Contributed by the South African Centre for Carbon Capture & Storage (SACCS)
The South African Centre for Carbon Capture & Storage (SACCCS) is a division of the South African National Energy Development Institute (SANEDI), a state owned entity established under Section 7 of the National Energy Act 2008 (Act No.34 of 2008. SACCCS has embarked on a Pilot CO2 Monitoring Capacity Building Project (PMP) which aims to use findings gathered from the monitoring research to establish a baseline monitoring for the Pilot CO2 Storage Project (PCSP). The PMP is conducted at the natural CO2 release (NCR) sites located within the Mbizana, in the Wild Coast Region of the Eastern Cape and Harding, in the South Coast of KwaZulu-Natal respectively.
South Africa is exploring ways to decarbonise its energy supply which is reliant on fossil fuels. Fossil fuels, mainly coal contribute over 90% of the country’s electricity production, making the country one of the significant emitters of CO2. Currently, SACCCS’ main focus is to develop a Pilot CO2 Storage Project (PCSP) which aims to demonstrate safe and secure geological storage of CO2 under the South African conditions. Critical to the successful development and execution of the PCSP will be monitoring of the injected, stored CO2 to ensure it is behaving as expected and to verify that it is indeed permanently stored.
Monitoring protocols developed through project
However, PCSP monitoring for the establishment of a baseline, can only commence once a site has been selected for the project. Prior to positively selecting an injection site it is important that SANEDI/SACCCS builds capacity and develop CO2 monitoring skills as well as learning how to use different monitoring equipment and applying the techniques thereof. To address this SANEDI/SACCCS has embarked on a monitoring capacity building program to acquire skills required to develop monitoring protocols for the PCSP.
In terms of the limited information gathered, based on the minimal research conducted at the identified sites thus far, the natural CO2 releases seem to be occurring along the ~80km long geological fault where the CO2 gas exhalations are observed. It is assumed that the CO2 gas exhalations originate from rain water migrating down the fault, dissolving carbonates at depth with the resulting CO2 traveling back up the fault to surface. At the surface the CO2 can be seen bubbling where it is released under water. It is however expected that the majority of the CO2 being released is under farmland and natural vegetation and so remains largely undetected.
The PMP activities commenced in September 2014 with a Research Scoping Workshop attended by national and international organizations, whereby various monitoring packages aimed at quantifying CO2 emissions were investigated and concluded upon. The workshop yielded the following key Work Packages:
- Social Impacts, Public Engagement and Communications;
- Atmosphere and Soil;
- Groundwater; and
- CO2 Migration and Attenuation in the Sub-Surface.
Based on the outcomes of the Research Scoping Workshop, Phase 1 of CO2 monitoring commenced in September 2015, focusing on the above mentioned packages thus providing a basis for future work. Phase 1 delegates were representing the following entities:
- South African National Energy Development Institute (SANEDI);
- Council for Geoscience (CGS);
- British Geological Science (BGS);
- University of KwaZulu-Natal (UKZN);
- School of Geoscience: University of Edinburg;
- School of Geoscience: Aberdeen University; and
- Department of Civil and Environmental Engineering, University of Strathclyde.
The plan for Phase 1 monitoring included site visits and sampling at three known sites, namely; (i) Farm Baker, (ii) Bongwana Gas Works and (iii) Umtamvuna Travertine cones.
The first site was Farm Baker, which hosts a borehole with CO2-poor characteristics and a ~60m deep borehole with limited groundwater rich in CO2.The BGS delegates measured for soil gas and gas flux with the help of CGS delegates. Delegates from UKZN and CGS sampled for water in both boreholes. The second site of interest, Bongwana Gasworks, was not accessed to respect the landowner’s wishes. The third site of interest was the Umtamvuna travertine cones and other CO2 release sites. Sampling of soil gas concentration, gas flux, gas sampling for isotope analyses, field mapping, and geological sampling was undertaken. Water sampling from all active springs, as well as water samples up and downstream of the fault zone was undertaken.
