14. MINERALS SAFEGUARDING STATEMENT NORTH SPROWSTON AND OLD CATTON OUTLINE PLANNING APPLICATION OCTOBER 2012
1. INTRODUCTION The development site for North Sprowston and Old Catton (NS&OC) incorporates land within a designated Minerals Safeguarding Area (MSA). This statement has been prepared by Stephen Daw MRICS, minerals surveying consultant, on behalf of Beyond Green.
1.1 Planning Policy Context In order to avoid the sterilisation of mineral resources by development it is the duty of Mineral Planning Authorities to safeguard mineral and mineral resources. This duty is incorporated in the National Planning Policy Framework dated March 2012 where, in preparing local plans, local planning authorities should, amongst other matters: • “define Minerals Safeguarding Areas and adopt appropriate policies in order that known locations of specific mineral resources of local and national importance are not needlessly sterilised by non-mineral development, whilst not creating a presumption that resources defined will be worked, and define Mineral Consultation Areas based on these Mineral Safeguarding Areas; [and] • set out policies to encourage the prior extraction of minerals, where practicable and
environmentally feasible, if it is necessary for non-mineral development to take place” These requirements are incorporated into a policy document entitled ‘Core Strategy and Mineral and Waste Development Management Policies Development Plan Document 2010-2026’ adopted by Norfolk County Council in September 2011. Of specific relevance to the issue of minerals safeguarding is Core Strategy Policy SC16 – Safeguarding mineral and waste sites and mineral resources. The Policy sets out a requirement on non-mineral developers to consult with the appropriate Mineral Planning Authority on all non-mineral development proposals within Mineral Consultation Areas.
1.2 Pre-Application Consultation In order to establish the presence or otherwise of Mineral Consultations Areas or Mineral Safeguarding Areas within the area of the proposed development, discussions commenced in the Autumn of 2011 with officers of Norfolk County Council in its role as Mineral Planning Authority. These initial discussions established two main facts concerning the development proposals: • firstly, that there are a number of Mineral Safeguarding Areas which in the view of the Mineral Planning Authority are Sand and Gravel Resource Areas and which would be affected by the development; and • secondly, that the Mineral Planning Authority would object to an outline planning application for development unless investigations had been carried out to establish whether a resource was viable for mineral extraction and this being the case, whether it could be extracted economically prior to development taking place. Having established these facts, it then became necessary to define precisely the extent of the Mineral Safeguarding Areas which would be affected by the development proposals and then to devise a programme of investigation acceptable to the Mineral Planning Authority. In this regard the Mineral Planning Authority was helpful in providing guidance as to the precise extent of the Mineral Safeguarding Areas and close liaison with the applicants’ advisor enabled the devising of a Borehole Investigation and Sampling Programme agreeable to both parties.
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2. Mineral Investigations The Borehole Investigation and Sampling Programme involved the drilling of 21 boreholes spread evenly across those parts of the Mineral Safeguarding Areas which would be affected by the development. The extent of the Mineral Safeguarding Areas and the position of the boreholes are illustrated on a plan agreed with the Mineral Planning Authority prior to the investigations commencing (see Borehole Location Plan at Appendix A). It should be noted this Plan also includes information on the position of recorded utilities and the establishment of Service Exclusion Zones in order to ensure such utilities were avoided by the drilling programme. A programme of borehole drilling took place over several days in March 2012. The drilling was overseen by the Applicants Agent and was visited by an Officer of the Mineral Planning Authority. Instructions were given to the Driller to bore all holes to a depth of at least 10 metres, unless there was no evidence of any significant Sand and Gravel within the first 6 metres of drilling, in which case the hole could be terminated at 6 metres deep. The Driller was also requested to record all findings and produce drilling logs of each borehole. In addition, any evidence of viable Sand and Gravel was to be sampled and the position of the samples recorded on the logs for possible later analysis. The results of the borehole investigations were received in the form of Borehole Logs together with Particle Side Distribution Graphs of the samples taken which have been analysed. The Borehole Logs show that 21 boreholes were drilled of which 4 were drilled to a depth of 6 metres with all the remainder to a depth of 10 metres (see Borehole Logs at Appendix B). The Logs record the various strata encountered in the drilling and should be cross referenced with the Borehole Location Plan.
