Heritage Statement for the Sasol Mining Sigma Colliery Ash Backfilling Project, Sasolburg, Free State Province
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HERITAGE STATEMENT FOR THE SASOL MINING SIGMA COLLIERY ASH BACKFILLING PROJECT, SASOLBURG, FREE STATE PROVINCE SASOL MINING (PTY) LTD 15 November 2013 _________________________________________________ Digby Wells and Associates (South Africa) (Pty) Ltd (Subsidiary of Digby Wells & Associates (Pty) Ltd). Co. Reg. No. 2010/008577/07. Fern Isle, Section 10, 359 Pretoria Ave Randburg Private Bag X10046, Randburg, 2125, South Africa Tel: +27 11 789 9495, Fax: +27 11 789 9498, [email protected], www.digbywells.com ________________________________________________ Directors: A Sing*, AR Wilke, LF Koeslag, PD Tanner (British)*, AJ Reynolds (Chairman) (British)*, J Leaver*, GE Trusler (C.E.O) *Non-Executive _________________________________________________ Heritage Statement for the Sasol Mining Sigma Colliery Ash Backfilling Project, Sasolburg, Free State Province SAS1691 This document has been prepared by Digby Wells Environmental. Report Title: Heritage Statement for the Sasol Mining Sigma Colliery Ash Backfilling Project, Sasolburg, Free State Province Project Number: SAS1691 Name Responsibility Signature Date Johan Nel Specialist & Report 15 November 2013 Unit Manager: HRM Writer Shahzaadee Karodia Khan Assistant Heritage Specialist 15 November 2013 Consultant: Contributor Palaeontology Specialist Justin du Piesanie 1st Reviewer 15 November 2013 Heritage Consultant Marcelle Radyn Project Manager & Environmental nd 15 November 2013 2 Reviewer Consultant This report is provided solely for the purposes set out in it and may not, in whole or in part, be used for any other purpose without Digby Wells Environmental prior written consent. ii Heritage Statement for the Sasol Mining Sigma Colliery Ash Backfilling Project, Sasolburg, Free State Province SAS1691 EXECUTIVE SUMMARY Introduction Sasol Mining (Pty) Ltd (Sasol) proposes to undertake a project which involves the backfilling of old underground voids in the northern defunct area at the Sigma Colliery with ash. This is intended to mitigate risk associated with subsidence of the surface caused by historical underground mining activity at Sigma. The ash backfilling process will utilise several pipelines located above ground to transport the ash slurry (comprising 20% fine ash and 80% water) from the Sasol Ash pump station to the underground voids. The return water pipelines will be used to abstract water from the mine voids to create space for backfilling. In order to comply with Section 38(8) of the National Heritage Resources Act, 1999 (Act No. 25 of 1999) (NHRA) a Heritage Statement Report (HSR) in support of a Notification of Intent to Develop (NID) was compiled detailing the current cultural landscape and possible sources of risk to cultural heritage resources. Project Background Sasol’s Sigma Colliery commenced operations in 1952 and holds mineral rights to coal deposits in the Sasolburg district. Underground mining was the primary method of extracting these reserves including board-and-pillar, rib pillar, long wall and high extraction methods. Access to the underground operations was via several shafts, and then conveyed to a ‘dry’ coal handling plant at 3 Shaft where the coal was screened and fed to silos. In 1992, the Wonderwater and Mohlolo strip mines were developed to extract coal from the north-eastern side of the reserves and the underground mining was scaled down and ceased by 1999. The proposed project is aimed at backfilling additional high risk mine voids with ash from Infrachem. The project will be undertaken in order to stabilise old underground mine workings which are considered to have a high potential risk for land subsidence. The pipelines transporting slurry will run aboveground on Sasol owned property and within existing servitudes where possible. Where this is not possible, existing culverts and crossings will be used; alternatively new agreements will be entered into with land owners. The pipeline route will be specifically selected to ensure that the pipes run along existing servitudes, linear infrastructure and disturbed areas to minimise the impact on the receiving environment. iii Heritage Statement for the Sasol Mining Sigma Colliery Ash Backfilling Project, Sasolburg, Free State Province SAS1691 Current Project Status Sigma Colliery has applied for the following authorisations required for identified listed activities relevant to the backfilling project and the construction and operation of the proposed infrastructure ■ An integrated Environmental Authorisation through a Basic Assessment in terms of the National Environmental Management Act, (Act No. 107 of 1998) (NEMA); ■ A waste licence through a Social and Environmental Impact Assessment (S&EIA) in terms