SBG response to Hanson Westdown Quarry expansion consultation – December 2020

The Somerset Bat Group has been asked to comment on the extension to Westdown Quarry, between Shepton Mallet and Frome.  The group has sent the response copied below, but if anyone would like to comment themselves, then the details we were sent are: 

SBG Consultation Response – First published 4th Dec 2020

Thank you for your invitation to take part in a consultation relating to Hanson’s proposals to reopen the Westdown quarry.

This is an initial partial response from the Somerset Bat Group.  We note that as we only received 10 working days notice of the consultation deadline, we have been unable to consult fully within our group yet, and hence we reserve the right to supply further feedback to this page on our website as it becomes available.

Our summary comments are in the list below, with the explanation and further details in numbered paragraphs below the list.

  1. Recent bat data – We request that any detailed ecological survey results and reports commissioned by Hansons be made available as soon as possible to ourselves, other specialist groups, and wildlife organisations, to allow proper scrutiny and comment.
  2. Proposed Bat Hibernacular – Created in Phase 3, the current suggested location in the east corner of the site is sub-optimal, and it should be created in a quieter location.
  3. New Bat hibernation roost – due to the potential disturbance to the existing greater horseshoe maternity roost a new roost should be created further away from the quarry northwards, before any works are undertaken to open up the Westdown quarry
  4. Habitat Regulations Assessment (HRA) – A HRA should be produced as the proposals could have a pronounced negative effect on the collective bats using this area.
  5. Mitigation for loss of potential bat roosts in Asham quarry faces – Survey of existing quarry faces for bat roosts before removal/covering, and inclusion of new roost features in the front face of the infill of Asham Void.
  6. Caves – Two Caves within the site area should be grilled and monitored for bats.
  7. Stream Corridor– Ensure this habitat is maintained for Bats and Otters and other wildlife.
  8. Lighting – Ensure any quarry lighting does not impact bats.
  9. Asham Stone Conveyor Tunnel Security – This greater horseshoe bat roost should be externally monitored regularly by Hansons staff to ensure it remains locked and secure.
  10. Asham Stone Conveyor Tunnel Access – Remedial works are carried out as specified by ecologists to Justin Collis from Hansons, to allow safe access to monitor the roost.
  11. Bat roost monitoring – We recommend all the roosts and hibernacular on the site are monitored quarterly by consultants and the results shared.
  12. Other enhancements for bats – We also suggest the following, Erection of Bat boxes prior to work commencing, and in the restoration phase creation of shallow water areas in the bottom of Asham Void, and larger marginal planting areas in the Westdown restored lake.

Details for each of the summary comments, are listed below:

1. Recent Bat Data

We regret that we do not have extensive recent bat activity data, for the Asham Void and Westdown Quarry areas.   We note the supplied “Environmental Impact Assessment (EIA) Scoping Report”, is high level, with little ecological detail.

In 2020 we had hoped to be able conduct a landscape scale activity survey of Asham/Wadbury Greater Horseshoe bats and all bats use of the wider Mells Valley Special Area of Conservation (SAC) Ecological Zone of Influence (EZI).    Unfortunately the funding promised by Hansons in Jan 2020 has not come through, and hence this project is on hold pending funding. Project details here:  

In the absence of our recent data for much of these comments below we have had to rely on the English Nature Research Report 403 (EN403 – 2000), when Geoff Billington which radio tracked the Mells greater horseshoe bats in the year 2000.

The group has had several requests from Wood PLC staff/consultants, who we are led to believe were undertaking Ecological surveys on behalf of Hansons over 2018/19/20 possibly including radio tracking of greater horseshoe bats.  If this is the case, then we request that any ecological survey results and reports be made available to ourselves, other specialist groups, and wildlife organisations, to allow proper scrutiny and comment as soon as possible.

2. Proposed “Bat HibernaculaR”

We note that in Westdown Quarry expansion Phase 3 a “Bat Hibernacular” is proposed to be constructed in the far east corner of the site nearest the A361 road junctions. We consider this location will be too disturbed by quarry blasting and operations, and should be relocated in a less disturbed location, nearer to prime foraging habitat. We would be interested to have knowledge of the ecologists reasoned statement for the siting of this in the proposals.

