The European standard EN 12566 is a suite of standards for wastewater treatment systems consisting of 7 parts of which parts 1, 3 and 4 are harmonised product standards. These standards set out the testing and factory production control regimes for septic tanks (Part 1 and 4) and packaged wastewater treatment systems (Part 3). Ireland recently set minimum performance levels for the tests in these standards through National Annexes which ensure that the products being used in Ireland are fit for purpose. The performance levels set are in line with current practice and are no more onerous than the existing requirements.
If a septic tank or biological treatment unit has to be replaced, for whatever reason, then the new product should conform with the relevant harmonised European Product standard and meet the requirements of the Irish National Annex.
There is no obligation under the Water Services (Amendment) Act 2012 to provide a specific type of on-site wastewater treatment unit.