KGETLENGRIVIER LOCAL MUNICIPALITY
Project No: MwB 20070
Rosmincol Bulk Water Supply to Swartruggens and Mazista
TECHNICAL FEASIBILITY AND PRELIMINARY DESIGN REPORT
Phase 2a and 2b (DWS Guidelines) Report 2 & 3
November 2016
PREPARED FOR: ON BEHALF OF PREPARED BY:
MAGALIES WATER KGETLENGRIVIER LM MwB Consulting Engineers 38 Heystek Street P O BOX 66 204 Beyers Naude Drive Rustenburg Koster Rustenburg 0299 0348 0300
Contact Person: Contact Person: Contact Person: Mr Mahlomola Mehlo Mr Ben Shikwambana Mr Marx Jordaan Tel: 014 597 4636 Tel: 014 543 2004 Tel: 014 592 8504 Fax: 014 597 4635 Fax: 014 543 2005 Fax: 014 592 2024
Email: Email: Email: [email protected] [email protected] [email protected]
FORM OF APPROVAL
PROJECT NAME: Rosmincol Bulk Water Supply to Swartruggens and Mazista
PREPARED BY: MwB Consulting Engineers (Pty) Ltd.
CLIENT: Magalies Water / Kgetlengrivier Local Municipality
REPORT STATUS: Technical Feasibility and Preliminary Design Report
DATE: November 2016
DISCLAIMER: This report has been prepared on behalf of Magalies Water / Kgetlengrivier LM, and for the exclusive use of Magalies Water / Kgetlengrivier LM, and is subject to and issued in accordance with the agreement between Magalies Water, Kgetlengrivier LM and MwB Consulting Engineers (Pty) Ltd.
MwB Consulting Engineers (Pty) Ltd accepts no liability or responsibility whatsoever for it in respect of any use of or reliance upon this report by any third party.
Copying this report without the permission of Magalies Water / Kgetlengrivier LM and/or MwB Consulting Engineers (Pty) Ltd is not permitted.
Consultant approval: Name Mr. AM Jordaan (Pr Eng), (Pr CMP)
Signature ______
Date ______
Name Client approval: Mr Mahlomola Mehlo
Signature ______
Date ______
Client approval: Name Mr Witsman
Signature ______
Date ______
Rosmincol Bulk Water Supply to Swartruggens and Mazista
Technical Feasibility and Preliminary Design Report
EXECUTIVE SUMMARY
Swartruggens and Borolelo are supplied with potable water from the Swartruggens Water Treatment Plant (WTP). Raw water to this plant is supplied from the Swartruggens Dam and augmented from a spring source in the Polkadraai Spruit.
The safe yield of the Swartruggens Dam is not able to meet the current requirements of the community and it runs dry during virtually every dry season, every year.
The Polkadraai Spruit water source is unreliable. It runs dry in periods of extreme draught and farmers are contesting the water use.
The Swartruggens Dam is silted up and constructed in an area where slate or mudstone dominates the geology of the basin. The dam regularly runs dry, normally towards the end of the dry season, just before the rainy season. The safe yield of the dam is smaller than the demand on the dam. During normal rainfall seasons the dam overflows for extended periods. The safe yield can therefore be increased by increasing the storage volume of the dam. The process of constructing more storage can be regarded as a long-term solution whereas the augmentation of supply into town from boreholes could be a medium term solution that can be constructed in a couple of months.
The projected water demand for 2030 of the greater Swartruggens is 5 M ℓ/d.
Over the years more than 34 boreholes were drilled, and some were developed, for water supply into town. Currently, only two of these remained and are still in production. Reports clearly state that it is not viable to explore for ground water sources in and around the town.
The following alternative water sources have been identified to augment the supply into the greater Swartruggens. These are:
• Importing raw water from the Lindleyspoort Dam;
• Increasing the storage of the Swartruggens Dam to increase the safe yield;
• Importing water from the dolomite areas some 40 km to the south of town ; and
• Re-using treated sewage effluent.
The Department of Water and Sanitation is considering funding this project through the emergency funds as a measure to address the immediate supply to the town.
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The following deliverables are envisaged:
The initial planning phase for a technical feasibility study where the need was 1 Scoping report Complete identified and all the relevant background information documented and assessed.
This report describes the proposed technical intervention and documents the analysis Technical and methodology on how the proposed solution was determined. An option analysis 2 Current report feasibility report is also included for larger projects particularly for water resource augmentation related projects.
This is the preliminary design of the bulk infrastructure scheme where various Preliminary 3 technical options are identified and evaluated. The deliverable from this study will Current report design report include a budget estimate for the development of the project.
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Rosmincol Bulk Water Supply to Swartruggens and Mazista
Table of Contents
ABBREVIATIONS ...... vi 1 INTRODUCTION ...... 7 2 METHODOLOGY ...... 8 3 DEMAND ANALYSIS ...... 10 3.1 Existing Demand Analysis ...... 10 3.2 Water Inefficiencies and Wastage ...... 11 3.3 Future Demand Projections ...... 11 4 WATER CONSERVATION / WATER DEMAND MANAGEMENT ...... 13 4.1 Impact on Planning of the Project ...... 13 4.2 Impact on the Economic / Financial Viability of Project ...... 13 5 WATER QUALITY INVESTIGATION ...... 14 6 ANALYSIS OF EXISTING INFRASTRUCTURE ...... 16 7 OPTIONS ANALYSIS ...... 16 7.1 Source Options Identified ...... 16 7.2 Identified pipe routes ...... 17 8 FurthEr research and investigationS ...... 18 8.1 Electricity supply ...... 18 8.2 Borehole exploratory yield testing ...... 19 8.2.1 General ...... 19 8.2.2 Hydrogeological investigation during November 2016...... 19 8.2.3 Potential groundwater areas / zones: ...... 20 8.3 Land Ownership and Servitudes ...... 22 8.4 Geological investigations ...... 22 8.4.1 General Perimeters ...... 22 8.4.2 Geological setting ...... 23 8.4.3 Site walk-over survey ...... 24 9 Hydraulic analysis ...... 27 9.1 Pressure Reducing Valve ...... 29 Page | iii
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9.2 Hydraulic Summary ...... 30 10 water use licence application ...... 31 11 eia approval process ...... 32 12 project implimentaTion plan ...... 33 12.1 Summary of Options Analysis and recommendations ...... 33 12.2 Recommendation on the preferred option ...... 34 12.3 Time Schedule ...... 35 13 O&m and asset management pLAns ...... 36 13.1 Asset Management ...... 36 13.2 Typical Operations and Maintenance plan (O&M) ...... 36 13.3 Asset Management Plan ...... 37 14 OCCUPATIONAL HEALTH AND SAFETY ...... 38 15 Conclusions ...... 39
APPENDICES:
APPENDIX A: Geotechnical Investigation ...... A
APPENDIX B: Environmental Impact Assessment ...... B
APPENDIX C: Preliminary Drawing Booklet ...... C
APPENDIX D: Project Cost Estimate ...... D
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Figures:
Figure 1 Locality map ...... 7 Figure 2 Layout of Identified pipe routes ...... 17 Figure 9-1 Dynamic Pressure (m) ...... 27 Figure 9-2 Static Pressure (m) ...... 28
Tables:
Table 1: Overview of different phases of study ...... 8 Table 5: Life cycle cost comparison of the Route Options ...... 18 Table 6 Borehole Pump Test Data ...... 22
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ABBREVIATIONS
DWS Department of Water and Sanitation
IDP Integrated Development Plan
KRLM Kgetlengrivier Local Municipality
MIG Municipal Infrastructure Grant
Mℓ mega litre
MwB Moedi wa Batho Consulting Engineers (Pty) Ltd
WC & WDM Water conservation and water demand management
WTP Water Treatment Plant
WSDP Water Services Development Plan
PGDS Provincial Growth and Development Strategy
PRV Pressure Reducing Valve
WTW Water Treatment Works
WSA Water Services Authority
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Technical Feasibility and Preliminary Design Report
Rosmincol Bulk Water Supply to Swartruggens and Mazista
1 INTRODUCTION The Kgetlengrivier Local Municipality (KRLM) appointed Moedi wa Batho Consulting Engineers and Project Managers (MwB) to carry out a feasibility study and this appointment was further supported by Magalies Water who in turn appointed MwB as the turnkey services provider to complete the final design and construct the infrastructure to augment the Bulk Water Supply from the Dolomitic areas to Swartruggens.
Swartruggens is a small town, Figure 1 below, situated adjacent to the N4 route between Rustenburg and Zeerust and serve as the centre to the surrounding agricultural communities.
Figure 1 Locality map
The primary water supply to town is from the Swartruggens dam in the Elands River and the transfer of water from the Rietvleispruit fountain. The Swartruggens and Borolelo communities are supplied with water through yard taps, although the Mabaalstad, Rusverby and Mazista informal settlements are supplied from local boreholes at below RDP service levels. The greater Swartruggens obtain water from the Swartruggens Dam. The demand from the dam exceeds the yield of the dam and the area runs out of water during the dry season of every year. Dolomitic water is available in the area. The solution to mitigate the annual water crisis is to create an economic viable solution of water supply from: Page | 7
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• The dolomites; and • By augmentation of the water supply from the Swartruggens Dam. This solution will be the low cost proposal, but in the extreme drought conditions, there will not be adequate water to supply from the dam – hence the proposal to import water from a different source.
2 METHODOLOGY The Methodology is structured and defined in the Department of Water and Sanitation, Guidelines for RBIG funding. Table 1: Overview of different phases of study
Phases: Deliverables Description Summary of proposed project Overview of available information
Report 1: Scoping – Review Strategic and planning issues inception (completed) Review integration with other schemes Determine social /economic component
Revision of scope of work for study Demand analysis Review of WC/WDM / use efficiency Water quality analysis /review Phase 2: Technical Analysis of existing infrastructure Feasibility (current Identify various options report) Define design /planning criteria Feasibility of various options Option analysis Preliminary design Limited field research / investigations Water license application Report 3: Preliminary Research for EIA approval process design (current report) Detailed cost estimates and time frames for implementation O&M / asset management plans
The goal of the Technical Feasibility is to identify water augmentation opportunities for Swartruggens and Mazista to meet projected demands from industrial, commercial, recreational and domestic sectors. To meet these goals, a methodology was developed in line with the details provided for by DWS. The
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high level work breakdown structure, based on the proposed methodology for the study is given in the table above.
The technical feasibility followed by the preliminary design was carried out. In line with the DWS guidelines this report is therefore is the combination of the two phases. It should however be noted that the PDR is only for the pipeline between the sources at the dolomite areas till the Swartruggens WTW. This is due to the funding availability from DWS.
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3 DEMAND ANALYSIS
3.1 EXISTING DEMAND ANALYSIS
SOURCE Magalies Water: Bulk Master Plan Magalies Water: Bulk Master Plan DWA: Reconciliation Bonjanala DM: Bulk Master Plan Volume 1 Volume 2 Strategy
Description Year Derby Derby Derby Derby Derby Derby Koster Koster Koster Koster Koster Mazista Mazista Swartruggens Swartruggens Swartruggens Swartruggens Swartruggens Swartruggens
2010 17 500 9 000 3 400 17 500 9 000 3 400 20 642 16 513 374 1 740 9 262 3 349
2015 ------13 036 3 909 Population 2020 ------15 315 4 422 (No) 2025 ------16 923 4 811
2030 ------18 169 5 111 Stands 2010 - - - 6 545 3 004 980 6 040 4 832 110 509 - - (No) Available Supply - 3.5 1 - 3.5 1 - 13.4 1.3 - 4.9 0.5 (Ml/day) 2010 5.4 1.8 0.8 5.4 1.8 0.8 - 4.6 1.5 - 2.5 0.6 2015 ------3.3 0.7 Water Demand 2020 - - - 9.7 - 8.6 1.9 - 4.1 0.8 (Ml/day) 2025 ------4.7 0.9 2030 5.9 2.1 1.3 10.1 - 9.3 2.7 - 5.0 1.0
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MwB was dubious regarding the information obtained from previous studies due to the major inconsistencies which is not justifiable to ensure credibility. The 2011 census statistics is available and should theoretically be used as reference for population statistics. Even this information has to be “modified” to meet the requirements. The census statistics provide population figures for 6 wards within KRLM and do not specifically provide information on the population living within the urban areas.
3.2 WATER INEFFICIENCIES AND WASTAGE
The current water crisis in Swartruggens is a result of the drop in capacity of the Swartruggens Dam. The extract below was published in the SABC news on the 16 th of January 2016.
“Taps have run dry in the North West town of Swartruggens near Rustenburg. This has left residents with a lot of stress and having to wait on a daily basis for water tankers to come to their rescue. The dam that supplies the community with water is also running dry, while community boreholes are dysfunctional. The situation has been dire for three months. Residents say they had a dry festive season, having to struggle to get water at the JoJo tanks distributed in certain parts of the town. “
No reliable water usage patterns and information was found for the study area. However measures will be put in place to monitor and determine the area’s water usage patterns to guard against water losses and reckless water wastages. The proposed infrastructure will be able to alleviate the current water stress and cater for a projected demand.
3.3 FUTURE DEMAND PROJECTIONS
WATER DEMAND PROJECTIONS FOR THE GREATER SWARTRUGGENS
The population and population growth figures of Swartruggens, Borolelo and Mazista was obtained from Stats SA’s census data of 2011. Using these figures the population was projected to 2030 and the water demand was calculated.
The table below summarises the calculations for the water demand projections.
