“Kelly” Guidelines for Classification of Contaminated Soils §

In October 1979, R.T. Kelly, the scientific advisor to the Greater London Council (GLC), delivered a paper to the Society of the Chemical Industry conference on the reclamation of contaminated land. In this paper he considered the risks to several recognized targets. He presented several useful lists, but this is the only one which is usually reproduced.

Used initially by the GLC this was quickly adopted by many waste regulation authorities in the UK as well as the Health & Safety Executive. These guidelines have been superceded by the Contaminated Land Exposure Assessment in the UK


Guidelines for classification of contaminated soils - suggested range of values (mg/kg) on air dried soils, except for pH

Parameter Typical values for uncontaminated soils Slight contamination Contamination Heavy Contamination Unusually Heavy contamination
  A B C D E
pH (acid) 6-7 5-6 4-5 2-4 <2
pH (alkaline) 7-8 8-9 9-10 10-12 >12
Antimony 0-30 30-50 50-100 100-500 >500
Arsenic 0-30 30-50 50-100 100-500 >500
Cadmium 0-1 1-3 3-10 10-50 >50
Chromium 0-100 100-200 200-500 500-2500 >2500
Copper (available) 0-100 100-200 200-500 500-2500 >2500
Lead 0-500 500-1000 1000-2000 2000-1.0% >1.0%
Lead (available) 0-200 200-500 500-1000 1000-5000 >5000
Mercury 0-1 1-3 3-10 10-50 >50
Nickel (available) 0-20 20-50 50-200 200-1000 >1000
Zinc (available) 0-250 250-500 500-1000 1000-5000 >5000
Zinc (equivalent) 0-250 250-500 500-2000 2000-1.0% >1.0%
Boron (available) 0-2 2-5 5-50 50-250 >250
Selenium 0-1 1-3 3-10 10-50 >50
Barium 0-500 500-1000 1000-2000 2000-1.0% >1.0%
Beryllium 0-5 5-10 10-20 20-50 >50
Manganese 0-500 500-1000 1000-2000 2000-1.0% >1.0%
Vanadium 0-100 100-200 200-500 500-2500 >2500
Magnesium 0-500 500-1000 1000-2000 2000-1.0% >1.0%
Sulphate 0-2000 2000-5000 5000-1.0% 1.0-5.0% >5.0%
Sulphur (free) 0-100 100-500 500-1000 1000-5000 >5000
Sulphide 0-10 10-20 20-100 100-500 >500
Cyanide (free) 0-1 1-5 5-50 50-100 >100
Cyanide 0-5 5-25 25-250 250-500 >500
Ferricyanide 0-100 100-500 500-1000 1000-5000 >5000
Thiocyanate 0-10 10-50 50-100 100-500 >500
Coal tar 0-500 500-1000 1000-2000 2000-1.0% >1.0%

§ Source: “Site Investigation and Materials Problems”, Proceedings of the Conference on Reclamation of Contaminated Land, Eastbourne, October 1979 (Society of the Chemical Industry, London, 1980).