{
  "url": "https://openlegislation.uk/surface-waters-abstraction-for-drinking-water-classification-scotland-regulations-1996/schedule-3/part-1",
  "json_url": "https://openlegislation.uk/surface-waters-abstraction-for-drinking-water-classification-scotland-regulations-1996/schedule-3/part-1.json",
  "legislation": "uksi/1996/3047",
  "legislation_title": "The Surface Waters (Abstraction for Drinking Water) (Classification) (Scotland) Regulations 1996",
  "legislation_url": "https://openlegislation.uk/surface-waters-abstraction-for-drinking-water-classification-scotland-regulations-1996",
  "path": "schedule/3/part/1",
  "kind": "part",
  "number": "1",
  "heading": "METHOD OF MEASURING THE VALUES OF PARAMETERS",
  "text": "No. in Annex I to the 1975 Directive\nParameters\nLimit of detection\nPrecision\nAccuracy\nMethod of measurement\nMaterials recommended for the container\nGeneral note: Samples taken at the abstraction point are analysed and measured after sieving (wire mesh sieve) to remove any floating debris such as wood or plastic.\n1For waters classified as DW1, Schedule 2 limit.\n2For waters classified as DW2 and DW3.\n3For waters classified as DW3.\n4For waters classified as DW1, DW2 and DW3, Schedule 1 limit.\n5For waters classified as DW2, Schedule 1 limit, and DW3.\n6For waters classified as DW2 and DW3, Schedule 2 limit.\n7Mixture of six standard substances all of the same concentration to be taken into consideration: fluoranthene; 3, 4-benzofluoranthene; 11, 12-benzofluranthene; 3, 4-benzopyrene; 1, 12-benzoperylene; indano/1, 2, 3-ed/pyrene.\n8Mixture of three substances all of the same concentration to be taken into consideration: parathion, hexachlorocyclohexane, dieldrin.\n9If the samples contain so much suspended matter as to require special preliminary treatment, the accuracy values shown in this Part of Schedule 3 may as an exception be exceeded and will be regarded as a target. These samples must be treated so as to ensure that the analysis covers the largest quantity of substances to be measured.\n10As this method is not in current use in all Member States it is not certain that the limit of detection required for checking values in the 1975 Directive can be attained.\n11Absence in 5,000 m1 (for waters classified DW1, Schedule 2 limit) and absence in 1,000 m1 (for waters classified DW2, Schedule 2 limit).\n12“Limit of detection” means the minimum value of the parameter examined which it is possible to detect.\n13“Precision” means the range within which 95% of the results of measurements made on a single sample, using the same method, are located.\n14“Accuracy” means the difference between the true value of the parameter examined and the average experimental value obtained.\n1\npH\npH unit\n–\n0.1\n0.2\n– Electrometry. Measured in situ at the time of sampling without prior treatment of the sample.\n2\nColoration (after simple filtration)\nmg/1 Pt Scale\n5\n10%\n20%\n– Filtering through a glass fibre membrane. Photometric method using platinum-cobalt scale.\n3\nTotal suspended solids\nmg/1 SS\n–\n5%\n10%\n– Filtering through a 0.45μm filter membrane, drying at 105°C and weighing\n– Centrifuging (for at least 5 mins with mean acceleration of 2,800 to 3,200g) drying at 105°C and weighing.\n4\nTemperature\n°C\n–\n0.5\n1\n– Thermometry. Measured in situ at the time of sampling without prior treatment of the sample.\n5\nConductivity at 20°C\nμs/cm\n–\n5%\n10%\n– Electrometry.\nNo. in Annex I to the 1975 Directive\nParameters\nLimit of\nPrecision detection\nAccuracy\nMethod of measurement recommended for the container\nMaterials\n6\nOdour\ndilution factor at 25 °C\n–\n–\n–\n– By successive dilutions.\nGlass.\n7\nNitrates\nmg/1 NO3\n2\n10%\n20%\n– Molecular absorption spectrophotometry.\n8\nFluorides\nmg/1 F\n0.05\n10%\n20%\nMolecular absorption spectrophotometry after distillation if necessary.\nIon selective electrodes.\n10\nDissolved iron\nmg/1 Fe\n0.02\n10%\n20%\nAtomic absorption spectrophotometry after filtering through a filter membrane (0.45μm).\nMolecular absorption spectrophotometry after filtering through a 0.45μm filter membrane.\n11\nManganese\nmg/1 Mn\n0.01\n0.02\n10%\n10%\n20%\n20%\nAtomic absorption spectrophotometry\nAtomic absorption spectrophotometry\nMolecular absorption spectrophotometry.