Borehole Prognosis and Assessment of Impact on Nearby Spring Supply

Borehole Prognosis and assessment of impact on nearby spring supply

Moorfield Barn, Derbyshire Level, SK13 7PR

For:

Paul Knowles Managing Director Arnfield Care Ltd by

Carbon Zero Consulting Tel. 01572 729510 Unit 4, E-mail. [email protected] 2B Gaol street Web. www.carbonzeroco.com Oakham , Rutland, LE15 6AQ

October 2019

TABLE OF CONTENTS

1 Background Information ...... 1

2 Summary ...... 2

2.1 Borehole water supply ...... 2 2.2 Risk assessment on potential impact on nearby spring and borehole ...... 2 3 Moorfield Barn, location and setting ...... 3

3.1 Site location ...... 3 4 Summary of Geology and Hydrogeology ...... 4

4.1 Geological setting...... 4 4.2 Summary table of geology and hydrogeology ...... 6 4.3 Proposed Borehole Construction ...... 7 4.4 Drilling risks ...... 8 4.5 Water treatment ...... 8 5 Risk assessment of potential impact of a new borehole abstraction ...... 9

5.1 Location of new borehole ...... 9 5.2 Potential impact of new abstraction on nearby spring ...... 9 6 General Guidance ...... 11

LEGEND

GSHP Ground Source Heat Pump BGS British Geological Survey CZC Carbon Zero Consulting EA Environment Agency GSHC Ground Source Heating and Cooling m bgl Metres Below Ground Level m bwt Metres Below Well Top m OD / mAOD Metres Above Ordnance Datum RWL Rest Water Level PWL Pumped Water Level SPF Seasonal Performance Factor DHW Domestic hot water TD Total Depth

Appendix; Nearby borehole Logs, Rose Bank, Kidd road.

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Carbon Zero Consulting Ltd Moorfield Barn Prognosis and Risk Assessment

Borehole Prognosis

1 Background Information

Address: Moorfield Barn, SK13 7PR

Elevation: 237mAOD

Required Yield Less than 2m3/day.

Use Potable water supply

This Borehole Prognosis is provided for the above address. The report aims to determine the viability of drilling a borehole at the above address to provide the building with a potable water supply for domestic consumption. The daily total volume of water required is proposed to be less than 2m3/day and thus not requiring a water abstraction license from the Environment Agency as there is no regulation of abstraction up to a maximum of 20m3/day.

The objectives of this report are outlined as follows:

 To outline and investigate the feasibility of abstracting a small domestic supply of groundwater for the above address. This will include assessment of yield from nearby boreholes penetrating the underlying aquifer and analysis of the aquifer potential to meet the required demand.  To provide detailed geological interpretation of the underground strata and determine an optimum depth for the well to be drilled.  To comment on the potential impact of the proposed abstraction on a nearby spring supply and a nearby private water supply.

Unit 4, 2B Gaol street e [email protected] Oakham, Rutland, LE15 6AQ t 01572 729510 w www.carbonzeroco.com

Carbon Zero Consulting Ltd Moorfield Barn Prognosis and Risk Assessment

2 Summary

2.1 Borehole water supply

(Qualitative) Percentage chance of obtaining water at given rate

0 – 20% No Chance to very low probability

20 – 40% Poor to Moderate

40 – 60% Moderate to Good

60 – 80% Good to very good

80 – 100% Very good/ high probability

 The potential for water being available from a borehole at Moorfield Barn at a rate of up to 2m3/day is judged as 80% - 100%. The same would be true of an abstraction of up to 20m3/day.

 The geology of the area comprises sandstone and shale of the Millstone grit formation of Namurian (Carboniferous) age.

 The rest water level of a borehole drilled in this area is approximately 10mbgl

 The site is not in an area of risk of mining. As the local area is predominantly agricultural there is some potential for the presence of contamination from fertilisers and other agricultural activities.

 The site is not within an Environment Agency groundwater source protection zone (SPZ) and is to the west of the Peak District SSSI.

 A search should be made for the presence of water, power or sewerage services prior to drilling.

 Further guidance on borehole design is provided in the body of this report.