of the National Environmental Management: Waste Act, 2008 (Act No. 59 of 2008) (NEM:WA); and ■ An integrated Water Use Licence Application (IWULA) in terms of the National Water Act, 1998 (Act No. 36 of 1998) (NWA). Regional Location Province Free State Magisterial district Sasolburg District municipality Fezile Dabi District Municipality Local municipality Metsimaholo Local Municipality Nearest town Sasolburg 1: 50 000 topographic map 2627DA, DB, DC & DD sheets Relative centre coordinates of 26.811244° S site / project area 27.789468° E Recording method Google Earth iv Heritage Statement for the Sasol Mining Sigma Colliery Ash Backfilling Project, Sasolburg, Free State Province SAS1691 Receiving Environment / Cultural Landscape The project area is situated in the Sasolburg-Vereeniging Coal Field which forms part of the Karoo Basin. The Karoo Basin is divided into the Dwyka, Ecca and Beaufort Groups. The rocks of the Vryheid formation of the Ecca Group are renowned for their wealth of plant fossils of the famous Gondwanan Glossopteris flora which has been described from the Permian aged-rocks. This flora is the source of the coal which is mined from the Vryheid Formation in South Africa. Important plant fossil localities have previously found in areas close to Vereeniging. The current cultural landscape is primarily agriculture with large parts having been altered by industry and mining. Agricultural activities would have, over the years, destroyed most archaeological resources that may have been present. Open cast mining and rehabilitation of sites would further have destroyed any viable archaeological sites and palaeontology that may have existed pre-1999 and before the NHRA came into effect. The entire area, underlain by the Vryheid Formation, which will be crossed by proposed pipelines required for the ash backfilling, is devoid of rock outcrops and is covered by either grassland or by ploughed fields. It is thus very unlikely that any fossil heritage will be damaged by activities relating to the ash backfilling. In addition, urban sprawls along the Vaal River banks have significantly reduced the potential of identifying Stone Age sites there. No historical built environment resources, townscapes or burial grounds were noted during the screening assessment, but any impact to such resources by the proposed project would be negligible. The impact due to subsidence on these resources would be far greater. A review of 13 heritage reports relevant to the Sigma Colliery project area further indicated that typical heritage resources occurring in the region are historical structures and burial grounds with relatively low significance. There are exceptions such as the Leeuwkuil engraving site and Iron Age stonewalled settlements. However, none of the reviewed reports explicitly addressed intangible heritage, including landscape character and sense of place. This omission is contrasted by the Fezile Dabi Integrated Development Plan (FD- IDP) that refers to the importance of heritage (with a bias towards intangible and liberation heritage) in the district as beneficial to tourism and good governance. v Heritage Statement for the Sasol Mining Sigma Colliery Ash Backfilling Project, Sasolburg, Free State Province SAS1691 Sources of Risk No sources of risk to heritage resources were identified in relation to the construction, operational and decommissioning phases of the Sigma Colliery ash backfilling project: ■ The project proposes to either recommission or upgrade existing pipelines and install similar pipes where required. The construction of the pipelines will be low-impact as the pipes will be above ground. The main intrusive activity will be the construction of concrete plinths to support the pipeline where required; ■ As most pipelines are within existing servitudes or along farm boundary lines, construction of access roads will not be required. Where access may be necessary it will merely entail bush or surface vegetation clearing in already disturbed areas; ■ The construction methods are furthermore of such a nature that should any heritage resource (e.g. a burial ground) be encountered, the pipeline route may be deviated to avoid any direct impact on a site; and ■ The proposed project is also not expected to impact or change the character of the landscape or sense of place. In fact, the potential risk of subsidence should be seen as a greater risk. Recommendations Given the current state of the cultural landscape, the apparent absence of any significant tangible heritage resource and the limited impact of the proposed Sigma Colliery ash backfilling project, the following recommendations are made: ■ The South African Heritage Resources Agency (SAHRA) and the Free State Provincial Heritage Authority (FSPRHA) must consider granting Sasol Mining exemption from a Heritage Impact Assessment (HIA)