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POPULATION IN KGETLENGRIVIER LOCAL MUNICIPALITY – FROM STATS SA 2011
% Growth: 2001 - 2011 1.60%
2001 Population in area 36,477
2011 Population in area 51,049 Average % growth / annum 3.42% % Population growth/ann 2011 2015 2020 2025 2030 um
Swartruggens 3.42% 1,969 2,252 2,665 3,152 3,152 Borolelo 3.42% 8,580 9,815 11,611 13,735 13,735 Mazista 3.42% 1,172 1,341 1,586 1,876 1,876
- Sub-total: 11,721 13,408 15,861 18,764 18,764
AVERAGE ANNUAL DAILY DEMAND (AADD) MwB - Per Capita water demand proposal
Formal / high income 250 ℓ/c/day homes Informal / low income 125 ℓ/c/day dwellings 2011 2015 2020 2025 2030 Township ℓ/c/day Mℓ Mℓ Mℓ Mℓ Mℓ
Swartruggens 250 0.492 0.563 0.666 0.788 0.788 Borolelo 125 1.073 1.227 1.451 1.717 1.717 Mazista 125 0.147 0.168 0.198 0.235 0.235 Sub-total: - 1.565 1.790 2.117 2.505 2.505
The average annual daily demand was calculated with a per capita allowance of 250 ℓ for formal areas, namely Swartruggens, and 125 ℓ per capita for informal and low income areas, namely Borolelo and Mazista. These figures were obtained from the Magalies Water Design Guidelines for water consumption in formal and informal settlements. Assuming a summer peak factor of 1.5 the seasonal peak demand for the project area (Swartruggens, Borolelo and Mazista) equates to 3.75M ℓ/d. A 20 % allowance for losses and unaccounted for water was incorporated into the demand. The overall seasonal peak demand is equal to 4.5 M ℓ/d which is approximately equal to the 5M ℓ/d projected by Department of Water and Sanitation’s All Towns Study for Swartruggens. The water demand projected for the greater Swartruggens obtained from the All Towns Study initiated by the Department of Water Affairs and Sanitation is also 5M ℓ/d.
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4 WATER CONSERVATION / WATER DEMAND MANAGEMENT
4.1 IMPACT ON PLANNING OF THE PROJECT
The National Water Audit requires the Water Services Authority (WSA) to prepare Water Conservation and Water Demand Management (WC/ WDM) strategies in order to achieve more efficient use of water. This requirement is fundamentally important to Swartruggens where there is extreme water scarcity. The recent investigations for additional water sources could alleviate the immediate problems, but the underlying problems of the inequitable distribution of water, operational issues and wastage of water by consumers need to be adequately addressed. WC & WDM is probably the most effective way to ensure effective supply of water to Swartruggens where the water crisis was described as by Eye Witness News, 23 January 2016 as, “One of the worst water crisis to hit South Africa in decades ”.
It is proposed that the Kgetlengrivier Local Municipality implement appropriate WC / WDM measures to optimise water supply to the communities. Bulk water meters will be installed on all pumping stations and bulk supply lines to monitor losses through the calculation of mass flow per time. This will also enable to monitor water usage by the end user.
4.2 IMPACT ON THE ECONOMIC / FINANCIAL VIABILITY OF PROJECT
The study area is generally arid therefore innovative approaches to water management are required to ensure the maximum benefit in terms of social, economic and environmental considerations in the area.
The bulk water will in total be supply to the town of Swartruggens. The impact for the town to receive sustainable water supply will be huge as the residents and businesses have been compromised over the past few years due to water shortages.
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5 WATER QUALITY INVESTIGATION
The investigation conducted on the farm Rosmincol was done to act as confirmation to proof the Dolomites remains the only viable groundwater option for water supply to the Swartruggens town with some surface water options to be added as combined effort to solve the current water shortages at Swartruggens / Mazista.
Three existing boreholes were tested of which two were not on the Dolomites and the results confirmed these two boreholes (BH-1 & BH-2) to be much lower yielding than the one tested on the Dolomites (B155 (4) – See attached Management recommendations & test graphs.
During the test at borehole B155 (4) monitoring of three boreholes inside a 1.5km radius was conducted. No influence was noted during the three day test. Although the three days is considered a short term test, the results proofed the Dolomites to be a very good groundwater source to be considered for water supply to Swartruggens.
From these results it is estimated approximately 1million litres can be abstracted from a single selected groundwater source per day.
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It was further estimated that an additional five boreholes to be located (2 existing and 3 new boreholes to be drilled) will supply approximately 6 million litres good quality water per day. It will be important to have these six production boreholes spread over approximately a 2.5km radius to ensure the water level influences between the boreholes are limited.
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6 ANALYSIS OF EXISTING INFRASTRUCTURE There is currently no infrastructure transferring water from the dolomites to Swartruggens. All existing infrastructure is related to treating raw water from the Swartruggens dam. The proposed supply from the dolomites will require no treatment excluding chlorination. The water will be chlorinated if required and discharged into the bulk storage reservoirs. The system will therefore be designed to receive water from either one of the two sources at the available flowrate.
7 OPTIONS ANALYSIS
7.1 SOURCE OPTIONS IDENTIFIED
The following alternative water sources have been identified to augment the supply into the greater Swartruggens. These are:
• Importing raw water from the Lindleyspoort Dam;
• Increasing the storage of the Swartruggens Dam to increase the safe yield;
• Importing water from the dolomite areas some 40 km to the south of town ; and
• Re-using treated sewage effluent.
High level evaluation was done on the alternatives and documented in the Scoping and Inception report.
The importation of water from the dolomitic areas proved to be the only viable and achievable project.
In summary the following:
o Importing raw water from the Lindleyspoort Dam - Water supply from the dam is a viable option
but the water rights are currently vested in the names of individuals. To obtain these rights
from farmers will be expensive and time consuming and the capital cost of the project will also
exceed the costs of some of the other alternatives. Swartruggens is currently out of water. An
emergency supply system has to be developed. The above is not preferred because the
Lindleyspoort dam was constructed as an irrigation dam and the entire system probably has to
be redesigned to meet the new requirements. The proposal is not preferred.
o Increasing storage of the Swartruggens Dam – This alternative is viable but it will take time to
develop and rainfall is required to fill up the dam. The capital expenditure can easily prove to
be fruitless expenditure if it does not rain in the foreseeable future.
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o Re-using sewage effluent – Once again a viable project if sewage is generated from water.
Currently there is no water to drive the sewage system and the sewage treatment plant is not
in use. The project can be evaluated for a further expansion of water supply once sustainable
water has been secured.
o Importation of water from the dolomite areas – water is available in the areas. The source is
sustainable and it is proposed that the water be used as primary source and once it rained the
source can be used in conjunction with other alternatives not to deplete the supply from the
dolomites.
7.2 IDENTIFIED PIPE ROUTES
Two pipe routes were identified to supply water to Swartruggens and Mazista from the dolomite areas.
Figure 2 Layout of Identified pipe routes
Route A: This route follows a gravel road from the farms where the water was identified to the WTP in Swartruggens. Water will generally flow under gravity from the source to the plant. From the plant the water will be pumped towards Mazista.
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Route B: This route is generally along the R53 tarred road from Swartruggens to Ventersdorp. Water has to be pumped onto the escarpment from where it will flow under gravity to the Swartruggens Water Treatment Works with the opportunity to also flow to Mazista.
A life cycle cost analysis based on the GRP pipe material was conducted. The capital costs quoted below excludes all professional fees and disbursements and is a mere high level capital cost.
Table 2: Life cycle cost comparison of the Route Options
Description Route A Route B Construction Cost R 145,254,722 R 153,036,494 Energy Cost over 20 years R 3,016,612 R 17,483,423 Life Cycle Cost R 148,271,334 R 170,519,917 Advantages • Lower Capital Cost • No additional pump station required • Lower Operational Cost apart from boreholes • Ability to supply Bo-Dorp Area Disadvantages • Extra pump station at • Higher capital cost Swartruggens WTW • High energy cost to displace water over alternative route • Bo-dorp will have to be supplied by alternative means.
The pumping head on Route B is more than the pumping on Route A – hence the much lower energy consumption and life cycle costs. Refer to Appendix D for detail Route options analysis.
8 FURTHER RESEARCH AND INVESTIGATIONS
8.1 ELECTRICITY SUPPLY
The boreholes to be pumped used to be irrigation boreholes that will be re-drilled and properly constructed. In most cases overhead lines are constructed to the boreholes and transformers are installed. These facilities will be renovated and re-used, where applicable.
Standby boreholes will be drilled. Where water is found and production boreholes be constructed and electricity supply is not available, the required infrastructure will be installed. For the purposes of this report it can be assumed that only standby facilities will be constructed as indicated in this paragraph.
Most boreholes to be used as production boreholes have electricity available.
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8.2 BOREHOLE EXPLORATORY YIELD TESTING
8.2.1 GENERAL
Water carrying dolomitic formations were identified some 35km south of Swartruggens. This is considered to be the only viable groundwater resource to be developed for water supply to the town of Swartruggens and Mazista.
During April 2016, borehole BH-155 was yield and chemical tested on the farm Rosmincol 442JP and a sustainable abstraction of 1036,8 m ᵌ/day was confirmed. The water quality was classified as Class- 0 (Ideal water quality) and no treatment will be required.
During November 2016, additional boreholes were visited on the farm Brakkuil 449JP and information such as estimated yields, water levels, depths and casing depths were collected. Selected boreholes were yield tested. The tests revealed that several boreholes are in various aquafers and when pumped simultaneously will not affect one another. It was also established that these existing boreholes are not constructed correctly and cannot be utilized for sustainable groundwater supply. The yield tests confirmed the availability of an abundance of water. More than the required yield can be drawn from the various aquafers should the boreholes be constructed as per specification.
8.2.2 HYDROGEOLOGICAL INVESTIGATION DURING NOVEMBER 2016
In summary the following was determined in the recently completed hydrological investigation: • Although many boreholes exist, very few were constructed correctly during the drilling phase. These have to be re-drilled and correctly constructed for long term water supply. • Un-used, existing boreholes were not properly protected with lids. Some were occupied by bees and others were damaged by people dropping stones into the holes. • The measurements and observations proved most of the existing boreholes have very little drawdown available. In other words, the column of water available between the static water levels and the borehole floors is inadequate. • The existing boreholes constructed by the farmers were either not deep enough and where it was drilled to acceptable depths casings were not installed to the appropriate depths and therefore boreholes collapsed over time. • Yield testing conducted proved the borehole yields to be high (above 20 ℓ/s) in spite of low drawdowns (as little as 3m to 6m). Water levels recovered rapidly, indicating high groundwater potential for further groundwater development.
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• This investigation confirms that new high yielding boreholes (1000m³/day) with good quality water can be developed within at least three potential areas.
8.2.3 POTENTIAL GROUNDWATER AREAS / ZONES :
The google map below indicates the boundary between the Shale and Dolomitic formations (Light blue line) as well as five high yielding groundwater potential zones of which the dark Blue zone is already confirmed and no borehole needs to be drilled within this zone. The pink zone is included but is not considered for water supply to the town because the area is utilized for irrigation and will not be considered as part of new well field development.
Dark blue zone: Borehole BH-155 is situated within this zone and is recommended to supply 1036,8 mᵌ/day. The borehole can be equipped as water supply source. Light blue zone: Borehole BH-218 was yield tested at approximately 20 ℓ/s. Due to limited drawdown and construction problems, the test could not be completed however the high yield potential was confirmed. Properly constructed production boreholes should be considered within this zone. Light green zone X2: According to available data high yielding boreholes is available within both these zones however due to small diameter casings, collapsing sides, obstructions etc. no boreholes could be tested to confirm their yields. It should therefore be considered to re-drill the two blocked, collapsed or small inside diameter boreholes with potential high yields (one at each zone) as the second and third new production boreholes.
It can be concluded that from the information collected through the yield testing high yielding boreholes can be developed. Farmers tend to develop boreholes in shallow caves in the dolomites. To secure sustainability for the boreholes it is proposed that deeper cavities be targeted. Page | 20
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Although we are confident about the high yields we will find through re-drilling, we recommend a detailed geophysical investigation “Gravity” and Magnetic” survey to ensure we can map any boundaries and cavity sizes at the production boreholes but also in general across the Dolomitic aquifer.
After the drilling, yield testing will be conducted to test and calculate safe abstraction yields for the three new production boreholes and detailed monitoring of the water levels will form part of the yield tests. It is of utmost importance to draft and run a groundwater reserve model for the entire well-field area to include the five clusters on the Google map.
Continuous monitoring of abstraction yields, water levels and rainfall will be essential not only at the production boreholes but also at any available groundwater sources within this area. We recommend a groundwater model be completed after approximately one year of abstraction when the time series groundwater data is available. Currently, limited information regarding the aquifer thickness / cavity sizes is available but through detailed Hydrogeological supervision during the drilling this valuable information will be collected and reported. This geological information is valuable when designing or running Groundwater models and will ensure more accurate drawdown and influences can be simulated.
From the borehole depths, casings, yields and water level depths measured, the probability of installing two sets of sleeves through the first cavity to approximately 60m where after each borehole will be drilled deeper to target additional cavities at depths greater than 80m but maximum 150m.
