We regret that former Chalk Pit in Otford, including the entrance in Pilgrims Way East, is closed to the public after an independent survey found large underground cavities throughout the site posing a danger to life.
In recent years, sink holes have appeared. As a safety precaution, we partially closed the site in September 2023 and brought in an independent surveyor to investigate the cause and extent of the problem using ground-penetrating radar.
The survey uncovered widespread evidence of large underground cavities, which may be filled with water. Many are believed to be close to the surface and could give way at any time, putting life in danger.
The site will be closed while we carry out further investigations with additional fencing and signage installed.
Members of the public should not enter the site for their own safety.
The public right of way between Tudor Drive and Station Road, around the edge of the Chalk Pit, currently remains open.
We have also surveyed the site in and around the nearby Scout Hut. The survey found no signs of subsidence or underground cavities.
A structural appraisal of the retaining wall and earth embankment adjacent to Pilgrims Way East chalk pit found the area to stable requiring no remedial works.
We remain committed to restoring the Chalk Pit so this popular open space can be reopened as soon as possible.
Survey results
Download and view the survey reports
Timeline
|
Phase |
Activity |
Location |
Date |
|---|---|---|---|
|
1 |
Ground Penetrating Radar Survey |
Chalk Pit |
10 June 2024 |
|
1 |
Ground Penetrating Radar Survey |
Scout Hut site |
19 June 2024 |
| 1 |
Geologist and KCC Engineers Site Survey |
Chalk Pit | 26 June 2024 |
| 2 |
Dimitrios Kalianidis BSc (Hons) CGeol FGS commissioned (Independent Chartered Geologist of the Geological Society, London) |
Chalk Pit | 26 June 2024 |
|
3 |
Commissioned a Geologist/Hydrologist to view all results |
Chalk Pit & Scout Hut sites |
Appointed 21 June 2024 |
| 2 |
Intrusive Ground Testing, such as boreholes, trenches and electronic survey |
Chalk Pit | From 8 October 2024 |
Intrusive Ground testing update
We have commissioned, through our appointed geologist team, the following three phases of works, which will begin from 8 October 2024.
Phase 1
Geophysical data collection (resistivity; non-destructive survey). These will include the data collection, interpretation and reporting of the underlying terrain to determine the resistivity characteristics of the ground, which can be attributed to the state of compaction/density of the wider underlying terrain. This will be done with the latest industry leading equipment from ABEM (Terrameter LS Advanced).
Phase 2
Ground Investigation – in-situ testing. This allows for a crew with a dynamic probing/sampling terrier rig machine, which will undertake probing exercise down to 10 metres or refusal over a period of two days (which will likely to achieve 10 to 15 tests) and based on the outcome of the surveys from phase 1.
Phase 3
Reporting - This will include the collation of the information and presentation of it in a report format providing conclusions of the findings from the previous two phases and any recommendations that will arise from the assessed results of the previous 2 phases.
Chalk pit questions and answers
Site history
During the Victorian period, the site was an open chalk pit and then used as a landfill site. In recent years, sink holes have appeared, which were subsequently filled in.
In 2021 Otford Parish Council ended its long-term lease on the former Chalk Pit due to mounting health and safety maintenance costs from Ash Dieback. We took back responsibility for the site.
As there is new evidence of underground voids filled with water, we will carry out further investigations. The surveys will provide recommendations and advice for our next steps.
There are no plans to develop the former Chalk Pit as the site is allocated as an open green space in our current and new Local Plan.
If you have any questions about the site, please contact Trevor Kennett, Head of Direct Services.