77
Former Gasworks, Pitwines, Poole, Dorset
Archaeological Monitoring for Crest Nicholson Residential (South) Ltd
by Andrew Mundin
Thames Valley Archaeological Services Ltd
Site Code PPD 03/45
June 2003 Summary
Site name: Former Gasworks, Pitwines, Poole, Dorset
Grid reference: SZ 018 905
Site activity: Archaeological Monitoring
Date and duration of project: 10th - 18th June 2003
Project manager: Steve Ford
Site supervisors: Andrew Mundin and Richard Oram
Site code: PPD 03/45
Area of site: c. 4.36ha
Summary of results: No archaeological finds or deposits were recorded. Archaeologically relevant levels were deeply buried by made ground/
Monuments identified: None
Location and reference of archive: The archive is currently held by Thames Valley Archaeological Services Ltd, 47-49 De Beauvoir Road, Reading, Berkshire, RG1 5NR and will be deposited with Waterfront Museum, Poole in due course.
This report may be copied for bona fide research or planning purposes without the explicit permission of the copyright holder
Report edited/checked by: Steve Ford 2.07.03 Steve Preston 02.07.03
i Former Gasworks, Pitwines, Poole, Dorset Archaeological Monitoring
by Andrew Mundin
Report 03/45b
Introduction
This report documents the results of archaeological monitoring carried out at the site of the former gasworks,
Pitwines, Poole, Dorset (SZ 018 905) (Fig. 1). The work was commissioned by Mr Malcolm Kirk, Technical
Manager, for Crest Nicholson Residential (South) Ltd, Nicholson House, 41 Thames Street, Weybridge, Surrey,
KT13 8JG. Planning permission is to be sought from Poole District Council for the construction of new housing on the site.
A desk-based assessment (Hodgkinson and Emmett 2002) highlighted the history and the possibility of archaeological remains on the site. It also highlighted the geotechnical data that had already been collected on the site in January 2000. This indicated that the site was heavily disturbed and that a considerable thickness of made ground (3.5m+) overlay the archaeologically relevant levels. In order to provide information on the presence and nature of any archaeological deposits present in order to inform any mitigation that might be required, field observation would be necessary, usually in the form of trial trenching. This requirement is accordance with the Department of the Environment’s Planning Policy Guidance, Archaeology and Planning
(PPG16 1990), and the District Council’s policies on archaeology. However, as the likely impact of the new development proposals were unlikely to have a serious effect on the archaeologically relevant levels, coupled with the logistical difficulties of conventional evaluation trenching on a contaminated and deeply buried site, an alternative strategy was proposed to provide relevant information.
A scheme was proposed to archaeologically monitor the excavation of geotechnical test pits and trenches which were to be carried out as a part of various remediation works on the site. This field investigation was carried out to a specification approved by Mr Keith Jarvis, Archaeological Officer for Poole Museum Service.
The archaeological monitoring was undertaken by Andrew Mundin and Richard Oram between the 10th and 18th June, 2003, and the site code is PPD 03/45. The archive is currently held by Thames Valley
Archaeological Services Ltd, 47-49 De Beauvoir Road, Reading, Berkshire, RG1 5NR and will be deposited with the Waterfront Museum, Poole in due course.
1 Location, topography and geology
The site is located on derelict land east of Poole Town (Fig. 1). The land was formerly the site of extensive gas works and it is possible that the land was subject to reclamation in late post-medieval period as well as in modern times. T underlying natural geology is river terrace gravel (BGS 1991) but with boreholes indicating that alluvium and peat overlie it. The land has a gradual slope from east to west and lies at c.3m above Ordnance
Datum. The site is split in two by Seldown Bridge, which is raised above the site, and is bounded to the north by the railway line that runs east-west (Fig. 2).
Archaeological background
The site is situated in an area where very little archaeological finds or sites are recorded in the Dorset Sites and
Monuments Record. The desk-based assessment noted that the origins of Poole could belong in Roman times, but its main growth stemmed from the 13th century as a port for trading Purbeck marble (Hodgkinson and
Emmett 2002). The desk-based assessment also contained maps of Poole from 1634, 1662 and 1751, which show the development of Poole and the extent of land reclamation around the harbour area (Hodgkinson and
Emmett 2002, figs 3–5). The site itself might be in an area where coastal conditions are favourable for preservation of prehistoric features, which have been sealed by made ground or flooding. The development of the harbour and waterfront, which is situated roughly half a kilometre from the site (Fig. 1) are areas of archaeological interest.
Objectives and methodology
The purpose of the archaeological monitoring was to:
Determine if any archaeological levels are present within areas of ground disturbance associated with the excavation of the geotechnical test pits and trenches. Excavate and record any archaeological deposits which would be damaged or disturbed during the excavation of the geotechnical test pits and trenches.
Twenty geotechnical test pits were to be dug with a tracked machine fitted with a toothed bucket. Eleven geotechnical test trenches were also to be dug in the same manner.
Results
The archaeological observation of this site was limited by the restriction of the size of the test pits dug, and their depth. However, it soon became apparent that the ground had been heavily truncated by the gasworks. The
2 ground had also been contaminated with an oily substance and clinker, making the ground hazardous to handle and noxious to inhale. Seventeen of the 20 test pits and five of the eleven test trenches were fully observed to the limit of excavation.
A complete list of testpits and trenches observed giving lengths, widths, depths and descriptions of sections and geology is given in Appendix 1. All spoil heaps were monitored to finds.
