Part I Guideline values in relation to the quality of salmonid and cyprinid watersI1
Northern Ireland Not yet in force
| No in Annex 1 to 78/659/EEC | Parameter | Salmonid waters (guideline values and comments) | Cyprinid waters (guideline values and comments) | Methods of analysis or inspection | Minimum sampling and measuring frequency | Observations |
|---|---|---|---|---|---|---|
| 2. | Dissolved oxygen (mg/1O2) | 50%≥9 100%≥7 | 50%≥8 100%≥5 | Winkler’s method or specific electrodes (electro- chemical method) | Monthly, minimum sample represent- ative of low oxygen conditions on the day of sampling. However, where major daily variations are suspected, a minimum of 2 samples in 1 day shall be taken | |
| 4. | Suspended solids (mg/1) | ≤25(O) | Filtration through a 0.45μm filtering membrane, or centrifugation (5 minutes minimum, average acceleration of 2,800 to 3,200g) 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. | BOD5 (mg/1O2) | ≤3 | ≤6 | Determination of O2 by the Winkler method before and after 5 days incubation in complete darkness at 20°C ±1°C (nitrification should not be inhibited) | ||
| 7. | Nitrites (mg/1 NO2) | ≤0.01 | ≤0.03 | Molecular absorption spectro- photometry | ||
| 10. | Non-ionized ammonia (mg/1 NH3) | ≤0.005 | ≤0.005 | Molecular absorption spectro- photometry using indophenol blue or Nessler’s method associated with pH and temperature determ-ination | Monthly | Values for non-ionized ammonia may be exceed in the form of minor peaks in the daytime. |
| 11. | Total ammonium (mg/1 NH4) | 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 0.04 mg/1 for salmonid waters and 0.2 mg/1 for cyprinid waters | ||||
| 14. | Dissolved copper (mg/1 Cu) | ≤0.04 | ≤0.04 | Atomic absorption spectrometry | The values correspond to a water hardness of 100 mg/1 CaCO3 For hardness levels between 10 and 300 mg/1 corresponding limit values can be found in Part II of this Schedule | |
Annotations
Commencement
- I1
Sch. 2 Pt. I in operation at 5.1.1998, see reg. 1