{
  "url": "https://openlegislation.uk/water-supply-water-quality-regulations-2018/schedule-2",
  "json_url": "https://openlegislation.uk/water-supply-water-quality-regulations-2018/schedule-2.json",
  "legislation": "wsi/2018/647",
  "legislation_title": "The Water Supply (Water Quality) Regulations 2018",
  "legislation_url": "https://openlegislation.uk/water-supply-water-quality-regulations-2018",
  "path": "schedule/2",
  "kind": "schedule",
  "number": "2",
  "heading": "INDICATOR PARAMETERS",
  "text": "1 The water should not be aggressive.\n2 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.\n3 Remedial action may be taken by the Welsh Ministers on radiological protection grounds without further consideration and deemed to be justified where radon concentrates exceed 1,000 Bq/1.\n4 If tritium concentration exceeds its parametric value, an investigation (which may include analysis) of the presence of artificial radionuclides is required.\n5 May be monitored from samples of water leaving treatment works or other supply point, as no significant change during distribution.\nItem Parameters\nSpecification\nConcentration or Value (maximum unless otherwise stated) or State\nUnits of Measurement\nPoint of compliance\n1\nAmmonium\n0.50\nμgAl/l\nConsumers' taps\n2\nChloride 1\n250\nmgCl/l\nSupply point 5\n3\nClostridium perfringens (including spores)\n0\nNumber/100 ml\nSupply point 5\n4\nColiform bacteria\n0\nNumber/100 ml\nConsumers' taps\n5\nColony counts\nNo abnormal change\nNumber/1 ml at 22°C\nConsumers' taps, service reservoirs and treatment works\n6\nConductivity 1\n2500\nμS/cm at 20°C\nSupply point 5\n7\nHydrogen ion\n9.5\npHvalue\nConsumers' taps\n6.5 (minimum)\n8\nIndicative dose 2\n0.10\nmSv\nSupply point 5\n(a) gross alpha\n0.1\nBq/l\nSupply point 5\n(b) gross beta\n1\nBq/l\nSupply point 5\n9\nRadon 3\n100\nBq/l\nSupply point\n10\nSulphate 1\n250\nmgSO4/l\nSupply point 5\n11\nTotal organic carbon (TOC)\nNo abnormal change\nmgC/l\nSupply point\n12\nTritium (for radioactivity) 4\n100\nBq/l\nSupply point\n13\nTurbidity\n1\nNTU\nTreatment works\nNotes:",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/wsi/2018/647/schedule/2",
    "retrieved_at": "2026-10-28T23:23:05.047051+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."
}