ANNEX I

Artificial pH variations with respect to the unaffected values shall not exceed ±0,5 of a pH unit within the limits falling between 6,0 and 9,0 provided that these variations do not increase the harmfulness of other substances present in the water. Phenolic compounds must not be present in such concentrations that they adversely affect fish flavour. Petroleum products must not be present in water in such quantities that they: form a visible film on the surface of the water or form coatings on the beds of water-courses and lakes, impart a detectable ‘hydrocarbon’ taste to fish, produce harmful effects in fish. In particular geographical or climatic conditions and particularly in cases of low water temperature and of reduced nitrification or where the competent authority can prove that there are no harmful consequences for the balanced development of the fish population, Member States may fix values higher than 1 mg/l. Parameter Salmonid waters Cyprinid waters Methods of analysis or inspection Minimum sampling and measuring frequency Observations G I G I 1. Temperature (°C) 1. Temperature measured downstream of a point of thermal discharge (at the edge of the mixing zone) must not exceed the unaffected temperature by more than: Thermometry Weekly, both upstream and downstream of the point of thermal discharge Over-sudden variations in temperature shall be avoided 1,5 °C 3 °C Derogations limited in geographical scope may be decided by Member States in particular conditions if the competent authority can prove that there are no harmful consequences for the balanced development of the fish population 2. Thermal discharges must not cause the temperature downstream of the point of thermal discharge (at the edge of the mixing zone) to exceed the following: 21,5 (0) 28 (0) 10 (0) 10 (0) The 10 °C temperature limit applies only to breeding periods of species which need cold water for reproduction and only to waters which may contain such species Temperature limits may, however, be exceeded for 2 % of the time. 2. Dissolved oxygen (mg/l O_(2)) 50 % ≥ 9 100 % ≥ 7 50 % ≥ 9 50 % ≥ 8 100 % ≥ 5 50 % ≥ 7 Winkler's method or specific electrodes (electro-chemical method) Monthly, minimum one sample representative of low oxygen conditions of the day of sampling However, where major daily variations are suspected, a minimum of two day samples in one day shall be taken When the oxygen concentration falls below 6 mg/l, Member States shall implement the provisions of Article 7(3). The competent authority must prove that this situation will have no harmful consequences for the balanced development of the fish population When the oxygen concentration falls below 4 mg/l, Member States shall implement the provisions of Article 7(3). The competent authority must prove that this situation will have no harmful consequences for the balanced development of the fish population 3. pH 6 to 9 (0) 6 to 9 (0) Electrometry calibration by means of two solutions with known pH values, preferably on either side of, and close to the pH being measured Monthly 4. Suspended solids (mg/l) ≤ 25 (0) ≤ 25 (0) Filtration through a 0,45 μm filtering membrane, or centrifugation (five minutes minimum, average acceleration of 2800 to 3200 g) drying at 105 °C and weighing The values shown are average concentrations and do not apply to suspended solids with harmful chemical properties Floods are liable to cause particularly high concentrations 5. BOD_(5) (mg/l O_(2)) ≤ 3 ≤ 6 Determination of O_(2) by the Winkler method before and after five days incubation in complete darkness at 20 ± 1 °C (nitrification should not be inhibited) 6. Total phosphorus (mg/l P) Molecular absorption spectrophotometry In the case of lakes of average depth between 18 and 300 m, the following formula could be applied: L ≤ 10 Z^(—) / Tw(1 + 2Tw) where: L = loading expressed as mg P per square metre lake surface in one year Z^(—) = mean depth of lake in metres Tw = theoretical renewal time of lake water in years In other cases limit values of 0,2 mg/l for salmonid and of 0,4 mg/l for cyprinid waters, expressed as PO_(4), may be regarded as indicative in order to reduce eutrophication 7. Nitrites (mg/l NO_(2)) ≤ 0,01 ≤ 0,03 Molecular absorption spectrophotometry 8. Phenolic compounds (mg/l C_(6)H_(5)OH) By taste An examination by taste shall be made only where the presence of phenolic compounds is presumed 9. Petroleum hydrocarbons Visual By taste Monthly A visual examination shall be made regularly once a month, with an examination by taste only where the presence of hydrocarbons is presumed 10. Non-ionised ammonia (mg/l NH_(3)) ≤ 0,005 ≤ 0,025 ≤ 0,005 ≤ 0,025 Molecular absorption spectrophotometry using indophenol blue or Nessler's method associated with pH and temperature determination Monthly Values for non-ionised ammonia may be exceeded in the form of minor peaks in the daytime In order to diminish the risk of toxicity due to non-ionised ammonia, of oxygen consumption due to nitrification and of eutrophication, the concentrations of total ammonium should not exceed the following: 11. Total ammonium (mg/l NH_(4)) ≤ 0.04 ≤ 1 ≤ 0.2 ≤ 1 12. Total residual chlorine (mg/l HOCl) ≤ 0,005 ≤ 0,005 DPD-method (dietyl-p-phenylenediamene) Monthly The I-values correspond to pH = 6 Higher concentrations of total chlorine can be accepted if the pH is higher 13. Total zinc (mg/l Zn) ≤ 0,3 ≤ 1,0 Atomic absorption spectrometry Monthly The I-values correspond to a water hardness of 100 mg/l CaCO_(3) For hardness levels between 10 and 500 mg/l corresponding limit values can be found in Annex II 14. Dissolved copper (mg/l Cu) ≤ 0,04 ≤ 0,04 Atomic absorption spectrometry The G-values correspond to a water hardness of 100 mg/l CaCO_(3) For hardness levels between 10 and 300 mg/l corresponding limit values can be found in Annex II General observation: It should be noted that the parametric values listed in this Annex assume that the other parameters, whether mentioned in this Annex or not, are favourable. This implies, in particular, that the concentrations of other harmful substances are very low. Where two or more harmful substances are present in mixture, joint effects (additive, synergic or antagonistic effects) may be significant. Abbreviations: G= guide. I= mandatory. (0)= derogations are possible in accordance with Article 11.

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Source: EUR-Lex (Cellar) · retrieved 2026-10-13 · Text as adopted (Official Journal); later amendments are not incorporated in this text.