Contaminated Land Inspection Strategy 2024 to 2029

Stockton-on-Tees has a considerable industrial heritage, and a legacy of historic unregulated waste disposal which now requires methodical recovery and remedial work to bring it back into everyday use. The Government's policy on dealing with this legacy is through the Contaminated Land Regime under Part 2A of the Environmental Protection Act 1990 as outlined in the DEFRA Contaminated Land Statutory Guidance (DEFRA 2012) whose aims are:

• (a) to identify and remove unacceptable risks to human health and the environment
• (b) to seek to ensure that contaminated land is made suitable for its current use
• (c) to ensure that the burdens faced by individuals, companies and society are proportionate, manageable, and compatible with the principles of sustainable development

Under these provisions (Part 2A of the Environmental Protection Act 1990 (inserted into that Act by section 57 of the Environment Act 1995) local authorities were required to implement a "strategic approach" to inspecting their areas to identify land where contamination is causing unacceptable risks to human health or the wider environment.

This document will review the existing strategy and outline its priorities for contaminated land. It is proposed in this strategy that emphasis shall continue to be upon the high-risk sites which are of most concern to human health and the environment and to prioritise pollution incidents where they occur. The Planning Development Regime is the main method of assessing and remediating all potentially contaminated land. This includes the lower risk sites as well as medium and high-risk sites.

Historic and built environment

The River Tees is a key feature of the Borough, historically acting as a trade route during the Eighteenth Century, bringing the area into economic prominence. Industries included mineral extraction, brick and tile manufacture, iron and steel manufacturing, shipbuilding in the early Nineteenth Century.

In 1825 the world's first steam locomotive train was operated between Stockton and Darlington railway, and this was used to transport coal.

This is evidenced by its archaeological remains and historic buildings. The Tees Archaeology Historic Environment Record (HER) is a database of heritage assets in Hartlepool and Stockton managed by Tees Archaeology. It includes archaeological sites and standing remains dating from the prehistoric and Roman periods through Anglo-Saxon and medieval periods, to post-medieval and industrial remains. The earlier sites in the Borough are complemented by more recent heritage, such as the new town of Billingham, founded around the ICI chemical works in the early 1920s and the latter 20th century oil and chemical industry based at Seal Sands.

Stockton contains 8 scheduled monuments which are afforded protection by the Ancient Monuments and Archaeological Areas Act 1979. Listed Buildings, also of national importance, are protected by the Planning Act 1990. Non-designated above and below-ground heritage assets (identified in the HER) are protected by policies in the Stockton Local Plan.

The Tees Barrage, completed at the end of 1994, acts as a flood defence from rising river levels, particularly to prevent local flooding in Yarm.

Characteristics of the area

Stockton-on-Tees is within the Tees Valley which adjoins the five Local Authority areas of Darlington, Hartlepool, Middlesbrough, and Redcar and Cleveland. The Borough is divided by the River Tees covering an area which is approx. 20,400 hectares.

Stockton has a population of 194,119 and consists of 84,0470 dwellings. The density of population is 9.5 persons per hectare. A substantial proportion (62.5 %) of the properties in the Borough has residential gardens.

Part of the Tees mouth and Cleveland Coast is a site of special scientific interest (SSSI) for its nationally important geological and biodiversity features that occur within coastal and freshwater habitats. This includes the Tees mouth and Cleveland Coast Special Protection Area (SPA) and Ramsar site (a wetland site designated of international importance under the Ramsar Convention).

Geological and hydro geological characteristics

The geology of the area impacts upon the groundwater vulnerability by means of its permeability, porosity, and geological composition. These geological factors affect the vulnerability to groundwater contamination from sources such as landfills, industrial sites, and agricultural practices.

The geology is divided into i) superficial deposits originating from the Quaternary Period (Boulder clay, alluvium and magnesian Limestone formation) ii) Solid bedrock comprising of Permian magnesian limestone, marl, and sandstone layers.

The Sherwood Sandstone Aquifer is the main source of groundwater in the area. Within the Borough, there are three principal water abstraction points where the water is abstracted for consumption. Ground Vulnerability maps indicate that most of the area has low permeability drift deposits which overlay the aquifers.

The Environment Agency has identified one groundwater Source Protection Zone [SPZ] for the protection for drinking water. Stockton-on-Tees Borough Council has no Indicative Flood Risk areas in accordance with the criteria produced by Defra.

