Encoding of discovery facet urls

Some characters are not encoded properly in discovery facet urls. Ampersands are one example, but other characters may do the same. An example of this behaviour can be seen at http://dspacedev.nt.gov.au/handle/10070/4/discover?fq=subject_filter:buildings,%20structures%20\&%20establishments\|||buildings,%20structures%20\&%20establishments

where instead of giving the facet "buildings, structures & establishments" it gives "buildings, structures"