Test pits
Each test pit was 3 to 4m long and 0.8m wide. As shown in Figure 2, these test pits were positioned on areas where the buildings of the gas works once stood. As they were opened it was soon observed that the footings and foundations for these buildings had reached far into the contaminated made ground, and it would seem that the made ground was contemporary with the gasworks building. It also seemed that any dumping and reclamation on this site had taken place quite recently, judging from the pottery in this made ground. None of these modern finds were retained.
All test pits became waterlogged, when the water table was reached at a maximum depth of 2.7m below the surface. Any alluvium that was seen in the test pits, which was usually at a depth of greater than 3m, contained no finds of archaeological note.
Test trenches
The test trenches uncovered similar stratigraphy to the pits, with much truncation and contamination of ground from the former gasworks. Less of the trenches were observed than the test pits, due to their greater depth and the instability of the ground around them that the digging caused. Where observed, these trenches were excavated through the alluvium at 3m down, and into the natural geology (sand) at a depth of over 4m. Again, however, no finds or archaeology was noted in any of the test trenches.
Finds
No archaeologically relevant finds were observed during the archaeological monitoring, and any late post- medieval or modern pottery from the contaminated made-ground was not retained.
Conclusion
The monitoring has confirmed what was expected from the borehole data, that is archaeologically relevant levels are deeply buried by made ground. No archaeological deposits were noted on the site nor were any pre-modern finds recovered. The contaminated made ground on the site was not of archaeological note. No archaeological
3 finds were observed in the alluvium from the bottom of the test pits nor from the natural sand at the bottom of the test trenches.
References
BGS, 1991, British Geological Survey, 1:50,000, Sheet 329, Solid and Drift Edition, Keyworth Hodgkinson, D and Emmett, J, 2002, Proposed Redevelopment at Former Gasworks at Pitwines and Poole- An Archaeological Desk Based Assessment , Wardell Armstrong job NL04504 report 01a, Cardiff PPG 16, 1990, Archaeology and Planning, Dept of the Environment Planning Policy Guidance 16, HMSO
4 APPENDIX 1: Test pits and trench details
Test Pit No. Length (m) Width (m) Depth (m) Comments 1 not seen 2 3-4m 0.8m 2.4m 0.3m concrete onto black contaminated clinker fill, +2m 3 3-4m 0.8m 2.6m 0.2m concrete onto 0.2m sand/silt then contaminated fill 4 3-4m 0.8m 2.6m 0.2m concrete, 0.2m sand/silt made ground, alluvium at base 5 3-4m 0.8m 2.7m 0.15m concrete, 2.4m contaminated silt/sand, alluvium at base 6 3-4m 0.8m 2.6m 0.1m concrete, 2.2m contaminated silt/sand, alluvium at base 7 3-4m 0.8m 2.3m 0.15m concrete, 2.3m contaminated silt/sand, alluvium at base 8 not seen 9 3-4m 0.8m 3.2m Modern sandy/gravel over concrete footings, alluvium at base 10 3-4m 0.8m 0.65m 0.4m concrete, 0.6m silt/sand, 0.65m contaminated silt 11 3-4m 0.8m 2.05m 0.6m concrete, shells at 0.61m, 2.05m+ made ground 12 3-4m 0.8m 2.1m top & subsoil over footings, 2.1m+ contaminated made ground 13 3-4m 0.8m 0.55m 0.2m concrete, 0.33m made ground, rubble to base of footing 14 3-4m 0.8m 0.6m 0.4m concrete, made ground, 0.5m asbestos 15 3-4m 0.8m 3m+ Tarmac, made ground to footing at 1.2m, alluvium at 3m 16 3-4m 0.8m 1.95m 0.2m limestone rubble, made ground with footings to depth 17 3-4m 0.8m 2.9m 0.2m limestone rubble, contaminated made ground, footings to 2.4m 18 not seen 19 3-4m 0.8m 1.14m+ Tarmac, made ground, footing at1.14m, contaminated ground below 20 3-4m 0.8m 3.1m Tarmac, made ground, footing at1.07m, contaminated ground below
Test trench No. Length (m) Width (m) Depth (m) Comments 1 6m 0.8m 4.7m Tarmac, contaminated ground to 2.8m, sandy clay onto sand 2 6m 0.8m 2.1m top & subsoil onto modern sandy backfill, alluvium at 2.1m 3 6m 0.8m 2.1m top & subsoil onto contaminated clinker, alluvium at 2.1m 4 not seen 5 not seen 6 4.5m 0.8m 2.2m Made ground to 1.4m onto contaminated clinker with footings 7 not seen 8 not seen 9 not seen 10 6m 0.8m 1.9m 0.15m limestone rubble, made ground, contaminated ground to base 11 40m 0.8m 4.3m top & subsoil onto modern backfill, contaminated ground to alluvium.
5 Shaftsbury SITE
92000 Blandford Forum Bridport Dorchester Poole
Bournemouth Swanage
Weymouth
91000
90000 SITE
SZ01000 02000 PPD03/45 Former Gasworks, Pitwines, Poole, Dorset, 2003 Archaeological Monitoring
Figure 1. Location of site within Poole and Dorset.
Reproduced from Ordnance Survey Outdoor Leisure 15 at 1:12500 Ordnance Survey Licence AL52324A0001 Former Gasworks, Pitwines, Poole, 2003
N
Pit win es C lose
90700 R 20 ailw ay Line 19 18
e 17 g 16 d ri B
n w o 11 d 15 l e S
1 9 1 10
1 8 7 2 2 3 9
6 14 5
3 4 4 13
12 8 10 5 7 6 11
Newfoundland Drive
90400
SZ01600 01700 01800
Test Trench Test Pit Location of Pre-existing gasworks
0 100m
Figure 2. Location of geotechnical test pits and trenches. PPD 03/45