Frequent Severity: 16 errors are listed in SQL Error logs which occur after a DBCC command (Ex: Error: 18210).
2014-01-15 13:44:22.49 spid70 DBCC CHECKCATALOG (xyz) executed by DOMAIN\user found 0 errors and repaired 0 errors. Elapsed time: 0 hours 0 minutes 0 seconds.
2014-01-15 13:44:23.50 spid70 Error: 18210, Severity: 16, State: 1.
2014-01-15 13:44:23.50 spid70 AsynchronousDiskAction::DoDeleteFile: delete failure on backup device 'h:\MSSQL\Data\xyz_data.mdf:MSSQL_DBCC52'. Operating system error 5(Access is denied.).
Referring to http://support.microsoft.com/kb/926070, the errors are actually due to database snapshot which gets created during DBCC operation.
This error indicates, DBCC Data integrity check is not completed successfully. Run DBCC integrity check once again on the database.