At the Public Inquiry in October 2022, Aggregate Industries pointed to the less-than-7-year landbank for sand and gravel in Devon, and claimed there was therefore an "urgent" need for a quarry at Straitgate Farm. As a result, in weighing up the planning balance, the Planning Inspectors concluded there were:
154. ... significant material considerations which weigh in favour of the proposal. These include its contribution to sand and gravel supply in Devon in circumstances where there is not currently a 7-year landbank as required by the Framework.
Ten months before, in December 2021, at the time Aggregate Industries’ application to quarry the farm was refused by Devon County Council, the landbank was actually above 7 years, according to a subsequent revision by the Council. However, by the time of the Public Inquiry, the landbank had indeed dropped to 6.4 years, based on permitted reserves of sand and gravel in the County at the end of 2021 of 3.317 million tonnes, divided by the 10-year sales average of 0.514 million tonnes per annum.
But, surprise, surprise. It now turns out that, at the time of the appeal, and unbeknown to the Planning Inspectors, Aggregate Industries had another 460,000 tonnes of sand and gravel up its sleeve, which, once permitted, would have pushed the landbank to over 7 years.
Aggregate Industries has recently lodged a planning application with Devon County Council for Hillhead Quarry near Uffculme – DCC/4399/2024 "Variation of conditions 2, 4, 6, 7, 12, 19, 22 and 25 of ROMP permission DCC/3655/2014... to vary the phasing; landform; drainage; and restoration of the site."
This application is concerned with modifications to the Houndaller part of the site – a site with the same sort of material that underlies Straitgate Farm – that has suffered from ponding problems, as we have posted about here, here and here.
The Planning Statement for the application reads:
3.4.1 Houndaller Extension Area is currently facing surface water ponding issues in Phase 6 which is preventing completion of restoration of this section of the quarry. It is considered that a similar situation will occur once extraction operations cease in Phase 7. During 2023 and to date in 2024, in excess of 1m dept [sic] of water has collected over much of the Phase 6 area. The consented final restoration landform does not allow for effective drainage. Therefore, Aggregate Industries are proposing a long-term solution for surface water ponding issues on site.
Clearly, the concern must be that if the company hasn’t been able to adequately manage surface water at Houndaller, it doesn’t stand much chance of complying with the no water bodies condition at Straitgate:
25. No water body shall be created within the site other than the approved weigh bridge lagoon.
However, the company’s application for Houndaller is not just concerned with surface water management. The application’s Non-Technical Summary says:
1.1.6 The proposed modifications to mineral operations at Houndaller include removal of two unsafe historic faces which will provide an estimated 460,000 tonnes of permitted reserves to Devon’s sand and gravel landbank.1.4.10 In addition, at present the approved plans under the extant consent contradict each other, with the approved restoration plan (ref. 2285/ROMP/4C) not showing the ridge along the northern boundary of phase 8, but it is in-situ on the working plans (ref. 2285/ROMP/3C & 2285/ROMP/73D) thereby creating an anomaly. Therefore, at present the approved restoration scheme cannot be delivered as currently consented.
A spare 460k tonnes? Unsafe quarry faces? Approved plans that contradict each other? How has Aggregate Industries allowed all this to happen?
But could it be that these perilous quarry faces were not known about at the time of the 2022 appeal? Not unless Aggregate Industries has been asleep for 20 years. The application’s Planning Statement points to The Quarries Regulations of 1999 and says:
3.2.6 It is proposed to remove the ridge escarpment which lies adjacent to the eastern edge of Houndaller Plantation Pond which is in the northern part of Houndaller Extension Area and former Phase 1 area.
3.2.7 The former Houndaller Phase 1 extraction area, north of the current Phase 8, had been worked pre-Quarry Regulations 1999 when long-term geotechnical stability of the final quarry faces when excavating sand and gravel material was not given the consideration which is now required for quarry legislative purposes. Whilst this area is now restored, the historical faces are currently up to 20m high and 65˚ to near-vertical therefore presenting both a stability, and health and safety issue.
3.2.8 Hillhead Quarry is now subject to a Regulation 33 geotechnical assessment every two years. Within this assessment, there are various design criteria that the quarry must use to ensure geotechnical stability for both active and inactive faces. These design criteria’s are derived from the specific geotechnical properties of the geology onsite and from various stability analyses undertaken alongside the assessment.
3.2.9 Based on the current design criteria for restoration slopes, the historic faces adjacent to the eastern edge of Houndaller Plantation Pond and along the northern boundary of the current approved Phase 8 extraction area have been assessed and are considered to be excessively steep and too high for long- term stability. They therefore currently present a significant geo-technical risk, and health and safety hazard. The current Regulation 33 Geotechnical Assessment for the site states that "Aggregate Industries must develop a plan to include remedial actions on these historic quarry faces". Further detail on the stability issues are presented within the Stability Assessment accompanying this planning application at Appendix 6.2.