In summary: 1. Adequate geohydrological information has been gathered and the information confirms the availability of sustainable groundwater in the dolomitic aquafer; 2. The required amounts of groundwater will be yielded from the identified aquifers; but 3. Special drilling techniques will be required to construct production boreholes; and 4. Drilling rigs are lined up to commence drilling in the next week. The boreholes will be scientifically constructed and drilled to target deeper caves of water, not to be affected by farmers’ irrigation systems that normally target the shallower caves.
The table below is a typical example of a testing report of one of the identified boreholes to be used for water supply to Swartruggens .
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Table 3 Borehole Pump Test Data
8.3 LAND OWNERSHIP AND SERVITUDES
The boreholes will be developed on private and tribal land. The required servitudes will be registered. Preliminary discussions indicated that the farmers will not lodge any complaints against the development. The specified procedures will be followed as soon as the boreholes have been drilled and tested and final servitudes can be determined.
The pipeline from the source to town will be constructed in the road reserve along a gravel road. The related authorities have been informed of the proposed project.
8.4 GEOLOGICAL INVESTIGATIONS
8.4.1 GENERAL PERIMETERS
The geotechnical investigation carried out had the following aims: • To assess the regional geological character of the site; • To determine and describe the generalized successions of soil and rock materials underlying the site by means of available information; and • To identify possible geological- and/or geotechnical constraints inferred to be encountered at the site that may have an adverse effect on construction and the sustainable utilization of a water supply pipeline in terms of the following main parameters: o Excavatability; o Geotechnical constraints; Page | 22
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o Re-use of excavated materials; and o Terrain mobility.
8.4.2 GEOLOGICAL SETTING
8.4.2.1 Regional stratigraphy
The regional stratigraphic setting of the area is indicated in graphical format by Figures 1a and 1b below:
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The area around Rosmincol is underlain by light banded dolomite with chert of the Eccles Formation , followed by dark chert-poor dolomite of the Frisco Formation , both forming part of the Chuniespoort Group, Transvaal Supergroup. The route then cuts across shale and giant chert known as the Rooihoogte Formation , Transvaal Supergroup. The remainder of the route is underlain by shale and slate of the Timeball Hill Formation that forms part of the Pretoria Group, Transvaal Supergroup. It must be noted that the extreme southern portion of the route in the vicinity of Rosmincol (i.e.: those portions underlain by water-soluble strata from the Eccles-, Frisco- and Rooihoogte Formations) is deemed “ dolomitic land ”.
8.4.2.2 Prominent geological structures
A prominent diabase- / dolerite sill intrusion underlies the route at Syferfontein. Several weakly defined diabase- / dolerite dyke intrusions are indicated to occur throughout the area. These structures may have given rise to the fracturing and alteration of the surrounding bedrock, in places forming localized pockets of bedrock exhibiting hard- to very hard rock consistency close to the surface, and may be present as discontinuous lines of rounded boulders at the surface. It is possible that several other even less prominent intrusions may also be encountered.
8.4.2.3 Regional seismic risk
According to Kijko et al. (2003) the regional seismic hazard of the area in general can be defined as relatively low, with a 10% probability of a seismic event with a peak ground acceleration exceeding 0.08 G probable within a period of 50 years.
8.4.3 SITE WALK -OVER SURVEY
A brief site drive-over survey was conducted on 09 November 2016, during which the following observations were made: • The route is predominantly underlain at shallow depth by fairly competent shale bedrock (Photo 1), with scattered dolomite and chert outcrops visible in the south.
PHOTO 1 Scattered shale outcrop within Land Type Ae59
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• Localized areas exhibiting thicker topsoil layers, mainly associated with the presence of termite mounds and/or specific vegetation types, were noted, but these invariably are also underlain by bedrock, albeit at slightly increased depths (Photo 2).
PHOTO 2 Hutton-type soil underlain by shale bedrock along an erosion donga within Land Type Ae59
• The prominent dolerite sill intrusion occurring in the south of the route was found to be associated with thicker, weakly structured clayey soils ( Shortlands soil form) containing occasional weathered dolerite boulders (Photo 3).
PHOTO 3 Thick Shortlands soil associated with a dolerite sill intrusion within Land Type Fb151
• The presence of thick layers of dense to very dense ferruginized material (i.e.: soft-, honeycomb- and/or hardpan ferricrete) possibly marginally suitable for use as bedding material was confirmed in the sidewalls of an excavation near the wells in the extreme south of the pipeline route (Photo 4).
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PHOTO 4 Thick layers of soft-, honeycomb- and in some places hardpan ferricrete within a borrow pit in Land Type Fa15
Attached to this report under Appendix A is a detailed report on the Swartruggens Water Supply Pipeline titled “ Initial geotechnical assessment in support of the proposed construction of a water supply pipeline from wells in the Rosmincol area to the town of Swartruggens ” prepared by our geotechnical specialist.
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9 HYDRAULIC ANALYSIS Within section 7, the option analysis, the proposal made use of a Ø 300mm pipeline supplying water from the Manifold chamber at the borehole field to the Swartruggens Water Treatment Plant Utilizing Route A. For the purpose of this project the hydraulic analysis will review the pressure requirements and determine suitable material or equipment to be used.
Only 5m of positive pressure is required at the manifold chamber to gravitate the water to the WTW. The figure below illustrates the pressure within the pipe at each node. It is noticed that after the 15km Chainage the pressure starts to rise as the pipe descend in elevation towards the WTW. The pressure peaks at a maximum of 211.6m
Figure 9-1 Dynamic Pressure (m)
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The increase in pressure limits the use of certain materials such as uPVC which is only manufactured up to 160m of operational pressure for a 300mm diameter pipe. On review of the static pressures within the pipeline if the valves at the WTW reservoir inlet closes it was noted that the pressure further increases to 260m in the lower laying regions.
Figure 9-2 Static Pressure (m)
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9.1 PRESSURE REDUCING VALVE
If a pressure reducing valve is incorporated at a strategic point, roughly 21km downstream from the manifold chamber, lower dynamic pressures can be observed. This allows the use of low cost material such as uPVC class 16. However, it must be noted that no isolation valve may be equipped at the reservoir inlet as it will result in a static pressure rise which will ultimately burst the class 16 pipe. Alternatives such as a pressure relieving discharge pipe could be installed downstream of the PRV to ensure that if the PRV fails or the pipe gets isolated downstream the pipe does not experience pressure outside the operational parameter.
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9.2 HYDRAULIC SUMMARY
With the results from the operational pressures indicated above, multiple options and combinations was selected. For the purpose of this report preference was given to non-ferrous materials as it is generally cheaper and does not require Cathodic protection. The following options was identified:
• Option 1 - A combination of GRP PN10 (22km) and PN25 (13km) material; • Option 2 - A combination of GRP PN 10 (32,5km) and PN25 (1,5km) material including a Pressure reducing valve; • Option 3 – A combination of uPVC (22km) and oPVC PN 25 (13km); and • Option 4 – uPVC the entire route including a pressure reducing valve
Option s Ad vantages Disadvantages
Option 1 • No operation and • Has the highest price tag. maintenance issues with a • A combination of GRP PN10 Material is very difficult to remote pressure reducing (22km) and PN25 (13km) work with and only valve. material. experience contractors can • No risk of pipe burst due to install this successfully a faulty PRV or pipeline • This material is prone to isolation in the low lying leaks in unstable soil. areas • Expensive bedding and blanket required.
Option 2 • Lower capital cost over • No isolation valve can be option 1, the majority of the installed at the reservoir A combination of GRP PN 10 pipeline requires lower inlet. (32,5km) and PN25 (1,5km) pressure material • material including a Pressure If PRV does not function reducing valve. properly or an isolation occurs the overflow pipe will create unnecessary water wastage. • The use of GRP material has difficulties as listed in option 1.
Option 3 • This option has the second • 2% more expensive than lowest price tag due to the option 4. A combination of uPVC (22km) low material cost. and oPVC PN 25 (13km). • No operation and maintenance issues with a remote pressure reducing valve.
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• No risk of pipe burst due to a faulty PRV or pipeline isolation in the low lying areas • uPVC and oPVC material is very easy to construct and local sub-contractors can be used to lay the pipes. Option 4 • The incorporation of a PRV • If PRV does not function allows lower class pipes to properly or an isolation uPVC the entire route including be used. occurs the overflow pipe will a pressure reducing valve. • Lowest construction price create unnecessary water tag. wastage. • The risk of the PRV not properly maintained due to remote location. • The risk of bursting pipes if the pressure relief does not work. • Life cycle cost will most probable be more than option 3 with maintenance and water wastage over 20 years.
10 WATER USE LICENCE APPLICATION
The site inspection identified ± five bridges (waterbodies) that will be affected by the installation of the bulk water pipeline. Though they are mostly dry (seasonal/perennial), it is important to lodge an application with the Department of Water and Sanitation (DWS) for permit as the pipeline will either trigger a listed activity 21 (i) “Altering the beds, banks, course or characteristics of a watercourse” and therefore will need a permit.
According to Section 28 of NEMA (National Environmental Management Act, Act 107 of 1998) which pertains to “Duty of care and remediation of Environmental Damage” states that: "(1) Every person who causes, has caused or may cause significant pollution or degradation of the environment, must take reasonable measures to prevent such pollution or degradation from occurring, continuing or recurring, or, in so far as such harm to the environment is authorised by law or cannot be
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reasonably avoided or stopped, to minimise and rectify such pollution or degradation of the environment."
11 EIA APPROVAL PROCESS
A site inspection was undertaken on the 09 th November 2016 with the intention to assess possible environmental factors that could negatively impact the site and find out if there is any part of the project that will trigger any listed activities according NEMA GN. Regulations 982 of the 04 December 2014, as read together with National Environmental Management Act, 108 of 1998.
pipeline installation and servitude The project intends to install a 300mm (0.3m) pipeline; which is below NEMA GN.R threshold of a listed activity 9 of 04 December 2014: “ The development of infrastructure exceeding 1000 metres in length for the bulk transportation of water or storm water-(i) with an internal diameter of 0, 36 metres or more; or (ii) with a peak throughput of 120 litres per second or more; excluding where (a) such infrastructure is for bulk transportation of water or storm water or storm water drainage inside a road reserve; or (b) where such development will occur within an urban area”.
The pipeline will be installed on the road servitude, triggering an exclusion (a), thus indicating that it is not a listed activity. Based on the NEMA Regulation listed activity no. 9, two indicatives show that the installation is non-listed, namely; the size of the pipeline and the location (within the road reserves). However, the Department of Environment and Agricultural Development (READ) has been informed of these findings and the intention of the Department of Water and Sanitation / Magalies Water through the Moedi wa Batho Consulting Engineers and Project Managers (Pty) Ltd of the installation of the pipeline prior to the construction taking place.
MwB has appointed a specialist to identify and address possible impacts/pollution or degradation of the environment that may occur as a result of the installation of bulk water pipeline; thus considering the requirements of Section 28 of NEMA as indicated above. The report will be in a form of an Environmental Management Programme (EMPr) which will detail all possible impacts and related mitigatory measures. The EMPr is a tool that will guide the contractor and will assist the competent authority, (in this case, Department of Environment and Agricultural Development) to monitor and assess compliance of the project with the EMPr.
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12 PROJECT IMPLIMENTATION PLAN
12.1 SUMMARY OF OPTIONS ANALYSIS AND RECOMMENDATIONS
Suitable groundwater was identified in volume and quality. Two routes were identified on how the water can be transported from source to Swartruggens. The routes were analysed and life cycle costs calculated. Route A is preferred for the lowest pumping head and the shortest pipe =to be installed.
With the pipe route fixed a number of configurations on pipe designs and materials were evaluated. These were called options and a brief description of each option is given below.
Option 1
This option is based on the usage of the 300mm GRP pipes. The first 21km section consists of PN10 pressure class GRP, and the last 13km section consisting of PN25 pressure class GRP to accommodate the higher static pressures.
Option 2
This option is based on the usage of the 300mm GRP. A total of 31.5km consist of PN10 GRP pipe. The installation of a pressure reducing valve and a 1.5km section of PN25 GRP will accommodate higher pressures. A pressure overflow pipe will also be installed to accommodate static pressures if the valve at the reservoir is closed during operation.
Option 3
This option is based on the usage of a combination of 315mm uPVC and oPVC pipes. The first 21km section utilises class 9 uPVC, and the last 13km section consists of class 9 oPVC to accommodate the higher static pressures.
Option 4
This option is based on the usage of 315mm uPVC. A total of 31.5km consist of class 9 uPVC. To accommodate for higher pressures, a pressure reducing valve and a 1.5km section of class 16 uPVC will be installed. A pressure overflow pipe will also be installed to accommodate static pressures if the valve at the reservoir is closed during operation.
Refer to Appendix E for the detail breakdown of each option.
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In summary
The table below is a competitive summary of the four identified options in terms of the description and costs.
Option 1 Option 2 Option 3 Option 4 32.5km PN10 32.5km Class 9 22km PN10 GRP 22km Class uPVC GRP 1.5km PN25 9 uPVC 1.5km Class 16 13km PN25 GRP 13km PN25 uPVC GRP Pressure oPVC Pressure reducing valve reducing valve
Total Construction Value (excl. VAT) R129,640,752 R122,091,088 R112,067,952 R110,095,888
Professional Fees and Disbursements R22,108,089 R21,017,162 R19,568,819 R19,283,856 Total Project Value (excl. VAT) R151,784,841 R143,108,250 R131,636,771 R129,379,744 Total Project Value (Incl. VAT) R173,000,000 R163,150,000 R150,070,000 R147,500,000
12.2 RECOMMENDATION ON THE PREFERRED OPTION
Based on the outputs of the option analysis, Option 4 is the preferred option.
