Date: 5th June 2013
Our ref: MW.0050/13
Ms Lucy Binnie
Land and Mineral Management
Environment & Economy
Speedwell House
Speedwell Street
Oxford OX1 1NE
Huw Jones
Director for Environment &
Economy
Sent by email
Dear Ms Binnie,
Extension to Gill Mill Quarry
Further information required to support planning application and under Regulation 22
of the Town and Country Planning (Environmental Impact Assessment) Regulations
2011
The consultation period on the above planning application has now ended and we have
received comments from a range of consultees. Therefore, I am now able to advise on the
further information we require to support the planning application and in respect to the
Environmental Statement.
Further Information Required:
• Elevations, floor plans and layout for the proposed eco-lodges
• Statement detailing foul water disposal from the eco- lodges and welfare office
• Plan showing the layout of existing plant and buildings which this application seeks to retain,
including maximum heights and photographs (as I understand that you are not able to provide
elevations)
• Trees – A British Standard 5837: 2012 Trees in relation to design, demolition and
construction survey
• Hydrology – further information as requested by the Environment Agency and detailed in
Annex 1 to this letter.
• Archaeology – a geophysical survey of those parts of the application area where geophysical
survey has not yet been undertaken.
• Biodiversity – Further information on the proposed mitigation of operational impacts
clarifications as requested in the Biodiversity Response and detailed in Annex 2 to this letter.
Regarding dust management, the West Oxfordshire District Council (WODC) response states
that the submitted Dust Management Plan appears to be weak and would benefit from some
further detail. Therefore, please provide an updated detailed plan.
WODC have also asked for an assessment of alternative sites located closer to main areas of
future growth in South Oxfordshire. It is a requirement that the Environmental Statement
considers alternatives and Chapter 5 in the submitted document considers this. However, the
submitted information does not appear to consider any specific alternative sites. Therefore,
please submit a revised Chapter 5 with further detail on alternative sites.
I understand that in some cases you are in discussion with the relevant consultee to establish
whether the information requested is essential prior to determination. In the case of any
information listed above specifically requested by a specialist consultee, if the consultee
confirms to us that the information is no longer required at this stage in the application
process, then we are likely to be able to agree that it does not need to form part of this
additional information request.
Copies of all the consultation responses are available to view on our website and we have
discussed the comments made at our meeting on 3rd June. Some of the consultees raised
points for clarification and suggestions for incorporation into the scheme. It would be helpful to
also have your response to these.
The application documents refer to the use of various buildings including old farm buildings
and site offices as part of the afteruse of the site and state that these would provide facilities
such as a visitors centre, office/workshop accommodation and a possible low-key renewable
energy facility. However, the description of development refers only to the retention of the
existing office complex. Therefore, I assume that the detailed afteruse of the farm and office
buildings, and any renewable energy facility, are intended to be considered in the future as the
proposals become more defined, and any necessary planning permissions required for these
uses will be sought at that time. Therefore, unless you advise otherwise and amend the
application accordingly with additional details, including detailed drawings as appropriate, I am
not seeking further information on these uses prior to the determination of the main
application.
As discussed, it would be helpful to have all the required information submitted at one time.
This would allow for all the new information to be consulted on simultaneously. We would need
this information to be submitted in electronic format with each file size less than 10 MB so that
it can be uploaded to our website for consultation. We also require one hard copy of the
complete submission.
Yours sincerely
M Thompson
Mary Thompson
Senior Planning Officer
Direct line: 01865 815901
Email: mary.thompson@oxfordshire.gov.uk
www.oxfordshire.gov.uk
Annex 1
Further clarification/information required by the Environment Agency:
a) Proposed phases of working:
The proposed phases of working and dewatering as displayed in the Gnat chart in Appendix B of the
Planning Supporting Statement conflicts with the quarry exploitation Plan in Figure K2 of Chapter 11 of
the Environmental Statement. The groundwater modelling should ideally reflect the phase of working
proposed by the Planning Statement. Where this is not the case, some evidence of the existing
modelling work’s appropriateness for the current proposed phase of working needs to be provided.
b) Recharge modelling and site restoration:
The recharge signal for the prediction period is generated by cycling the 1995 to 2010 recharge signal
from the end of the historical model period. This uses SNIFER methodology for determine rainfall for
Arable, Grass and Open Water. It is unclear how much the change in land use during restoration to reed
beds and open lakes changes effective rainfall across the site and its implications for the assessment. In
Section 8.2 it is stated that the addition of 30 ha of open water will result in an average loss of water
resources of 100 m3/day. How has this value been derived – is it based upon the final restoration
groundwater model?
c) Impact on the Windrush
Figure 16a only present leakage impacts on the River Windrush between 2015 and 2035 during the
operational phase of the development. Leakage impacts between 2035 and 2050 should be presented to
show any impacts of the proposed restoration on leakage within the Windrush. Proposed lakes adjacent
to the Windrush could induce leakage rates above baseline conditions if set at a lower water levels than
the level of the Windrush. It also needed to be clarified if these plots represent total leakage across the
various arms of the Windrush within the groundwater model or leakage observed at a specific river
monitoring point within the model.
