2016:173 - Grousemount Wind Farm, Kerry

John Cronin and Associates were commissioned by ESBI to undertake a phased programme of test trenching at the Grousemount Wind Farm development near Kilgarvan, Co. Kerry in order to comply with a grant of planning issued by Kerry Co. Co. (planning ref. 10/1333). The proposed wind farm development will involve the amalgamation of two previously approved wind farms: Barnastooka Wind Farm (14 wind turbines) and Grousemount Wind Farm (24 wind turbines). Phase 1 of test trenching was carried out between 05/04/16 and 14/04/16. Testing began to the south of the substation location and progressed upslope in a south-westerly direction. A total of 1.5km of 2m wide centre line test trenching and 615m of test trenching at the locations of BP-H and BP-Q was completed during the Phase 1 investigations at Grousemount Wind Farm.

Two relict field boundaries, of probable post-medieval date, were observed in the general location of BP-Q. The presence of such boundaries in the general wind farm development area was noted in the Cultural Heritage chapter of the EIS prepared for the development. These features were not designated as Cultural Heritage Sites in the EIS and no mitigation strategy was recommended. Aside from the field boundaries no finds, features, deposits of archaeological interest were uncovered during Phase 1 of testing.

Phase 2 was carried out between 28/04/16 and 01/06/16, an approximate total of 7,310m of trenching was completed along the proposed centre line of the main wind farm access roads, turbine access spurs, met mast locations and the turbine base/hardstand locations. While the vast majority of the excavated trenches proved to be sterile with no finds, features or deposits of archaeological interest generally encountered, a number of previously unrecorded archaeological sites, both extant and sub-surface, were encountered along, and in the vicinity of, the trench route and proposed construction areas. As well as that, a number of previously recorded sites proved to be either in the path of or in close proximity to the proposed access roads. Appropriate mitigation procedures will be implemented at the location of these sites prior to the construction phase of the project in order to protect them and their immediate environment. Mitigation recommendations for the affected sites are:

•On the approach to the T12, 13 and 14 access spurs the cultural heritage chapter of the E.I.S. has identified a number of hut sites/booley huts to the north-east of the access road (CH 19, 20, 21, 22, 24), while they will not be directly impacted by construction works, a marked 20m protective buffer zone will be erected around them to prevent against any accidental damage or encroachment of plant or materials to their vicinity.

•A previously unrecorded probable hut site/booley hut was observed c.40m to the west of the T12 access spur at ITM grid co-ordinate 509234, 569213. A marked 20m protective buffer zone will be erected around this feature prior to the construction phase to prevent against any encroachment of plant or materials to its vicinity.

•A previously recorded site identified in the Cultural Heritage chapter of the E.I.S., CH25 - hut site/booley hut, ITM grid co-ordinate 508754, 569706, was found to be directly in the centre line of the main wind farm access route leading to BP-F. A 20m buffer zone was maintained to the north and south of the site. It has been recommended that it would be appropriate to re-align the road a distance of at least 20m to the west of the existing site, a marked protective buffer zone will also be erected prior to the construction phase of the project to prevent against any encroachment of plant or materials to the vicinity of the site.

•A previously unrecorded probable hut site/booley hut was observed 15m east of the centre line of the proposed access road to BP-F, at ITM grid co-ordinate 508726, 568838. The planned route of the access road will be re-aligned to the west of the structure to allow for the erection of a marked 20m protective buffer zone around the site.

•A previously unrecorded sub-surface deposit of charcoal-enriched peaty soil and heat-shattered stone, which has been interpreted as a possible burnt spread, was uncovered beneath 0.3m of peaty soil on the centre line of the proposed access road to the west of BP-F at ITM grid co-ordinate 508195, 568593. Approximately 40m to the west of this deposit the top of the sub-surface remains of a stone bank were also uncovered beneath 0.3m of peaty soil, also on the centre line of the proposed access route, at ITM grid co-ordinate 508169, 568595. The stone bank, which was constructed of loosely placed, large sub-angular and sub-rounded stones, measured 1.5m in width (east-west) and 0.45m in height. Additional test trenches which were excavated 15m north of the northern extent of both discoveries proved to be sterile. To allow for the possible burnt spread and stone bank to be preserved in situ, the main access road will be re-aligned to follow a more due west orientation (a minimum of 30m from the identified features) as it exits Borrow Pit – F. This will facilitate a route to the north of the sites to be taken before rejoining the original proposed route to the east of the Roughty River.

•Approximately 95m of the access spur to T09 could not be tested due to excessive peat depths. It is recommended that this area be monitored during the construction phase of the project.

•A possible bedrock mortar was observed on small rock measuring 0.83m east-west by 0.5m at ITM grid co-ordinate 509350, 569640. The hollow is oval in shape measuring 0.2m east-west by 0.16m and is c.60mm in depth, it is located approximately 30m south-east of the main access road between the substation location and Borrow Pit H. A marked 20m protective buffer buffer zone will be erected around the possible feature prior to the commencement of the construction phase of the project to protect against any encroachment of plant or materials to the vicinity of the rock.

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