NIS2 for Waste water
The exclusion turns on the place of waste water in the undertaking's activity, not on its size: collecting, disposing of or treating urban, domestic or industrial waste water brings an undertaking in, unless that activity is a non-essential part of its general activity.
Which entities are covered
Undertakings collecting, disposing of or treating urban waste water, domestic waste water or industrial waste water as defined in Article 2, points (1), (2) and (3), of Council Directive 91/271/EEC, excluding undertakings for which collecting, disposing of or treating urban waste water, domestic waste water or industrial waste water is a non-essential part of their general activity.
Sub-sectors named in the annex
None. Annex I divides this sector into no sub-sectors: it names the types of entity directly.
Essential or important
A large entity of this sector — one exceeding the ceilings for medium-sized enterprises of Recommendation 2003/361/EC — is essential (art. 3(1)(a)); a medium-sized one is important (art. 3(2)). A small or micro entity is covered only under article 2(2) or 2(3). Whatever its size, an entity is essential where article 3(1)(e) to (g) applies: identification by the member state as an essential entity under article 2(2)(b) to (e), critical-entity status under Directive (EU) 2022/2557, or, where the member state so provides, earlier identification as an operator of essential services. An entity the member state identifies as an important entity under the same points is important (art. 3(2)).
Essential entities face ex ante and ex post supervision (art. 32, recital 122) and, for infringing article 21 or 23, administrative fines with a maximum of at least EUR 10,000,000 or 2% of the total worldwide annual turnover in the preceding financial year of the undertaking to which the entity belongs, whichever is higher (art. 34(4)); important entities face ex post supervision only (art. 33) and a maximum of at least EUR 7,000,000 or 1.4% of that turnover (art. 34(5)).
Traps specific to this sector
Trap 1
Industrial waste water is covered alongside urban and domestic waste water; an undertaking that collects, disposes of or treats it is excluded only where that activity is a non-essential part of its general activity.
Trap 2
The annex defines the waste waters by reference to Directive 91/271/EEC, which Directive (EU) 2024/3019 (urban wastewater treatment, recast) repeals with effect from 1 August 2027; references to the repealed directive are then read as references to the recast, through its correlation table (art. 32(1) and 32(8)).
Trap 3
Public control does not alter the size test: NIS2 disapplies the rule that an enterprise 25 % or more controlled by public bodies cannot be an SME (art. 2(1), second subparagraph; Recommendation 2003/361/EC, Annex, art. 3(4)).
Trap 4
An undertaking identified as a critical entity under Directive (EU) 2022/2557 (CER) is covered whatever its size and is essential (art. 2(3), 3(1)(f)).
What else applies to you
Directive (EU) 2024/3019 (urban wastewater treatment, recast), which replaces Directive 91/271/EEC from 1 August 2027; Directive (EU) 2022/2557 (CER), for critical entities.
Article 4 disapplies a NIS2 provision only where a sector-specific Union act requires cybersecurity risk-management measures or incident notification at least equivalent in effect — and only for the entities that act covers.