<P> The 1990 report documented deterioration of the marble's surface . As much as 2.85 mm of the marble surface has been lost through weathering . The study projected that before 2010, the Tomb Monument will have been weathered enough to have a negative effect on the experience of the visitors and concludes the only solutions are to enclose or replace the monument . </P> <P> Several options have been considered to deal with the damage . Officials at Arlington National Cemetery determined that proper repair can return the Tomb Monument to an acceptable appearance . However, because the cracks will continue to lengthen and widen, continuous grouting, regrouting, touch - up, monitoring, and maintenance would be required . Therefore, a report commissioned by Arlington National Cemetery and published in June 2006 confirmed the Cemetery's conclusion that "replacement of the three pieces of the Tomb Monument is the preferred alternative". A final decision was scheduled to be made on September 30, 2007 . </P> <P> The National Trust for Historic Preservation objects to the plan to replace the authentic Tomb Monument . The Trust expressed concern that Arlington National Cemetery seeks to replace the existing monument with marble from the original quarry, which experts agree is likely eventually to crack . </P> <P> The Trust has observed that the Cemetery's own 1990 report recommended that the monument be repaired and that the Cemetery, in fact, commissioned Oehrlein Architects to repair the stone . In 2007, Mary Oehrlein informed Congressional staff members that: "The existing monument can easily be repaired, as was done 17 years ago, using conventional conservation methods to re-grout the cracks . Once repaired, the fault lines would be virtually invisible from the public viewing areas ." </P>

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