York Historic Environment Record

On the 12th July 2021 York Archaeological Trust (YAT) conducted a borehole evaluation at Mill House, North Street. Following on from this work three Test Pits were excavated on 11th and 12th January 2022. The boreholes and test pit evaluation were undertaken at the preplanning stage to determine the nature of deposits that would be encountered at the site. The works involved the drilling and recording of six windowless sample boreholes. Cores were recovered from five of the six boreholes which were inspected, recorded and sampled. A six-month groundwater and water quality-monitoring program was undertaken between July 2021 and January 2022. This included the instillation of water level and quality water monitoring equipment and sampling for baseline environmental and geochemical conditions. Modern material, including the current ground surface and underlying rubble accounted for a maximum of 2.36m at the top of the observed sequence. The upper surface of earlier archaeological deposits was identified at around 0.4m below ground level (BGL). Archaeological deposits were observed to extending up to 8.5m BGL. Encountered within the archaeological deposition were layers interpreted as potential pit fills, a probable wall constructed from mortar-bonded limestone and numerous layers containing preserved organic material. The Test Pits revealed some medieval deposits largely dating to the 13–16th century, together with modern walls and surfaces.