\n12\nCopper\nmg/1 Cu\n0.005\n0.02\n10%\n10%\n20%\n20%\nAtomic absorption spectrophotometry\nPolarography\nAtomic absorption spectrophotometry\nMolecular absorption spectrophotometry\nPolarography.\nNo. in Annex I to the 1975 Directive\nParameters\nLimit of detection\nPrecision\nAccuracy\nMethod of measurement\nMaterials recommended for the container\n13\nZinc\nmg/1 Zn\n0.01\n0.02\n10%\n10%\n20%\n20%\nAtomic absorption spectrophotometry\nAtomic absorption spectrophotometry\nMolecular absorption spectrophotometry.\n14\nBoron\nmg/1 B\n0.1\n10%\n20%\nMolecular absorption spectrophotometry\nAtomic absorption spectrophotometry\nMaterials not containing boron in any significant quantities.\n19\nArsenic\nmg/1 As\n0.002\n0.01\n20%\n20%\nAtomic absorption spectrophotometry\nAtomic absorption spectrophotometry\nMolecular absorption spectrophotometry.\n20\nCadmium\nmg/1 Cd\n0.0002\n0.0015\n30%\n30%\nAtomic absorption spectrophotometry\nPolarography.\n21\nTotal Chromium\nmg/1 Cr\n0.01\n20%\n30%\nAtomic Absorption spectrophotometry\nMolecular absorption spectrophotometry.\n22\nLead\nmg/1 Pb\n0.01\n20%\n30%\nAtomic absorption spectrophotometry\nPolarography.\n23\nSelenium\nmg/1 Se\n0.005\n– Atomic absorption spectrophotometry.\n24\nMercury\nmg/1 Hg\n0.0001\n0.0002\n30%\n30%\n– Flameless atomic absorption spectrophotometry (cold vaporisation).\n25\nBarium\nmg/1 Ba\n0.02\n15%\n30%\n– Atomic absorption spectrophotometry.\n26\nCyanide\nmg/1 CN\n0.01\n20%\n30%\n– Molecular absorption spectrophotometry.\n27\nSulphates\nmg/1 SO4\n10\n10%\n10%\nGravimetric analysis.\nEDTA compleximetry.\nMolecular absorption spectrophotometry.\n28\nChlorides\nmg/1 C1\n10\n10%\n10%\nTitration (Mohr’s method).\nMolecular absorption spectrophotometry.\n29\nSurfactants (reacting with methylene blue)\nmg/1 (laury1 sulphate)\n0.05\n20%\n– Molecular absorption spectrophotometry.\n30\nPhosphates\nmg/1 P2O5\n0.02\n10%\n20%\n– Molecular absorption spectrophotometry.\n31\nPhenols (phenol Index)\nmg/1 C6H5OH\n0.0005\n0.0015\n0.0005\n30%\n0.0005\n50%\nMolecular absorption spectrophotometry 4-aminoantipyrine method.\nParanitraniline method.\nGlass.\n32\nDissolved or emulsified hydrocarbons\nmg/1\n0.01\n0.04\n20%\n30%\nInfra-red spectrometry after extraction by carbon tetrachloride\nGravimetry after extraction by petroleum ether.\nGlass.\n33\nPolycyclic aromatic hydrocarbons\nmg/1\n0.00004\n50%\n50%\n– Measurement of fluorescence in the UV after thin layer chromatography.\nComparative measurement in relation to a mixture of six control substances with the same concentration.\nGlass or aluminium.\n34\nTotal pesticides (parathion, hexachlorocyclohexane, dieldrin)\nmg/1\n0.0001\n50%\n50%\n– Gas or liquid chromatography after extraction by suitable solvents and purification. Identification of the constituents of the mixture. Quantitative analysis.\nGlass.\n35\nChemical oxygen demand (COD)\nmg/1 02\n15\n20%\n20%\n– Potassium dichromate method.\n36\nDissolved oxygen saturation rate\n%\n5\n10%\n10%\nWinkler’s method\nElectrochemical method.\nGlass.\n37\nBiochemical oxygen demand (BOD5) at 20°C without nitrification\nmg/1 02\n2\n1.5\n2\n– Determination of dissolved oxygen before and after five day incubation at 20 °C ± 1°C in complete darkness. Addition of a nitrification inhibitor.\n38\nNitrogen by Kjeldahl method (except in NO2 and NO3)\nmg/1 N\n0.3\n0.5\n0.5\n– Mineralisation, distillation by Kjeldahl method and ammonium determination by means of molecular absorption spectrophotometry or titration.\n39\nAmmonium\nmg/1 NH4\n0.01\n0.1\n0.03\n10%\n0.03\n20%\n– Molecular absorption spectrophotometry.\n40\nSubstances extractable with chloroform\nmg/l\n– Extraction at neutral pH value by purified chloroform, evaporation in vacuo at room temperature, weighing of residue.\n43\nTotal coliforms\n/100ml\n5\n500\nCulture at 37 °C on an appropriate specific solid medium (such as Tergitol lactose agar, Endo agar, 0.4% Teepol broth) with filtration or without filtration and colony count. Samples must be diluted or, where appropriate, concentrated in such a way as to contain between 10 and 100 colonies. If necessary, identification by gasification.\nMethod of dilution with fermentation in liquid substrates in at least three tubes in three dilutions. Sub-culturing of the positive tubes on a confirmation medium. Count according to MPN (most probable number). Incubation temperature: 37°C ± 1 °C.