3.-4. New Bat hibernation roost / Habitat Regulations Assessment (HRA)

Bat group member and consultant Geoff Billington shared comments with the group regarding this. Geoff was employed by English Nature in 1999/2000 and undertook the last radio tracking of horseshoe bats on the site that we are aware of. His comments are:

“<70m from the proposed quarry is a greater horseshoe bat nursery site which in 2000 had about 40 adults, part of the Mells Bat SAC. This roost in the old Asham Stone Convevor tunnel is linked to a larger roost at Wadbury, near Mells. Looking at the proposal plan it does affect the large part of the network of foraging areas and flight routes occurs across this area for this roost. Also some of the bats from Mells roost fed here

I note there is no mention of mitigation for bats, even though a number of the habitat enhancements look good, that wants closely looking at, and a Habitat Regulations Assessment (HRA) produced as it could have a pronounced negative effect on the collective bats using this area.

I got involved with a quarry proposal in South Devon several years ago, and there was great concern expressed about blasting much further away from roosts and in that case it was not a nursery roost.”

The EIA scoping document says the area contains features for greater horseshoes, but fails to acknowledge proven flight routes and foraging areas. (shown in figure 1 below)

Extract from EN403(2000) - Asham bat foraging areas/flight routes in yellow. Approx foraging area within red shading. Point 2 is the Asham Stone Conveyor Tunnel roost.
Extract from EN403(2000) – Asham bat foraging areas/flight routes in yellow. Approx foraging area within red shading. Point 2 is the Asham Stone Conveyor Tunnel roost.

It is my view as it stands an objection should be raised that full evaluation for greater horseshoe bats in/around the proposal is made and good proposals to include a new roost would have to be created further away from the new quarry (northwards) and new hedgerows created between the A361 and to the North East to mitigate for loss of key greater horseshoe areas which would still need to be subject to a HRA to determine if the effects are low enough to not impact on the SAC.”

We also note there is the potential of creating linear landscape features (hedges), to act as bat navigation routes in Asham Void along various contours of the created slope, and in the flat upper area, and also in Westdown.

5. Mitigation for loss of quarry cliff faces

In Asham Void there are long lengths of 20-30m high shattered quarry faces facing south east, which are proposed to be covered completely with Oolitic limestone overburden from Westdown. Likewise in Westdown there are large lengths of existing quarry faces, facing north west that will be totally removed during the reworking.

There is probably over 2 km of quarry face in total which will be changed. These cliff faces have many cracks, crevices, openings and fissures. While accepting the geology the rock here does not lend itself to multiple cave formations (unlike other quarries), these features could potentially lead to larger openings or chambers. As the quarry has been dormant for many years, any of these could be potential bat roosts or winter hibernation roost features, and due to the unstable nature of the faces they would be impossible to survey. There are likely to be hundreds of potential hibernation roost features in these faces. Hence each section of face would need to be surveyed as it becomes accessible before removal or covering by quarry tips.

Mitigations to compensate for the loss of potential roosts could include the creation of new potential hibernation roosts, such as the use of grilled concrete pipe openings and networks (possibly linked underground) in the front of the newly created tip faces, buried during the infill process in Asham Void. We consider there is the potential for at least a dozen such new underground hibernation roosts to be created at various levels, and during various phases of infill.

6. Grilling of Caves

We have been made aware there are 3 caves within the site/site boundary two of which are reported by a third party to be bat roosts.

  1. Bradshaw’s Cave – explored to 300 feet of passage with bat roosts, formations and unusual and rare geology.
  2. Hovvy’s Rift Cave – a short cave 4m high & 1m wide with ideal bat roost shelving that was revealed by a rock fall a few years back.
  3. Yogi Pot – a small pot hole that becomes a resurgence in the wetter winter months in some years. This along with another resurgence some 20m west could probably be sacrificed as part of the proposed development but may need piping to take the resurgence water into Whatley Brook.

Whilst the bat group has not confirmed the presence of bats in the two caves mentioned, as a precaution it would be wise to ensure they are grilled and regularly surveyed for bats.

7. Stream CORRIDOR

During a visit in November 2020, we confirmed the presence of Otter (spraint) on the steam through the site, and it is a known bat foraging/flight route. Therefore any proposals should ensure they maintain the existing steam corridor through the site, with associated trees lining the corridor for foraging bats, and not illuminate this with quarry lighting.

