{
  "url": "https://openlegislation.uk/water-supply-water-quality-regulations-1989/schedule-3",
  "json_url": "https://openlegislation.uk/water-supply-water-quality-regulations-1989/schedule-3.json",
  "legislation": "uksi/1989/1147",
  "legislation_title": "The Water Supply (Water Quality) Regulations 1989",
  "legislation_url": "https://openlegislation.uk/water-supply-water-quality-regulations-1989",
  "path": "schedule/3",
  "kind": "schedule",
  "number": "3",
  "heading": "SAMPLING FREQUENCIES",
  "text": "TABLE 1:\nSampling frequencies at consumers' taps\nParameters\nWater Supply Zone\nSampling Frequency (number per annum)\nVolume distributed (m3/d) for domestic purposes\nPopulation Supplied\nReduced\nStandard\nIncreased\nGround water\nSurface water\nConductivity or\n≤100\n≤500\n4\n12\nhydrogen ion\n101– 1000\n501– 5000\n4\n4\n6\n12\nOdour\n1001– 2000\n5001–10000\n4\n6\n12\n24\n(qualitative)\n2001– 4000\n10001–20000\n6\n2\n24\nTaste\n4001– 7000\n20001–35000\n11\n21\n42\n(qualitative)\n7001–10000\n35001–50000\n15\n30\n60\nTABLE 2:\nSampling frequencies at consumers' taps\nParameters\nWater Supply Zone\nSampling Frequency (number per annum)\nVolume distributed (m3/d) for domestic purposes\nPopulation Supplied\nReduced\nStandard\nIncreased\nGround water\nSurface water\nOdour (quantitative)\nTaste (quantitative)\nTurbidity\n≤100\n≤500\n4\n12\nTemparture\n101– 1000\n501– 5000\n4\n12\nHydrogen ion\n1001– 2000\n5001–10000\n4\n24\nNitrate\n2001– 4000\n10001–20000\n4\n4\n6\n24\nNitrate\n4001– 7000\n20001–35000\n4\n5\n10\n36\nAmmonium\n7001–10000\n35001–50000\n4\n5\n10\n48\nIron\nAluminium\nManganese\nColour\nTABLE 3:\nSampling frequencies at consumers' taps\nParameters\nWater Supply Zone\nSampling Frequency (number per annum)\nVolume distributed (m3/d) for domestic purposes\nPopulation Supplied\nReduced\nStandard\nIncreased\nNotes\n(i) ie any fungicide, herbicide or insecticide; increased or reduced sampling, where required or permitted, may be confined to the substance in question.\n(ii) The sum of the detected concentrations of fluoranthene, benzo 3.4 fluoranthene, benzo 11.12 fluoranthene, benzo 3.4 pyrene, benzo 1.12 perylene and indeno (1,2,3-cd) pyrene.\nTrihalomethanes\n≤7000\n≤35000\n1\n4\n12\nTetrachloromethane\nTrichloroethene\nTetrachloroethene\nCopper\nLead\n7001–10000\n35001–50000\n1\n4\n24\nZinc\nPesticides(i)\nPolycyclic aromatic hydrocarbons(ii)\nTABLE 4:\nSampling frequencies at consumers' taps\nParameters\nSampling Frequency(number per annum)\nStandard\nIncreased\nChloride\nSulphate\nCalcium\nMagnesium\nSodium\nPotassium\nDry residues\nOxidizability (permanganate value)\nTotal organic carbon\nBoron\nSurfactants\nPhosphorus\n1\n12\nFluoride\nBarium\nSilver\nArsenic\nCadmium\nCyanide\nChromium\nMercury\nNickel\nAntimony\nSelenium\nTotal hardness\nAlkalinity\nTABLE 5:\nSampling frequencies at supply points\nWater Supply Zone or Combination of Zones\nSampling Frequency (number per annum)\nVolume distributed (m3/d) for domestic purposes\nPopulation