Soil Testing Guidance
1. Common Chemical Testing Suites for Soils
1.1 Waste Classification Test
The classification assesses the composition of the material and determines the concentrations of the hazardous substances in the material. The Waste can be classified as non-hazardous or hazardous on the basis of a standard range of inorganic and organic chemical analysis. Waste classification also includes allocation of an EWC code.
- Metals (total: As,Cd,Cr,Cu,Pb,Hg,Ni,Se,Zn)
- Chromium (III and VI)
- PAH (EPA16 & Oil 8)
- VPH (>C5-C10)
- EPH (>C10-25, >C25-C40)
This suite forms the basis of any waste classification. These are key contaminants without which no classification would be complete. Additional contaminants can be added if required based on type of site, site history or any other suspected contaminates that may be encountered on site.
Clients often expect to see “inert” in their waste classification report.
This suite can only classify waste as non-hazardous or hazardous.
Within the non-hazardous range there are two sub-categories: chemically clean and contaminated.
- Chemically clean – the levels are below the contaminated thresholds
- Contaminated – the levels are above clean thresholds but below hazardous thresholds
Waste cannot be classified as Inert without an Inert passing WAC test. (additional to chemically clean non-hazardous result by a Waste Classification Test)
1.2 WAC Testing
It is designed to simulate how waste will behave once it has been consigned to landfill, primarily by the analysis of leachates derived from that waste.
The Council Decision (EU) sets specific limits, commonly referred to as 'WAC leaching limits', for a sub-set of the components that the waste producer must consider. These apply to all wastes destined for disposal in a landfill for hazardous, stable non-reactive hazardous and inert waste.
WAC analysis (specifically leaching test results) must not be used for waste classification and hazardous waste assessment purposes. This analysis is only applicable for landfill acceptance and does not give any indication as to whether a waste may be hazardous or non-hazardous.
So, this testing only needs to be carried out if 'non-hazardous' material needs to be landfilled as inert or hazardous soils need to be landfilled. In the event that non-hazardous or hazardous material is being removed from site for treatment or restoration then waste acceptance criteria (WAC) is often unnecessary.
Vast majority of the haulage companies think a WAC test is always required prior to disposal of the waste due to lack of understanding and knowledge of EA and EU regulations. Haulage companies then advise their clients to arrange for a WAC test and classify waste using the WAC results only.
POPs are Persistent Organic Pollutants (synthetic organic chemicals). Since the Environment Agency issued new guidance on the assessment of hazardous waste (guidance note WM3), waste containing specified POPs at concentrations of 50mg/kg or below qualifies as hazardous waste. If the waste is pop tested and contains dioxins or furans, a concentration of only 15 µg/kg will render the waste hazardous.
- You can only store (‘stockpile’) material that contains POPs if you have a legal use for it, under exceptions to the POPs ban. You must tell the Environment Agency if at any time you store more than 50kg of material containing POPs within your business, ie across all the sites that you operate.
- Any material that contains a POP counts towards your 50kg limit, no matter how low the concentration of the POP within the material.
- If you take material out of storage to use it, it still counts towards your 50kg limit as long as it remains within your business.
- You must tell the Environment Agency that you’re storing POPs within 6 months if you exceed the 50kg limit.
- You must then update the Environment Agency every year if your business continues to store more than 50kg of material containing POPs.
Dioxins & Furans
polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF),
- DDT (1,1,1-trichloro-2,2-bis (4- chlorophenyl)ethane),
- hexachlorocyclohexanes (including lindane),
PCBs (ICES 7 & WHO 12)
toxaphene hexabromobiphenyl polychlorinated biphenyls (PCB’s)
2. Sampling plan for waste classification and assessment
2.1 Background Information
In order to have a clear idea which analysis is required, one would need the following information as a minimum requirement:
- site details
- reason for testing
- process or nature of arising
- type, form and amount of material
- known physical, biological or chemical characteristics
- operational procedures that may affect characteristics
- previous investigations or analysis
- Sampling should be taken in accordance with the sampling plan. Any deviations from the sampling plan should be documented on the sampling record.
- Observations made during sampling should also be recorded. These can be useful when interpreting the results.
- Providing photographic evidence (e.g. where sample taken from, stockpiles, quarantine areas and background features which will aid locating the photograph etc)