2.1 Results In overall terms the boreholes failed to establish the presence of a mineral resource viable for mineral extraction. Many of the boreholes encountered considerable thicknesses of Clay within the upper reaches of the strata, i.e. boreholes 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 17, 18 and 20. The presence of such extensive, and in many cases such thick bands of Clay, would in most circumstances make any underlying mineral unviable for extraction. However, where Sand and Gravel (and in particular Sand) was present it was of a poor quality, being normally associated with Silt and/or being of a fine or very fine nature and so of little commercial value, i.e. boreholes 1, 2, 3, 15, 16 and 19. Thus even in those boreholes where Clay was either absent or less significant, the Sand and Gravel encountered was of such poor quality or was present in such limited quantities so as not to constitute a mineral resource viable for extraction. Whilst therefore the investigations established the absence of a resource viable for extraction, some borehole did contain limited quantities of Sand and Gravel which may be of some use in the development. A close examination of the boreholes shows a thin seam of Sand and Gravel being present just below the soil covering layer in a number of the holes, i.e. 1, 2, 3, 6, 10, 11, 13 and 15. Typically this seam is between 1.0m and 1.25m in thickness and immediately beneath 0.2m of soil. The seam is not continuous but is concentrated in three blocks all lying immediately to the north west of the A1151. A version of the Borehole Location Plan has been prepared to show the indicative extent of each of these blocks (see Sand & Gravel Occurrence Plan at Appendix C). Table 1 provides details of each of these blocks and the potential quantity of Sand and Gravel within each. Block
Area (ha)
Sand and Gravel (m)
Volume (m続)
Tonnage
A
4.15
1.23
51,045
86,777
B
2.29
1.15
26,335
44,770
C
2.75
1.05
28,875
49,088
2
180,635
Total Table 1: Quantities of Sand and Gravel
In order to provide information as to the quality of the Sand and Gravel present within these blocks a number of the samples taken at the time of the drilling have been subject to a Particle Size Distribution Analysis (see Sample Analysis Results at Appendix D). The results of the sample analysis are summarised in Table 2. Sample
Gravel (%)
Sand (%)
Silt (%)
01/1 0.3 – 1.2m
14
78
8
03/1 0.6 – 1.5m
51
45
4
06/1 1.0 – 1.5m
52
45
3
10/1 0.3 – 1.2m
53
29
18
11/1 0.5 – 1.5m
37
45
18
13/1 1.0 – 1.5m
38
51
11
Average
40.8
48.8
10.3
Table 2: Sample Analysis Results
Whilst a resource viable for mineral extraction is not present, there is some limited occurrence of Sand and Gravel. This mineral occurs in a thin seam across a number of blocks and is present close to the surface. It is also of a quality which is likely to be suitable for use in the development of the site. However, before being able to accurately assess the quantity and precise quality of this mineral, it will be necessary to carry out further testing and sampling concentrated within the three identified blocks.
2.2 Summary and Conclusions In order to accord with National and Local Mineral Planning Policy it has been necessary to demonstrate the development will not sterilise a resource viable for mineral extraction. An investigation programme devised by the Applicant, but with the assistance of the Mineral Planning Authority, was undertaken throughout Mineral Safeguarding Areas which would be affected by the development. The results of the programme have demonstrated the overall absence of a resource viable for mineral extraction. However, there is some limited occurrence of Sand and Gravel within three blocks to the northwest of the A1151 Wroxham Road which is likely to be suitable for use in the development. The precise quantity and quality of this occurrence will need to be the subject of more detailed investigation and sampling before its use in the development can be fully established.
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APPENDIX A: BOREHOLE LOCATION PLAN FEBRUARY 2012
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APPENDIX B: BOREHOLE LOGS
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
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APPENDIX C: SAND AND GRAVEL OCCURRENCE PLAN
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APPENDIX D: SAMPLE ANALYSIS RESULTS
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29
30
31
32
33
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