Contaminated Land Inspection Strategy 2019-2024

The following priority actions will be undertaken in accordance with the procedure outlined in Figure 2 "Procedures for Investigating Sites":

• to complete inspections of all remaining PPC1 sites in accordance with this strategy
• to respond to complaints/enquiries from the public and other agencies on contaminated land issues and to take appropriate action
• to encourage developers and landowners to remediate potentially contaminated land to the appropriate standard using workable planning conditions /agreements
• to supervise voluntary remediation of sites  
• to continue to provide guidance to developers through the Planning Regime.
• development of the SBC website to assist developers during the planning process and submitting Environmental Information Enquiries, which can form the basis of an enquiry prior to a planning application being submitted.

4.1 Environmental Search Report

The Environmental Health Department presently uses the QGIS4 to risk assess and prioritise potentially contaminated land. It is proposed that the geographical information system will be updated to incorporate new themes (such as archaeological sites of interest) and update the environmental information which have been obtained from contaminated land reports submitted through the planning process.

The information obtained by the search will be used to support planning application and Environmental Information requests under the Environmental Information Regulations 2004. The reports will be used during strategic preliminary inspections of sites and to determine whether further intrusive site investigations are required.

4.2 Strategic Preliminary Risk Assessment (Desk Top Study)

Strategic Preliminary Risk Assessments (desk top studies) will be produced in accordance with the risk assessment principles based on the contaminant-pathway-receptor approach.  The studies will normally be carried out by the Senior Environmental Protection Officer. These risk assessment studies will aid the understanding and the associated uncertainties of the land in question and findings will be developed into a conceptual model for each site to identify whether or not there are any potentially unacceptable risks.

4.3 Sampling

Where a strategic preliminary risk assessment (desk top study) has been carried out and the site conceptual model identifies the potential for one or more significant contaminant linkages to exist, Stockton Borough  Council will aim to carry out sampling of soil and / or water (subject to funds being available) to further develop knowledge and identify uncertainties.

4.4 Funding Site Investigation Work

Defra withdrew its Capital Grant funding in March 2017 for contaminated land remediation. To fund the investigation work, the Council shall seek to negotiate with current land owners, occupiers and known permitters of contamination. If possible other sources of funding will be investigated. Stockton Council may also fund the works, and where required will use it powers under Part 2A definition of contaminated land.

4.5 Site Investigation and Strategic Preliminary Risk Assessment

Further to sampling having been carried out to enhance the understanding of a site conceptual model, any land identified in a strategic preliminary risk assessment (desk top study) as having the potential for one or more significant contaminant linkages to exist will require a detailed investigation, e.g. intrusive site investigation and risk assessment.

The decision to progress to an intrusive site investigation and risk assessment is taken by the Senior Environmental Protection Health Officer and the Environmental Protection Team Manager with the agreement of the Head of Service. The scope of the risk assessment will be considered, and in cases where intrusive site investigation is proposed, the Council will also consider the need for an archaeological evaluation of the site before works commences. Stockton Borough Council may choose to carry out site investigation and risk assessment works itself, or alternatively may employ the services of environmental consultants to carry out the work on their behalf. 

Environmental consultants would be selected following a tendering process.  Regardless of who carries out the intrusive works and risk assessment, the final decision as to whether the land constitutes contaminated land lies with Stockton Borough Council.

Site investigation and risk assessments will be carried out in accordance with the Contaminated Land Statutory Guidance (2012) and the standards available at the time for general site investigations, soil quality standards, water sampling, and assessment of ground gases.

Currently these are; Land Contamination Risk Management (Environment Agency, 2020), BS EN ISO 21365:2020 (Soil Quality: Conceptual site models for potentially contaminated sites). BS 10175:2011+A2:2017 (Code of Practice for Investigation of Potentially Contaminated Sites), BS 5930:2015+A1:2020 (Code of Practice for Ground Investigations) and BS 8576: 2013 (Guidance in Investigations for Ground Gases), BS 8485:2015+A1:2019 (Code of Practice for the Design of Protective Measures for Methane and Carbon Dioxide Ground Gases for New Buildings), BS 8676:2013 (Guidance on investigations for ground gas - permanent gases and volatile compounds.)

The results will be compared against the relevant assessment criteria.

Following the outcome of the site investigation and risk assessment process the Council will then assign the land into one of the 4 categories detailed in paragraphs 4.19 to 4.29  of the revised Statutory Guidance and a decision will be made as to whether the land meets the definition of contaminated land under Part 2A of the Environmental Protection Act 1990.

4.6 Dealing with Unforeseen Urgent Sites

Where information is received indicating the possibility of imminent significant harm to health or imminent significant pollution of controlled waters, a strategic preliminary site assessment (desk top study) will be carried out to determine the likelihood of such an event occurring.  Where it is identified that a significant contaminant linkage is likely to exist, urgent action to carry out further investigation will be necessary and an action plan will be drawn up and implemented. 

This work would take priority over the scheduled programme of work for 2019 to 2024.

List of unforeseen urgent sites remediated between 2014-2019

4.7 Work Programme and Timescales for 2019-24

Table 3. Work programme and Timescales for 2019-24