Contaminated land strategy

5.1 Introduction

In undertaking its duty to inspect the Borough under Part 2A, the Council will take into consideration the characteristics of the area, including:

• Potential sources of contamination.

• Relevant geology, hydrogeology and hydrology.

• Potential specified receptors (all human receptors, sensitive water receptors, sensitive property receptors and relevant ecological receptors).

Before a piece of land can be considered as possibly being “contaminated land”, a “pollutant linkage” must be identified. The process of identifying pollutant linkages and of assessing the significance of each linkage is based on “contaminant-pathway-receptor” methodology.

A contaminant is a substance which is in, on or under the land and which has the potential to cause harm to a relevant receptor, or cause pollution of controlled waters.

A receptor is either (a) a living organism, a group of living organisms, an ecological system or piece of property that is being or could be harmed by a contaminant, or (b) controlled waters that are being or could be polluted by a contaminant.

A pathway is one or more route(s) or means by or through which a receptor (a) is being exposed to or affected by a contaminant or (b) could be so exposed or affected.

Unless all three elements of a pollutant linkage are identified, land cannot be considered contaminated. All search strategies will therefore be prioritised on areas where both contaminants and receptors are known or likely to exist.

For example, if an area had a land use that was likely to have been affected by contaminants it would not be considered of the highest priority if there were no specified receptors within the area of interest. This would also apply if receptors were present but pathways by which they could be exposed to the contaminants were absent. However, if one or more pathway or receptor were present then the same land use would be considered a higher priority.

5.2 Potential Sources of Contamination

Any site with the potential to cause pollution will be identified at this preliminary stage. A non-exhaustive list of land uses considered to be potentially contaminative can be found in Appendix 3. Both historical and current land uses will be considered.

Past Industrial, Commercial, Waste Disposal & Mineral Extraction Activities

The majority of potentially contaminated sites will be identified through the examination of historical data digitised layers on a Geographical Information System (GIS) showing the locations of historical potentially contaminating land uses. Documentation and records held with EHBC archives will also be utilised. Consultation with the Town and Parish Councils and with members of the public for local knowledge of past industry will also be an information source.

It must be recognised that many of those former industrial sites will have been redeveloped over the years. In some cases, they will have been redeveloped with residential dwellings, schools or other land uses that are inherently more vulnerable to the presence of contamination than the original land use. In such cases the methods and extent of remediation may be unknown; in others it may be known but the adequacy of the remediation will need to be examined. This will be a factor considered during Stage 2 (Methodical Detailed Inspection of Prioritised Sites) of the process to identify potentially contaminated sites (Section 6).

Current Industrial, Commercial, Waste Disposal & Mineral Extraction Activities

The present industrial areas of the Borough are also potential sources of historical contamination, and these will be inspected in accordance with the statutory guidance to establish whether there is a potential for contamination, and if there is, whether it is controlled by another regulatory regime.

5.3 Potential Specified Receptors

Land can only be considered contaminated if the contamination adversely impacts specified receptors:

Human

The present population of the Borough is approximately one-hundred and twenty thousand. The potential for persons either living on or frequenting a potentially contaminated site will be considered within the prioritisation process, with higher priority assigned to sites occupied and frequented by children.

Property - Buildings

All buildings are potential receptors and will be considered in every case where contamination and buildings exist. Ancient Monuments as listed by English Heritage will also be specifically identified as part of the strategy.

Property - Crops including Timber

Being a largely rural area, crop growing regions will not be specifically identified but taken into consideration as necessary. Where contamination is known or suspected, associations with poor yield and crop failure can be investigated. Crop failure as a result of contamination is, however, unlikely.

Property - Produce Grown Domestically and on Allotments

There are many acres of allotments within the Borough and these will be factored into the risk prioritisation process as will the presence of domestic gardens.

Property - Livestock, Game and other Owned Animals

Again, being a largely rural area, the presence of livestock or other animals in an area will not be specifically identified but taken into consideration as necessary.

Ecological Receptors

All identified ecological receptors will be considered as part of the strategy. There are several specified sites including four Sites of Special Scientific Interest (SSSI), three Local Nature Reserves (LNR) and other areas of ecological importance.

Water - Controlled Waters

All surface water receptors, such as rivers, streams, tributaries, reservoirs and lakes, will be considered as part of the inspection strategy. All groundwater receptors including Principal, Secondary and non-aquifers will be identified and factored into the risk prioritisation process.

Water - Public Water Supplies

All public water supply abstraction points will be considered as well as their respective Source Protection Zones. All other authorised abstraction points will also be considered including those used for agricultural or recreational use.

Water - Private Water Supplies

There are 17 known private water supplies in the Borough and their existence will be factored into the risk prioritisation process. The protection of these is particularly important due to the heavy reliance on them by local communities. The Council already monitors these supplies as part of its duties under the Private Water Supplies (England) Regulations 2016 and 2018 (Amendment) Regulations.

5.4 Potential Pathways of Exposure to Contamination

Pathways by which receptors can be exposed to contamination are many and will vary considerably depending on the contaminant and the different types of receptors. It is neither practical nor appropriate to summarise all potential pathways in this document, but for context two examples are provided below.

For volatile contaminants, or gases a pathway to human exposure could be through cracks in, or service penetrations through, concrete floor slabs. Whereas for contaminants in a liquid or solid phase this pathway to human exposure would not be significant, but direct contact with the soil, or dusts from the soil, containing the contaminants may well be.

For contaminants in the ground that can be mobilised by precipitation, or that exist in a liquid form, a porous/permeable geology will represent a viable pathway through which those contaminants could move laterally or vertically to impact on a surface water or groundwater receptor. Whereas, if those same contaminants were present in, or were contained by, an impermeable or low porosity/permeability geology then that pathway would be much less significant or not viable at all.