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12.3 TIME SCHEDULE
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13 O&M AND ASSET MANAGEMENT PLANS
13.1 ASSET MANAGEMENT
Kgetlengrivier Local Municipality should undertake infrastructure asset management planning and infrastructure investment planning processes in order to determine the long-term consequences of capital investment including operations and maintenance and the implications to the beneficiaries. This process should link a number of variables such as the service profile of a community, household profiles, socio-economic profile, infrastructure backlogs and growth, reticulation, bulk and connector costs, capital costs, capital budget and operational budgets and household bills.
The consequences of capital investment and the implications to the beneficiaries should be aligned with the tariff structure of the municipality. It is important that Kgetlengrivier Local Municipality develop their Capital Investment Plan as output of the asset management and infrastructure investment planning processes.
13.2 TYPICAL OPERATIONS AND MAINTENANCE PLAN (O&M)
A typical O&M Plan will contain the following:
Routine O&M System Description Other areas Procedures
•The Source – Being this •Start-up & Shut-down •Emergency Response or project operations Action plan •Type of Treatment •Daily operations •Water Quality Monitoring •Distribution •Routine operations Plan •Storage facilities •Emergency flags •Water Quality Violation •Emergency Power •Routine recordkeeping Response Procedures •Equipment inventory •Employee Training •Spare parts inventory •O&M Cost •Equipment repair/supply contact info
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13.3 ASSET MANAGEMENT PLAN
The Government Immovable Asset Management Act, No 19 of 2007 (GIAMA), seeks to introduce measures to ensure a uniform framework for the management of immovable assets that are used by (or is reserved for) a national or a provincial department in support of its service delivery objectives.
Framework and content of User immovable asset management plans (U-AMP).
Section 1: An Introduction that summarizes the overall Strategic intent of the User regarding its existing and long-term immovable asset requirements. The User must set objectives to improve the efficient and effective utilization of the existing immovable assets and how it is going to measure itself to achieve such objectives. Section 2: Service delivery objectives and immovable asset requirements as expressed in the User’s annual strategic plan and must be underpinned by budget programme objectives. Section 3: Acquisition plan must contain a summary of current and proposed acquisitions, as informed by the impact of service delivery objectives. Section 4: Refurbishment plan must contain a summary of current and proposed refurbishments and reconfiguration of existing immovable assets, as informed by the impact of service delivery objectives. Section 5: Repairs required reinstating immovable assets to their original state. Section 6: Surplus immovable assets that no longer support the service delivery objectives of the User and must be surrendered to the Custodian. Section 7: Budget requirements to fund immovable asset needs of the User. Section extracted from – Department Public Works, User Asset Management Plan (2008, p9).
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14 OCCUPATIONAL HEALTH AND SAFETY An Occupational Health and Safety Agent was appointed to comply in terms of the Construction regulations 2014 Section 5 (1)(2)(3)(4)(7) and (8).
The duties of such agent are as follows: • Liaise with the project team and make inputs throughout project stages no 1 to no 6; • Prepare a project-specific baseline risk assessment as of per scope works for the intended construction work project; • Prepare a sufficiently documented and coherent project-specific health and safety specification, which must be based on the baseline risk assessment contemplated above; • Provide the designer(s) of works with the project-specific health and safety specification; • Ensure that the designer(s) take(s) the site specific health and safety specifications into consideration during the design stage of the project; • Ensure that the designer(s) carry(ies) out all responsibilities contemplated in regulation 6 of Construction Regulations, 2014; • Ensure that the project-specific health and safety specification is included in the tender documents; • Ensure that potential principal contractors submitting tenders have made adequate provision for the cost of health and safety measures; • Ensure that principal contractor(s) to be appointed have/has the necessary competencies and resources to carry out the construction work safely; • Ensure before every work commences on a site that every contractor (both principal contractors and sub-contractors) is registered and in good standing with the compensation fund or with a licensed compensation insurer as contemplated in the Compensation of Occupational Injuries and Diseases Act, 1993 (Act No. 130 of 1993); • Ensure that every principal contractor is appointed in writing by the Client; • Review and approve the principal contractor’s health and safety plan; • Ensure that each contractor’s health and safety plan is implemented and maintained; • Conduct monthly health and safety audits and document verification; • Ensure that the health and safety file contemplated in regulation 7(1)(b) of Construction Regulations 2014, is kept and maintained by the principal contractor; • Ensure that a copy of health and safety audit is provided to the principal contractor within seven days after the audit; • Stop any contractor from executing a construction activity which poses a threat to the health and safety of persons which is not in accordance with the Client’s site specific health and safety specification and the principal health and safety plan;
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• Where changes are brought about to the design or construction work, make sufficient health and safety information available to the principal contractor to execute the work safely; • Ensure that the principal contractor reports all reportable incidents as contemplated in section 24 of Occupational Health and Safety Act, 1993 (Act No. 85 of 1993) to the provincial director, in accordance with regulations 8 and 9 of General Administrative Regulations, 2003; and, • Be ready to apply for the construction work permit when the time arrives.
The following deliverables were completed by the OHS Agent and included under Appendix H as an all-inclusive Occupational Health and Safety report: • Stage 1 – Project Initiation and Briefing Document • Stage 2 – Risk Profile Matrix • Stage 2 – Baseline Risk Assessment • Stage 2 – Draft Health and Safety Specifications • Stage 2 – Site Specific Survey Report • Stage 2 – Preliminary OHS schedule of quantities • Stage 2 – Planned Hygiene Control Report
15 CONCLUSIONS We trust that the information presented in this report is sufficient to enable the DWS to approve the proposals for the detailed design and construction of the infrastructure required to supply the Swartruggens WTW.
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APPENDIX A:
GEOTECHNICAL INVESTIGATION
A
Technical Report 2016/11/18/IGTA Swartruggens Water Supply Pipeline: Initial geotechnical assessment in support of the proposed construction of a water supply pipeline from wells in the Rosmincol area to the town of Swartruggens
Prepared for: MWB Consulting Engineers November 2016 F I N A L Compiled by: F. Calitz
Technical report: 2016/11/18/IGTA
Prepared by
Technical report: 2016/11/18/IGTA
Swartruggens Water Supply Pipeline: Initial geotechnical assessment in support of the proposed construction of a water supply pipeline from wells in the Rosmincol area to the town of Swartruggens
18 November 2016
Prepared for:
MWB Consulting Engineers
204 Beyers Naude Drive
Rustenburg
0299
Compiled by:
Mr Fred Calitz (M.Sc.)
Sent Electronically ______F. Calitz (M.Sc. Soil Science), Pr.Sci.Nat., MSAIEG SACNASP Reg. No.: 400050/96
NORTH WEST PROVINCE: 76 Steve Biko Avenue, Potchefstroom, P.O. Box 19460, Noordbrug, Tel: +27 18 297 6588, Fax: +27 18 297 4813,www.ages-group.com
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Technical report: 2016/11/18/IGTA
REPORT DISTRIBUTION LIST
Name Institution Mr. M. Jordaan MWB Consulting Engineers
DOCUMENT HISTORY
Report no. Date Version Status 2016/11/18/IGTA 18 November 2016 1.0 F I N A L
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Technical report: 2016/11/18/IGTA
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This document contains confidential and proprietary information of AGES (PTY) Ltd and is protected by copyright in favour of AGES (PTY) Ltd and may not be reproduced, or used without the written consent of AGES (PTY) Ltd, which has been obtained beforehand. This document is prepared exclusively for Messrs. MWB Consulting Engineers and is subject to all confidentiality, copyright and trade secrets, rules, intellectual property law and practices of South Africa.
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Initial geo-environmental assessment: Swartruggens Water Supply Pipeline
Table of contents 1 INTRODUCTION ...... 1 1.1 GENERAL ...... 1 1.2 TERMS OF REFERENCE ...... 1 1.3 SCOPE OF THE INVESTIGATION ...... 1 1.4 INFORMATION SOURCES ...... 2 1.5 DEVELOPMENT WITHIN 1 : 100 YEAR-FLOOD LINES ...... 2 2 INVESTIGATIVE METHODOLOGY AND TECHNIQUES ...... 3 2.1 DESK STUDY ...... 3 2.2 REPORTING ...... 6 3 SITE DESCRIPTION ...... 8 3.1 LOCATION OF THE STUDY AREA ...... 8 4 GEOLOGICAL SETTING ...... 9 4.1 REGIONAL STRATIGRAPHY ...... 9 4.2 PROMINENT GEOLOGICAL STRUCTURES ...... 9 4.3 REGIONAL SEISMIC RISK ...... 9 5 REGIONAL GEOTECHNICAL SETTING ...... 10 5.1 LAND TYPES ...... 10 5.2 REGIONAL SOILS DISTRIBUTION ...... 10 5.3 SITE WALK-OVER SURVEY ...... 10 6 PRELIMINARY GEOTECHNCIAL ASSESSMENT ...... 16 6.1 LAND TYPE AC71 ...... 16 6.1.1 Uplands ...... 16 6.1.2 Bottomlands ...... 16 6.1.3 Other issues in general...... 17 6.2 LAND TYPE AE59 ...... 19 6.2.1 Uplands ...... 19 6.2.2 Bottomlands ...... 19 6.2.3 Other issues in general...... 20 6.3 LAND TYPE BC43 ...... 22 6.3.1 Uplands ...... 22 6.3.2 Bottomlands ...... 23 6.3.3 Other issues in general...... 24 6.4 LAND TYPE FA15 ...... 25 6.4.1 Uplands ...... 25 6.4.2 Bottomlands ...... 25 6.4.3 Other issues in general...... 26 6.5 LAND TYPE FB14 ...... 28 6.5.1 Uplands ...... 28 6.5.2 Bottomlands ...... 28 6.5.3 Other issues in general...... 29 6.6 LAND TYPE FB151 ...... 31 6.6.1 Uplands ...... 31 6.6.2 Bottomlands ...... 31 6.6.3 Other issues in general...... 32
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Initial geo-environmental assessment: Swartruggens Water Supply Pipeline
7 RECOMMENDATIONS ...... 34 8 BIBLIOGRAPHY ...... 35
MAPS ...... 36
APPENDIX A ...... 41
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Initial geo-environmental assessment: Swartruggens Water Supply Pipeline
1 INTRODUCTION
1.1 General
This report described the results of an initial geotechnical assessment (IGTA) conducted along the proposed route of a water supply pipeline from wells in the Rosmincol area to the town of Swartruggens.
1.2 Terms of reference
The investigation was requested by Messrs. MWB Consulting Engineers, as confirmed telephonically on 04 November 2016.
This assessment is rendered as specialist input for planning purposes.
1.3 Scope of the investigation
The investigation had the following aims:
To assess the regional geological character of the site
To determine and describe the generalized successions of soil- and rock materials underlying the site by means of available information
To identify possible geological- and/or geotechncial constraints inferred to be encountered at the site that may have an adverse effect on construction and the sustainable utilization of a water supply pipeline in terms of the following main parameters:
o Excavatability
o Geotechnical constraints
o Re-use of excavated materials
o Terrain mobility
It must be noted that this assessment was conducted only to identify potentially adverse geotechnical conditions along the route to facilitate the decision making process regarding proposed construction, and as such the information herein is not intended for detailed design- and construction purposes.
It is assumed that the pipeline will be installed at a depth of between 1.2 and 1.5 m.
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Initial geo-environmental assessment: Swartruggens Water Supply Pipeline
1.4 Information sources
The following sources of information were utilized:
Geological maps:
2526 RUSTENBURG; scale 1 : 250 000 (digital copy)
Land Type map and memoirs:
2526 RUSTENBURG; scale 1 : 250 000 (digital copy)
Remote sensing information:
Google Earth ProTM imagery (digital images)
1.5 Development within 1 : 100 year-flood lines
The National Water Act (Act 36 of 1998) states the following regarding development within the 1 : 100 year-flood line of any stream or river (Thompson, 2006):
‘Section 21(c):
Impeding or diverting the flow of water in watercourses (including alteration of the hydraulic characteristics of flood events) requires licensing according to the Act
Section 21(i):
Any action that may alter the bed, banks, courses or characteristics of watercourses (including flood events) requires licensing according to the Act, including:
- widening or straightening of the bed or banks of a river to allow for the construction of a bridge, sports ground or housing development
- altering the course of a river partially or completely (i.e.: river diversion) to be able to use or develop the area where the watercourse originally was’
It must be noted that the National Water Act does not prohibit development within 1 : 100 year-flood lines, but rather requires the careful study of the effects of the proposed development on surface- and groundwater flow within and downstream of these areas, and requires that suitable precautionary measures be implemented to minimize and control these effects.
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Initial geo-environmental assessment: Swartruggens Water Supply Pipeline
2 INVESTIGATIVE METHODOLOGY AND TECHNIQUES
2.1 Desk study
The assessment of the regional geological- and geotechnical characteristics of the soil- and rock materials underlying the route was conducted as follows:
The establishment of a regional geological model by means of regional geological mapping based on the published 1 : 250 000-scale geological maps and remote sensing images. This model focussed on known geotechnical constraints associated with underlying stratigraphy (e.g.: strata prone to slaking, erosion, water-soluble rocks, and/or adverse consequences of weathering), as well as determining the structural geological setting of the area.
