HEATHROW THIRD RUNWAY CONSULTATION:
MINERALS ISSUES
1
Content of the consultation document
1.1
The presence of minerals in the proposed airport extension area is
referred to in four places in the consultation document:
1.2

In Annex B (Impact Assessment) in paragraph 2.33 on page 142,
in the discussion of Option 1, the section headed ‘Landscape’
notes that “the land within the extended boundary includes 80ha of
sand and gravel deposits”.

In the same Annex, on pages 153 and 160, the same point is
made (by means of a cross-reference) in the equivalent sections
on Option 2 (paragraph 2.71) and Option 3 (paragraph 2.92).

Still in Annex B, in the section ‘Sustainable development
assessment’ in the sub-section ‘Community Effects Landscape/Townscape/Housing’, paragraph 5.21 states that
“Using the indicative plans from BAA we have estimated that the
landscape/townscape impacts of the additional runway at
Heathrow may lead to the following adverse impacts … the land
within the extended boundary comprises 80ha sand and gravel
deposits [sic]”.
Although the above extracts are included in sections that purport to be
“assessments”, no assessment is actually made in the consultation
document of the significance (if any) of the presence of a claimed 80ha
of sand and gravel deposits within the Heathrow Extension Area. Such
an assessment is therefore made in the following paragraphs.
2
Area of sand and gravel deposits within the area of the proposed
third runway
2.1
We calculate that the area of sand and gravel deposits within the area
of the proposed third runway is about 108.5ha rather than the claimed
80ha. Using the site reference numbers and estimated yields from the
Council’s Minerals Background Report [MBR], this total area is made
up as follows:
Site ref
H9
Total site
Area
Total
Est yield
area
within
estimated
in
(hectares)
Heathrow
yield
Heathrow
30
Extension
Extension
Area (ha)
Area
30
1.8 mt
1.8 mt
Notes
16ha of site (est yield
0.75mt) is identified as a
proposed Preferred Area in
emerging LDF
H10
6.7
6.7
0.3 mt
0.3 mt
H12
40
40
2.4 mt
2.4 mt
Not proposed as a Preferred
Area
37ha of site (est yield 2.2mt)
is identified as a proposed
Preferred Area in emerging
LDF
H13
5.8
5.8
0.3 mt
0.3 mt
H14
30
26
1.8 mt
1.7 mt
Not proposed as a Preferred
Area
29ha of site (est yield 1.8mt)
- of which 26ha (1.7mt) is
within the Heathrow
Extension Area - is identified
as a proposed Preferred
Area in emerging LDF
TOTAL
112.5
108.5
6.6 mt
6.5mt
A total of 79ha within the
proposed airport extension
Area (est yield 4.65mt) is
identified as proposed PAs in
the emerging LDF.
2.2
The exact areas in this table would need to be verified, but it seems
clear that the consultation paper’s figure of 80ha of deposits within the
Heathrow Extension Area is a significant underestimate. The yield
figures are acknowledged to be estimates (see MBR paragraph 8.3.1).
2.3
As the details of the proposed Preferred Areas are in the public domain
(through earlier LDF consultations), they may be the source of the
consultation paper’s figure of 80ha of sand and gravel deposits within
the proposed third runway area. But as indicated, the proposed
Preferred Areas are not the only remaining deposits within that area.
3
Deposits in the Heathrow Extension Area in relation to the
proposed Preferred Areas
3.1
The three sites identified as Preferred Areas above (parts of H9, H12
and H14) are the only sites that are proposed as Preferred Areas in the
current iteration of the LDF. They have emerged from a rigorous
process of site assessment, as described in the MBR. Their combined
area (including land outside the proposed third runway area) is 82ha,
with an estimated combined yield of 4.75mt.
3.2
The Preferred Areas within H9 and H12 are wholly inside the proposed
third runway area, as is the great majority of H14. In total, 96.3% of the
area of the proposed Preferred Areas lies within the proposed third
runway area, contributing 97.9% of the Preferred Areas’ estimated
yield.