A total of twelve (12) water samples were collected in the study area from different water sources comprising of 2 boreholes, 5 rivers and 1 spring samples and 3 travertine cones samples.
The aim of water sampling study included inter alia:
- Identify any variations in the water quality and stable isotope signature from the CO2-rich sites and nearby CO2-poor sites at the three sites?
- In addition, ascertain if there are any differences in the water chemistry and stable isotope signature of the CO2-rich groundwater sites (i.e. travertine cones, rivers, spring and boreholes) in the CO2-rich river sites?
The findings marked a difference between CO2-rich sources and CO2-poor sources. The pH was lower in CO2-rich sources. Total Dissolved Solids (TDS) and Electrical Conductivity (EC) were found to be higher in CO2-rich sources, and Dissolved O2 in rivers was observed to be within desirable limits for aquatic life to survive.
The soil gas findings show that there was high CO2 concentration found in the ground with a range of 13.8 – 422.2 g/m2/day. When the results are overlain on the geological map produced by Du Toit (1911-1916), the values correlate with a small fault system defined on the map by silicified breccia. Repeat sampling with the CO2 borehole closed to atmosphere showed a variation in soil concentrations with values along the fault line increasing to 80% CO2 (capped) in two samples. Little variation was noted away from the fault zone with background values being obtained at similar points to the uncapped survey.
Phase 2 plans in place
Phase 1 monitoring laid the basis to the requirements of Phase 2 monitoring. The Work Packages identified in the Scoping Workshop will continue being the main focus in the PMP life cycle where appropriate equipment and methodologies will be selected carefully based on the results obtained on Phase 1. Phase 2 will focus on rolling out a comprehensive monitoring plan that will monitor diurnal and seasonal variations as well as ecosystem impacts.
The monitoring program will see collaborative efforts being strengthened with national and international organizations that have vested interest in carbon capture and storage (CCS) and environmental management, while gaining invaluable understanding of monitoring requirements in a CCS project.
Stakeholder Engagement activities at the potential sites is and will continue to be one of the critical steps for the Pilot CO₂ Monitoring Capacity Building Project. To this end, structured consultations with key stakeholder groups, including provincial and local government and the affected communities preceded all the Phase 1 Work Packages. This will be the norm for subsequent phases going forward.
Introductory and iterative consultations constitute the modus operandi to achieve inter alia the following objectives and the expected outcomes of the Stakeholder Engagement Work Package:
- Create awareness of the Pilot CO2 Monitoring Capacity Building Project, the benefits and potential risks;
- Dispel misconceptions about and articulate the differences between Carbon Capture and Storage (CCS) and natural CO₂ release;
- Build mutually beneficial relations with the relevant stakeholders;
- Provide Stakeholders with an opportunity to raise concerns/issues and make suggestions;
- Identify relevant landowners & stakeholders;
- Leverage on local Indigenous Knowledge (IK) and traditional beliefs/mores that might contribute to geological characterization and environmental monitoring;
- Stakeholder Engagement opportunities and threats:
- Methods for communication and messaging;
- Researchers must respect the communities and observe protocol at all times;
- The sustainable development, cultivation and transference of monitoring skills for local government officials throughout the project cycle;
- Understand impacts and efficacies of a capacity building program;
- Understand ownership and land use; and
Keep the Provincial and Local AmaKhosi (Traditional Leaders) as well as the government officials up-to-date with the project findings.
AmaKhosi and the private landowners gave SANEDI/SACCCS permission to conduct CO2 monitoring for Phase 1 of the PMP on the proviso that they will be kept abreast of the findings and other developments before they are released to the general public.
Ms. Polly Modiko
Stakeholder Engagement Lead
Tel: +27(0)11 038 4334
Ms. Gcobisa Melamane
Environmental Monitoring Lead
Tel: +27(0)11 038 4374
Mr. Wiseman Ngcobo (Alternative contact person)
Stakeholder Engagement Analyst
Tel: +27(0)11 0384351