Colchester Archaeological Trust excavated three test pits within the building. <1> All of the observations were made from the top of the three test-pits: Test-pit 1 (TP1) The uppermost 1.1m of TP1 consisted of two layers of concrete and two layers of crushed brick which are all associated with the construction of the modern Colnebank House building. A brick wall constructed of large, unfrogged, soft red bricks (230mm x 110mm x 60mm), bound in a white mortar, was encountered beneath the modern building layers. This wall is part of the remains of an early 19th-century silk mill which formerly occupied the site. The wall continued to a depth of around 2.0m below modern ground-level where it appeared to rest on a shallow concrete foundation. The brick wall was cut into a soft dark grey/black alluvial silt which contained frequent stones and oyster shells (L3 in the 2009 evaluation; CAT Report 526). <2> Occasional small CBM fragments and animal bone were observed in the silt layer. The water-table was reached at a depth of 2.54m below the internal ground-level. Just below the water-table, a relatively compact gravel level was encountered consisting of large rounded flint nodules. A close examination of the gravels in the upcast material revealed Roman pottery sherds mixed with the flint nodules. It is most likely that the Roman finds were stratified just above the gravel in the base of the dark silt deposit just below the watertable. Smaller gravels in a light grey/orange sandy matrix were encountered at a depth of 2.7m below internal ground-level. This deposit was interpreted as the natural river gravel. Test-pit 2 (TP2) In TP2, the concrete floor overlay a layer of crushed bricks and concrete rubble, as in TP1. The second layer of concrete only covered the southern third of the test-pit in the area to the south of a large east-west orientated brick wall. The brick wall was constructed of large, unfrogged soft red bricks (230mm x 110mm x 60mm), bound in a white mortar, and is presumed to be associated with the 19th-century silk mill. A small north-south orientated section was excavated through the wall, which continued below the water-table to a depth of approximately 2.6m below the internal ground-level at which point a solid ?concrete foundation was encountered. The concrete layer to the south of the wall overlay a very loose, deep deposit of crushed concrete, which in turn overlay a thin concrete ?floor. A layer of render on the southern face of the brick wall suggests that this may be the internal face of a wall, perhaps a cellar which was backfilled prior to the construction of Colnebank House. To the north of the wall, a loose dark silt containing frequent brick fragments continued beneath the watertable. This deposit is interpreted as the backfill material which was banked up against the wall following its construction. Two old services were encountered in the loose dark silt. In summary, all the ground excavated in TP2 had been disturbed/built up between the construction of the silk mill in 1826 and the construction of Colnebank House following the demolition of the mill in 1967. Test-pit 3 (TP3) The uppermost 1.0m of TP3 consisted of two layers of concrete and two layers of crushed brick which are all associated with the construction of the modern Colnebank House building. The modern building layer overlay the same soft dark grey/black alluvial silt identified in TP1 (L3 in the 2009 evaluation). As well as small stones and oyster shells, post-medieval pottery, animal bone and Roman tile were all observed in the uppermost 1.0m of the dark silt (to a depth of approximately 2.0m below internal ground-level). Just above the water-table, at a depth of 2.4m below modern ground level, a layer consisting mostly of medium-sized flint nodules was encountered. As well as flint nodules, four septaria blocks were identified (the largest of which was 210mm x 100mm) and fragments of Roman pottery vessels and animal bone were recovered. This deposit continued below the water-table and was approximately 250mm deep. At a depth of 2.65m below internal ground-level, the same river gravel in a light grey/orange sandy matrix was encountered as in TP1. The evaluation followed trial trenching around the building in 2009 (CAT Report 526). <2>