NPS Technical Briefs # 1, 5, 8, and 12 - all by Robert Thorne, 1988 through 1991 - address this issue.  All are available at:
http://www.nps.gov/archeology/PUBS/TECHBR/index.htm

-Jack Eastman


-----Original Message-----
>From: HISTARCH automatic digest system <[log in to unmask]>
>Sent: Jun 10, 2013 2:00 AM
>To: [log in to unmask]
>Subject: HISTARCH Digest - 7 Jun 2013 to 9 Jun 2013 (#2013-132)
>
>There are 2 messages totaling 94 lines in this issue.
>
>Topics of the day:
>
>  1. Info on capping sites (2)
>
>----------------------------------------------------------------------
>
>Date:    Sun, 9 Jun 2013 12:36:03 -0400
>From:    [log in to unmask]
>Subject: Info on capping sites
>
>I recall a bulletin issued by NPS several years ago about best practices on 
>capping sites for protection, materials to use, and cautionary issues.   
>Any references to anything on this subject would be greatly appreciated.
>
>Bob Hoover
>
>------------------------------
>
>Date:    Sun, 9 Jun 2013 10:05:22 -0700
>From:    Allen Dart <[log in to unmask]>
>Subject: Re: Info on capping sites
>
>The Arizona SHPO has issued a "guidance point" on capping sites for
>preservation:
>
> 
>
> <http://azstateparks.com/SHPO/downloads/SHPO_4_Burial.pdf>
>http://azstateparks.com/SHPO/downloads/SHPO_4_Burial.pdf 
>
> 
>
>This guidance document does not provide much encouragement for this
>preservation option.
>
> 
>
> 
>
>al
>
> 
>
>Allen Dart, RPA, Executive Director
>
>Old Pueblo Archaeology Center
>
>PO Box 40577
>
>Tucson AZ 85717-0577 USA
>
>            520-798-1201 office, 520-798-1966 fax
>
>            Email: [log in to unmask]
>
>            URL: www.oldpueblo.org
>
> 
>
>Disclosure: Old Pueblo Archaeology Center's Executive Director Allen Dart is
>a USDA Natural Resources Conservation Service cultural resources specialist
>who volunteers his time to Old Pueblo. Views expressed in Old Pueblo
>Archaeology Center communications do not necessarily represent views of the
>U.S. Department of Agriculture or of the United States.
>
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> 
>
> 
>
> 
>
>-----Original Message-----
>From: HISTORICAL ARCHAEOLOGY [mailto:[log in to unmask]] On Behalf Of
>[log in to unmask]
>Sent: Sunday, June 09, 2013 9:36 AM
>To: [log in to unmask]
>Subject: Info on capping sites
>
> 
>
>I recall a bulletin issued by NPS several years ago about best practices on 
>
>capping sites for protection, materials to use, and cautionary issues.   
>
>Any references to anything on this subject would be greatly appreciated.
>
> 
>
>Bob Hoover
>
>------------------------------
>
>End of HISTARCH Digest - 7 Jun 2013 to 9 Jun 2013 (#2013-132)
>*************************************************************