The inferred geotechnical impacts of the different soil materials covering the route were assessed on a regional scale by application of an updated version of the Soils Effects Grouping- (SEG-) System (Calitz & Hattingh, 2007, currently being revised by the author). This innovative system is based on the study of freely available Land Type maps and memoirs to obtain an estimation of the spatial distribution of the different soil forms covering the route. The inferred geotechnical characteristics exhibited by the different soil forms, as defined by the ten SEG’s correlated with industry-standard parameters proposed by Partridge et al. (1973), allow the qualification of possible adverse effects thereof on development (rule of thumb: the higher the SEG-number, the more severe the inferred effects on development). This assessment allows the flagging of issues of a geological- or geotechnical nature for strategic decision making purposes.
The following parameters are addressed, expressed as a graph indicating severity to aid assessment and collation of the regional soils distribution within each terrain unit) namely:
Example of a soils effects graph AGES -3-
Initial geo-environmental assessment: Swartruggens Water Supply Pipeline
o Excavatability Factor
The excepted excavatability (given machine excavation under restricted conditions) at the site to a depth of approximately 1.5 m was assessed in terms of the indicated average soil thicknesses, underlying materials, and soil rippability:
- Rock and/or hardpan pedocretes comprise less than 10% of the volume of material to a depth of 1.5 m – inferred topsoil thickness exceeds 1.35 m (deep soils – Partridge et al. Class 1F)
- Rock and/or hardpan pedocretes comprise between 10 and 40% of the volume of material to a depth of 1.5 m – inferred topsoil thickness varies between 0.6 and 1.35 m (soils of variable thickness – Partridge et al. Class 2F)
- Rock and/or hardpan pedocretes comprise in excess of 40% of the volume of material to a depth of 1.5 m – inferred topsoil thickness less than 0.6 m (shallow soils to lack of soil – Partridge et al. Class 3F)
o Geotechnical Factor
The inferred geotechnical characteristics of the different soil types in and on which the pipe will be placed have a significant effect on the long-term integrity of the development itself. These were assessed as follows, based on the inferred properties of each soil type:
- Soil material may potentially undergo collapse settlement under loading or when saturated, thus reducing the load bearing strength of the material that may lead to a loss of support beneath structures, buried tanks and/or pipes over time in areas near roads used by heavy vehicles, or suddenly in case of a leak (Partridge et al. Classes 1A and 2A)
- Periodic groundwater seepage may be encountered (Partridge et al. Classes 2B and 3B)
- Soil material may heave or shrink with changes in moisture content and as such may cause structural damage over time (Partridge et al. Classes 2C and 3C)
- Soil material may potentially undergo consolidation (i.e.: compressible material) under loading or when saturated, including so-called ‘soft clays’, thus reducing the load bearing strength of the material that may lead to a gradual loss of support beneath structures, buried tanks and/or pipes over time in areas near roads used by heavy vehicles, or suddenly in case of a leak (Partridge et al. Classes 2D and 3D)
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Initial geo-environmental assessment: Swartruggens Water Supply Pipeline
- Soils may be prone to erosion (e.g.: dispersive material, or non-cohesive material located along steep slopes or within areas prone to concentrated surface flow), and as such may mobilize and dissipate from beneath structures, buried tanks and/or pipes, leading to localized loss of support (Partridge et al. Classes 2E and 3E)
- Soils may undergo saturation for prolonged periods of time, leading to severe structural damage due to rising damp (Partridge et al. Classes 2B and 3B)
o Re-Use Factor
A generalized indication of the re-use suitability of the materials to be excavated from trenches or earthworks along the route is obtained for the following applications:
- Pipe bedding material (as specified by SABS 1200 LS, 1983), based on the indicated minimum clay content of the different soil types, as well as its inferred mechanical characteristics (e.g.: sandy soils will in all probability be more suitable than moderately- to strongly structured clayey soils)
- Fill- (Subgrade-) material, based mainly on the occurrence of sandy- and/or gravelly soils, including saprolite, but excluding those soil forms that exhibit clayey topsoil, as clayey material generally does not compact well
- Selected subgrade- / gravel wearing course material, mainly identified by the presence of gravelly soils, or those underlain by a significant volume of saprolite without much clay
- Subbase material, mainly comprising sandy- and/or gravelly soils, including clay-poor saprolite
o Terrain Mobility Factor
Construction work may be hampered or delayed by the following inferred issues:
- Scattered- to extensive boulders at surface may restrict access to the construction site for most wheeled- and even some tracked vehicles
- Most soils exhibiting a high clay content may become slippery when wet (e.g.: after heavy precipitation events), hampering access to the construction site for mainly wheeled vehicles
- Some soils comprising sandy topsoil underlain by a relatively impermeable material may in the presence of groundwater seepage undergo a degree of liquefaction (e.g.: quicksand conditions) under loading, severely hampering access to the construction site for especially heavier vehicles
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Initial geo-environmental assessment: Swartruggens Water Supply Pipeline
o Other issues
The structural integrity of structures, buried engineering services and/or pipelines may be compromised by any of the following additional issues:
- Moderately steep- to steep slopes may lead to localized slope failure beneath structures or pipes, especially in areas where the natural vegetation cover and drainage paths have been disturbed during construction - corresponding to Partridge et al. Classes 2J and 3J
- Strata exhibiting adverse geotechnical characteristics (for example: slaking rocks) may deteriorate over time, and as such reduce the bearing strength of the underlying material
- Dolomite land (i.e.: areas underlain by water-soluble strata) poses a specific risk to development, as the formation of subsidences or sinkholes in areas where leaks and/or poor surface drainage occur may severely damage or even destroy structures and engineering services – corresponding to Partridge et al. Classes 1H to 3H
The results of the above-mentioned actions were represented by means of a GIS-generated map.
Flag issues, identified in terms of the inferred geological- and geotechnical character by means of tables (decision- and ranking matrices) and associated figures, were identified according to the criteria noted in Table 1.
NOTES: It must be noted that the Land Type information utilized during this study renders generalized data based on large-scale mapping, and as such is suitable only for pre-feasibility assessments with small-scale variations in sub-surface conditions possible. This assessment does, however, take the personal experience with the geotechnical character of the area into account.
The Land Type soils information references the Binomial Soil Classification System (Soil Classification Working Group, 1977) that describes soil horizons to a maximum depth of 1.2 m with some materials occurring at depth not deemed diagnostic, and as such not included in the descriptions.
2.2 Reporting
Results with regard to the regional geological- and geotechnical characteristics were collated in an Initial Geotechnical Assessment- (i.e.: Pre-Feasibility-) report, with recommendations on follow-up work required to accurately investigate the site.
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3 SITE DESCRIPTION
3.1 Location of the study area
The proposed pipeline route will be constructed from a proposed manifold chamber in the Rosmincol area, into which a number of pipelines from wells in the area will feed, along existing roads to the water treatment plant to the south of Swartruggens, with a total length of approximately 23 Km. The study area is located in the Ditsobotla- and Kgetlengrivier Local Municipalities that form part of the Bojanala- and Ngaka Modiri Molema District Municipalities respectively, Northwest Province (Figures 1a and 1b). The following coordinates apply (WGS84 datum, decimal degrees):
Rosmincol Manifold Chamber
Latitude: 25.83963°S Longitude: 26.51365°E
Swartruggens Water Treatment Plant
Latitude: 25.66288°S Longitude: 26.68814°E
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4 GEOLOGICAL SETTING
4.1 Regional stratigraphy
The regional stratigraphic setting of the area is detailed in Table 2, and indicated in graphical format by Figures 1a and 1b.
The area around Rosmincol is underlain by light banded dolomite with chert of the Eccles Formation, followed by dark chert-poor dolomite of the Frisco Formation, both forming part of the Chuniespoort Group, Transvaal Supergroup.
The route then cuts across shale and giant chert known as the Rooihoogte Formation, Transvaal Supergroup.
The remainder of the route is underlain by shale and slate of the Timeball Hill Formation that forms part of the Pretoria Group, Transvaal Supergroup.
It must be noted that the extreme southern portion of the route in the vicinity of Rosmincol (i.e.: those portions underlain by water-soluble strata from the Eccles-, Frisco- and Rooihoogte Formations) is deemed “dolomitic land”.
4.2 Prominent geological structures
A prominent diabase- / dolerite sill intrusion underlies the route at Syferfontein.
Several weakly defined diabase- / dolerite dyke intrusions are indicated to occur throughout the area.
These structures may have given rise to the fracturing and alteration of the surrounding bedrock, in places forming localized pockets of bedrock exhibiting hard- to very hard rock consistency close to the surface, and may be present as discontinuous lines of rounded boulders at the surface. It is possible that several other even less prominent intrusions may also be encountered.
4.3 Regional seismic risk
According to Kijko et al. (2003) the regional seismic hazard of the area in general can be defined as relatively low, with a 10% probability of a seismic event with a peak ground acceleration exceeding 0.08 G probable within a period of 50 years.
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5 REGIONAL GEOTECHNICAL SETTING
5.1 Land Types
According to the available Land Type map and memoir, the site is covered by soils of the following Land Types (Figure 1a and 1b, and Table 2):
LAND TYPE Ac71 red- and yellow apedal, freely draining soils that have undergone leaching
LAND TYPE Ae59 red apedal, freely draining soils in excess of 0.3 m thick that have undergone little or no leaching, without the regular occurrence of dunes
LAND TYPE Ba43 plinthic (ferruginized) catena, uplands duplex and/or margalitic soils (moderately structured clayey soils) rare, with red- and yellow apedal soils that have undergone leaching dominant
LAND TYPE Fa15 generally lime-poor shallow soils on bedrock
LAND TYPE Fb14 shallow soils on bedrock, with topsoil in bottomlands generally lime- rich
LAND TYPE Fb151 shallow soils on bedrock, with topsoil in bottomlands generally lime- rich
5.2 Regional soils distribution
Utilizing the available information, a detailed description of the different soil groupings to be expected along the route is shown by Table 2.
5.3 Site walk-over survey
A brief site drive-over survey was conducted on 09 November 2016, during which the following observations were made:
The route is predominantly underlain at shallow depth by fairly competent shale bedrock (Photo 1), with scattered dolomite and chert outcrops visible in the south.
Localized areas exhibiting thicker topsoil layers, mainly associated with the presence of termite mounds and/or specific vegetation types, were noted, but these invariably are also underlain by bedrock, albeit at slightly increased depths (Photo 2).
The prominent dolerite sill intrusion occurring in the south of the route was found to be associated with thicker, weakly structured clayey soils (Shortlands soil form) containing occasional weathered dolerite boulders (Photo 3).
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The presence of thick layers of dense to very dense ferruginized material (i.e.: soft-, honeycomb- and/or hardpan ferricrete) possibly marginally suitable for use as bedding material was confirmed in the sidewalls of an excavation near the wells in the extreme south of the pipeline route (Photo 4).
