Soil Guideline Values

Produced by Defra and based on human toxicity data, SGVs are indicators of levels of contamination in soil that may present an unacceptable risk to human health as a result of exposure to that soil.

Typically set at a conservatively low level, SGVs are "trigger values"; exceeding them means only that further site-specific investigation is necessary and does not automatically indicate that there is a risk to health requiring remedial measures.

Intended to serve as an aid to local authorities in the determination of contaminated land under Part 2A, it has since been acknowledged by Defra and the Health Protection Agency that the scientific data is lacking that would enable SGVs to provide irrefutable evidence of potential harm to human health.