# Commission Implementing Decision (EU) 2017/1442 of 31 July 2017 establishing best available techniques (BAT) conclusions, under Directive 2010/75/EU of the European Parliament and of the Council, for large combustion plants (notified under document C(2017) 5225) (Text with EEA relevance), Division BAT 5: BAT is to monitor emissions to water from flue-gas treatment with at least the frequency given below and in accordance with EN standards. If EN standards are not available, BAT is to use ISO, national or other international standards that ensure the provision of data of an equivalent scientific quality.

Extent: E+W+S+N.I.

TOC monitoring and COD monitoring are alternatives. TOC monitoring is the preferred option because it does not rely on the use of very toxic compounds.
Substance/Parameter
Standard(s)
Minimum monitoring frequency
Monitoring associated with
Total organic carbon (TOC)
EN 1484
Once every month
BAT 15
Chemical oxygen demand (COD)
No EN standard available
Total suspended solids (TSS)
EN 872
Fluoride (F–)
EN ISO 10304-1
Sulphate (SO4 2–)
EN ISO 10304-1
Sulphide, easily released (S2–)
No EN standard available
Sulphite (SO3 2–)
EN ISO 10304-3
Metals and metalloids
As
Various EN standards available (e.g. EN ISO 11885 or EN ISO 17294-2)
Cd
Cr
Cu
Ni
Pb
Zn
Hg
Various EN standards available (e.g. EN ISO 12846 or EN ISO 17852)
Chloride (Cl–)
Various EN standards available (e.g. EN ISO 10304-1 or EN ISO 15682)
—
Total nitrogen
EN 12260
—

---
Source: https://www.legislation.gov.uk/eudn/2017/1442/annex/division/1/division/1.2/division/4 (the official version)
Page: https://openlegislation.uk/eu-decision-2017-1442/annex/division-1/division-1.2/division-4
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.