Supplied\nTable 1 Parameters\nTable 2 Parameters\nTable 3 Parameters\nTable 4 Parameters\nReduced\nStandard\nIncreased\nReduced\nStandard\nIncreased\nReduced\nStandard\nIncreased\nReduced\nStandard\nIncreased\nGW\nSW\nGW\nSW\nGW\nSW\nGW\nSW\nGW = Ground water\nSW = Surface water\n≤100\n≤500\n4\n12\n4\n12\n1\n2\n4\n12\n1\n12\n101– 1000\n501– 5000\n4\n4\n6\n12\n4\n12\n1\n2\n4\n12\n1\n12\n1001– 2000\n5001– 10000\n4\n6\n12\n24\n4\n24\n1\n2\n4\n12\n1\n12\n2001– 4000\n10001– 20000\n6\n12\n24\n4\n4\n6\n24\n1\n2\n4\n12\n1\n12\n4001– 10000\n20001– 50000\n15\n30\n60\n4\n5\n10\n60\n1\n2\n4\n12\n1\n12\n10001– 20000\n50001– 100000\n30\n60\n120\n5\n10\n20\n60\n2\n3\n6\n24\n1\n1\n2\n24\n20001– 30000\n100001– 150000\n45\n90\n180\n8\n15\n30\n60\n2\n3\n6\n24\n1\n2\n3\n24\n30001– 60000\n150001– 300000\n90\n180\n360\n15\n30\n60\n120\n2\n3\n6\n24\n2\n3\n6\n24\n60001–100000\n300001– 500000\n90\n180\n360\n30\n60\n120\n3\n5\n10\n24\n3\n5\n10\n24\n100001–200000\n500001–1000000\n90\n180\n360\n30\n60\n120\n5\n10\n20\n36\n5\n10\n20\n36\nTABLE 6:\nSampling frequencies at consumers' taps\nParameters\nWater Supply Zone\nSampling Frequency (number per annum)\nVolume distributed (m3/d) for domestic purposes\nPopulation Supplied\nStandard\nTotal coliforms }\n≤100\n≤500\n12\nFaecal coliforms }\n101–1000\n501– 5000\n12\nResidual disinfectant }\n1001–2000\n5001–10000\n24\nColony counts }\n2001–4000\n10001–20000\n48\n20001–50000\nat the rate of 12 per 5000 population except in the case of colony counts where the standard number is 5.\nTABLE 7:\nSampling frequencies for treatment works\nParameters\nVolume of water supplied (m3/d) for domestic purposes\nSampling frequency (number per annum)\nReduced\nStandard\n1 Total and faecal coliforms,\n≤2000\n12\n52\nresidual disinfectant and colony counts\n2001–6000\n52\n104\n2 Total and faecal coliforms\n6001–12000\n104\n208\nand residual disinfectant\n>12000\n104\n365\n3 Colony counts\n>6000\n52\n104",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [
    {
      "type": "amended",
      "affecting": "uksi/1991/1837",
      "affecting_title": "The Water Supply (Water Quality) (Amendment) Regulations 1991"
    },
    {
      "type": "word substituted",
      "affecting": "uksi/2001/2885",
      "affecting_title": "The Water Supply (Water Quality) (Amendment) Regulations 2001"
    },
    {
      "type": "entry substituted",
      "affecting": "uksi/2001/2885",
      "affecting_title": "The Water Supply (Water Quality) (Amendment) Regulations 2001"
    },
    {
      "type": "inserted",
      "affecting": "wsi/2001/3911",
      "affecting_title": "The Water Supply (Water Quality) Regulations 2001"
    },
    {
      "type": "inserted",
      "affecting": "uksi/2000/3184",
      "affecting_title": "The Water Supply (Water Quality) Regulations 2000"
    }
  ],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/uksi/1989/1147/schedule/3",
    "retrieved_at": "2026-10-29T15:41:13.785707+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."
}