Deepham’s Sewage Works, Edmonton, Greater London

In May 2010 Oxford Archaeology South (OAS) were commissioned by Thames Water Ltd to maintain a Watching Brief on geotechnical boreholes at Deepham's
Sewage Works, Edmonton, Greater London. The purpose of the field investigation was to provide baseline data on the underlying sedimentary sequence at the Site,
which lies partly on the floodplain just to the west of the River Lea. This work forms part of an initial phase of archaeological investigation aimed at assessing the
archaeological potential of the Site prior to redevelopment.
Following the recommendations of the previous desk-based assessment, and in consultation with Greater London Archaeological Advisory Service and Thames
Water, five out of the eight borehole locations were selected for monitoring. A 2m deep Holocene alluvial sequence was recorded towards the east of Site in BHMW8.
This comprised minerogenic silts and sands with inter-bedded organic silt and peat deposits. The alluvial sequence overlay the Pleistocene gravels at +6.90m OD. No
evidence of archaeological activity was identified, although similar peat deposits in the area are known to preserve remains dating from the Neolithic to Bronze Age.
The waterlogged condition of the sediments also have excellent potential to preserve organic remains suitable for palaeoenvironmental reconstruction.
The remaining boreholes (BHMW1-7) encountered the Pleistocene gravels at higher elevations, between +10.40m and +10.10m OD, suggesting the gravel terrace is
located towards the northwest of the Site. This is confirmed by the geological mapping of the area that suggests the terrace edge crosses the center of the Site
on a north-south alignment. Victorian and Modern make-up deposits were also identified overlying Langley Silts in this area, with clear signs of truncation in some
areas down to Pleistocene gravel.
This initial phase of work suggests in prehistory the Site would have been located atthe interface of an important ecotonal zone, between the gravel terrace and
floodplain. Topographically these areas are known to have been a focus of activity in the past due to the abundance of wetland resources available for exploitation, as
well as the close proximity of dry ground suitable for more permanent settlement.
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