2014:609 - Ballynashallog/Ballynagard (Thornhill College), Derry

Pre-development test trenching was undertaken during 9–28 July 2014 at a proposed development site at Thornhill College, 142 Culmore Road, Derry, Co. Londonderry, having been commissioned by Whitemountain Quarries Ltd. The works undertaken relate to a request for additional information by the Northern Ireland Environment Agency: Historic Monuments Unit (NIEA:HMU) prior to making a Planning Decision under Planning Policy Statement 6: Built Heritage 4 (PPS 6:BH4) in response to a Planning Application for the development of the site comprising the construction of a surfaced car park providing 93 spaces with associated landscaping and car parking and all necessary associated site works including provision of drainage and lighting (Planning Ref: A/2013/0508/F).
A total of 235m of linear trenches, comprising nine trenches each c.1.5–1.8m wide, was excavated within the area of proposed invasive groundworks. No archaeological features, remains or deposits were identified during the test-trenching evaluation works.
Test Trench 1 extended through the centre of the PDA, along its long axis (east-south-east/west-north-west), for a distance of 72m. Within the east-south-eastern end of Trench 1, removal of topsoil revealed natural subsoil at a depth of 0.1–0.25m. A series of parallel linear marks were noted cutting into the subsoil within this portion of the trench and appear similar to the type of marks caused by the teeth of the digging bucket of a mechanical excavator.
Further excavation of this trench revealed that the shallow topsoil overlay layers of modern infill from approximately 25m from the east-south-eastern end of Trench 1 to its west-north-western limit. Within the central portion of Trench 1, these layers of modern infill measured 0.25–0.5m in depth. Within the west-north-western portion of the trench, however, these layers of modern infill were up to 1.7mm deep. Within the central portion of the trench, these layers of infill primarily comprised various redeposited clays containing modern bricks, concrete blocks, hand tools and general waste construction materials. However, within the west-north-western portion of the trench very considerable quantities of steel reinforcing bars, plastic sheeting and concrete pipes were noted.
Excavation of the remaining eight test trenches confirmed the results of Test Trench 1. Within Test Trenches 2 – 5 the infill deposits measured 1–1.4m in depth, while in Trench 6 the deposits were 1.7m deep at its north-north-western end and 0.7m deep at the south-south-eastern end of the trench. Subsoil was encountered at a depth of 0.4–0.6m in Trench 7 and 0.2–0.4m in Trenches 8 and 9.

150 Elmvale, Culmore, Derry BT48 8SL.