Contaminated land—category four screening levels
Produced in partnership with Adam Czarnecki of Earth, Environmental & Geotechnical Ltd
Contaminated land—category four screening levels

The following Environment guidance note Produced in partnership with Adam Czarnecki of Earth, Environmental & Geotechnical Ltd provides comprehensive and up to date legal information covering:

  • Contaminated land—category four screening levels
  • What are Category 4 Screening Levels?
  • Role of C4SL in the contaminated land regime
  • Soil Guideline Values
  • Development of C4SL guidance
  • Priority contaminants
  • Toxicological guidance
  • Use and levels of risk
  • Use of C4SL in the planning process

What are Category 4 Screening Levels?

Category 4 Screening Levels (C4SL) provide technical guidance for environmental consultants and regulators when assessing land affected by contamination.

By testing the levels of contamination in soil against the C4SL values, an initial assessment of the risks to human health can be made.

C4SL will play an essential role in the contaminated land regime. If contamination levels in soil are found to be below the C4SL values, the regulators can dismiss the site as clearly not contaminated land.

The screening levels can also be referred to in environmental reports submitted by developers in planning applications.

Role of C4SL in the contaminated land regime

Local authorities have a statutory duty under Part IIA of the Environmental Protection Act 1990 to identify and secure remediation of contaminated land in their areas. See Practice Note: Contaminated land—local authority duty to inspect land.

Sites should be determined as ‘contaminated land’ if they meet the statutory definition, ie where:

  1. significant harm is being caused or there is a significant possibility of such harm being caused, or

  1. significant pollution of controlled waters is being caused, or is likely to be caused

See Practice Note Contaminated land—definition of contaminated land.

EPA 1990, Pt IIA takes a risk based approach to defining contaminated land. Local authorities need to focus on land which might pose an ‘unacceptable