{
  "url": "https://openlegislation.uk/public-water-supplies-scotland-regulations-2014/schedule-3/paragraph-3",
  "json_url": "https://openlegislation.uk/public-water-supplies-scotland-regulations-2014/schedule-3/paragraph-3.json",
  "legislation": "ssi/2014/364",
  "legislation_title": "The Public Water Supplies (Scotland) Regulations 2014",
  "legislation_url": "https://openlegislation.uk/public-water-supplies-scotland-regulations-2014",
  "path": "schedule/3/paragraph/3",
  "kind": "paragraph",
  "number": "3",
  "heading": null,
  "text": ". . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\nMinimum performance characteristic: uncertainty of measurement\nParameter\nUncertainty of measurement (% of prescribed concentration or value, except pH) (Note 1)\nNotes\nNotes—\nNote 1: Uncertainty of measurement is a non-negative parameter characterising the dispersion of the quantity values being attributed to a measurand, based on the information used. The performance criterion for measurement uncertainty (k = 2) is the percentage of the parametric value stated in the table or any stricter value. The uncertainty of measurement must be estimated at the level of the parametric value, unless otherwise specified.\nNote 2: If the value of uncertainty of measurement cannot be met, the best available technique must be selected (up to 60%).\nNote 3: The method determines total cyanide in all forms.\nNote 4: The value for the uncertainty of measurement is expressed in pH units.\nNote 5: Reference method European standard EN ISO 8467:1995 entitled “Water quality - Determination of permanganate index (ISO 8467:1993)”.\nNote 6: The performance characteristics for individual pesticides are given as an indication. Values for the uncertainty of measurement as low as 30 % can be achieved for several pesticides, higher values up to 80% may be allowed for a number of pesticides.\nNote 7: The performance characteristics apply to individual substances, specified at 25% of the prescribed concentration or value for the corresponding parameter in Table B.\nNote 8: The performance characteristics apply to individual substances, specified at 50% of the prescribed concentration or value for the corresponding parameter in Table B.\nNote 9: The uncertainty of measurement must be estimated at the level of 3 mg/l of the total organic carbon in accordance with European standard EN 1484:1997 entitled “Water analysis - Guidelines for the determination of total organic carbon and dissolved organic carbon”.\nNote 10: The uncertainty of measurement must be estimated at the level of 1.0 nephelometric turbidity units in accordance with European standard EN ISO 7027-1:2016 entitled “Water quality - Determination of turbidity - Part 1: Quantitative methods (ISO 7027-1:2016)” or another equivalent standard method.\nAluminium\n25\nAmmonium\n40\nAcrylamide\n30\nAntimony\n40\nArsenic\n30\nBenzo(a)pyrene\n50\nNote 2\nBenzene\n40\nBisphenol A\n50\nBoron\n25\nBromate\n40\nCadmium\n25\nChloride\n15\nChlorate\n40\nChlorite\n40\nChromium\n30\nConductivity\n20\nCopper\n25\nCyanide\n30\nNote 3\n1,2-dichloroethane\n40\nEpichlorohydrin\n30\nFluoride\n20\nHAAs\n50\nHydrogen ion concentration (in pH)\n0.20\nNote 4\nIron\n30\nLead\n30\nManganese\n30\nMercury\n30\nMicrocystin-LR\n30\nNickel\n25\nNitrate\n15\nNitrite\n20\nOxidisability\n50\nNote 5\nPesticides\n30\nNote 6\nPFAS\n50\nPolycyclic aromatic hydrocarbons\n40\nNote 7\nSelenium\n40\nSodium\n15\nSulphate\n15\nTetrachloroethene\n40\nNote 8\nTrichloroethene\n40\nNote 8\nTrihalomethanes – total\n40\nNote 7\nTotal organic carbon\n30\nNote 9\nTurbidity\n30\nNote 10\nUranium\n30\nVinyl chloride\n50",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "F",
      "label": "F1",
      "text": "Sch. 3 Pt. B para. 3 omitted (1.1.2023) by virtue of The Public Water Supplies (Scotland) Amendment Regulations 2022 (S.S.I. 2022/387), regs. 1(1), 18(4)(b)"
    },
    {
      "type": "F",
      "label": "F2",
      "text": "Sch. 3 substituted (27.10.2017) by The Public Water Supplies (Scotland) Amendment Regulations 2017 (S.S.I. 2017/281), reg. 1(1), sch. 2 (as amended by The Public and Private Water Supplies (Miscellaneous Amendments) (Scotland) Regulations 2017 (S.S.I. 2017/321), regs. 1, 3(3)(a)(b))"
    },
    {
      "type": "F",
      "label": "F3",
      "text": "Sch. 3 Pt. B Table and notes substituted for sch. 3 Pt. B Table 1, 2 and notes (1.1.2023) by The Public Water Supplies (Scotland) Amendment Regulations 2022 (S.S.I. 2022/387), reg. 1(1), sch. 3"
    }
  ],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/ssi/2014/364/schedule/3/paragraph/3",
    "retrieved_at": "2026-10-28T21:32:08.441116+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."
}