2.2 Risk assessment on potential impact on nearby spring and borehole

A borehole drilled at the barn would take water from sandstone layers approximately 35m – 50m below ground level and so separated vertically from the base of the nearby spring by about 50m. Much of this 50m section would be made up of impermeable shale as seen in the nearby geological record from the borehole at Rose Bank, section 4.3 and Appendix.

 Abstraction of water from a new borehole drilled at the barn would have no impact upon the flow, collection or utilisation of water from the spring located up-gradient of the proposed borehole.  Abstraction of water at a rate of 2m3/day from a borehole drilled at the barn would have no measurable impact on the existing borehole and abstraction located at a distance of 450m to the south-west at Rose Bank.  Likewise, there will be no measurable impact on the flow or quality of water taken from springs located near to Jumble Farm.

It should be noted that the proposed abstraction for domestic water consumption is to be less than 2m3/day. This is very much less than the limit of abstraction requiring an Environment Agency licence, being 20m3/day.

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3 Moorfield Barn, location and setting

3.1 Site location

The Barn is located at grid reference SK 04761 92839 and at an elevation of 237mAOD, to the south-east of Glossop. High ground of over 500m is located to the east with a smaller hill to the west. The Bray clough flows to the west at a distance of 600m to the south of the barn. The barn is located outside of the large area of special scientific interest (SSSI) to the east.

Moorfield barn

Rose Bank Borehole

Moorfield barn

SSSI

Figure 1 and 1a. Site location and site setting. Ordnance Survey Licence/Customer Number (100060212)

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4 Summary of Geology and Hydrogeology

4.1 Geological setting

Geological map number 99 for Chapel en le Frith shows Moorfield barn to be located on the ‘d4’ formation being the Millstone Grit Series of Namurian age within the Carboniferous (about 322 million years old). Subdivision of the d4 series are seen adjacent to the barn, including ‘KG’ formation (KG being Kinderscout Grit). A section of the map is shown in Figure 2. In general, the Millstone grit consist of a thick series of sandstone, shale and mudstone beds. The sandstone layers in particular can be quartz-rich and very hard.

Figure 2 shows the beds to the south of the barn to be dipping to the west-north-west at an angle of about 14°.

The shale layers have a low intrinsic porosity and permeability. The sandstone has higher porosity, but flow of groundwater is governed by the presence and nature of fracturing within those layers of sandstone. The mapped faults in the vicinity might provide some benefit in terms of fracturing and cracking of the underlying formations.

Moorfield barn

Bed dip and direction

Figure 2. The geology of the site.

Springs might issue from the base of sandstone layers Springs

Figure 2a. A schematic cross-section of geology in the region. CG, RoG and KG are mapped sandstone layers within the Millstone grit series. The intervening strata contain a higher percentage of impermeable shale, although other smaller sandstone layers also exist within the shale.

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A number of springs are recorded emerging from the millstone grit within 1km of the barn. These are found at:

 Rose bank, Kidd road 450m to the south-west of Moorfield barn  Moorfield farm, 120m to the east of Moorfield barn  Highbank cottage 600m to the west  Jumble Farm 500m to the north-west

Springs occur at the base of sandstone layers at the junction between sandstone and impermeable shale. The groundwater flows to the exit point (the spring) from the zone of rainfall recharge at a higher elevation, in this case from high ground to the east. Springs can also occur on the up-dip outcrop of a sandstone layer when that layer is fully saturated.

The nature of the Millstone grit aquifer is a succession of beds of sandstone separated by impermeable layers of shale. The layers can be of the order of 0.5m up to tens-of-metres. The shale layers provide a degree of isolation of water held in adjacent sandstone layers such that they rarely interact and in many cases the nature and chemistry of water held in adjacent layers is different. It also means that abstraction (via a borehole or spring) of water from one sandstone layer is unlikely to impact on water held in sandstone layers below or above.

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4.2 Summary table of geology and hydrogeology

Site Description / local Water features

 Elevation of approximately 237mAOD.

Geology

Group/Formation Description Expected Thickness

Kinderscoutian - Fine- to very coarse-grained and pebbly, feldspathic sandstone interbedded with grey siltstone and Millstone Grit >100m mudstone, with subordinate marine black shales, thin Age 322M years coals and seatearths.

