Guardbridge geothermal technology demonstrator project: feasibility report

11. Regulatory Considerations

11.1 Introduction to the environmental concerns

Fig. 13: Guardbridge is sited next to the Eden Estuary which has SSSI, SPA, SAC and Ramsar status. Data are gathered from Scottish Natural Heritage.

The key environmental concerns about the development and production of a geothermal well are related to the exploitation of a groundwater resource, the impact of exploration and operation on the surrounding environment in the sensitive and protected area of the Eden Estuary, and what happens to the geothermal water after the heat is extracted. The Eden Estuary is part of the Firth of Tay and Eden Estuary Special Area of Conservation ( SAC) site and the estuaries represent high quality Annex 1 estuarine habitats (Regulation 33(2) of the Conservation Regulations). The Eden Estuary is a Site of Special Scientific Interest and a Local Nature Reserve. The Guardbridge Energy Centre sits between the Eden River and the Motray Water, directly adjacent to the tidal flats of the upper estuary (Fig. 11.1). Species include tidal reed beds of Phragmites australis and mudflats contain mud-dwelling invertebrates, such as the amphipod Corophium volutator, the mud snail Hydrobia ulvae and ragworm Hediste diversicolor; these species support the over-wintering waders and wildfowl. Saltmarsh communities include Juncus gerardii, Scirpus spp. and Puccinellia spp. with Festuca spp. (Bates et al., 2002). Sparse beds of eelgrass Zostera angustifolia can also be found to some extent in both estuaries and reefs of the mussel Mytilus edulis are common on the intertidal banks of the main Eden Estuary channel (Bates et al., 2002). The reefs support the common starfish Asterias rubensin. The mussel reefs are confined to the intertidal muddy areas where they support ephemeral green algae, such as Enteromorpha sp. that extend as thick mats during the summer months. Several species listed in Annex II of the Habitats and Species Directive also occur regularly in the Firth of Tay and Eden Estuary SAC. There is a non-breeding population of grey seals ( Halichoerus grypus) that travel up and down the estuary, and otters Lutra lutra occur on the River Eden above Guardbridge. The intertidal sediment flats (to mean low water springs) are an existing Ramsar site and classified SPA for overwintering wildfowl and waders, as well as for the marsh harrier Circus aeruginosus and little tern Sterna albifrons (Bates et al., 2002).

As a tidal estuary, the salinity changes from upstream of Guardbridge to the estuary mouth and over tidal and seasonal cycles. Salinities approaching 0 psu are associated with the River Eden flows upstream of Guardbrdige, but can reach 25 psu within the mudflats at and around Guardbridge, or as high as 46 psu in salt flats (Spears et al., 2008). Any water disposal to sea as part of the water geothermal water management would need to accommodate these spatially and temporally varying salinities.

11.2 Regulatory requirements

The regulatory issues involve licensing to abstract a groundwater resource and for disposal to sea, and also adherence to EC habitat regulations. The relevant regulatory authorities and organisations involved are the Scottish Environmental Protection Agency ( SEPA), Fife Council, Scottish Natural Heritage, and Scottish Water. Exploration for, and disposal of, water is regulated under the Water Environment (Controlled Activities) Scotland Regulations ( CAR) 2011 (amended 2013). Geothermal exploration and abstraction will require registration and a Simple License (for a borehole > 200 m deep and abstracting 50 - 2000 m ³/d). Disposal to sea will require a Complex License that covers surface water run-off during drilling and inorganic and thermal effluents as point source pollutants (> 100m ³/d). Applications to SEPA for registration and authorisation will also need to follow guidance covered in WAT-RM-05: Regulation of Trade Effluent Discharges to Surface Waters or WAT-RM-06: Regulation of Trade Effluent Discharges to Groundwater.

Table 11.1: Identified environmental issues associated with a hot saline aquifer geothermal project at Guardbridge.

Article 6(3) of the EC Habitats Directive is adhered to in Scotland through a Habitat Regulations Appraisal ( HRA) which is required for any plan or project which is likely to have a significant or uncertain effect on the integrity of a site ( HRA of Plans: Guidance for Plan-making bodies in Scotland, 2015). Since the Eden Estuary is a Special Area of Conservation ( SAC), a Special Protected Area ( SPA) and a Ramsar site, as well as a Site of Special Scientific Interest (Fig. 11.1), any developments surrounding such sites and involving noise, disruption of soils and rock, or disposal of water and sediments to sea requires careful consideration, licensing and permissions.

For this report, an outline of the recommended developments for a geothermal well as proposed in Section 4 has been discussed with the Scottish Environmental Protection Agency and Scottish Natural Heritage, in order to identify the main concerns and the appropriate licensing and legislative requirements. As part of this report, the potential factors, effects and impacts associated with a Guardbridge geothermal project, were it to go ahead, have been listed in Table 11.1, and this would need to be formalised for the screening stage of a Habitat Regulations Appraisal.

11.3 Requirements for Phase 2 Stage

SNH (Gavin Johnson of SNH Cupar) were contacted as part of this feasibility study and this section summarises their response. If the project is to go to the stage of exploratory test drilling, or is to be completed as a production well, it is very likely to that an Environmental Impact Assessment and an Environmental Statement from the developer will be required before any work on site can commence, due to adjacency of the Guardbridge site to the Eden estuary SPA; the final decision for this lies with Fife Council. The project is " likely to have a significant effect" which will need to be evaluated. Regardless of whether an EIA is required, a legislative assessment will be required by the developer in the form of a Report to Inform an Appropriate Assessment.

As part of the planning applications for the biomass plant (Fife Council 14/02334/ EIA), Environmental Statements were submitted which have been reviewed as part of this report. These extensive documents provide an existing baseline for any future Environmental Statements and are therefore very useful in identifying the risks to the sensitive surrounding areas. SNH have noted that while the investigation into the environmental impacts of exploration and operation of a geothermal well will be a function of the scale of the proposed construction, operation, waste water disposal and heat storage if developed, the project will be viewed in conjunction with other ongoing operations at Guardbridge.

SNH was advised by their ornithologist that construction and operational (direct and indirect) impacts will need to be assessed. For Phase 2, detailed plans will be required to provide more information on partial and/or full disposal-to-sea, the disposal location and the nature of what is being disposed in terms of salinity, pH, and elemental geochemistry, as well as the temperature, volume, flow rate of the water. An assessment of any disposal will need to evaluate the impact upon the biota within the intertidal sediments or the eelgrass growth, i.e. the prey/food base for the qualifying bird interests of the SSSI, SPA and Ramsar sites. To evaluate the impact of the disposal-to-sea option on the biota, particularly the saltmarsh, SNH will require values for the maximum disposal quantities and frequencies, along with the Eden River river flow data and estuarine flushing.

Given the potential for the project to progress with a recommendation for some or all of the geothermal water to be disposed to sea, a competent authority ( SNH or Fife Council with the latter's consultation) will need to complete an Appropriate Assessment. Phase 2 of the Guardbridge Geothermal Project will need to consider all of the conservation objectives below:

1. Population of the species as a viable component of the site
2. Distribution of the species within site
3. Distribution and extent of habitats supporting the species
4. Structure, function and supporting processes of habitats supporting the species
5. No significant disturbance of the species

Table 11.2 summarises some of the environmental and legislative guidance that will be relevant to developing Phase 2 of the project.

Table 11.2: Review of environmental and legislative guidance relevant to local authorities.