{
  "url": "https://openlegislation.uk/surface-waters-shellfish-classification-regulations-northern-ireland-1997/schedule-2",
  "json_url": "https://openlegislation.uk/surface-waters-shellfish-classification-regulations-northern-ireland-1997/schedule-2.json",
  "legislation": "nisr/1997/489",
  "legislation_title": "The Surface Waters (Shellfish) (Classification) Regulations (Northern Ireland) 1997",
  "legislation_url": "https://openlegislation.uk/surface-waters-shellfish-classification-regulations-northern-ireland-1997",
  "path": "schedule/2",
  "kind": "schedule",
  "number": "2",
  "heading": "Guideline values in relation to the quality of shellfish waters",
  "text": "No in Annex 1 to 79/923/EEC\nParameter\nUnits\nGuideline values and comments\nReference methods of analysis\nMinimum sampling and measuring frequency\n2.\nTemperature\n°C\nA discharge affecting shellfish waters must not cause the temperature of the water to exceed by more than 2°C the temperature of waters not so affected\n— Thermometry Measured in situ at the time of sampling\nQuarterly\n5.\nSalinity\n‰\n12 to 38‰\nConductivity\nMonthly\n6.\nDissolved oxygen\nsaturation %\n≥80%\nWinkler’s method\nElectrochemical method\nMonthly, with a minimum of 1 sample representative 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\n8.\nOrganohalo- genated substances\nThe concentration of each substance in shellfish flesh must be so limited that in contributes, in accordance with Article 1 of Directive 79/923/EEC, to the high quality of shellfish products\nGas chromatography after extraction with suitable solvents and purification\nHalf-yearly\n9.\nMetals\nSilver Ag\nArsenic As\nCadmium Cd\nChromium Cr\nCopper Cu\nMercury Hg\nNickel Ni\nLead Pb\nZinc Zn\nmg/1\nThe concentration of each substance in shellfish flesh must be so limited that it contributes in accordance with Article 1 of Directive 79/923/EEC, to the high quality of shellfish products\nSpectrometry of atomic absorption preceded, where appropriate, by concentration and/or extraction\nHalf-yearly\n10.\nFaecal coliforms\n≤300 in the shellfish flesh and intervalvular liquid\nMethod of dilution with fermentation in liquid substrates in at least 3 tubes in 3 dilutions.\nSubculturing of the positive tubes on a confirmation medium. Count according to MPN (most probable number).\nIncubation temperature 44° ± 0.5°C\nQuarterly",
  "extent": "N.I.",
  "status": "prospective",
  "version": "current",
  "annotations": [
    {
      "type": "I",
      "label": "I1",
      "text": "Sch. 2 in operation at 5.1.1998, see reg. 1"
    }
  ],
  "outstanding_effects": [
    {
      "type": "coming into force",
      "affecting": "nisr/1997/489",
      "affecting_title": "The Surface Waters (Shellfish) (Classification) Regulations (Northern Ireland) 1997"
    },
    {
      "type": "words substituted",
      "affecting": "nisr/2009/61",
      "affecting_title": "The Surface Waters (Shellfish) (Classification) (Amendment) Regulations (Northern Ireland) 2009"
    }
  ],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/nisr/1997/489/schedule/2",
    "retrieved_at": "2026-10-29T02:26:19.805844+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}