Kinderscoutian - Similar to above >150m Shale Grit

BGS Records

SK09SW39 at Rose Bank, Kidd road, 450m to the SW. The borehole is 44m deep and intercepts layers of shale and sandstone. Water was struck at a depth of 34m, rising to a rest level of 9.8m below ground. The borehole is able to support a pumping rate in excess of 2l/s (equivalent to over 170m3/day).

Hydrogeology

Rest Groundwater Level Groundwater RWL approx 10m below ground level

Aquifer Potential Millstone grit Minor Aquifer;

Productive for domestic and some larger supplies.

Water Quality

Water quality will be good, although potentially with elevated iron or manganese, requiring filtration.

Regulation

An abstraction licence will NOT be required from the Environment Agency (EA) as it is proposed to abstract < 20m3/day

Private Water Supplies Regulations (2016)

There is a requirement for all private water supplies, large and small, to be risk assessed and to meet the water quality standards stipulated in the Regulations. The quality of water from supplies over 10m3day or supplying over 50 people or any commercial activity must be monitored in accordance with specified frequencies to determine compliance. In all cases, water supplied for human consumption, food or domestic use, must be of a quality that is ‘wholesome’, whereby:

• it does not contain any microorganism, parasite or substance, alone or in conjunction with any other substance, at a concentration or value that would constitute a potential danger to human health;

• it complies with the concentrations or values tabulated within Part 1 of Schedule 1 of the Regulations,

• the water meets requirements specific to nitrate alone, and a separate limit for nitrite and nitrate combined.

The Regulations also include limits for indicator parameters. These are not part of the definition of wholesome water. These parameters indicate if there is a potential problem with the supply which needs investigating.

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4.3 Proposed Borehole Construction

In addition to the geological background derived from the published map, the borehole located at Rose Bank, Kidd road, provides a degree of control on the likely strata to be encountered by drilling at Moorfield Barn.

This borehole is located 450m to the south-west, at the same elevation as the barn and approximately along the direction of strike of the millstone grit formation, Figure 3. There is a fault located between the barn and Rose Bank, so precise depths cannot be given, but the existing borehole log (see Appendix) reports:

 Sandy clay to a depth of 4.5m  Shale to 11.2m  Brown sandstone and shale bands to 13.7m  Shale to 19.2m  Grey sandstone and shale partings to 28.7m  Shale to 31m  Grey sandstone and shale partings to 44.2m

The borehole record is typical of the millstone grit with potentially water-bearing sandstone layers shown in italic. Water was reported to have been encountered at a depth of 34m, within the lowest sandstone band.

The borehole is reported to have been tested at a pumping rate of 2.5l/s, equivalent to over 170m3 per day. This is far in excess of the (up to) 2m3/day required as a domestic water supply to the barn.

Moorfield barn Nearby borehole

Figure 3. Location of the Barn and the nearest water supply borehole.

Based on the available geological data it is recommended to drill the borehole to a depth of up to 60m for penetration through sufficient layers of sandstone. Permanent surface casing (steel) should be grouted into place at a minimum depth of 15m to provide a good sanitary seal and provide long-term support for the weaker, weathered layers near surface.

The borehole should be located at a maximum distance from an oil store. The oil store should be well protected from potential impact from traffic and be bunded. In reality, the permeability of the millstone grit shale layers is very low and provides a high level of protection against vertical movement of contaminants.

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4.4 Drilling risks

Drilling Risks

Contaminated land Presence of contamination within superficial deposits and groundwater is unlikely.

Artesian flow Artesian flow at this site is unlikely due the recorded RWL recorded within a nearby borehole. It is likely that the water will be confined within a sandstone bed located at a depth of about 30m, with the level rising to within 10m of surface.

Coal mining There is no evidence of historic coal mining in or around the site area.

Metalliferous mining There is no evidence of historic metalliferous mining in or around the site area.

Borehole instability The formations are considered to be competent and thus borehole instability is unlikely to be an issue.

Caves, fissures and faults Fractures in the sandstone layers may result in some loss of drilling fluid.

4.5 Water treatment

The quality (chemical and microbiological) will be established through detailed analysis of water samples taken from the borehole. As a minimum, the water will require chlorination and/or UV sterilisation prior to distribution to the property. In some locations in the millstone grit, elevated manganese might be present and require filtration treatment.