\nSterilised glass.\n44\nFaecal coliforms\n/100ml\n2\n200\nCulture at 44 °C on an appropriate specific solid medium (such as Tergitol lactose agar, Endo agar, 0.4% Teepol broth) with filtration or without filtration and colony count. Samples must be diluted or, where appropriate, concentrated in such a way as to contain between 10 and 100 colonies. If necessary, identification by gasification.\nMethod of dilution with fermentation in liquid substrates in at least three tubes in three dilutions. Sub-culturing of the positive tubes on a confirmation medium. Count according to MPN (most probable number). Incubation temperature 44 °C ± 0.5 °C.\nSterilised glass.\n45\nFaecal streptococci\n/100 ml\n2\n200\nCulture at 37 °C on an appropriate solid medium (such as sodium azide) with filtration or without filtration and colony count. Samples must be diluted or, where appropriate concentrated in such a way as to contain between 10 and 100 colonies.\nMethod of dilution in sodium azide broth in at least three tubes in three dilutions. Count according to MPN (most probable number).\nSterilised glass.\n46\nSalmonella\n1/5,000ml\n1/1,000ml\nConcentration by filtration (on membrane or appropriate filter).\nInoculation into pre-enrichment medium. Enrichment and transfer into isolating gelese – Identification.\nSterilised glass.",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "footnote",
      "label": "f1",
      "text": "12“Limit of detection” means the minimum value of the parameter examined which it is possible to detect."
    },
    {
      "type": "footnote",
      "label": "f2",
      "text": "13“Precision” means the range within which 95% of the results of measurements made on a single sample, using the same method, are located."
    },
    {
      "type": "footnote",
      "label": "f3",
      "text": "14“Accuracy” means the difference between the true value of the parameter examined and the average experimental value obtained."
    },
    {
      "type": "footnote",
      "label": "f4",
      "text": "1For waters classified as DW1, Schedule 2 limit."
    },
    {
      "type": "footnote",
      "label": "f5",
      "text": "2For waters classified as DW2 and DW3."
    },
    {
      "type": "footnote",
      "label": "f6",
      "text": "9If the samples contain so much suspended matter as to require special preliminary treatment, the accuracy values shown in this Part of Schedule 3 may as an exception be exceeded and will be regarded as a target. These samples must be treated so as to ensure that the analysis covers the largest quantity of substances to be measured."
    },
    {
      "type": "footnote",
      "label": "f7",
      "text": "3For waters classified as DW3."
    },
    {
      "type": "footnote",
      "label": "f8",
      "text": "4For waters classified as DW1, DW2 and DW3, Schedule 1 limit."
    },
    {
      "type": "footnote",
      "label": "f9",
      "text": "5For waters classified as DW2, Schedule 1 limit, and DW3."
    },
    {
      "type": "footnote",
      "label": "f10",
      "text": "7Mixture of six standard substances all of the same concentration to be taken into consideration: fluoranthene; 3, 4-benzofluoranthene; 11, 12-benzofluranthene; 3, 4-benzopyrene; 1, 12-benzoperylene; indano/1, 2, 3-ed/pyrene."
    },
    {
      "type": "footnote",
      "label": "f11",
      "text": "8Mixture of three substances all of the same concentration to be taken into consideration: parathion, hexachlorocyclohexane, dieldrin."
    },
    {
      "type": "footnote",
      "label": "f12",
      "text": "10As this method is not in current use in all Member States it is not certain that the limit of detection required for checking values in the 1975 Directive can be attained."
    },
    {
      "type": "footnote",
      "label": "f13",
      "text": "6For waters classified as DW2 and DW3, Schedule 2 limit."
    },
    {
      "type": "footnote",
      "label": "f14",
      "text": "11Absence in 5,000 m1 (for waters classified DW1, Schedule 2 limit) and absence in 1,000 m1 (for waters classified DW2, Schedule 2 limit)."
    }
  ],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/uksi/1996/3047/schedule/3/part/1",
    "retrieved_at": "2026-10-29T12:30:44.273061+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."
}