{
  "url": "https://openlegislation.uk/water-supply-water-quality-regulations-2018/schedule-1",
  "json_url": "https://openlegislation.uk/water-supply-water-quality-regulations-2018/schedule-1.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/1",
  "kind": "schedule",
  "number": "1",
  "heading": "PRESCRIBED CONCENTRATIONS AND VALUES",
  "text": "Table A Microbiological Parameters\n1 Compliance required as to 95% of samples from each service reservoir (regulation 4(6)).\nPart 1: Directive requirements\nItem\nParameters\nConcentration or Value (maximum)\nUnits of Measurement\nPoint of compliance\n1\nEnterococci\n0\nnumber/100 ml\nConsumers' taps\n2\nE.coli\n0\nnumber/100 ml\nConsumers' taps\nPart 2: National requirements\n1\nColiform bacteria\n0\nnumber/100 ml\nService reservoirs 1 and water treatment works\n2\nE. coli\n0\nnumber/100 ml\nService reservoirs and water treatment works\nNote:\nTable B Chemical Parameters\nPart 1: National requirements\n1 The parametric value refers to the residual monomer concentration in the water as calculated according to specifications of the maximum release from the corresponding polymer in contact with the water. This is controlled by product specification.\n2 See also regulation 4(2)(d).\n3 See the definition of “pesticides and related products” in regulation 2.\n4 The parametric value applies to each individual pesticide.\n5 “Pesticides: Total” means the sum of the concentrations of the individual pesticides detected and quantified in the monitoring procedure.\n6 The specified compounds are:\nbenzo(b)fluoranthene\nbenzo(k)fluoranthene\nbenzo(ghi)perylene\nindeno(1,2,3-cd)pyrene.\nThe parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.\n7 The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.\n8 The specified compounds are:\nchloroform\nbromoform\ndibromochloromethane\nbromodichloromethane.\nThe parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.\nItem\nParameters\nConcentration or Value (maximum)\nUnits of Measurement\nPoint of compliance\n1\nAcrylamide\n0.10\nμg/l\n1\n2\nAntimony\n5.0\nμgSb/l\nConsumers' taps\n3\nArsenic\n10\nμgAs/l\nConsumers' taps\n4\nBenzene\n1.0\nμg/l\nConsumers' taps\n5\nBenzo(a)pyrene\n0.010\nμg/l\nConsumers' taps\n6\nBoron\n1.0\nmgB/l\nConsumers' taps\n7\nBromate\n10\nμBrO3/l\nConsumers' taps\n8\nCadmium\n5.0\nμgCd/l\nConsumers' taps\n9\nChromium\n50\nμgCr/l\nConsumers' taps\n10\nCopper\n2.0\nmgCu/l\nConsumers' taps\n11\nCyanide\n50\nμgCN/l\nConsumers' taps\n12\n1, 2 dichloroethane\n3.0\nμg/l\nConsumers' taps\n13\nEpichlorohydrin\n0.10\nμg/l\n1\n14\nFluoride\n1.5\nmgF/l\nConsumers' taps\n15\nLead\n10\nμgPb/l\nConsumers' taps\n16\nMercury\n1.0\nμgPb/l\nConsumers' taps\n17\nNickel\n20\nμgNi/l\nConsumers' taps\n18\nNitrate 2\n50\nmgNO3/l\nConsumers' taps\n19\nNitrite 2\n0.50\nmgNO2/l\nConsumers' taps\n0.10\nTreatment Works\n20\nPesticides 3,4\nAldrin\n0.030\nμg/l\nConsumers' taps\nDieldrin\nHeptachlor\nHeptachlor\nepoxide\nother pesticides\n0.10\nμg/l\nConsumers' taps\n21\nPesticides: Total 5\n0.50\nμg/l\nConsumers' taps\n22\nPolycyclic aromatic hydrocarbons 6\n0.10\nμg/l\nConsumers' taps\n23\nSelenium\n10\nμgSe/l\nConsumers' taps\n24\nTetrachloroethene and Trichloroethene 7\n10\nμg/l\nConsumers' taps\n25\nTrihalomethanes: Total 8\n100\nμg/l\nConsumers' taps\n26\nVinyl chloride\n0.50\nμg/l\n1\nNotes:\nPart 2: National requirements\nItem\nParameters\nConcentration or Value (maximum unless otherwise stated)\nUnits of Measurement\nPoint of compliance\n1\nAluminium\n200\nμgAl/l\nConsumers' taps\n2\nColour\n20\nmg/l Pt/Co\nConsumers' taps\n3\nIron\n200\nμgFe/l\nConsumers' taps\n4\nManganese\n50\nμgMn/l\nConsumers' taps\n5\nOdour\nAcceptable to consumers and no abnormal change\nConsumers' taps\n6\nSodium\n200\nmgNa/l\nConsumers' taps\n7\nTaste\nAcceptable to consumers and no abnormal change\n…\nConsumers' taps\n8\nTetrachlorome-thane\n3\nμg/l\nConsumers' taps\n9\nTurbidity\n4\nNTU\nConsumers' taps",
  "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/1",
    "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."
}