The legislation has been published, you can read it here: http://www.environ.ie/en/Environment/Water/WaterServices/PublicationsDocuments/FileDownLoad,28352,en.pdf (Water Services Amendment Bill 2011).
Quote:
" 'domestic waste water treatment system’ means a system involving physical, chemical, biological or thermal processes, or a combination of such processes, utilised for the treatment or disposal of domestic waste water, or the sludge derived from domestic waste water, and includes—
(a) all septic tanks and waste water tanks and systems receiving, storing, treating or disposing of domestic waste water and all drains associated with such tanks or systems, and
(b) all drains associated with the discharge of domestic waste water, whether or not they discharge to a septic tank or waste water tank"
QED, I'd say.