Figure 16b also needed further clarification - flows at Newbridge Gauging station are presented between
Jan 2016 and Jan 2032 though these haven’t been collected yet – obviously some inferring has been
done but this needs to be clarified.
d) Use of clay liners on site and mitigation
Currently the planning statement tells us that only to the north of Phase 10 and to the south of Phase
2A/Phase 2B (some conflict within the planning statement as to where this is) will have clay liners to
protect Ducklington Mead. The hydrogeological assessment does a model run of barriers ‘constructed at
the edge of the working area facing either the East Windrush of Ducklington Mead’ – which from Figure
K3 seems to be in the vicinity of Phase 2B and Phase 1A. As a result there is some uncertainty as to
where clay liners are going to be used.
The assessment states in Section 8.2 that ‘Where clay barriers have been constructed as a mitigation
measure to minimise the lowering of groundwater levels these will be removed if they have an adverse
effect on groundwater (e.g. rise in groundwater levels upstream of the barrier of a fall downstream of the
barrier)’. Currently there is little information on how this will be looked at.
e) Hydraulic conductivity of areas of infill
There is some concern about the high hydraulic conductivity values selected for areas of infilling for
restoration. The planning statement indicates that onsite clays are going to be used for backfilling of
Phase 2B, Phase 4, Phase 6 and clay margins will be put in place for the lake in Phase 14. Currently in
section 7.4 there is some confusion as to the value that has been selected for inert infill areas. One
section states that a hydraulic conductivity of 0.1 m/d to 1m/d has been selected (Section 7.5), yet
following paragraphs state that a permeability of 70-100 m/day has been selected, which isn’t a change
from the baseline parameters for some parts of the model.
Clays are low permeability as rightly presented in the selected hydraulic conductivity of 0.0035 m/d (4 x
10-8 m/s) for the clay liners and are unlikely to be represented by either of these hydraulic conductivities.
In addition it is unclear from the distribution of hydraulic conductivity that there is any difference between
the base line model (Figure K1) and the Site Operation Model (Figure K3). There should be a final plot
that shows the restoration of the site once all operations are complete.
It is mentioned section 7.5 that there has been permeability testing of monitoring boreholes installed in
Area 1 (an area of inert fill) and that this data has been used to model hydraulic conductivity of inert fills
to be used on site. This information is not presented within the assessment and is important at
understanding if it is an appropriate conductivity to use for clay rich infill materials proposed to be used
across the site.
f) Impact on Ducklington Mead groundwater levels due to down gradient lakes
Groundwater modelling is stated to show that ‘water level below the Mead may be affected by the
overflow level set in lakes down gradient of the Mead – therefore it will be important to ensure these
overflows are set at an appropriate level which will be determined as part of on-going monitoring and
modelling’. Currently there is little information on how this will be looked at.
Other Notes:
It is reported that the results of the groundwater modelling indicates that maximum groundwater levels
are unlikely to rise above levels recorded over the last 10 years. Comparing Figure L17 – Modelled
groundwater levels (historic) August 2011 with those of Figure L20 – Modelled groundwater levels
(predicted) restoration phase November 2048 (low groundwater levels) [there isn’t one for high
groundwater levels], there is a large degree of groundwater level rise, typically between 1m to 1.5m in
the northern sections of the site, presumably where clay liners have been left in place. This indicates that
maximum groundwater levels could rise above levels recorded over the last 10 years.
The local lead flood authority may consider this a groundwater flood risk and could need this to be
explored further.
Annex 2
Further information requested and questions from the Biodiversity Officer.
1. Existing site conditions & mitigation during operation
Mitigation during extraction period
Further information is needed at this stage about the proposed mitigation of operational impacts.
This should include an overarching management plan for the operational phase for both habitats
and species.