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(Table 2 . . . continued)
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PHOTO 1 Scattered shale outcrop within Land Type Ae59
PHOTO 2 Hutton-type soil underlain by shale bedrock along an erosion donga within Land Type Ae59
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PHOTO 3 Thick Shortlands soil associated with a dolerite sill intrusion within Land Type Fb151
PHOTO 4 Thick layers of soft-, honeycomb- and in some places hardpan ferricrete within a borrow pit in Land Type Fa15
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6 PRELIMINARY GEOTECHNCIAL ASSESSMENT
6.1 Land Type Ac71
6.1.1 Uplands
The different soil types covering ridge crests, scarp edges and mid slopes within this land type along the route are expected to exhibit roughly the same geotechnical characteristics. The effects of the generalized geotechnical characteristics of the soils covering these portions of the pipeline route can be summarized as follows (Figures 2a and 2b, and Table 3a):
Excavatability predominantly shallow soils (between 95 and 100%), with very highly localized pockets of soils of variable thickness (up to 5%)
excavation to installation depth only possible by mechanical means, with heavy mechanical excavators, power tools and/or blasting needed to remove bedrock and/or hardpan ferricrete boulders
Geotechnical constraints soils expected to consolidate under loading or when wet some soils may be prone to erosion, due to an inferred dispersive nature, as well as concentrated surface flow along steep slopes suitable precautionary measures indicated to counter the effects of consolidation (it should be noted that hardpan ferricrete boulders may be underlain by material exhibiting poor strength)
efficient surface drainage to prevent concentrated surface flow that may cause soil erosion and/or inundation of upper topsoil (may cause loss of cohesion and bearing strength)
Re-use of excavated materials most- to all natural materials deemed unsuitable for re-use
more suitable material for especially pipe bedding should be obtained from either existing- or newly developed sources in the area
Terrain mobility scattered boulders may occur at surface topsoil may become slippery in localized areas after rain
some loose boulders on the surface may have to be removed by heavy mechanical equipment to allow access
clayey topsoil may hamper the movement of most wheeled- and some tracked construction vehicles (e.g.: LDV’s and 4x2 TLB’s) after heavy precipitation events
6.1.2 Bottomlands
The different soil types covering foot slopes and valley floors within this land type along the route are expected to exhibit roughly the same geotechnical characteristics. The effects of the generalized geotechnical characteristics of the soils covering these portions of the pipeline route can be summarized as follows (Figures 2a and 2b, and Table 3a):
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Excavatability predominantly shallow soils (between 79 and 83%), with highly localized- to localized pockets of soils of variable thickness (between 18 and 22%)
excavation to installation depth only possible by mechanical means, with heavy mechanical excavators, power tools and/or blasting needed to remove bedrock and/or hardpan ferricrete boulders
Geotechnical constraints localized groundwater seepage may occasionally occur, especially after heavy precipitation events some soils may heave / shrink with changes in moisture content soils expected to consolidate under loading or when wet some soils may be prone to erosion, due to an inferred dispersive nature, as well as concentrated surface flow some soils may undergo periodic inundation, especially after heavy precipitation events
suitable precautionary measures indicated to counter the effects of consolidation (it should be noted that hardpan ferricrete boulders may be underlain by material exhibiting poor strength), and/or expansive materials
efficient surface drainage to prevent concentrated surface flow that may cause soil erosion and/or inundation of topsoil (may cause loss of cohesion and bearing strength)
Re-use of excavated materials most- to all natural materials deemed unsuitable for re-use
more suitable material for especially pipe bedding should be obtained from either existing- or newly developed sources in the area
Terrain mobility scattered boulders may occur at surface topsoil may become slippery in localized areas after rain
some loose boulders on the surface may have to be removed by heavy mechanical equipment to allow access
clayey topsoil may hamper the movement of most wheeled- and some tracked construction vehicles (e.g.: LDV’s and 4x2 TLB’s) after heavy precipitation events
6.1.3 Other issues in general some portions may exhibit steep- to very steep slopes, that may lead to localized slope instability, especially in areas where the natural vegetation has been removed or the natural drainage paths disturbed
requires careful consideration of the widespread disturbance of the natural vegetation and surface drainage, with the implementation of suitable precautionary measures to prevent concentrated surface flow in these areas
the extreme southern portion of the route may be underlain by dolomite
a Dolomite Risk Management Strategy (DRMS) and -Plan (DRMP) will be required to manage the risk posed by the presence of water-soluble strata beneath the pipeline, according to the requirements of SANS 1936 (2012)
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concentrated surface flow (i.e.: flooding) may occur along valley floors after heavy precipitation events
requires the implementation of suitable precautionary measures to prevent scouring of the pipe footings along valley floors and stream channels
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6.2 Land Type Ae59
6.2.1 Uplands
The different soil types covering ridge crests and scarp edges within this land type along the route are expected to exhibit roughly the same geotechnical characteristics. The effects of the generalized geotechnical characteristics of the soils covering these portions of the pipeline route can be summarized as follows (Figures 2a and 2b, and Table 3b):
Excavatability predominantly shallow soils (± 100%)
excavation to installation depth only possible by mechanical means, with heavy mechanical excavators, power tools and/or blasting needed to remove bedrock and/or hardpan ferricrete boulders
Geotechnical constraints soils, where present, expected to consolidate under loading or when wet some soils may be prone to erosion, due to an inferred dispersive nature, as well as concentrated surface flow along steep slopes suitable precautionary measures indicated to counter the effects of consolidation (it should be noted that hardpan ferricrete boulders may be underlain by material exhibiting poor strength)
efficient surface drainage to prevent concentrated surface flow that may cause soil erosion and/or inundation of upper topsoil (may cause loss of cohesion and bearing strength)
Re-use of excavated materials most- to all natural materials deemed unsuitable for re-use
more suitable material for especially pipe bedding should be obtained from either existing- or newly developed sources in the area
Terrain mobility scattered boulders may occur at surface
some loose boulders on the surface may have to be removed by heavy mechanical equipment to allow access
6.2.2 Bottomlands
The different soil types covering mid slopes, foot slopes and valley floors within this land type along the route are expected to exhibit roughly the same geotechnical characteristics. The effects of the generalized geotechnical characteristics of the soils covering these portions of the pipeline route can be summarized as follows (Figures 2a and 2b, and Table 3b):
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Excavatability mainly- to predominantly shallow soils (between 59 and 70%), with localized pockets of soils of variable thickness (between 26 and 37%), and very highly localized pockets of deep soils (between 4 and 5%)
excavation to installation depth only possible by mechanical means, with heavy mechanical excavators, power tools and/or blasting needed to remove bedrock and/or hardpan ferricrete boulders
Geotechnical constraints localized groundwater seepage may occasionally occur, especially after heavy precipitation events some soils may heave / shrink with changes in moisture content soils expected to consolidate under loading or when wet some soils may be prone to erosion, due to an inferred dispersive nature, as well as concentrated surface flow some soils may undergo periodic inundation, especially after heavy precipitation events
suitable precautionary measures indicated to counter the effects of consolidation (it should be noted that hardpan ferricrete boulders may be underlain by material exhibiting poor strength), and/or expansive materials
efficient surface drainage to prevent concentrated surface flow that may cause soil erosion and/or inundation of topsoil (may cause loss of cohesion and bearing strength)
Re-use of excavated materials most- to all natural materials deemed unsuitable for re-use
more suitable material for especially pipe bedding should be obtained from either existing- or newly developed sources in the area
Terrain mobility scattered boulders may occur at surface topsoil may become slippery in localized areas after rain sandy topsoil overlying denser material may undergo loss of cohesion
some loose boulders on the surface may have to be removed by heavy mechanical equipment to allow access
clayey topsoil may hamper the movement of most wheeled- and some tracked construction vehicles (e.g.: LDV’s and 4x2 TLB’s) after heavy precipitation events
sandy topsoil may hamper the movement of wheeled construction vehicles (e.g.: LDV’s and TLB’s) after heavy precipitation events
6.2.3 Other issues in general some portions may exhibit steep- to very steep slopes, that may lead to localized slope instability, especially in areas where the natural vegetation has been removed or the natural drainage paths disturbed
requires careful consideration of the widespread disturbance of the natural vegetation and surface drainage, with the implementation of suitable precautionary measures to prevent concentrated surface flow in these areas
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concentrated surface flow (i.e.: flooding) may occur along valley floors after heavy precipitation events
requires the implementation of suitable precautionary measures to prevent scouring of the pipe footings along valley floors and stream channels
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6.3 Land Type Bc43
6.3.1 Uplands
The different soil types covering ridge crests within this land type along the route are expected to exhibit roughly the same geotechnical characteristics. The effects of the generalized geotechnical characteristics of the soils covering these portions of the pipeline route can be summarized as follows (Figures 2a and 2b, and Table 3c):
Excavatability mainly soils of variable thickness (± 48%) and shallow soils (± 43%), with very highly localized pockets of deep soils (± 9%)
excavation to installation depth only possible by mechanical means, with heavy mechanical excavators, power tools and/or blasting needed to remove bedrock and/or hardpan ferricrete boulders
Geotechnical constraints some soils may undergo collapse settlement when saturated localized groundwater seepage may occasionally occur, especially after heavy precipitation events soils expected to consolidate under loading or when wet some soils may be prone to erosion, due to an inferred dispersive nature, as well as concentrated surface flow some soils may undergo periodic inundation, especially after heavy precipitation events
suitable precautionary measures indicated to counter the effects of consolidation (it should be noted that hardpan ferricrete boulders may be underlain by material exhibiting poor strength)
efficient surface drainage to prevent concentrated surface flow that may cause soil erosion and/or inundation of topsoil (may cause loss of cohesion and bearing strength)and/or inundation of upper topsoil (may cause loss of cohesion and bearing strength)
Re-use of excavated materials most- to all natural materials deemed unsuitable for re-use
more suitable material for especially pipe bedding should be obtained from either existing- or newly developed sources in the area
Terrain mobility scattered boulders may occur at surface topsoil may become slippery in localized areas after rain sandy topsoil overlying denser material may undergo loss of cohesion
some loose boulders on the surface may have to be removed by heavy mechanical equipment to allow access
clayey topsoil may hamper the movement of most wheeled- and some tracked construction vehicles (e.g.: LDV’s and 4x2 TLB’s) after heavy precipitation events
sandy topsoil may hamper the movement of wheeled construction vehicles (e.g.: LDV’s and TLB’s) after heavy precipitation events
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6.3.2 Bottomlands
The different soil types covering mid slopes, foot slopes and valley floors within this land type along the route are expected to exhibit roughly the same geotechnical characteristics. The effects of the generalized geotechnical characteristics of the soils covering these portions of the pipeline route can be summarized as follows (Figures 2a and 2b, and Table 3c):
Excavatability mainly- to predominantly soils of variable thickness (between 25 and 75%) and shallow soils (between 25 and 71%), with very highly localized pockets of deep soils (between 4 and 7%)
excavation to installation depth only possible by mechanical means, with heavy mechanical excavators, power tools and/or blasting needed to remove bedrock and/or hardpan ferricrete boulders
Geotechnical constraints some soils may undergo collapse settlement when saturated localized groundwater seepage may occasionally occur, especially after heavy precipitation events some soils may heave / shrink with changes in moisture content soils expected to consolidate under loading or when wet some soils may be prone to erosion, due to an inferred dispersive nature, as well as concentrated surface flow some soils may undergo periodic inundation, especially after heavy precipitation events
suitable precautionary measures indicated to counter the effects of consolidation (it should be noted that hardpan ferricrete boulders may be underlain by material exhibiting poor strength), and/or expansive materials
efficient surface drainage to prevent concentrated surface flow that may cause soil erosion and/or inundation of topsoil (may cause loss of cohesion and bearing strength)and/or inundation of upper topsoil (may cause loss of cohesion and bearing strength)
Re-use of excavated materials most- to all natural materials deemed unsuitable for re-use
more suitable material for especially pipe bedding should be obtained from either existing- or newly developed sources in the area
Terrain mobility scattered boulders may occur at surface topsoil may become slippery in localized areas after rain sandy topsoil overlying denser material may undergo loss of cohesion
some loose boulders on the surface may have to be removed by heavy mechanical equipment to allow access
clayey topsoil may hamper the movement of most wheeled- and some tracked construction vehicles (e.g.: LDV’s and 4x2 TLB’s) after heavy precipitation events
sandy topsoil may hamper the movement of wheeled construction vehicles (e.g.: LDV’s and TLB’s) after heavy precipitation events
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6.3.3 Other issues in general concentrated surface flow (i.e.: flooding) may occur along valley floors after heavy precipitation events
requires the implementation of suitable precautionary measures to prevent scouring of the pipe footings along valley floors and stream channels
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6.4 Land Type Fa15
6.4.1 Uplands
The different soil types covering ridge crests within this land type along the route are expected to exhibit roughly the same geotechnical characteristics. The effects of the generalized geotechnical characteristics of the soils covering these portions of the pipeline route can be summarized as follows (Figures 2a and 2b, and Table 3d):
Excavatability predominantly shallow soils (± 94%), with very highly localized pockets of soils of variable thickness (± 5%) and deep soils (± 2%)
excavation to installation depth only possible by mechanical means, with heavy mechanical excavators, power tools and/or blasting needed to remove bedrock and/or hardpan ferricrete boulders
Geotechnical constraints soils, where present, expected to consolidate under loading or when wet some soils may be prone to erosion, due to an inferred dispersive nature, as well as concentrated surface flow suitable precautionary measures indicated to counter the effects of consolidation (it should be noted that hardpan ferricrete boulders may be underlain by material exhibiting poor strength)
efficient surface drainage to prevent concentrated surface flow that may cause soil erosion and/or inundation of upper topsoil (may cause loss of cohesion and bearing strength)
Re-use of excavated materials most- to all natural materials deemed unsuitable for re-use
more suitable material for especially pipe bedding should be obtained from either existing- or newly developed sources in the area
Terrain mobility scattered boulders may occur at surface
some loose boulders on the surface may have to be removed by heavy mechanical equipment to allow access
6.4.2 Bottomlands
The different soil types covering mid slopes, foot slopes and valley floors within this land type along the route are expected to exhibit roughly the same geotechnical characteristics. The effects of the generalized geotechnical characteristics of the soils covering these portions of the pipeline route can be summarized as follows (Figures 2a and 2b, and Table 3d):
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Excavatability mainly- to predominantly shallow soils (between 53 and 77%), with highly localized- to localized pockets of soils of variable thickness (between 18 and 34%), and very highly localized- to highly localized pockets of deep soils (between 6 and 14%)
