DCAN 12: Planning Control for Hazardous Substances
Standard conditions applying to deemed consents: area where a substance may be present
51. The information required in Part 4 Table B of the deemed consent claim form (Form 5) will establish the manner in which a substance was present during the establishment period. The standard conditions at paragraphs 2 to 6 of Schedule 2 to the Regulations, which regulate how a substance may be present in a vessel within a vessel area under the terms of a deemed consent, relate directly to the information given by the claimant in Table B. These conditions ensure that a substance can only be kept or used in a particular manner within a vessel area if it has been similarly kept or used within that same vessel area during the establishment period (as indicated by the information given in Table B).
52. For every substance covered by the claim, separate information must be given by the claimant in respect of how the substance was present in each vessel area. The explanatory notes to Table B explain how the various columns are to be completed. The Table does not need to be completed for substances in moveable containers as these are not subject to the standard conditions at paragraphs 2 to 6 of Schedule 2. Furthermore, for the purposes of completing Table B and of the abovementioned conditions, no account is to be taken of the presence in a vessel of a quantity of a substance not exceeding 10 % of the controlled quantity.
53. The conditions in paragraphs 2 to 6 of Schedule 2 will operate in the following way. Either it will be wished to keep or use a substance -
- at below ambient temperature; or,
- at ambient temperature; or,
- at above ambient temperature.
54. Whichever of these is appropriate will determine which set of conditions applies. If, for example, it is intended to store a substance in a vessel at below ambient temperature, it will be necessary to satisfy three requirements -
- the substance must have been present at below ambient temperature in a vessel in the same vessel area during the establishment period;
- the vessel in which it is to be stored must not have a greater capacity than the largest capacity vessel in the same vessel area in which the substance was present at below ambient temperature during the establishment period; and,
- the pressure at which it is to be stored must not exceed either -
a) atmospheric pressure, if the substance was not present at above atmospheric pressure at below ambient temperature in a vessel in the same vessel area during the establishment period; or,
b) in any other case, the highest vessel design pressure of any vessel in which the substance was present in that vessel area at above atmospheric pressure at below ambient temperature during the establishment period.
If it is intended to store a substance at ambient temperature, it will be necessary for the conditions at either paragraphs 3 or 4 of Schedule 2 to the Regulations to be fulfilled, depending upon whether or not the substance is to be present in buried or mounded vessels. This additional distinction may be particularly significant in hazard terms where a substance is stored at ambient temperature. If it is intended to store a substance at above ambient temperature, the conditions at paragraphs 5 or 6 of Schedule 2 will need to be fulfilled, depending upon whether or not the substance is to be present at or below, or above, its boiling point at 1 bar absolute. For the purposes of establishing whether a substance is to be treated as being at ambient temperature, attention is drawn to regulation 16(4). This clarifies that a substance shall not be regarded as being present at other than ambient temperature by virtue only of, for example, heating to maintain its fluidity during seasonal variations in temperature.
55. For moveable containers, no conditions regulating temperature or pressure are considered necessary. However, the quantity of a substance stored in such containers within a moveable container storage area must not exceed the maximum amount of that substance previously stored in moveable containers within that area during the establishment period. Furthermore, the capacity of any individual moveable container in which the substance is present within that area must not exceed 10 % of the controlled quantity, if it was not stored in that area in a moveable container area, or if it were to be kept in a different area of the site where it has not previously been present.