Environment Agency Finally Responds and Objects to Thames Farm Planning Proposal

The Environment Agency has objected to the engineering operations associated with ground stabilisation works at Thames Farm proposed housing development this week due to its “unacceptable risk to the environment.”

The EA were previously asked to respond to former planning applications at Thames Farm, the last one in August 2024 for a variation on conditions for outline planning and responded “this for development we do not wish to be consulted on.”

In this response the EA states, “We recommend that planning permission refused for the following reason – The risks to groundwater from the development are unacceptable. The applicant has not supplied adequate information to demonstrate that the risks posed to groundwater can be satisfactorily managed.”

“The Environment Agency’s approach to groundwater protection opposes development proposals that may pollute groundwater especially where the risks of pollution are high and the groundwater asset is of high value. Groundwater is particularly sensitive in this location because the proposed development site is within source protection zone 1 and is located upon principal aquifer for drinking water.”

The response goes on to say that “To ensure development is sustainable, applicants must provide adequate information to demonstrate that the risks to groundwater posed by development can be satisfactorily managed. In this instance the applicant has failed to provide this information, and we consider that the proposed development may pose an unacceptable risk of causing a
detrimental impact to groundwater quality because of two broad aspects of concern: 1. The use of grout in a sensitive groundwater location and need for monitoring, and 2. the implications of the proposed surface water disposal mechanism. We are not satisfied that either of these broad areas have been adequately assessed at this stage.”

The Thames Farm site latest planning application is for a reduced number of dwellings (84) as opposed to the original 96 with a new sustainable water drainage system proposed.

The EA is concerned about the new proposed infiltration basin.  In their response they states “The basin to the east of the site is where there are low apparent conductivity values, possibly related to potential voiding within the underlying chalk. It is also noted to be a low-lying part of the site which has the most risk of flooding at present. The Environment Agency has concerns that the proposed infiltration of the site’s surface water (from most, if not all, of the site) into a single concentrated area of the site will promote increased dissolution of the bedrock in this area of the site, and thus reduced attenuation of any contaminants before reaching the water table. It is also unclear how the infiltration will perform in an area that is proposed to be altered by the stabilisation works.”

The EA says to overcome their objection they will need “satisfactory risk assessment and full supporting information that demonstrates that the risks to groundwater posed by this development can be satisfactorily managed” and that an Environmental Permit may be required on this site.

Henley Town, Harpsden and Shiplake Councils along with the Thames Farm Action Group have all objected to this application.  The Councils commissioned, a hydrogeological expert, to conduct a thorough assessment of the proposed drainage strategy.

Peter Boros from Thames Farm Action Group said, “Very glad to see that at last they (EA) seem to be taking this matter seriously.”