4
Deposits in the area of the proposed third runway in relation to all
sand and gravel deposits in Hillingdon
4.1
The studies reported in the MBR identified a total of 278ha of
remaining sand and gravel resources within the whole of Hillingdon,
with an estimated total yield of 15.33mt (MBR Table 8.1). Of these
amounts, 114.4ha, yielding 5.9mt, were considered to be unsuitable for
working at any time, barring some unforeseen major change of
circumstance, such as a willingness to allow extraction from large
areas of public open space (MBR Table 2 and paragraph 8.5.5). A
further 24.6ha (est yield 1.26mt) was identified, on an initial
assessment, as ‘not favoured’ for extraction because of some
significant reservations, as described in MBR Annex 8.1. This left
139ha of deposits, with an estimated yield of 8.17ha, as being
‘possible’ locations for future extraction, on this initial assessment.
4.2
Of the two sites within the proposed third runway area that have not
been selected as Preferred Areas for the LDF, Site H10 was assessed
as a ‘possible’ site, but Site H13 was regarded as ‘unsuitable’ because
of the conflict with existing community/recreational land uses.
4.3
In total, 102.7ha of the ‘possible’ sites, with an estimated combined
yield of 6.2mt, lie within the proposed third runway area (i.e. the figures
of 108.5ha and 6.5mt from the above table, minus the area and yield of
site H13). This amounts to 73.9% of the total area, and 75.9% of the
estimated yield, of all the ‘possible’ sites in Hillingdon; or 62.8% of the
area, and 65.7% of the estimated yield, of the ‘possible’ and ‘not
favoured’ sites combined. This leaves a total of 36.3ha (estimated yield
just under 2mt) of ‘possible’ reserves outside the proposed third
runway area or 60.9ha (estimated yield 3.23mt) in the ‘possible’ plus
‘not favoured’ sites combined.
4.4
It is stressed that the above are the results of an initial assessment. It
is highly probable that it will have correctly identified the resources
whose extraction would be subject to strong reservations, but the
resultant ‘possible’ areas need more detailed consideration before they
can be regarded as ‘realistically workable’, in whole or in part. The
results of that further assessment are in the following section of this
report.
5
Deposits in the Heathrow Extension Area in relation to realistic
future extraction prospects
5.1
Table 8.6 of the MBR analysed the ‘possible’ sites in more detail, as a
step in the process of identifying the proposed Preferred Areas. The
following table summarises its findings. Sites with an asterisk are
wholly or (in the case of H14) partly within the proposed third runway
area.
Site
General
Area
Est
location
(ha)
yield
Finding
(mt)
H1
S Harefield
1.6
0.1
Potentially harmful to adjacent Conservation Area,
H2
S Harefield
3.0
0.15
but may be workable if sensitively designed
H5
Cowley
3.9
0.2
No suitable access. Unlikely to be workable.
H9*
Harm’sworth
30
1.8
Western half unlikely to be suitable for working impact on cultural heritage interests. Eastern half
acceptable for mineral working (and proposed as
a Preferred Area)
H10*
Harm’sworth
6.7
0.3
Too small to justify working on its own, but might
be workable in conjunction with other nearby sites
(e.g. H9) - but to do so would displace an existing
business.
H11
Harm’sworth
7.4
0.4
As H10, with added reservation relating to impact
of mineral working on nearby sensitive computer
centre. Unlikely to be suitable for working.
H12*
Harm’sworth
40
2.4
Suitable for extraction (and proposed as a
Preferred Area), apart from small area in NW
affected by cultural heritage constraints.
H14*
Sipson
29
1.8
Suitable for extraction (and proposed as a
Preferred Area).
H17
Longford
3.9
0.25
Too small to justify working on its own. Potential
for working as an extension to H18, but possible
nature conservation issues.
H18
Bedfont
13.5
0.77
Possible potential for working in the longer term,
but not favoured at this time because outside the
established A4/M4 area of mineral working.
5.2
This assessment indicates that, apart from the proposed Preferred
Areas, there is only one site - H18 - where mineral extraction may be
acceptable in future on its own merits. Three other sites - H1, H2 and
H17 - are not considered at this stage to be completely unsuitable for
working, but significant reservations have been identified at all three
which may, in practice, preclude extraction at any time. A fourth site H10 - could only be worked (if at all) in conjunction with other nearby
sites, all of which are within the proposed third runway area, as is H10
itself.
5.3
Therefore, outside the proposed third runway area there is an
estimated 0.77mt of remaining mineral reserves - all at a single site that are definitely considered to have longer-term potential for
extraction, and a total of 1.27mt at this site together with the three
others that are not immediately regarded as unsuitable for future
working.
