WORKING GROUPS / POSITION PAPERS

POSITION PAPER ON THE MANAGEMENT OF ARSENIC IN SOUTH AFRICA.

Arsenic concentrations in soils and waters that exceed contaminated soil and drinking water quality screening levels respectively are commonly encountered in South African contaminated land projects.  Assessment of atmospheric arsenic is rarely undertaken in South Africa, and the extent of atmospheric arsenic impact is not known.  Currently there is no South African guidance on arsenic assessment and contamination management.

Champion: Dr Meris Mills (Service Provider) | Email: meris@millswater.co.za

Members:
David Love, Jon McStay, Neville Paxton, Carl Steyn, Richard O’Brien

Reviewed by:
Professor Heather Jamieson

POSITION PAPER ON ASSESSING AND MANAGING RISKS ASSOCIATED WITH ETHER OXYGENATE CONTAMINATION, INCLUDING BEST PRACTICE FOR SITE ASSESSMENTS AND MULTI-TIER RISK ASSESSMENTS.

Ether oxygenates are hydrocarbon compounds that contain one or more oxygen atom, and are commonly used as gasoline additives to improve combustion and decrease exhaust emissions. The primary oxygenates include methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE), and tertiary amyl methyl ether (TAME).

During a gasoline spill or release, ether oxygenates may enter the subsurface and contaminate soil and/or groundwater. Ether oxygenates generally have a high solubility in water, poor biodegradability and a greater likelihood for migration throughout the subsurface. Risks to human health and the environment from ether oxygenates vary per compound, but generally include inhalation, dermal contact, ingestion, and aesthetic (e.g. taste or odour) risks to human health, and groundwater migration and ecological risks to the environment. It is because of these characteristics that ether oxygenates have become an important group of groundwater pollutants. However, only limited information exist for characterising the possible risks of oxygenates in water, and limited guidance exists for determining levels that would be acceptable or unacceptable from the standpoint of public health or consumer acceptability.

This position paper has been developed to summarise the Network for Industrially Contaminated Land in Africa (NICOLA) position on assessing and managing risks associated with ether oxygenate contamination, including best practice for site assessments and multi-tier risk assessments. NICOLA’s position is based on international guidance from various regulatory and/or industry specific consortiums.

Champion: Kirby Gimson (kirbygimson@gmail.com)

Working group members:
Dipitseng Manamela (Dihlashana Consulting), Ian Luden (SRK) and Charles Mills (Mills and Otten)

Technical reviewers:
Hayley Thomas (Shell), Takalani Telekisa (DFFE), Mpho Mavhega (DFFE) and the NICOLA Steering Committee

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The South African Practitioner’s guide for the risk assessment and management of LNAPL contamination. Members interested in being part of the LNAPL Working Group should please contact the Champion.

Champion: Jon McStay (Service Provider) / Narusha Govender (Industry).
email: jon.mcstay@wspgroup.co.za / nerusha.govender@total.co.za

Abstract, Objectives and Added Value:
The Practitioner’s Guide aims to provide a practical, step by step process for the risk assessment, management and remediation of LNAPL contamination. The document is based on recently emerging international best practice aims to bridge the gap between industry and regulators by establishing best practice guidelines for LNAPL management that are scientifically sound and sustainable in the South African Regulatory context.

The technical content reviews the following aspects:

• Types of LNAPL.
• LNAPL toxicity and environmental risk.
• Behaviour of LNAPL in the subsurface.
• LNAPL mobility and longevity.
• Residual saturation and dissolved phase partitioning.
• Vapour Phase.

The practical guidance includes:

1. Stepwise Approach To The Investigation And Risk Assessment Of LNAPL –

• Phase 1: Investigations and desktop review.
• Phase 2: Detailed site characterisation.
• Phase 3: Conceptual Site Models – data collation, interpretation and visualisation.

2. LNAPL Management and Remediation Plans –

• Setting LNAPL remediation objectives.
• Defining LNAPL remediation end points.
• LPNPL remediation technology selection.

3. Implementation of Remediation Systems –

• Pilot testing.
• System Operation.
• Performance Monitoring.
• Close-Out Reporting.

Members:
Jon McStay (Service Provider).
Narusha Govender (Industry).

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Members interested in being part of the Vapour Intrusion Screening Values Working Group should please contact the Champion.

Champion: Stephen McKeown (Service Provider).
Email: steve.mckeown@erm.com

Abstract, Objectives and Added Value:
To develop a set of generic standards using international best practice to assess indoor air quality from potential exposure to commonly occurring volatile organic compounds (VOCs).

South Africa does not have guidance on vapour intrusion and this is the most relevant exposure pathway at most commercial and industrial sites, where VOC contamination has occurred.

Members:
Grant von Mayer (Service Provider).
Dr. Jon McStay (Service Provider).

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What does significant mean in the context of contamination? Developing a common sector understanding of significant contamination. This working group aims to build on the deliberations of the conference to formulate a sector wide common understanding of the term “significantly contaminated” in order to guide the sector on when notification is appropriate.

Members interested in being part of the Significance Working Group should please contact the Champion.

Champion: Dr. Heidi Snyman (Service Provider).
email: hsnyman@golder.co.za

Abstract, Objectives and Added Value:
The National Environmental Management: Waste Act, 2008 (Act 59 of 2008) (NEMWA) makes provision for the management of contaminated land in Part 8 of NEMWA which was promulgated on 2 May 2014.

Section 36 (5) of NEMWA stipulates that “an owner of land that is significantly contaminated, or a person who undertakes an activity that caused the land to be significantly contaminated, must notify the Minister and MEC ….”

Although the use of the word “significant” (or “significantly”) is commonly used in law without defining the term, it has caused some confusion in industry as it is not clear, when notification is required. The delegates attending the Nicola conference dated 3 and 4 November 2015 debated the term and attempted to define a common sector understanding.

This working group aims to formulate a sector wide common understanding of the term “significantly contaminated” in order to guide the sector on when notification is appropriate.

Members:
Erika Reynolds (Industry).
Tina Costas (Service Provider).
Richard O’Brien (Service Provider).
Martin Ginster (Industry).
Marcus van Zutphen (Industry).
Fabiola Rossato (Industry).
Claudia du Plessis (Service Provider).

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Identify nationwide groundwater methodology for contaminated sites in South Africa. Members interested in being part of the Groundwater Working Group should please contact the Champion.

Champion: Willem van Biljon (Service Provider).
email: willem@gptglobal.com

Abstract, Objectives and Added Value:
Currently service providers and industry choose their own methodology to determine screening values for groundwater contaminants. The aim of this working group would be to provide a general framework towards performing such risk assessments, based on international best practice, without being too prescriptive. The outcome would be a proposed methodology or set of methodologies that can be used to perform risk assessment, which screening criteria would be used and where screening will take place.

The general approach would be to refine the process whereby drinking water screening levels are used at the point of sampling, to a methodology where the such stringent screening levels are applied at the point of impact or point of compliance. Using ultra conservative screening levels at the point of sampling ignores the inherent attenuation that takes place in a groundwater environment.

A second important factor that is often not considered by authorities, is that background water quality might not conform to drinking water standards, especially in the case of naturally occurring minerals and compounds. In such cases the use of a screening methodology or risk assessment needs to take the background water quality into account and conclude in a scientifically justified manner whether conditions at a site pose an unacceptable risk.

Members:
Charles Mills (Service Provider).
Dale Barrow (Service Provider).
Robin Jeffrey (Industry).

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