{
  "url": "https://openlegislation.uk/surface-waters-abstraction-for-drinking-water-classification-regulations-1996/schedule-1",
  "json_url": "https://openlegislation.uk/surface-waters-abstraction-for-drinking-water-classification-regulations-1996/schedule-1.json",
  "legislation": "uksi/1996/3001",
  "legislation_title": "The Surface Waters (Abstraction for Drinking Water) (Classification) Regulations 1996",
  "legislation_url": "https://openlegislation.uk/surface-waters-abstraction-for-drinking-water-classification-regulations-1996",
  "path": "schedule/1",
  "kind": "schedule",
  "number": "1",
  "heading": "CRITERIA FOR CLASSIFICATION OF WATERS",
  "text": "The limits set out below are maxima\nNo. in Annex II to 75/440/EEC\nParameters\nUnits\nLimits\nDW1\nDW2\nDW3\n(O) See regulation 4(1)(b).\n* See regulation 4(1)(d).\n2\nColoration (after simple filtration)\nmg/1 Pt Scale\n20\n100\n200\n4\nTemperature\n°C\n25\n25\n25\n7\nNitrates\nmg/l NO3\n50\n50\n50\n8\nFluorides\nmg/l F\n1.5\n10\nDissolved iron\nmg/l Fe\n0.3\n2\n12\nCopper\nmg/l Cu\n0.05\n13\nZinc\nmg/l Zn\n3\n5\n5\n19\nArsenic\nmg/l As\n0.05\n0.05\n0.1\n20\nCadmium\nmg/l Cd\n0.005\n0.005\n0.005\n21\nTotal chromium\nmg/l Cr\n0.05\n0.05\n0.05\n22\nLead\nmg/l Pb\n0.05\n0.05\n0.05\n23\nSelenium\nmg/l Se\n0.01\n0.01\n0.01\n24\nMercury\nmg/l Hg\n0.001\n0.001\n0.001\n25\nBarium\nmg/l Ba\n0.1\n1\n1\n26\nCyanide\nmg/l CN\n0.05\n0.05\n0.05\n27\nSulphates\nmg/l SO4\n250\n250\n250\n31\nPhenols (phenol index) paranitraniline 4-aminoantipyrine\nmg/l C6H5OH\n0.001\n0.005\n0.1\n32\nDissolved or emulsified hydrocarbons\nmg/l\n0.05\n0.2\n1\n33\nPolycyclic aromatic hydrocarbons\nmg/l\n0.0002\n0.0002\n0.001\n34\nTotal pesticides (parathion, hexachlorocyclohexane, dieldrin)\nmg/l\n0.001\n0.0025\n0.005\n39\nAmmonium\nmg/l NH4\n1.5\n4",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "footnote",
      "label": "f1",
      "text": "(O) See regulation 4(1)(b)."
    },
    {
      "type": "footnote",
      "label": "f2",
      "text": "* See regulation 4(1)(d)."
    }
  ],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/uksi/1996/3001/schedule/1",
    "retrieved_at": "2026-10-29T12:31:11.165973+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."
}