Water Services (Amendment) Act 2012
http://www.environ.ie/en/Legislation/Environment/Water/FileDownLoad,29427,en.pdf

Domestic Waste Water Treatment Systems (Registration) Regulations 2012
http://www.environ.ie/en/Legislation/Environment/Water/FileDownLoad,30599,en.pdf

Water Services Acts 2007 and 2012 (Domestic Waste Water Treatment Systems) Regulations 2012
http://www.environ.ie/en/Legislation/Environment/Water/FileDownLoad,30627,en.pdf

Protect Our Water
https://www.protectourwater.ie

The Environmental Protection Agency
http://www.epa.ie/whatwedo/advice/wastewater/legislation/

A series of information leaflets regarding the operation and maintenance of domestic waste water treatment systems, inspections of such systems and the risks to well water quality is also available:
http://www.environ.ie/en/Publications/Environment/Water/FileDownLoad,33591,en.pdf
http://www.environ.ie/en/Publications/Environment/Water/FileDownLoad,33590,en.pdf
http://www.environ.ie/en/Publications/Environment/Water/FileDownLoad,33589,en.pdf