5.4
These figures compare with the 4.75mt of reserves within the identified
Preferred Areas. If sites within the proposed third runway area were to
be ruled out from identification as Preferred Areas, the amount of
‘acceptable’ mineral resources elsewhere in the Borough would not
come anywhere near to matching the quantity of reserves that are
proposed to be identified as Preferred Areas in the LDF.
6
The significance for Hillingdon of the size of remaining workable
reserves
6.1
The size of the total (estimated) reserves within the proposed Preferred
Areas was not chosen randomly. Rather, it derives directly from
national and London-wide guidance.
6.2
Local authorities with sand and gravel deposits are expected to make a
contribution to meeting society’s needs for these minerals. National
guidelines setting out the levels of aggregates provision expected in
each region (including London) are issued by central government, and
are then included (following appropriate testing) in regional spatial
strategies (or in London’s case, the spatial development strategy - i.e.
The London Plan). These regional documents also subdivide the
expected levels of provision down to sub-regional level. Outside
London, this breakdown or ‘apportionment’ is usually taken to the level
of counties and unitary authorities. Within London, because of the
pattern of distribution of sand and gravel within the Boroughs, the
apportionment divides the London-wide figure into separate figures for
East London and for West London.
6.3
In The London Plan (incorporating the Early Alterations adopted in
2006), London’s agreed level of provision for sand and gravel is set at
1.0mt/year, and this is apportioned evenly between West and East
London. In West London the main minerals-bearing Boroughs are
Hillingdon and Hounslow, and it is therefore these Boroughs that are
looked to provide the bulk of the West London provision of 0.5mt/year.
6.4
In the emerging LDF, Hillingdon has indicated a preparedness to seek
to account for 50% of the required level of provision in West London that is, a figure of 250,000 tonnes per year. Taking account of the
amount of sand and gravel in Hillingdon for which planning permission
already exists, the MBR calculates (paragraph 4.4.4) that an additional
4 million tonnes of reserves need to be identified in the Borough if this
level of provision is to be maintained until 2023.
6.5
To allow for a degree of flexibility, and for possible overestimation of
the yield from individual sites, mineral planning documents generally
look to identify sites containing somewhat more than the minimum
amount of mineral needed to maintain the required level of provision. In
Hillingdon’s case, the three potential Preferred Areas identified in the
MBR are estimated to contain 18.75% more than the minimum
‘requirement’ - i.e. 4.75mt rather than 4mt. This is considered by the
Borough to provide an acceptable degree of flexibility in the Plan.
6.6
If the sites within the proposed third runway area were no longer
available for extraction, however, it is clear that the remaining
realistically available reserves in the Borough could not between them
provide for the extraction of 4mt over the period to 2023, let alone any
higher figure designed to allow flexibility. The 0.77mt of material in the
one site considered to have definite potential represents under a fifth
(19.25%) of the 4mt ‘requirement’, while the 1.27mt in this site and the
three others not immediately regarded as unsuitable represents under
a third (31.75%) of that figure.
6.7
Put another way, the 0.77mt at Site H18 represents provision
equivalent to about 3 years’ worth at the level accepted by Hillingdon
(250,000tpa), and the 1.27mt at sites H1, H2, H17 and H18 together
represents provision for just over five years. Permitted reserves in the
Borough at the start of 2004 were estimated at 1mt; at the 250,000tpa
rate (MBR paragraph 4.4.4), these reserves would be exhausted by the
end of 2007.
6.8
Therefore, if reserves in the proposed third runway area were to be
unavailable, the remaining acceptable or ‘possibly acceptable’ mineral
resources in the whole of Hillingdon would be the finite limit of
potentially workable mineral resources in the Borough without
breaching major planning constraints; and they would only be sufficient
to last for 3-5 years. This compares with a requirement in national
policy (MPS1) that local authorities should aim to maintain a stock of
permitted reserves which, at any one time, is the equivalent of seven
years’ worth of production at the relevant ‘apportionment rate’.
6.9
If Hillingdon were required to maintain an annual level of provision
equivalent to 250,000tpa over the period to 2023, it would be
necessary to identify a minimum of about 3 million tonnes of resources
from sites outside the ‘not immediately unacceptable’ sites in the
Borough. This would inevitably mean having to give mineral extraction
priority over some highly valued constraints relating to the safeguarding
of archaeology and the protection of conservation areas, and/or the
protection of residential areas from heavy traffic; and/or it could mean
having to sacrifice established areas of public open space (such as
perhaps Lake Farm Country Park in Hayes, or Cranford Park) for
mineral extraction.
