The proposed construction area has been greatly affected by volcanic activity since the end of the Ice Age that occurred almost 10,000 years ago. Most of the area is covered by tephra, which mostly covers the underlying lava and pseudocraters. Geological research was conducted in the area between 2013 and 2015. The following information is based on the results of this research (see Appendix 4).
Lava has flowed from the fissure swarms at Veiðivatn on at least eleven occasions. The fissure swarms are connected to the Bárðarbungu volcano, and portions of six of the eleven lava fields are located within the demarcation of the proposed Búrfell Wind Farm site. The two youngest lava fields from the Veiðivatn fissure swarm cover most of the proposed Búrfell Wind Farm site. The 3,000 year old Búrfell lava is closest to the surface beneath a layer of loose material comprised of tephra and sand. The average depth down to the lava is approximately 4 m. The other four lava fields from the Veiðivatn fissure swarm probably followed river channels in the area. This conclusion is based on the fact that these four lava fields have not been discovered in as many boreholes as the two youngest lava fields mentioned above.
The Sölvahraun lava field and the Taglgígahraun lava field are the only lava fields that do not originate from the from the Veiðivatn fissure swarm. The lava originates from the Hekla volcano and is approximately 1,200 years old. The loose materials and tephra layers between the layers of lava also originate from Hekla. The Sölvahraun lava field is to the south of the area in proposals 1 and 3, and the Taglgígahraun lava field is at the surface in the northeast corner of proposal 2. Core drilling results showed the minimum depth to solid ground to be 1.3 m and the maximum depth to solid ground to be 10.5 m.
The Búrfell Wind Farm is located in a recently formed lava field under a tephra layer with an average thickness of 4 m. The area is rather flat, and pseudocraters are quite common. Lava fields and pseudocraters are landscape types under special protection by the law on nature conservation. However, these landscape types are barely visible at the surface since a layer of tephra covers the area. The area, therefore, has a low protection value. The tephra is not protected according to the outlined criteria.
Impact on geological formations
Possible disturbance to land in proposal 1 as a result of the proposed construction work: 0.9 km2
Tephra will, in some cases, be replaced by ground material with a better load bearing capacity to facilitate the construction of wind turbines and roads. The magnitude will depend on the conditions within each area. The total volume of the material used for the foundation of wind turbines will depend on the foundation method used for implementation. Wind turbines can either be constructed directly on bedrock or rock anchors can be used in the construction process. These methods do not cause any significant disturbance to geological formations, although the anchor method does cause slightly more disturbance to the environment. Any visible disturbance to geological formations is barely registrable.
The material extraction areas that will be used for construction work (discussed here ) are not within areas that have a protection value according to the General Plan and nature conservation laws. Landsvirkjun is committed to the responsible treatment of the area and the completion of finishing work to a high standard (discussed below). This commitment to responsible development includes construction work pertaining to the wind turbines, creation of roads and material extraction.
Possible disturbance to land in proposal 2 as a result of the proposed construction work: 1 km2
The proposed construction work will have a localised, negative impact on geological formations with a protection value. These include lava fields and pseudocraters under special protection by Act No. 60/2013 on nature conservation. The effects will be permanent as the soil layer will be removed and partially utilised for material processing in connection with construction work. However, these geological formations are presently, almost completely covered by tephra. Their protection value is limited as a result of their coverage, and the effects are considered to be insignificant. The design and installation of the masts and other construction work within the area will be executed with minimum disturbance to soil.
The effect on geological formations with a protection value that are located within material extraction area is considered to be insignificant. There is no difference in impact significance between proposals.
The design process ensures that the scope of roads, platforms, storage areas and other construction components is kept to a minimum. This reduces the impact on geological formations.
Landsvirkjun also outlines strict requirements on environmental and safety issues for its contractors and service providers. The following requirements are outlined with regard to finishing work and site behaviour. The objective is to minimise any disturbance and to reduce the impact on geological formations. The requirements are as follows:
- Any disturbance to soil outside the construction area is prohibited..
- Any unnecessary disturbance to soil within the authorised construction area shall be avoided. Off- road driving is prohibited.
- The disposal of oil or oil based substances into water, groundwater or soil is prohibited.
- The provisions outlined in the project specifications with regard to finishing work on permanent structures, material extraction mines, spoil areas and work areas for work camps and other facilities, shall be followed.
- The construction site should be kept tidy by all employees during the construction period.
FThe requirements will be implemented in this project as they are in all other Landsvirkjun projects. Landsvirkjun’s Environmental Management System monitors construction work and ensures that the impact on the environment is limited to the specifications detailed in the results of the EIA, licensing requirements and Landsvirkjun’s policies.