{
  "url": "https://openlegislation.uk/water-supply-water-quality-regulations-northern-ireland-2017/schedule-2",
  "json_url": "https://openlegislation.uk/water-supply-water-quality-regulations-northern-ireland-2017/schedule-2.json",
  "legislation": "nisr/2017/212",
  "legislation_title": "The Water Supply (Water Quality) Regulations (Northern Ireland) 2017",
  "legislation_url": "https://openlegislation.uk/water-supply-water-quality-regulations-northern-ireland-2017",
  "path": "schedule/2",
  "kind": "schedule",
  "number": "2",
  "heading": "INDICATOR PARAMETERS",
  "text": "1 May be monitored from samples of water leaving treatment works or other supply point, as no significant change during distribution.\n2 The water should not be aggressive.\n3 Where radon concentrations exceed 1000Bq/l, remedial action must be carried out on radiological protection grounds without further consideration.\n4 Excluding tritium, potassium-40, radon and radon decay products.\n5 Elevated levels of tritium may indicate the presence of other artificial radionuclides. If the tritium concentration exceeds its parametric value, an analysis of the presence of other radionuclides is required.\n6 Where treatment to reduce the level of radionuclides in water intended for human consumption has been taken, monitoring must be carried out to ensure the continued efficacy of the treatment.\n7 If the gross alpha activity exceeds 0.1Bq/l or gross beta activity exceeds 1.0Bq/l, analysis for specific radionuclides is required.\n(1) Item\n(2) Parameters\n(3) Specification Concentration or Value (maximum unless otherwise stated) or State\n(4) Units of Measurement\n(5) Point of monitoring\n1\nAmmonium\n0.50\nmg/l\nConsumers' taps\n2\nChloride12\n250\nmg/l\nSupply point\n3\nClostridium perfringens (including spores)1\n0\nNumber/100ml\nSupply point\n4\nColiform bacteria\n0\nNumber/100ml\nConsumers' taps\n5\nColony counts\nNo abnormal change\nNumber/1ml at 22°C Number/1ml at 37°C\nConsumers' taps, service reservoirs and treatment works\n6\nConductivity12\n2500\nµS/cm at 20°C\nSupply point\n7\nHydrogen ion2\n9.5\npH units\nConsumers' taps\n6.5 (minimum)\n8\nRadon (for radioactivity)136\n100\nBq/l\nSupply point\n9\nSulphate12\n250\nmg/l\nSupply point\n10\nIndicative dose (for radioactivity)1467\n0.10\nmSv\nSupply point\n11\nTotal organic carbon (TOC)1\nNo abnormal change\nmg/l\nSupply point\n12\nTritium (for radioactivity)156\n100\nBq/l\nSupply point\n13\nTurbidity\n1\nNTU\nTreatment works",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/nisr/2017/212/schedule/2",
    "retrieved_at": "2026-10-29T00:51:01.047970+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."
}