NRW sets three-year backstop for wastewater-levy assessment

North Rhine-Westphalia has cut short the open-ended start of the limitation period for assessing its wastewater levyNRW and given the environment ministry power to dictate how the annual wastewater volume is calculatedNRW. Both changes sit in the Abwasserabgabengesetz Nordrhein-Westfalen (AbwAG NRW) as amended by Article 12 of the act of 21 October 2026NRW, published as GV. NRW. 2026 p. 748 and in force since 30 October 2026NRW.

The change practitioners will feel first concerns finality. The levy is still assessed annually by the competent authority, with a two-year Festsetzungsfrist running from the end of the assessment periodNRW. Where the assessment rests on the payer's levy declaration, that period starts when the payer submits the necessary data and documentsNRW — but now with an absolute backstop: no later than the end of the third calendar year following the calendar year in which the levy aroseNRW. A declaration filed late therefore no longer postpones the start of the limitation period indefinitelyNRW. Applied to a levy arising in calendar year 2026, the period starts no later than 31 December 2029NRW. The ten-year period for cases where the levy was evaded or recklessly understated is untouchedNRW.

The second change is an empowerment, not yet a duty. A new sentence in § 5(2) AbwAG NRW authorises the environment ministry to lay down by ordinance (Rechtsverordnung) how the Jahresschmutzwassermenge — the annual volume of dirty water — is determined and how the bases of that determination are documentedNRW. The statute's own method is unchanged: the annual volume is extrapolated from individual volumes of precipitation-free wastewater measured over shorter periods, with due allowance for regularly recurring fluctuations in wastewater volumes over the year or shorter intervalsNRW. The amendment itself sets no calculation methodNRW; the new sentence creates the power to regulate one, while the two sentences stating the existing method stand unchangedNRW. The ministry's 2017 circular, issued to implement § 5(2) in its respectively applicable version, derives the annual volume for mixed wastewater from dry-weather daily flows measured at treatment-plant meters and extrapolated to the year.

The volume matters because, alongside the monitoring values, it fixes the number of Schadeinheiten on which the levy for a dirty-water discharge is computedNRW, and the authority must set it in the discharge permit, review it at least every five years, and can demand the payer's computation with the underlying readings and data by 1 March of the following year.

Payers liable under the AbwAG NRW — municipalities, including for small dischargers and rainwater from public sewers, wastewater associations and industrial direct dischargers — and the advisers who compute and document their volumes should diary the new backstop for declaration casesNRW and watch for the ministry's ordinance, since it will govern the evidence they must keep. Declarations should still be filed complete and on time: incomplete data remains punishable by a fine of up to 50,000 Euro under § 18 AbwAG NRWNRW.

Legal basis: § 5 Absatz 2 and § 11 Absatz 2 of the Abwasserabgabengesetz Nordrhein-WestfalenNRWNRW, each “geändert durch Artikel 12 des Gesetzes vom 21. Oktober 2026, in Kraft getreten am 30. Oktober 2026” (GV. NRW. 2026 S. 748).