{
  "url": "https://openlegislation.uk/preesall-underground-gas-storage-facility-order-2015/schedule-9/paragraph-6",
  "json_url": "https://openlegislation.uk/preesall-underground-gas-storage-facility-order-2015/schedule-9/paragraph-6.json",
  "legislation": "uksi/2015/1561",
  "legislation_title": "The Preesall Underground Gas Storage Facility Order 2015",
  "legislation_url": "https://openlegislation.uk/preesall-underground-gas-storage-facility-order-2015",
  "path": "schedule/9/paragraph/6",
  "kind": "paragraph",
  "number": "6",
  "heading": "Details of operational cavern layout and design",
  "text": "(1) No more than 19 operational caverns, with—\n(a) a total storage capacity of up to 900 million standard cubic metres; and\n(b) a working capacity of up to 600 million standard cubic metres but not less than 130 million standard cubic metres,\nin each case specified at the standard temperature and pressure, shall be constructed within the “area for cavern development” shown on the approved development plan with reference A-1000-030 Rev B.\n(2) Unless the safety reports (to be submitted pursuant to regulations 7(1), 7(5) and 8 of the 1999 Regulations), following communication of the competent authority’s conclusions of its examination of those reports pursuant to regulation 17 of the 1999 Regulations (and directions if any), allow otherwise—\n(a) in this paragraph, where an operational cavern is not of a constant radius, reference to the radius of that operational cavern shall mean the largest radius for that operational cavern; and the maximum radius of any operational cavern shall not exceed approximately 50 metres;\n(b) the thickness of the remaining salt between the operational cavern roof and the upper surface of the Preesall halite deposit shall be not less than the radius of each operational cavern;\n(c) a minimum thickness of 20% of the radius of the operational cavern shall be maintained between the deepest point of the operational cavern and the basal surface of the Preesall halite deposit;\n(d) wall to wall separation of proposed operational caverns, operational caverns, proposed decommissioned caverns or decommissioned caverns of equal diameter shall be no less than three times the radius of the proposed operational caverns, operational caverns, proposed decommissioned caverns or decommissioned caverns; wall to wall separation of proposed operational caverns, operational caverns, proposed decommissioned caverns or decommissioned caverns of unequal diameter shall be no less than the sum of one and a half times the radius of the smaller proposed operational cavern, operational cavern, proposed decommissioned cavern or decommissioned cavern plus one and a half times the radius of the larger proposed operational cavern, operational cavern, proposed decommissioned cavern or decommissioned cavern;\n(e) the minimum distance between any operational cavern and the Burn Naze fault or any intra-grabinal fault shall be no less than three times the radius of that operational cavern;\n(f) the minimum distance between any operational cavern and any existing brine cavern or existing mineworking shall be no less than four times the radius of that operational cavern (save that where the size of an existing brine cavern is not known the minimum separation distance between an operational cavern and the well head of that existing brine cavern shall be five times the radius of that operational cavern);\n(g) the minimum distance between any operational cavern and any exploratory borehole drilled into the Preesall halite deposit shall be no less than twice the radius of that operational cavern;\n(h) the minimum distance between any operational cavern and wet rockhead areas shall be four times the radius of that operational cavern.\n(3) Within 7 days of the submission of the safety reports (to be submitted to the competent authority pursuant to regulations 7(1), 7(5) and 8 of the 1999 Regulations), copies shall be made available and submitted to Lancashire County Council.",
  "extent": "E+W",
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "I",
      "label": "I1",
      "text": "Sch. 9 para. 6 in force at 7.8.2015, see art. 1"
    }
  ],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/uksi/2015/1561/schedule/9/paragraph/6",
    "retrieved_at": "2026-10-28T23:33:26.805703+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."
}