Additional Information Prior to Each Phase of Working
The preliminary ecological assessment by Ecoconsult found the following protected species to be
present within the application area: breeding barn owl, badger, grass snake and water vole. The site
is also used by ground-nesting and over-wintering birds, brown hare and at least six species of
foraging bats. Only one tree with high potential to support roosting bats was found within the
extension area. Whilst the proposals will lead to the displacement of some of these species, it is
unlikely that it would have a detrimental impact on individuals or the local population, given
appropriate mitigation measures and the availability of other suitable habitats nearby.
Watervole may be affected by the proposal due to the installation of new crossing points over the
river. Properly managed, this would not have an adverse impact on the species and the amount of
habitat lost would be negligible. However, consideration should be given to incorporating otter
crossings under these bridges to allow them safe access along the river corridor.
No assessment within the current Environmental Statement has been made of the likely impact of
the construction phase on protected species during and how this can be mitigated. Due to the length
of time over which the site would be worked, updated protected species surveys and Construction
Environmental Management Plans (CEMPs) should be submitted prior to the start of each new
phase.
Ducklington Mead SSSI
The quality of the SSSI is dependent on the hydrology of the site. Meadows such as this of the
National Vegetation Classification MG4 type are very sensitive to changes in hydrology. If you are
minded to grant consent, then a Water Management Plan must be submitted and agreed by the
Minerals Planning Authority. This should include information on:
ggers would be set to stop works if groundwater levels or surveys show that works may be
impacting on the SSSI
Watervole Data
I am aware that BBOWT’s Watervole Project may have more recent data – please ask the applicant
to include this data and its interpretation within the ES Biodiversity chapter.
River/Brook
Please ask the applicant to clarify the width of the standoff to the river and the brook.
Further information on potential impacts on the river and proposed mitigation measures should be
provided.
Seed Mix
I suggest that the lowland meadow (and other planting/seeding) mixes should be specified by the
National Vegetation Classification that is intended e.g. lowland meadow MG4/MG5. This would help
to clarify the restoration proposals. The details of the seed and planting mixes and methods of
establishment could be dealt with by condition.
The applicant may be able to find sources of species-rich green hay that could be used to assist in
habitat creation and I suggest that the applicant explores this.
Linking the ecology of the site to the surrounding area
The ecology of the site should link to, and improve, the SSSI and Witney Lakes. Whilst the proposed
restoration proposals probably do this, the applicant needs to demonstrate this more clearly in the
ES.
Arable Weeds
I suggest that the applicant explores whether it is possible to transplant or collect and sow the seeds
of the Petroselinum segetum, either on their own sites or elsewhere on suitable habitat within the
Witney area.
2. Phasing of works
Path Closures
I assume that permissive paths within the site could be temporarily closed if this is necessary for
nature conservation purposes e.g. if needed during bird nesting season. Please ask the applicant to
confirm this.
Managing Visitor Access
It would be helpful to have further information on how visitor access to the site would be managed
during the phased extraction period.
Dogs
Please ask the applicant to provide further information on this management issue, particularly in
relation to the reedbeds and bittern and also breeding birds.
3. Restoration Proposals
Restoration Plans
The proposed Restoration Masterplan (GML/009) would deliver substantial gains for biodiversity.
This includes a very large area of reedbed, suitable for the Bittern and many other species.
Therefore, I support the restoration proposals.
The applicant proposes that detailed restoration plans would need to be submitted prior to each
phase of working. I consider that, along with detailed restoration plans, a Restoration Scheme would
be required for each phase of development which would need to be submitted and agreed by the
Minerals Planning Authority prior to the commencement of restoration works on each phase. These
Restoration Schemes would need to take into account up to date groundwater monitoring and
survey data to avoid any potential impact on Ducklington Mead SSSI from restoration.
Commencement of Aftercare
Please can you clarify whether the 5 year aftercare (followed by 20 year management) period would
commence at the end of each phase or when extraction of the whole site has been completed?
Bird Hides
There do not appear to be any bird hides shown on the restoration plan. Please can you ask the
applicant to confirm that they intend to construct bird hides and the locations?
4. S106 and funding
A Section 106 Agreement would be required to secure the long-term management of the site (5 year
aftercare + 20 year management period) and contributions towards the Lower Windrush Valley
Project to help to mitigate from the operational impacts on the community, landscape, biodiversity
and amenity.
5. Other issues relating to the functioning of the site
Cogges Lane
- Would the education unit and offices at the former “Beef Unit” be using Cogges Lane as access?
- If so, what improvements could be made to make it safer to use?
Renewable Energy Facility
Would there be sufficient reed/wood from the site to supply the renewable energy facility? If not,
would materials be brought in via Cogges Lane?