There is enough silt in Kings Pond to fill almost four Olympic-sized swimming pools, a survey has revealed.

Alton company Ground & Water – which did silt sampling, analysis and reporting for Alton Town Council – said the volume of silt in the pond was 9,400m³, similar to that dredged in 1996.

The council said: “The silt is contaminated with high levels of some metals, particularly lead and zinc, and also with high levels of polycyclic-aromatic hydrocarbons (PAHs). The PAHs are from road run-off traffic pollution.

“Although the silt contains plenty of organic matter and nutrients, the contamination levels mean that it cannot be used for agriculture, allotments or gardens.

“The contamination is also above the levels recommended for recreational land use, but the silt could be re-used at Kings Pond provided that the surface is capped with cleaner material.

“Despite the level of contamination, the silt would not be classified as hazardous waste in landfill.”

The survey drawings and the silt report are available on the council website at

In accordance with council resolutions from January, the next stage is assessment of the feasibility and cost of removing the weir.

The council picked Surbiton firm Water Environment Limited to do this assessment.

It was also asked to provide an outline of the possible options for river and pond if the weir was to be removed.

This report will be received by the end of December.

The council will review it in January and consider if there are options that could be developed alongside dredging.

There will be public consultation on dredging and any other options in spring 2024 before discussion and decision at a full council meeting.

No work will be done until investigation and feasibility study results, and any project or management plans, have gone to public consultation.