Wandle Housing Association

Brief:

To investigate the soil in the gardens on an estate following complaints from residents of poor plant growth and adverse impacts on the health of pets.

A typical rear garden

Project:

The houses were situated on a “T” shaped cul-de-sac, each with a private garden. A previous visual investigation had been undertaken and report prepared by others following tenants raising concerns regarding builders’ rubble found in their gardens and poor plant growth. Go Contaminated Land Solutions reviewed the previous investigation and undertook sampling to assess the site conditions using a mix of boreholes and shallow trial pits. A drive-in sampler which could be carried through the properties was used to form the boreholes.

Items we found in just one trial pit included a scaffold clip, builders’ rubble and car parts.

In many of the gardens pieces of builders’ rubble protruded above ground, in one the end of a scaffold pole was visible and in another a whole pre-cast concrete edging was found. It would appear that over time rain had washed the original thin dressing of topsoil down into the voids between the underlying rubble.

The samples were tested for a typical range of metals, hydrocarbons and polycyclic aromatic hydrocarbons. While no elevated levels of contaminants were identified the soil was found to be of a poor quality as a growing medium and advice was provided on improving the soil quality so that the residents could enjoy the proper use of their gardens.