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5 Risk assessment of potential impact of a new borehole abstraction

5.1 Location of new borehole

It is proposed to drill the borehole within the boundary of Moorfield Barn, see Figure 4.

Figure 4. Location of the Barn and proposed borehole

The proposed location of the (bunded) oil store is located at a distance of 50m from the proposed borehole.

5.2 Potential impact of new abstraction on nearby spring

The location of Moorfield Barn and the source of water supply to Moorfield farm buildings is marked in Figure 5.

Moorfield barn

237mAOD

Spring; elevation 250mAOD

Figure 5. Location of the Barn and nearby spring

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The spring is located 100m to the east of the barn at an elevation of 250mAOD, some 13m higher than the proposed location of the new borehole.

The presence of the spring indicates a junction between a water-bearing sandstone layer and an impermeable shale surface beneath, as shown conceptually below in Figure 6.. The red arrow shows the potential location of a spring issuing from the base of a sandstone layer. In this case, groundwater would flow down-gradient from the point of rainfall recharge to the point of issue at the spring. The spring supplying water to the farm buildings will be as a result of a similar mechanism.

Rainfall recharges the sandstone strata

Predominantly impermeable shale layers

Groundwater emerges at the Spring

Figure 6. Schematic springs in Millstone grit

A borehole drilled at the barn would take water from sandstone layers approximately 35m – 50m below ground level and so separated vertically from the base of spring by about 50m. Much of this 50m section would comprise impermeable shale as seen in the nearby geological record from the borehole at Rose Bank, section 4.3 and Appendix.

We can therefore say with confidence that one or more impermeable layers of shale lie in the vertical rock section separating the ground at the barn and the base of the spring. A borehole abstracting groundwater at Moorfield barn would therefore have no impact on the spring.

The borehole at Rose Bank is recorded as being capable of providing a flow rate of over 2.5l/s or 170m3/day. As such, a new 2m3 per day abstraction at the barn, located at a distance of 450m from this borehole, would take such a small proportion of the water available within the sandstone aquifer that its’ impact would not be measurable. Similarly, the rate of flow from the springs located at Jumble farm (which feed a small tributary of the Hurst brook) is again orders of magnitude higher than the proposed domestic water supply.

In summary it is concluded that:

 Abstraction of water from a new borehole drilled at the barn would have no impact upon the flow, collection or utilisation of water from the spring located up-gradient of the proposed borehole.  Abstraction of water at a rate of less than 20m3 per day from a borehole drilled at the barn would have no measurable impact on the existing borehole abstraction located at a distance of 450m at Rose Bank, or the springs at Jumble farm

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6 General Guidance

Carbon Zero Consulting Ltd has a great deal of experience and expertise with the use of borehole water and water quality requirements for domestic & commercial requirements

If the water is to be used for human consumption, it must be sampled, analysed and passed as fit by the local Environmental Health Officer. We also recommend the installation of an ultra violet and/or chlorination water treatment system to minimise the risk of bacteriological contamination.

Furthermore, as part of the borehole development it is recommended that the borehole is sanitised using a suitable product such as hypochlorite solution to reduce the risk of microbiological build-up (bio fouling), particularly if the borehole is left open or unused for any period of time. Similarly, the pumping equipment should be sanitised before and after installation. On top of this, the borehole should not be sited within 50m of potentially polluting activities such as: Septic tanks, silage clamps, chemical or fuel stores.

Upon completion of drilling there is a general requirement to inform the BGS of the intent to drill a borehole greater than 15m in depth and to supply the geological information from the borehole to them.

This report has been prepared based on available geological and hydrogeological information. Although we have applied our experience and expertise to the data available, no guarantee can be made as to the performance of the borehole.

Development of boreholes has an inherent risk. Developers should be aware that it is possible that unforeseeable ground conditions may exist that result in increased development costs.

Carbon Zero Consulting Ltd standard terms of engagement apply to this report. Copies can be supplied on request.

References

 BGS Geology map for Chapel en le Frith (Sheet 99)  Jones H K, et al. 2000 The physical properties of minor aquifers in England and Wales. BGS Technical Report. WD/00/04. Environment Agency R&D public. 68.  OS map copying Licence/Customer Account Number (100060212)

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Appendix

Nearby borehole log taken from BGS Geoindex.

Rose Bank, Kidd Road located 450m to the SSW of the Barn

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