excavation to installation depth only possible by mechanical means, with heavy mechanical excavators, power tools and/or blasting needed to remove bedrock and/or hardpan ferricrete boulders
Geotechnical constraints localized groundwater seepage may occasionally occur, especially after heavy precipitation events some soils may heave / shrink with changes in moisture content soils expected to consolidate under loading or when wet some soils may be prone to erosion, due to an inferred dispersive nature, as well as concentrated surface flow some soils may undergo periodic inundation, especially after heavy precipitation events
suitable precautionary measures indicated to counter the effects of consolidation (it should be noted that hardpan ferricrete boulders may be underlain by material exhibiting poor strength), and/or expansive materials
efficient surface drainage to prevent concentrated surface flow that may cause soil erosion and/or inundation of topsoil (may cause loss of cohesion and bearing strength)
Re-use of excavated materials most- to all natural materials deemed unsuitable for re-use
more suitable material for especially pipe bedding should be obtained from either existing- or newly developed sources in the area
Terrain mobility scattered boulders may occur at surface topsoil may become slippery in localized areas after rain sandy topsoil overlying denser material may undergo loss of cohesion
some loose boulders on the surface may have to be removed by heavy mechanical equipment to allow access
clayey topsoil may hamper the movement of most wheeled- and some tracked construction vehicles (e.g.: LDV’s and 4x2 TLB’s) after heavy precipitation events
sandy topsoil may hamper the movement of wheeled construction vehicles (e.g.: LDV’s and TLB’s) after heavy precipitation events
6.4.3 Other issues in general some portions may exhibit steep- to very steep slopes, that may lead to localized slope instability, especially in areas where the natural vegetation has been removed or the natural drainage paths disturbed
requires careful consideration of the widespread disturbance of the natural vegetation and surface drainage, with the implementation of suitable precautionary measures to prevent concentrated surface flow in these areas
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concentrated surface flow (i.e.: flooding) may occur along valley floors after heavy precipitation events
requires the implementation of suitable precautionary measures to prevent scouring of the pipe footings along valley floors and stream channels
most of this portion of the route may be underlain by dolomite
a Dolomite Risk Management Strategy (DRMS) and -Plan (DRMP) will be required to manage the risk posed by the presence of water-soluble strata beneath the pipeline, according to the requirements of SANS 1936 (2012)
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6.5 Land Type Fb14
6.5.1 Uplands
The different soil types covering ridge crests and scarp edges within this land type along the route are expected to exhibit roughly the same geotechnical characteristics. The effects of the generalized geotechnical characteristics of the soils covering these portions of the pipeline route can be summarized as follows (Figures 2a and 2b, and Table 3e):
Excavatability predominantly shallow soils (between 98 and 100%), with very highly localized pockets of soils of variable thickness (up to 2%) and deep soils (up to 1%)
excavation to installation depth only possible by mechanical means, with heavy mechanical excavators, power tools and/or blasting needed to remove bedrock and/or hardpan ferricrete boulders
Geotechnical constraints soils, where present, expected to consolidate under loading or when wet some soils may be prone to erosion, due to an inferred dispersive nature, as well as concentrated surface flow suitable precautionary measures indicated to counter the effects of consolidation (it should be noted that hardpan ferricrete boulders may be underlain by material exhibiting poor strength)
efficient surface drainage to prevent concentrated surface flow that may cause soil erosion and/or inundation of upper topsoil (may cause loss of cohesion and bearing strength)
Re-use of excavated materials most- to all natural materials deemed unsuitable for re-use
more suitable material for especially pipe bedding should be obtained from either existing- or newly developed sources in the area
Terrain mobility scattered boulders may occur at surface
some loose boulders on the surface may have to be removed by heavy mechanical equipment to allow access
6.5.2 Bottomlands
The different soil types covering mid slopes, foot slopes and valley floors within this land type along the route are expected to exhibit roughly the same geotechnical characteristics. The effects of the generalized geotechnical characteristics of the soils covering these portions of the pipeline route can be summarized as follows (Figures 2a and 2b, and Table 3e):
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Excavatability mainly- to predominantly shallow soils (between 59 and 84%), with highly localized- to localized pockets of soils of variable thickness (between 12 and 39%), and very highly localized pockets of deep soils (between 1 and 7%)
excavation to installation depth only possible by mechanical means, with heavy mechanical excavators, power tools and/or blasting needed to remove bedrock and/or hardpan ferricrete boulders
Geotechnical constraints Some soils may undergo collapse settlement when saturated localized groundwater seepage may occasionally occur, especially after heavy precipitation events some soils may heave / shrink with changes in moisture content soils expected to consolidate under loading or when wet some soils may be prone to erosion, due to an inferred dispersive nature, as well as concentrated surface flow some soils may undergo periodic inundation, especially after heavy precipitation events
suitable precautionary measures indicated to counter the effects of consolidation (it should be noted that hardpan ferricrete boulders may be underlain by material exhibiting poor strength), and/or expansive materials
efficient surface drainage to prevent concentrated surface flow that may cause soil erosion and/or inundation of topsoil (may cause loss of cohesion and bearing strength)
Re-use of excavated materials most- to all natural materials deemed unsuitable for re-use
more suitable material for especially pipe bedding should be obtained from either existing- or newly developed sources in the area
Terrain mobility scattered boulders may occur at surface topsoil may become slippery in localized areas after rain sandy topsoil overlying denser material may undergo loss of cohesion
some loose boulders on the surface may have to be removed by heavy mechanical equipment to allow access
clayey topsoil may hamper the movement of most wheeled- and some tracked construction vehicles (e.g.: LDV’s and 4x2 TLB’s) after heavy precipitation events
sandy topsoil may hamper the movement of wheeled construction vehicles (e.g.: LDV’s and TLB’s) after heavy precipitation events
6.5.3 Other issues in general some portions may exhibit steep- to very steep slopes, that may lead to localized slope instability, especially in areas where the natural vegetation has been removed or the natural drainage paths disturbed
requires careful consideration of the widespread disturbance of the natural vegetation and surface drainage, with the implementation of suitable precautionary measures to prevent concentrated surface flow in these areas
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concentrated surface flow (i.e.: flooding) may occur along valley floors after heavy precipitation events
requires the implementation of suitable precautionary measures to prevent scouring of the pipe footings along valley floors and stream channels
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6.6 Land Type Fb151
6.6.1 Uplands
The different soil types covering ridge crests and scarp edges within this land type along the route are expected to exhibit roughly the same geotechnical characteristics. The effects of the generalized geotechnical characteristics of the soils covering these portions of the pipeline route can be summarized as follows (Figures 2a and 2b, and Table 3f):
Excavatability predominantly shallow soils (± 100%)
excavation to installation depth only possible by mechanical means, with heavy mechanical excavators, power tools and/or blasting needed to remove bedrock and/or hardpan ferricrete boulders
Geotechnical constraints soils, where present, expected to consolidate under loading or when wet some soils may be prone to erosion, due to an inferred dispersive nature, as well as concentrated surface flow suitable precautionary measures indicated to counter the effects of consolidation (it should be noted that hardpan ferricrete boulders may be underlain by material exhibiting poor strength)
efficient surface drainage to prevent concentrated surface flow that may cause soil erosion and/or inundation of upper topsoil (may cause loss of cohesion and bearing strength)
Re-use of excavated materials most- to all natural materials deemed unsuitable for re-use
more suitable material for especially pipe bedding should be obtained from either existing- or newly developed sources in the area
Terrain mobility scattered boulders may occur at surface
some loose boulders on the surface may have to be removed by heavy mechanical equipment to allow access
6.6.2 Bottomlands
The different soil types covering mid slopes, foot slopes and valley floors within this land type along the route are expected to exhibit roughly the same geotechnical characteristics. The effects of the generalized geotechnical characteristics of the soils covering these portions of the pipeline route can be summarized as follows (Figures 2a and 2b, and Table 3f):
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Excavatability mainly- to predominantly shallow soils (between 59 and 84%), with highly localized- to localized pockets of soils of variable thickness (between 12 and 39%), and very highly localized pockets of deep soils (between 1 and 7%)
excavation to installation depth only possible by mechanical means, with heavy mechanical excavators, power tools and/or blasting needed to remove bedrock and/or hardpan ferricrete boulders
Geotechnical constraints Some soils may undergo collapse settlement when saturated localized groundwater seepage may occasionally occur, especially after heavy precipitation events some soils may heave / shrink with changes in moisture content soils expected to consolidate under loading or when wet some soils may be prone to erosion, due to an inferred dispersive nature, as well as concentrated surface flow some soils may undergo periodic inundation, especially after heavy precipitation events
suitable precautionary measures indicated to counter the effects of consolidation (it should be noted that hardpan ferricrete boulders may be underlain by material exhibiting poor strength), and/or expansive materials
efficient surface drainage to prevent concentrated surface flow that may cause soil erosion and/or inundation of topsoil (may cause loss of cohesion and bearing strength)
Re-use of excavated materials most- to all natural materials deemed unsuitable for re-use
more suitable material for especially pipe bedding should be obtained from either existing- or newly developed sources in the area
Terrain mobility scattered boulders may occur at surface topsoil may become slippery in localized areas after rain sandy topsoil overlying denser material may undergo loss of cohesion
some loose boulders on the surface may have to be removed by heavy mechanical equipment to allow access
clayey topsoil may hamper the movement of most wheeled- and some tracked construction vehicles (e.g.: LDV’s and 4x2 TLB’s) after heavy precipitation events
sandy topsoil may hamper the movement of wheeled construction vehicles (e.g.: LDV’s and TLB’s) after heavy precipitation events
6.6.3 Other issues in general some portions may exhibit steep- to very steep slopes, that may lead to localized slope instability, especially in areas where the natural vegetation has been removed or the natural drainage paths disturbed
requires careful consideration of the widespread disturbance of the natural vegetation and surface drainage, with the implementation of suitable precautionary measures to prevent concentrated surface flow in these areas
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Initial geo-environmental assessment: Swartruggens Water Supply Pipeline
concentrated surface flow (i.e.: flooding) may occur along valley floors after heavy precipitation events
requires the implementation of suitable precautionary measures to prevent scouring of the pipe footings along valley floors and stream channels
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Initial geo-environmental assessment: Swartruggens Water Supply Pipeline
7 RECOMMENDATIONS
In follow-up to this desk study, it is recommended that the following actions be undertaken to obtain more detailed site-specific information within the study area of relevance to the proposed construction of a pipeline and related bulk service infrastructure:
The excavation of a number of test pits, backed up by Dynamic Cone Penetrometer (DCP) tests, to verify the precise succession of soil- and rock material, as well as to quantify the depth to bedrock and/or hardpan pedocretes across the site
The taking of soil samples for the determination of the precise geotechnical characteristics of the different natural soil materials underlying the route, especially with regard to the re- use- and compaction potential of specific layers (where deemed necessary)
Interpretation of the results of the detailed investigation to more accurately assess excavatability, the occurrence of soils exhibiting potentially adverse geotechnical characteristics that may affect design and construction of structures and/or engineering services
A Dolomite Risk Management Strategy (DRMS) and Plan (DRMP) will have to be compiled and implemented for those sections of the pipeline that cut across areas underlain by dolomite.
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8 BIBLIOGRAPHY
CALITZ, F and HATTINGH, J M, 2007. The value of Land Type information with regard to Initial Geotechnical Assessments in South Africa. Proceedings of the 14th African Regional Conference for Soil Mechanics and Geotechnical Engineering: Soils of Africa Vol. 1. Yaounde, Cameroon.
(CALITZ, F, -. Improved efficacy of geotechnical soil assessments as specialist studies for Environmental Impact Assessments. Unpublished Ph.D.-thesis in Geography and Environmental Management at the Potchefstroom Campus of the North-West University, currently in preparation.)
DEPARTMENT OF PUBLIC WORKS, 2007. Identification of problematic soil in Southern Africa – Technical notes for civil and structural engineers. PW2006/1, June 2007.
KIJKO, A, GRAHAM, G, BEJAICHUND, M, ROBLIN, D and BRANDT, M B C, 2003. Probabilistic peak ground acceleration and spectral seismic hazard maps for South Africa. Council for Geoscience report 2003/0053.
PARTRIDGE, T C, WOOD, C K, and BRINK, A B A, 1993. Priorities for urban expansion within the PWV metropolitan region. The primary of geotechnical constraints. South African Geographical Journal Vol. 75.
SOIL CLASSIFICATION WORKING GROUP, 1977. Soil classification. A binomial system for South Africa. Scientific Bulletin No. 390. Department of Agriculture Technical Services, Pretoria.
SOUTH AFRICAN BUREAU OF STANDARDS (SABS), 1983. SABS 1200 LB: Standardized specification for civil engineering construction: LB: bedding (pipes).
THOMPSON, H, 2006. Water Law. A practical approach to resource management & the provision of services. JUTA & Co. Ltd.
WEINERT, H H, 1980. The natural road construction materials of Southern Africa. Academia, Cape Town.
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MAPS
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APPENDIX A
REGIONAL SOILS ASSESSMENT TABLES
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APPENDIX B:
ENVIRONMENTAL IMPACT ASSESSMENT
B
APPENDIX C:
PRELIMINARY DRAWING BOOKLET
APPENDIX D:
ROUTE OPTION ANALYSIS
D
1.1 ROUTE OPTIONS IDENTIFIED
Two pipe routes were identified to supply water to Swartruggens and Mazista from the dolomite areas.
Figure 1 Layout of Identified pipe routes
Route A: This route follows a gravel road from the farms where the water was identified to the WTP in Swartruggens. Water will generally flow under gravity from the source to the plant. From the plant the water will be pumped towards Mazista.
Route B: This route is generally along the R53 tarred road from Swartruggens to Ventersdorp. Water has to be pumped onto the escarpment from where it will flow under gravity to the Swartruggens Water Treatment Works with the opportunity to also flow to Mazista.
1.1.1 ESTIMATED CONSTRUCTION COSTS
The following assumptions was made to be able to compare the pipelines:
• Both routes will be constructed of GRP material • Future supply to Mazista was taken into account • No professional fees nor disbursements were taken into account only construction cost excluding VAT.
Table 1 High Level Route Cost Comparisons
Route A Route B
Item Description Unit Qty. Rate Cost Qty. Cost
1 Boreholes 9,120,200.00 9,120,200.00 Manifold chamber at 2 Boreholes 1,000,000.00 1,000,000.00 Gravity Supply from 3 Boreholes to Swartruggens m 33,200 77,582,000 35,800 88,938,000
Swartruggens Pump Station 4 to Mazista kW 5.7 168,000.00 957,600.00 0 0 Rising Main from Swartruggens 5 to Mazista m 13200 1,200.00 15,840,000.00 9,200 11,040,000.00 Sub-Total (exc VAT) 104,499,800.00 110,098,200.00 Preliminary and General 20% 20,899,960.00 22,019,640.00 Occupational Health and Safety - Contractor 4% 4,179,992.00 4,403,928.00 Contingencies 15% 15,674,970.00 16,514,730.00 Total Construction Value (exc VAT) 145,254,722.00 153,036,494.00
On initial capital comparison Route A costs R 7 781 772.00 less than Route B to implement.
