging area is," he said. The road will allow trucks only to travel in one direction.

About 24,000 cubic yards of cement kiln dust will be removed for construction of the road and later for construction of the wall and placed in a depression up on top of the pile.

"It will be deposited there and it will be covered over with a soil," O'Neill said.

Some of the pile is very hard, but it is believed it will moveable with heavy equipment. It may require pneumatic hammers, but blasting isn't anticipated. The road along the wall will be made stable with the same stone as is used on the wall and will be 36-40 inches thick.

"The revetment is somewhat over-designed. When we first started looking at this four years ago and proposing a revetment, National Gypsum wanted to assure 100 percent that this thing was always going to be there and they wouldn't have to deal with it again. So, we went with an over-design. It's a very reinforced revetment," O'Neill said.

Bassett said the actual design of this type of revetment is done by Baird and Associates of Madison, Wis., one of the world's foremost designers of ocean and lakefront shoreline protection systems.

Another 3,000 feet of the pile which is not eroding to the extent of the bluff portion will be addressed in a second phase of work.

"National Gypsum has told the state of Michigan that they will develop a work plan to be submitted this fall on how the remaining 3,000 feet will be addressed," he said.

As to the issue of the cement kiln dust on the lake bottom, O'Neill said National Gypsum only is responsible for "due care" of the pile produced by former owner Huron Cement Co. National Gypsum said it only purchased the cement plant property on which the pile already existed.

And regarding the issue of cement kiln dust which may continue to blow off the top of the pile, O'Neill said National Gypsum was "talking about that, too," with the DEQ.