Minerals Plan: Key Issues & Options

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Comment Information
Document Section Derby & Derbyshire Minerals Core Strategy: Key Issues & Options Part Two: Vision, Objectives, Issues & Options Chapter 6: Plan Objectives the Plan Objectives [List all comments on this document part]
Comment ID /3881121/1
Respondent Geoff Mason [List all comments by this respondent]
Response Date 28 Jun 2010
For the last nine months I have been making a detailed study of the Leicestershire Minerals Framework and its application to hard rock quarries. These pose a major, if not impossible, restoration problem. Some of the ideas that have emerged may be appropriate for Derbyshire.
The key idea is that all hard rock quarries should have a restoration plan at all times and that "Concurrent restoration to amenity" should be the default plan. Operators (landowners) would be free to produce alternative plans if they could show that theirs were more practicable.
The time that restoration should be carried out is whilst the quarry is actually working (hence the "concurrent"). This is because heavy equipment is on site, the quarry is generating revenue and all Heath & Safety protocols are in place. If any remedial blasting is required then there is equipment to process and market any removed material. During downturns in the market, men and machines can be re-deployed on the restoration work. Also, it makes the operator think about restoration whilst there is still time to do something about it. Operators will no longer be attracted by the possibility of dragging out the lifetime of almost-exhausted quarries just to avoid the expense of restoring them. It also gives time to change any remediation processes in the light of experience. In comparison, for super quarries, waiting until the quarry has stopped extraction before restoration starts is a hopelessly inadequate methodology.
The most important single factor affecting quarry restoration is the condition in which the faces of the quarries are left. This did not use to be a problem but modern quarrying techniques can leave the rock faces much more shattered. Because there is no longer a supply of waste to fill the voids and thus cover the faces, the rock faces will be exposed in perpetuity. Filling with water takes over a hundred years because in the Midlands the evaporation rate is almost the same as the rainfall.
One, if not the only, use for disused quarry faces is recreational rock climbing (and associated activities) supplemented, almost by default, by the residual faces being a nature reserve. For this, faces must be left much more stable than current practice. It is only the final cut that needs be done differently - all other blasting can be done using ANFO - and so the extra cost is quite small if it is done at the time the quarry benches can be accessed. Attempting a new softer final cut later as part of a restoration plan for a super quarry would be ruinously expensive and time consuming.
Leaving more stable faces also means that, because of the reduced risk of rockfall, the bench width can be reduced and so the reserves increased. For deep quarries this is particularly advantageous.
I suggest Derbyshire's Minerals Core Strategy (Chapter 6 K) should be amended to include the requirement that every minerals extraction site must have a current and continuously updated restoration plan and that "Concurrent restoration to amenity" is included in the Strategy as the default plan for any hard rock quarries that do not submit alternative plans. There should also be a requirement that restoration progress will be monitored.