x-Forward-For HTTP client IP

XFF should work from the assigned HTTP profile however, if not working or just want to do it via an iRule simple add the line of your second iRule

HTTP::header insert X-Forwarded-For [IP::remote_addr]

As the first line of your first script, i.e. Insert XFF header first before selecting the pool, see below.

when HTTP_REQUEST {

HTTP::header insert X-Forwarded-For [IP::remote_addr]

 if { [string tolower [HTTP::host]] contains "cpacd." } { 
   if {[active_members ACD_CPACD_Pool] > 0} { 
      pool ACD_CPACD_Pool
   } else { 
      HTTP::redirect "http://maintenance.acc.org" 
      event disable all 
   } 
 }
 elseif { [string tolower [HTTP::host]] contains "hfacd" } { 
   if {[active_members ACD_HFACD_Pool] > 0} { 
      pool ACD_HFACD_Pool
   } else { 
      HTTP::redirect "http://maintenance.acc.org" 
      event disable all 
   } 
 }
 elseif { [string tolower [HTTP::host]] contains "afacd" } { 
   if {[active_members ACD_AFACD_Pool] > 0} { 
      pool ACD_AFACD_Pool
   } else { 
      HTTP::redirect "http://maintenance.acc.org" 
      event disable all 
   } 
 }
 elseif { [string tolower [HTTP::host]] contains "fsedacd" } { 
   if {[active_members ACD_FSEDACD_Pool] > 0} { 
      pool ACD_FSEDACD_Pool
   } else { 
      HTTP::redirect "http://maintenance.acc.org" 
      event disable all 
   } 
 }
 elseif { [string tolower [HTTP::host]] contains "acdanalytics" } { 
   if {[active_members ACD_ACDANALYTICS_Pool] > 0} { 
      pool ACD_ACDANALYTICS_Pool
   } else { 
      HTTP::redirect "http://maintenance.acc.org" 
      event disable all 
   } 
 }
 elseif { [string tolower [HTTP::host]] contains "cpdmt" } { 
   if {[active_members ACD_CPDMT_Pool] > 0} { 
      pool ACD_CPDMT_Pool
   } else { 
      HTTP::redirect "http://maintenance.acc.org" 
      event disable all 
   } 
 }
 elseif { [string tolower [HTTP::host]] contains "hfdmt" } { 
   if {[active_members ACD_HFDMT_Pool] > 0} { 
      pool ACD_HFDMT_Pool
   } else { 
      HTTP::redirect "http://maintenance.acc.org" 
      event disable all 
   } 
 }
else {
      HTTP::respond 404 content "Unrecognized request to [HTTP::uri]" "Content-Type" "text/html" 
    }
}