Three boreholes were drilled using conventional shall and augur methods on a site to the west of North Station Road and adjacent to the River Colne. General ground level was relatively flat but with spoil heaps on parts of the site. The three boreholes revealed a similar sequence consisting of made ground over sand and gravel which overlay silty clay underlain by silty sandy clay. The depth and thickness of each deposit varied between boreholes. The made ground comprised brick and concrete rubble, ash etc. in a matrix of clay. In borehole 1 it extended to a depth of 2.3m. In borehole 2 to a depth of 1.8m, and in borehole 3 to a depth of 2.3m. Sandy river terrace gravel was found to depths of 4.3m. This rested upon the London clay. Groundwater was encountered beneath this site on reaching the gravel layer. It rose to within approximately two metres of the ground level in boreholes 1 and 3.<1>