The company would therefore have known for years that these hazardous quarry faces did not comply with the 1999 regulations, and that removing them would likely yield extra material.
But perhaps it forgot all about them at the time of the Straitgate appeal in October 2022? This isn’t likely either. The Stability Assessment referenced in Appendix 6.2 says:
1.3 ...It was identified in 2022 that the restoration plan needed to be updated to include improved drainage and to update the final profiles in relation to the materials available for backfilling the extraction area. At this point it was a natural way to deal with this legacy face to ensure the whole Houndaller excavation area is left in an adequate way that it supports long term stability and no hazards remain when Aggregate Industries complete this area.
So, how very clever of Aggregate Industries to keep all this material – about half the quantity available at Straitgate – up its sleeve.
Prior to the determination of its Straitgate Farm application, Aggregate Industries had been in the habit of losing material – including at Houndaller – which had the inevitable effect of reducing the landbank and creating the impression of need for Straitgate. Miraculously, after Straitgate is determined, we now discover the company has found material again. How convenient. How cunning.
What does this application for Hillhead mean for the County’s sand and gravel supplies:
3.2.16 The current estimate completion date for extraction [at Houndaller] is end of 2029 with completion of restoration and landscaping by 2031, this is based on an average production rate of 350,000 tonnes per annum.
Assuming production for the years 2024,25,26,27,28,29 this implies that some 2.1 million tonnes remain, or 1.64 million tonnes excluding the newly found 460,000 tonnes. Aggregate Industries helpfully confirmed in 2019:
The company's reserves schedule for Houndaller was subsequently revised to 2.9 million tonnes as at 1st January 2019.
Subtracting those two figures implies that over the 5 years 2019,20,21,22,23, some 1.26 million tonnes of sand and gravel has been produced, at a rate of 250,000 tonnes per annum.
At this rate, Houndaller would in fact last another 8 years.
Of course, this is why Aggregate Industries – knowing all along it had extra material at Hillhead – has been in no rush to advance its plans for Penslade, despite starting groundwater monitoring in 2021.
Penslade is owned by Aggregate Industries, and again has the same type of material that underlies Straitgate. Whilst Aggregate Industries claims there is 1.06 million tonnes of saleable aggregate at Straitgate, Penslade is a 23 million tonne sand and gravel resource, 8 million of which is allocated in the Devon Minerals Plan. It sits next to the company's processing plant, not – like Straitgate – 23 miles away.
At the appeal, the Council’s Mineral Planning Authority said:
5.1.13 The Appellant has stated at meetings of the local liaison group for Hillhead Quarry that it is preparing a planning application for their West of Penslade Cross site (to the east of Hillhead Quarry), having undertaken investigative boreholes and intending to seek pre-application advice from the Council before the end of 2022, with a view to submission of an application in 2023. It is also understood that remaining reserves at Hillhead Quarry are sufficient to maintain supply until a new quarry at Penslade has been approved and is capable of being implemented.
However, to date, no planning application for Penslade has arrived. All Aggregate Industries would say at the appeal was:
8.4 Aside from the appeal site, the only other allocated site is West Penslade. West Penslade is also AI controlled which [sic] and would be an extension for the Hillhead quarry (planning permission ends in 2028). West Penslade will not come online until then.
The bottom line is that Straitgate is not quite so urgent after all.
Furthermore, as we posted last month, Aggregate Industries now says that if current market conditions persist then Straitgate will have to be "mothballed". Local people will wonder what strategic thinking goes on at Aggregate Industries, if any.
What else does DCC/4399/2024 tell us? In relation to groundwater and nearby water users:
5.7.3 Throughout the lifetime of the development, some 2 m thickness of unsaturated material will be retained beneath the quarry floor at the western margin of the Houndaller Extension.
Compare and contrast that with extraction all the way down to the maximum water table at Straitgate, a site with more than 10 times the number of nearby private water supplies at risk than at Houndaller. Even so, Aggregate Industries again recognises that private supplies will be put at risk:
5.7.14 In the unlikely event that a supply is shown to have been impacted by quarry-related drawdown, the following approach is proposed to provide mitigation… The fallback position would be the provision of mains water. AIUK would cover the costs for mains water connection and usage at any property where the water supply is affected by the quarry development.
What ecological damage will be done in removing those treacherous quarry faces?
3.5.3 As part of the remedial works for the two unstable ridges within the northern extent of Houndaller, approximately 28,863m2 of lowland mixed deciduous woodland is required to be removed.
Which rather undoes this PR piece pushed out by Aggregate Industries last year, congratulating itself for planting saplings at Hillhead.
Devon County Council is accepting comments on DCC/4399/2024 until 29/06/2024.
