Professor of Hydrogeology, Rick Brassington, recent winner of the Geological Society's Whitaker Medal, has sent three substantive responses to the Environment Agency – all objecting to Aggregate Industries’ plans to quarry Straitgate Farm. We have posted about them here, here and here. His latest response warns:
It is my view that this application should be turned down and that no quarrying be permitted as to allow it will threaten these water resources for many years to come.
It is clear however that the Environment Agency has had enough. Haven’t we all? At the end of last year, in its reply to Prof Brassington’s latest response, the EA set out its position:
We have concluded that the applicant has undertaken appropriate risk assessment and proposed appropriate mitigation measures to protect water resources. We therefore do not have any objections to this planning proposal. We have provided SAG and other stakeholders the opportunity to give their views on our advice to DCC. Where appropriate we have incorporated their views and requested additional information from the applicant. Whilst we are happy to continue to receive additional information from stakeholders, we will not be providing further responses over-and-above the information contained within this position statement.
So there. No attempt to explain why the EA disagrees with Prof Brassington, and clearly little thanks to stakeholders for all their help. But plainly the EA is tired of hearing about Straitgate Farm and tired of modifying its conditions based on new information fed to them by stakeholders; information that has not been supplied by the applicants, information they had not uncovered for themselves.
But whilst the EA may be tired of Straitgate, and may not be providing any further responses, only last month it was forced to recommend yet another change to Aggregate Industries' plans.
Readers may remember that in June 2018, we posted AI has ‘forgotten’ one 1990 borehole – that puts groundwater 2.8M ABOVE MWWT, 2.8m above the base of a quarry that was proposed to be worked dry. Previously, the EA had dismissed data from this borehole. In an email to us in July 2018:
The data you highlight in your email of 12 June 2018 is one ‘spot reading’ of groundwater level from 1990. As such, it is difficult to judge its significance.
A year later, the EA provided exactly the same response to Prof Brassington’s report:
We note the groundwater level reading from 1990. However, because this is just one spot reading it is difficult to judge its significance.
Aggregate Industries’ consultants agreed with the EA. In September, Wood wrote a letter responding to Prof Brassington and was adamant this measurement should have no significance. This despite this measurement being undertaken by ECC Quarries (Aggregate Industries’ predecessor), and despite this and other measurements forming part of a report used to support the site’s inclusion in the Devon Minerals Plan. Previously, Aggregate Industries’ consultants had argued "A comprehensive review of the geology across the site was undertaken in 1990… to confirm the local geological characteristics and groundwater levels". These same consultants have now changed their tune, being at pains to argue that "the reliability of this record is, at best, questionable":
The isolated (in time) water level measurement recorded at SG1990/021 cannot be considered reliable because there is insufficient context provided regarding the circumstances under which it was recorded.
Wood’s arguments dismissing the water level reading recorded in borehole SG1990/021 have been shown to be untrue.
I am surprised that the Environment Agency has accepted that this water level should be ignored particularly in the absence of any contradictory evidence.
Based on further information received from SAG we recommended to Devon County Council that the applicant updates the Maximum Winter Water Table grid with groundwater levels recorded at the site in 1990.
Why is this important? As we previously posted, the measurement in question showed groundwater 2.8m higher than the base of the proposed quarry, 2.8m higher than the MWWT – Aggregate Industries’ prediction of the maximum winter water table – the surface its consultants had merrily claimed:
Monitoring over the exceptionally wet winters of 2013 and 2014 allow this surface to be defined with confidence. 6.2.2
The groundwater level recorded in 1990 should now be used to create a new interpolated surface of the maximum water table.
Given that water was recorded at 1.26m below ground level, there will be no recoverable resource in the area surrounding this location.
As we’ve posted below, Aggregate Industries was asked to provide a level of accuracy, "a description of tolerance levels", for the MWWT. The company’s consultants were reluctant to provide an answer, but eventually claimed the MWWT was "based on the higher of the two interpolated surfaces", that the MWWT was the "upper limit of interpretation". They claimed the difference between those two surfaces provided a "reflection of the ‘tolerance’". The claim is nonsense.
If proof were needed, the 1990 figure shows that the interpolated surface, the claimed "upper limit of interpretation", is inaccurate in one location to the tune of 2.8m. There are four other locations where it has become apparent that the MWWT model has been guesstimated wrongly. Across some 55 acres, there are likely to be other areas. As Dr Rutter made clear, the MWWT:
is only a model of reality, and may not represent actual groundwater levels across the site.
The steep hydraulic gradient combined with limited monitoring, in my opinion, is likely to result in errors in the actual depth to maximum groundwater across the site.
We have in the past posted that without more boreholes, and years of further groundwater monitoring, AI and its band of consultants are just groping in the dark.
It all underlines the need for a tolerance, a safeguard, a margin of error, to be built into the MWWT across the whole site. The 2.8m figure gives an indication of the scale of safeguard needed. Many quarries leave 1m unquarried above groundwater levels for this very reason. Aggregate Industries is trying to be clever, trying to be greedy.
The company claims, by only working the mineral when groundwater levels recede during the summer and autumn months, there will always be at least 1m between where extraction is taking place and groundwater levels. The EA conditions:
Continuous monitoring of all site piezometers (and interpolation between them) shall be used to ensure, during working, that the base level to which the quarry is worked is no closer to the contemporaneous groundwater level than 1m.
If the base of proposed extraction is inaccurate by as much as 2.8m, this condition is plainly insufficient.
Remember: Aggregate Industries is proposing to leave a 0m unquarried safeguard above the MWWT to protect surrounding drinking water sources, surrounding farms, wetland habitats in ancient woodlands and mediaeval fishponds. The 1990 figure was recorded in the middle of June, when groundwater levels would have already declined significantly from their spring maximums. The 1990 figure was recorded in the same location where AI has proposed infiltration areas to control flooding, an area where there is clearly insufficient depth of material to perform such a task.
A new MWWT prediction should now be produced using all of the available maximum data – the 1990 level, plus the four levels that exceeded the MWWT in 2018 – in exactly the same way it would have been produced originally, had these values been available then. In addition, a tolerance level, a margin of error, should be built in, particularly in areas distant from piezometers.
The MWWT should not be a fudged. There should not be some trivial finger-in-the-air localised adjustments, not some trivial lifting of contours, not some fiddle as there has been in this document – where changes to the MWWT to reflect the higher 2018 figures are not based on interpolation between other site piezometers, but rather an opinion from Aggregate Industries' consultants:
In the specialist opinion of Wood E&IS, the revised contours represent a realistic assessment of the change in MWWT arising from the readings in April 2018.
The problem is, this so-called specialist opinion has been found lacking at every turn. This specialist opinion has no rational basis for tweaking the MWWT as they have – other than to recover the maximum resource for their paymasters. The higher figures now available should be used to reinterpret the whole surface, the whole of the proposed quarry base, as indeed the EA’s condition – "interpolation between them" – calls for.
