Submitted by on 26 October 2015 UK Ammonia Network 2007 Ammonium concentration (NH4+) 2006 Ammonium concentration (NH4+) 2005 Ammonium concentration (NH4+) 2004 Ammonium concentration (NH4+) 2003 Ammonium concentration (NH4+) 2002 Ammonium concentration (NH4+) 2001 Ammonium concentration (NH4+) 2000 Ammonium concentration (NH4+) 1999 Ammonium concentration (NH4+)