8. Lighting

To ensure the quarry operation lighting does not impact bats and their foraging areas the lighting should be planned to:

  • Avoidance of any light spill into quarry perimeter/screenbanks.
  • Allow no lighting of Asham quarry and void tip areas in hours of natural darkness.

9. Asham Stone Conveyor Tunnel Security

The report EN403 (2000) recommended that the Asham Stone Conveyor Tunnel “is very vulnerable and requires grilling urgently, during this study the bats were disturbed and over half the colony left”.

The bat group was very pleased that in 2019 Hansons paid for the grilling of the Asham Stone Conveyor Tunnel.  However, on four separate external visits in 2020 group members noted: 

  • The roost is unlocked and the access door swinging wide open on each visit
  • There is evidence on each occasion of fresh access into the tunnel, muddy feet marks on the doorways, and climbing aids .. etc
  • The metal plating has been used for paintball practice and fireworks set off nearby.

It is therefore possible that the unlocked grilled tunnel has resulted in illegal disturbance of the roost. This greater horseshoe bat roost should be externally monitored regularly by Hansons staff/security to ensure it remains locked and secure without any disturbance.

10. Asham Stone Conveyor Tunnel Access

In Jan 2020 a meeting between Justin Collis from Hansons, First Ecology and SBG agreed remedial works and working practices (RAMS) to allow safe access to survey and monitor this roost. It is believed these have not been completed, and in summary they are:

  • Hansons to provide welded tethers to the outside of the door to allow firm fixing of the ladder to prevent side slippage. Hansons to provide ladder stiles and provide straps for this.
  • The inside rungs are round, slippy and flex in use. Hansons to review the NE ladder guidance then carry out remedial works to bring them up to spec. Flat ladder stiles were suggested by Mr Collis, which can be retro fitted. This work should not be undertaken whilst bats maybe in hibernation – ideal time early April 2021, with ecologist survey prior to works being undertaken.
  • Site surveyors to use hard hats with chin straps and PPE, safety boots. A ladder longer than 4.2m must be used.
  • The transition from tethered outside ladder, to inside rungs was discussed. Each surveyor to use waist harness to clip onto grille, whilst undoing padlock, and climbing up/down, which Hanson will supply.
  • Confined spaces and safe use of ladders training and protocol must be applied and a minimum of 2, preferably 3 people are needed for safe survey, one of which must stay outside.
  • It was also confirmed that neither mobile phones or quarry radios work outside the Tunnel, but to check in/out of site with Whatley quarry reception or text site manager once on/off site.

11. Bat roost monitoring

Currently we do not know if greater horseshoes or other bat species are still using the Asham Stone Conveyor Tunnel after its grilling in 2019. Unfortunately the bat group are unable to assist in the ongoing monitoring of the bat roosts on site due to IUCN/BCT guidelines, safety issues, and our own policies. Hence we suggest that all the roosts and hibernacular on the site are monitored quarterly by CIEEM accredited consultants following IUCN/CIEEM Covid-19 guidelines, and the results shared with SBG,  and Somerset Environmental Records Centre (SERC).

12. Other Asham void enhancements for bats

A number of other suggestions for further biodiversity net gain and bat habitat enhancement:

Bat Boxes

To accommodate any bats displaced by quarrying activities, prior to any works commencing on site there is the potential for erection of many bat boxes on suitable standard trees around the perimeter of site, (not Ash – due to Ash die back). Also with the increased loss of suitable roost sites in Ash trees, bat boxes will help to lessen the impact of lack of potential roosts. Bat boxes are not used by horseshoe bats, so other roost mitigation measures are necessary, ie purpose built structure or concrete pipes.

Shallow Water

During restoration a large area of shallow water area could be created in the lower area of Asham Void, linked to the stream, to act as a bat foraging site.

Marginal planting areas

In the flooded Westdown Quarry restoration, the current plan shows “1:2 to 1:3 slopes to create shallows for marginal planting”. Assuming a maximum marginal planting depth of 0.45m, this means at best the margins would be only be 1.35m wide. Hence we suggest the slope of these marginal areas to be reduced to 1 in 10 to allow wider, more species rich marginal plantings, to benefit the insects population and provide better bat foraging areas.