7
The wider significance of the size of remaining workable reserves
in Hillingdon
7.1
The finite nature of the mineral reserves in Hillingdon is recognised in
the MBR (paragraph 8.3.2 and paras 8.5.7 to 8.5.9). At the 250,000 tpa
rate, the ‘possible’ reserves were calculated to last about 32 years.
Although not a long period of time, this was not considered to create an
immediate issue that needed to be addressed either within the Borough
(e.g. in the LDF) or in wider forums (e.g. in the discussions of the
London Aggregates Working Party, or in the content of The London
Plan).
7.2
7.3
7.4
1
However, if the remaining resources within the proposed third runway
area are taken out of the equation, Hillingdon’s ‘acceptable’ resources 1
will only last for 3-5 years. This gives rise to a very serious and
immediate concern, in an area of planning where a minimum timehorizon is set at seven years, and where national and regional/Londonwide policies cover the period to 2016 (with the national policies
expected to be extended shortly - see paragraph 9.13).
One way in which (it might be thought) this issue could be addressed
would be for other West London Boroughs to agree to increase their
contributions towards the overall West London provision of 0.5mt/year,
with a corresponding reduction in Hillingdon’s contribution from the
currently-accepted figure of 250,000tpa. Reducing Hillingdon’s
contribution to 100,000tpa would in theory allow the ‘acceptable’
resources to last for between 8 and 13 years - still a very short period,
and still giving rise to an issue that would need to be addressed
urgently within the forums referred to in paragraph 9.1, but not quite
such an immediate problem. (Reducing the figure below 100,000tpa is
considered unrealistic, since this is the minimum output that may
reasonably be expected from a single sand and gravel working.)
However, there is no reason to think that the other West London
Boroughs have the mineral resources to enable them to increase their
levels of provision to compensate for any enforced reduction in
Hillingdon’s. Hounslow is believed to be the only other major mineralbearing Borough in West London, though there are may be some
additional resources in Richmond and in Ealing. It is understood that
Hounslow are currently carrying out an exercise which will allow them
to estimate the size and suitability for working of their own mineral
resources. At the moment, there is some doubt as to whether they
have sufficient ‘acceptable’ resources to enable them to provide the
greater part of the balance of 250,000tpa between Hillingdon’s
proposed contribution to meeting the West London apportionment
figure, and that total figure of 500,000tpa. If this proved to be the case,
a consequence might be that pressure would be put on Hillingdon to
increase its share from its proposed contribution of 250,000tpa. If sites
in the proposed third runway area were excluded from consideration,
this would not realistically be possible. But for Hounslow or the other
West London Boroughs to contemplate increasing their contribution
above their present assumed figure of 250,000tpa would, in these
circumstances, be equally unrealistic.
Wherever this term is used in this report, it should not be taken to mean that all the resources
referred to will necessarily prove to be acceptable for future working once detailed assessments have
been made by mineral operators, or once the environmental implications of mineral working at each
site have been considered in greater detail.
7.5
Unless the other West London Boroughs were able to absorb any
reduction in Hillingdon’s contribution of 250,000tpa, the only ways of
accommodating such an enforced reduction - or an enforced curtailing
of the period over which that level of provision could be sustained would be either by a move away from the 50:50 split of the London
apportionment between West London and East London (i.e. requiring
East London to accept an apportionment figure in excess of
500,000tpa), or by a reduction in the total level of primary aggregates
provision expected from London. The latter in turn could necessitate a
possible consequential increase in the levels expected from other
regions.
7.6
Both these options would require discussions in wider forums - in the
London Aggregates Working Party, in discussions between the
mineral-bearing Boroughs, in discussions with the GLA, and in
discussions with DCLG (who are ultimately responsible for the issue of
the guidelines at regional level - although these are subject to testing at
the more local level before being incorporated into RSS/SDS).
7.7
The construction of proposed third runway would represent a demand
for aggregates on a scale that was not foreseen when the present
national and regional guidelines were drawn up. It should therefore be
accounted for in new national guidelines, rather than by trying to fit it in
with the existing guidelines (which date from 2003).
7.8
To take a substantial proportion of the available material from within
London for use, in effect, as a borrow pit on a single construction
project raises issues about the continuing availability of resources for
these more general purposes.