2001:713 - KILKENNY: Guinness Ireland Complex, River Breagagh, Kilkenny

Monitoring was carried out at the Guinness Ireland Group plant in Kilkenny city during July–September 2001. This work entailed monitoring of the excavation of river gravels from the River Breagagh, a tributary of the River Nore. During the early 1980s a quantity of PCB (a substance used as a coolant in refrigerated units) leaked into the River Breagagh. Accordingly, a depth of approximately 1.7m of gravels was excavated from the riverbed as part of the River Breagagh PCB Remediation Project in 2001.

The Guinness brewery in Kilkenny is bounded to the east by the River Nore, to the south by Bateman Quay, to the west by Horse Barrack Lane and a lane known as The Ring, and to the north by the properties on Vicar Street and Green Street. The brewery is divided into a northern and a southern section by the River Breagagh. The abbey of St Francis occupies a central place within the southern portion of the brewery. The church remains consist of a 13th-century choir with a later belfry. The River Breagagh, which appears in summer to be a small stream, can develop into a fast-flowing torrent after heavy rainfall. Its name is derived from the Irish bréagach, meaning deceitful, and probably refers to the ability of the river to change from a stream into a torrent after inclement weather. The river is confined to a relatively narrow channel, approximately 8m wide. Prior to excavation the riverbed varied in height from 43m to 41.56m OD.

The river is bounded along its southern side by a masonry wall that formed the boundary of the medieval friary precinct. This wall, which appears to be medieval, has been altered and repaired in antiquity. A modern concrete wall marks the northern line of the river channel. At the point where the River Breagagh meets the River Nore a small structure, known as Evan’s Tower, survives.

As the excavation progressed, two profiles of the river gravels became available for recording. A north-facing section, approximately 1m north of the medieval wall, was exposed. Prior to excavation the top of the riverbed rested at approximately 42.7m OD at this point. It was apparent that, in this location, at a depth of approximately 1m below the upper surface of the riverbed, the river gravels and silts ceased to contain cultural material such as slate, plastics, glass and ceramics.

A second profile was obtained upstream, where a masonry wall was revealed. The wall comprised the lowermost foundation courses of a riverside wall which had been used as the foundation for a modern concrete brewery wall. The remains of a doorway were present in the upstream end. The wall, which survived for a length of approximately 11.7m and a height of 0.6m, was composed of large subangular limestone boulders sitting in two roughly deposited courses. At the upstream side of the door ope the wall survived to a maximum height of 5.2m. A compact brownish-grey mortar bonded the masonry. Some 0.8m of alluvial silts and gravels were sealed under the wall. It is likely that the wall dates from the post-medieval period.

At the point where the rivers Nore and Breagagh converge, sampling had revealed a PCB contamination ‘hotspot’. In order to safely excavate this material a sheet pile coffer-dam was constructed, measuring approximately 22m south-west/north-east by 5m. The deposits within this dam were excavated to a depth of approximately 3m. A portion of a single-edged iron sword was retrieved from a depth of approximately 1m below the upper surface of the riverbed. Traces of a leather scabbard adhered to the metal.

The sword is presently undergoing conservation and treatment for PCB contamination. Several fragments of cut stone were also retrieved from the river. Conservation works aimed at stabilising Evan’s Tower were also undertaken.

2 Killiney View, Albert Road Lower, Glenageary, Co. Dublin