Regulatory and policy context

In April 2000, Part 2A of the Environmental Protection Act 1990 (inserted into that Act by section 57 of the Environment Act 1995) came into force. The main objective requires local authorities to implement a "strategic approach" to inspecting their areas to identify land where contamination is causing unacceptable risks to human health or the wider environment.

This is the sixth review of the Contaminated Land Strategy to reflect the changes in service provision, contaminated land legislation, and published guidance. This should be read in conjunction with the Contaminated Land Statutory Guidance issued by the Defra (April 2012). 

The Statutory Guidance recognises that there are two broad types of "inspection" likely to be carried out by local authorities:

• (a) strategic inspection, for example collecting information to make a broad assessment of land within an authority's area and then identifying priority land for more detailed consideration
• (b) carrying out the detailed inspection to obtain information on ground conditions and carrying out the risk assessments which support decisions under the Part 2A regime relevant to that land

Stockton-on-Tees Borough Council assumes all the land within the Borough is not deemed "contaminated land" under Part 2A of the Environmental Protection Act unless a detailed assessments of the land have been undertaken which outlines the information gathering procedure.  

If the local authority intends to carry out a detailed inspection it will use statutory powers of entry under section 108 of the Environment Act 1995. For special sites (as defined under the Contaminated Land Regulations 2006) the local authority may request the Environment Agency carry out an intrusive inspection of the land on behalf of the Authority.

Strategic implementation

Stockton-on-Tees Borough Council's Local Plan (2019) and associated National Planning Policy Framework (NPPF) is a key mechanism for the Council to deliver its priorities to protect the vulnerable; create economic prosperity; tackle inequality; and help people to be healthier.

Local Plan Policy ENV7 (Ground, Air, Water, Noise and Light Pollution) within the Local Plan (2019) states that where contamination exists, planning proposals must demonstrate via site investigation that any issues will be satisfactorily addressed by appropriate mitigation measures to ensure that the site is suitable for the proposed use and does not result in unacceptable risks which would adversely impact upon human health and the environment.

It is envisaged that the Contaminated Land Strategy will be incorporated into other strategic documents such as Stockton Councils Air Quality Strategy 2024 to 2029, the Public Health Plan and the Joint Health and Well-being Strategy to support the health protection role of the Council. 

Progression of the strategy

This is the sixth strategy document setting out Stockton-on-Tees Borough Council's proposals for the identification, assessment, and remediation of contaminated land within the Borough of Stockton. This replaces the previous Strategies published in 2001, 2003, 2009, 2014 and 2019.

The original Strategy ('A Strategy for Remediation and Reclamation of Contaminated Land', April 2001) focused upon identifying and prioritising areas of contaminated land within the Borough. The Council in partnership with the Jacobs Babtie Group Ltd carried out a site categorisation exercise using a computer model. The methodology for the model is set out in the Identification, Prioritisation and Risk Ranking of Potentially Contaminated Land: Babtie Group Limited [June 2002].

The 2003 and 2009 to 2014 Contaminated Land Strategy focused upon preliminary site inspections of the sites and final prioritisation of the sites requiring specific site information.

The fourth strategy document (2014 to 2019) reflected a change of approach to the inspection regime, as most of the sites had been inspected and assigned a risk category. The high-risk category sites (PPC1 sites) where given priority for assessment and remediation due to the greatest potential risk to human health.

This prioritisation continued in the 2019 to 2024 strategy, with a focus upon voluntary remediation of high-risk sites, reactive work, and dealing with contaminated land through the development control regime.

Role of the Environment Agency

The Environment Agency (EA) also plays a major role in supporting the Council with contaminated land matters and assists with:

• advice regarding the pollution of controlled waters and remediation for sites which have the potential to be a "special site"
• advice where significant pollution or significant possibility of significant pollution is occurring on a site
• providing information which the Local Authority may rely upon to decide whether a site meets the legal definition of contaminated land
• advice on whether a site meets the requirements for designation as a "special site"
• inspecting potential special sites on behalf of the Local Authority
• formalising designation of special sites, for which the Environment Agency are the enforcing authority

Contaminated controlled waters also have the potential to impact upon the quality of land. The local authority will therefore liaise closely with the Environment Agency wherever the contamination of controlled waters is likely.