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Frequently Asked Questions

Why is the residential with plant uptake SSV for Zinc so low?
Zinc is not tabulated in CLR 8 as a potential contaminant for human receptors. The residential without plant uptake and commercial / industrial values are very high for zinc, as would be expected. However, the residential with plant update value is not. This is assumed to be as a result of an unduly conservative component of the vegetable uptake algorithm. Hence if exceedances of the zinc residential with plant update SSV are identified it is recommended that a more detailed risk evaluation or site specific risk assessment should be undertaken. If you would like more information on this please contact a member of the ATRISKsoil team.
How do I access the sample data?
Click here to login to view the sample data. You will then be transferred to the SSV Data area.
Who do I contact if I have a question about the website?
Please send an e-mail to webmaster@atrisksoil.co.uk with any questions you might have.
I have registered but cannot access the SSV Data. What should I do?
You will not be able to access the data until you have received an authorisation e-mail. Please wait for your e-mail, or contact a member of the team
I have registered but cannot access the SSV Data. What should I do?
You will not be able to access the data until you have received an authorisation e-mail. Please wait for your e-mail, or contact a member of the team
Why was the new version of the SNIFFER methodology not used to develop the SSVs?
The SNIFFER methodology is a useful tool for site-specific human health risk assessment in that it has been developed within the UK regulatory framework. However, Atkins has chosen to use a customised version of the BP RISC 4.0 model rather than the SNIFFER methodology for several reasons associated with the nature of the contaminants for which we needed to derive SSVs and preferred modelling approaches, including: SNIFFER does not currently include the dermal pathway. It contains a prominent warning to users that it should not be used for any contaminants for which the dermal pathway is significant; these include many semi-volatile organic compounds, such as phenol and the PAHs. Atkins required SSVs for many of these contaminants and wished to use a single risk assessment tool for all SSVs. The approach to modelling indoor vapour intrusion within SNIFFER requires the user to select an appropriate dilution factor between soil vapour and indoor air. The approach does not account for soil or contaminant properties. Atkins wished to use the Johnson and Ettinger model (as incorporated in the BP RISC 4.0 model) for modelling vapour intrusion as this approach is recommended in the Environment Agency 2002 report on vapour intrusion.
Do the confidentiality clauses in the Terms and Conditions for the use of ATRISKsoil prohibit practical use of the SSVs?
No, not at all. The confidentiality clauses are designed to prevent wholesale copying and distribution of the Soil Screening Values and supporting data to non-subscribers. It is felt that this could result in misapplication, and in due course the use of out of date values, as well as compromising Atkins intellectual property rights. However, it is understood that to use these values in the manner intended (e.g. to appraise screening values quoted in reports, to appraise the need for site-specific DQRA, or to identify potential mistakes in approaches taken to risk assessment) there may be a need for a subscriber occasionally to present both specific SSVs and selected background information to a third party. This is why toxicological and modelling parameter information which supports the use of the SSVs is available to subscribers to the website. Such use of the information contained on the website would not be considered by Atkins to be a breach of the subscription agreement.
What happens when Defra and the Environment Agency publish an SGV for one of the contaminants included in ATRISKsoil?
At any time in the future, when an SGV is published this will of course take precedence over the SSV, which has no formal status. An SGV will have been accepted by both Defra and the Environment Agency and in addition the toxicological parameters will have been sanctioned by the Department of Health. The database will be amended to reflect this situation, i.e. the SSV will be removed and a note posted on the website.
What will happen if the newly published SGV differs from the SSV, would this prompt a complete reassessment of any site to which the SSVs have been applied?
This would depend on the exact circumstances, perhaps including whether the assessment was still in progress. Past experience suggests that it is unlikely that the release of an SGV would prompt a wholesale reassessment; for example, the currently available SGVs did not result in a wholesale re-evaluation of sites addressed prior to 2002. Also, there is no greater (and perhaps even less) a risk of this happening with the SSVs than there is with any other non-SGV screening criteria which are used to assess contamination.
Can SSVs be used within Part IIA assessments?
SSVs are designed to be used as an initial screening tool for land contamination assessment, including identification of sites where further assessment may be required to establish their status under Part IIA. However, it is considered likely that a more detailed study would be needed to support PIIA determination of a site, for instance a full pollutant linkage assessment and/or DQRA. Additionally, unlike the SGVs, SSVs have no formal status.