PLEASE NOTE The capital cost indicated above is not actual construction costs and are only used for route comparison. The actual construction cost estimate will be indicated in the report.
1.1.2 LIFE CYCLE COSTS COMPARISON
Electricity or else known as energy cost is the most expensive component during operation. It therefore assumed that all other operation and maintenance costs for both the option will be almost identical. This section will compare the energy cost of each option over a 20-year life cycle.
Route A: This route option will require a pumping station at the Swartruggens WTW to convey water towards Mazista. In addition to the Mazista supply a flow allocation was made to Bo-Dorp area of Swartruggens.
It was calculated that this pump station will consume roughly 7kW/h. At a rate of R 1,20 per 1 kW/h with 7% inflation per annum the following energy costs was estimated.
Table 2 Life Cycle Cost of Route A
Year 1 Year 5 Year 10 Year 15 Year 20 R 73,584.00 R 423,162.38 R 1,016,669.51 R 1,849,093.96 R 3,016,612.31
Route B:
Figure 2 Layout of Route B
This route option requires more input energy from the boreholes. It was calculated that the first 20km of the pipeline will have to be pumped. The additional energy required was calculated at 40.57Kw.
Table 3: Life Cycle Cost of Route B
Year 1 Year 5 Year 10 Year 15 Year 20
R 426,471.84 R 2,452,528.25 R 5,892,325.98 R 10,716,820.25 R 17,483,423.04
1.1.3 OVERALL COST COMPARISON OF ROUTE OPTIONS
Table 4: Cost Comparison of Route Options
Description Route A Route B Construction Cost R 145,254,722.00 R 153,036,494.00 Energy Cost over 20 years R 3,016,612.31 R 17,483,423.04 Life Cycle Cost R 148,271,334.31 R 170,519,917.04 Advantages • Lower Capital Cost • No additional pump station required • Lower Operational Cost apart from boreholes • Ability to supply Bo-Dorp Area Disadvantages • Extra pump station at • Higher capital cost Swartruggens WTW • High energy cost to displace water over alternative route • Bo-dorp will have to be supplied by alternative means.
In conclusion , Route A was selected as the desired option which the preliminary design was based upon in the following sections.
APPENDIX E:
PIPE MATERIAL OPTIONS ANALYSIS
SUMMARY OF COST ESTIMATES
After Route A was selected as the most cost effective route, four different options of pipe material and configuration were compared and the total cost of the project was estimated for each option based on Route A. Below the total project cost for the four options are summarized. A more elaborative breakdown of the cost of each option follows after this summary.
Option 1 Option 2 Option 3 Option 4 32.5km PN10 32.5km Class 9 22km PN10 GRP 22km Class 9 uPVC GRP 1.5km PN25 uPVC 1.5km Class 16 13km PN25 GRP 13km PN25 uPVC GRP Pressure oPVC Pressure reducing valve reducing valve
Total Construction Value (excl. VAT) R129,640,752 R122,091,088 R112,067,952 R110,095,888 Professional Fees and Disbursements R22,108,089 R21,017,162 R19,568,819 R19,283,856 Total Project Value (excl. VAT) R151,784,841 R143,108,250 R131,636,771 R129,379,744 Total Project Value (Incl. VAT) R173,000,000 R163,150,000 R150,070,000 R147,500,000
COST ESTIMATES FOR OPTION 1
This option is based on the usage of the 300mm GRP pipes. The first 22km section consists of PN10 pressure class GRP, and the last 13km section consisting of PN25 pressure class GRP to accommodate the higher static pressures.
Dolomites to Swartruggens (Option 1) Item Description Unit Total Rate Amount 1 Construction costs 1.1 160mm Ø class 9 uPVC (Borehole line 1) m 3,500 R1,552.00 R5,425,609.00 1.2 250mm Ø class 9 uPVC (Borehole line 2) m 3,500 R2,467.00 R8,629,254.00 1.3 300 mm Ø PN10 GRP m 22,000 R2,825.00 R62,122,946.00 1.4 300 mm Ø PN25 GRP m 13,000 R2,973.00 R38,612,943.00 1.5 Construction of manifold chamber No 1 R1,000,000.00 R1,000,000.00 1.6 Erect temprary cattle fence m 34000 R100.00 R3,400,000.00 1.7 Erect temporary game fence m 34000 R150.00 R5,100,000.00 1.8 Installation of gates No 33 R1,000.00 R33,000.00 1.9 Swartruggens reservoir inlet chamber No 1 R350,000.00 R350,000.00 1.10 Drilling and testing of boreholes No 5 R300,000.00 R1,500,000.00 1.11 Submersible Pump No 5 R100,000.00 R500,000.00 1.12 Borehole House and Fittings No 5 R70,000.00 R350,000.00 1.13 Electricity Supply No 5 R500,000.00 R2,500,000.00 1.14 100mm HDPE pipe into Borehole m 300 R390.00 R117,000.00
Total Construction Value (exc VAT) R129,640,752.00
Professional Fees and Disbursements Design Fees 6% R7,778,445.12 Disbursements: Environmental Impact Assessment 0.30% R388,922.26 WULA – Water Use License applications 0.10% R129,640.75 Geotechnical Assessments 0.50% R648,203.76 Ground Water Resource Development 1.50% R1,944,611.28 Health and Safety – Agent fees 1.25% R1,620,509.40 Survey 0.30% R388,922.26 Registration of Servitudes ha 63 R25,000.00 R1,575,000.00 Construction Monitoring 6 R 300,000.00 R1,800,000.00 Mitigation of Community Issues 0.50% R648,203.76 Project Management Fees 4.00% R5,185,630.08 Total Project Value (exc VAT) R151,748,840.66 Total Project Value (Inc VAT) R173,000,000.00
COST ESTIMATES FOR OPTION 2
This option is based on the usage of the 300mm GRP. A total of 32.5km consist of PN10 GRP pipe. The installation of a pressure reducing valve and a 1.5km section of PN25 GRP will accommodate higher pressures. A pressure overflow pipe will also be installed to accommodate static pressures if the valve at the reservoir is closed during operation.
Dolomites to Swartruggens (Option 2) Item Description Unit Total Rate Amount 1 Construction costs 1.1 160mm Ø class 9 uPVC (Borehole line 1) m 3,500 R1,552.00 R5,425,609.00 1.2 250mm Ø class 9 uPVC (borehole line 2) m 3,500 R2,467.00 R8,629,254.00 1.3 300 mm Ø PN10 GRP m 32,500 R2,686.00 R87,212,223.00 1.4 300 mm Ø PN25 GRP m 1,500 R3,285.00 R4,924,002.00 1.5 Construction of manifold chamber No 1 R1,000,000.00 R1,000,000.00 1.6 Erect temporary cattle fence m 34000 R100.00 R3,400,000.00 1.7 Erect temporary game fence m 34000 R150.00 R5,100,000.00 1.8 Installation of gates No 33 R1,000.00 R33,000.00 1.9 Swartruggens reservoir inlet chamber No 1 R350,000.00 R350,000.00 1.10 Drilling and testing of boreholes No 5 R300,000.00 R1,500,000.00 1.11 Submersible Pump No 5 R100,000.00 R500,000.00 1.12 Borehole House and Fittings No 5 R70,000.00 R350,000.00 1.13 Electricity Supply No 5 R500,000.00 R2,500,000.00 1.14 100mm HDPE pipe into Borehole m 300 R390.00 R117,000.00 1.15 Pressure reducing valve and chamber construction No 1 R1,000,000.00 R1,000,000.00 1.16 110mm HDPE overflow pipe m 500 R100.00 R50,000.00
Total Construction Value (exc VAT) R122,091,088.00 Design Fees Professional Fees and Disbursements Professional Fees 6% R7,325,465.28 Disbursements: Environmental Impact Assessment 0.30% R366,273.26 WULA – Water Use License applications 0.10% R122,091.09 Geotechnical Assessments 0.50% R610,455.44 Ground Water Resource Development 1.50% R1,831,366.32 Health and Safety – Agent fees 1.25% R1,526,138.60 Survey 0.30% R366,273.26 Registration of Servitudes ha 63 R25,000.00 R1,575,000.00 Construction Monitoring 6.00 R 300,000.00 R1,800,000.00 Mitigation of Community Issues 0.50% R610,455.44 Project Management Fees 4.00% R4,883,643.52 Total Project Value (exc VAT) R143,108,250.22 Total Project Value (Inc VAT) R163,150,000.00
COST ESTIMATES FOR OPTION 3
This option is based on the usage of a combination of 315mm uPVC and oPVC pipes. The first 21km section utilises class 9 uPVC, and the last 13km section consists of class 9 oPVC to accommodate the higher static pressures.
Dolomites to Swartruggens (Option 3) Item Description Unit Total Rate Amount 1 Construction costs 1.1 160mm Ø class 9 uPVC (Borehole line 1) m 3,500 R1,552.00 R5,425,609.00 1.2 250mm Ø class 9 uPVC (borehole line 2) m 3,500 R2,467.00 R8,629,254.00 1.3 315 mm Ø uPVC class 9 m 22,000 R2,299.00 R50,559,746.00 1.4 315 mm Ø oPVC class 9 m 13,000 R2,509.00 R32,603,343.00 1.5 Construction of manifold chamber No 1 R1,000,000.00 R1,000,000.00 1.6 Erect temporary cattle fence m 34000 R100.00 R3,400,000.00 1.7 Erect temporary game fence m 34000 R150.00 R5,100,000.00 1.8 Installation of gates No 33 R1,000.00 R33,000.00 1.9 Swartruggens reservoir inlet chamber No 1 R350,000.00 R350,000.00 1.10 Drilling and testing of boreholes No 5 R300,000.00 R1,500,000.00 1.11 Submersible Pump No 5 R100,000.00 R500,000.00 1.12 Borehole House and Fittings No 5 R70,000.00 R350,000.00 1.13 Electricity Supply No 5 R500,000.00 R2,500,000.00 1.14 100mm HDPE pipe into Borehole m 300 R390.00 R117,000.00
Total Construction Value (exc VAT) R112,067,952.00
Professional Fees and Disbursements Design Fees 6% R6,724,077.12 Disbursements: Environmental Impact Assessment 0.30% R336,203.86 WULA – Water Use License applications 0.10% R112,067.95 Geotechnical Assessments 0.50% R560,339.76 Ground Water Resource Development 1.50% R1,681,019.28 Health and Safety – Agent fees 1.25% R1,400,849.40 Survey 0.30% R336,203.86 Registration of Servitudes ha 63 25000 R1,575,000.00 Construction Monitoring 6 R 300,000.00 R1,800,000.00 Mitigation of Community Issues 0.50% R560,339.76 Project Management Fees 4.00% R4,482,718.08 Total Project Value (exc VAT) R131,636,771.06 Total Project Value (Inc VAT) R150,070,000.00
COST ESTIMATES FOR OPTION 4
This option is based on the usage of 315mm uPVC. A total of 31.5km consist of class 9 uPVC. To accommodate for higher pressures, a pressure reducing valve and a 1.5km section of class 16 uPVC will be installed. A pressure overflow pipe will also be installed to accommodate static pressures if the valve at the reservoir is closed during operation.
Dolomites to Swartruggens (Option 4) Item Description Unit Total Rate Amount 1 Construction costs 1.1 160mm Ø class 9 uPVC (Borehole line 1) m 3,500 R1,552.00 R5,425,609.00 1.2 250mm Ø class 9 uPVC (borehole line 2) m 3,500 R2,467.00 R8,629,254.00 1.3 315 mm Ø uPVC class 16 m 1,500 R3,431.00 R5,143,602.00 1.4 315 mm Ø uPVC class 9 m 32,500 R2,309.00 R74,997,423.00 1.5 Construction of manifold chamber No 1 R1,000,000.00 R1,000,000.00 1.6 Erect temporary cattle fence m 34000 R100.00 R3,400,000.00 1.7 Erect temporary game fence m 34000 R150.00 R5,100,000.00 1.8 Installation of gates No 33 R1,000.00 R33,000.00 1.9 Swartruggens reservoir inlet chamber No 1 R350,000.00 R350,000.00 1.10 Drilling and testing of boreholes No 5 R300,000.00 R1,500,000.00 1.11 Submersible Pump No 5 R100,000.00 R500,000.00 1.12 Borehole House and Fittings No 5 R70,000.00 R350,000.00 1.13 Electricity Supply No 5 R500,000.00 R2,500,000.00 1.14 100mm HDPE pipe into Borehole m 300 R390.00 R117,000.00 1.15 Pressure reducing valve and chamber construction No 1 R1,000,000.00 R1,000,000.00 1.16 110mm HDPE overflow pipe m 500 R100.00 R50,000.00
Total Construction Value (exc VAT) R110,095,888.00 Design Fees Professional Fees and Disbursements Professional Fees 6% R6,605,753.28 Disbursements: Environmental Impact Assessment 0.30% R330,287.66 WULA – Water Use License applications 0.10% R110,095.89 Geotechnical Assessments 0.50% R550,479.44 Ground Water Resource Development 1.50% R1,651,438.32 Health and Safety – Agent fees 1.25% R1,376,198.60 Survey 0.30% R330,287.66 Registration of Servitudes ha 63 R25,000.00 R1,575,000.00 Construction Monitoring 6.00 R 300,000.00 R1,800,000.00 Mitigation of Community Issues 0.50% R550,479.44 Project Management Fees 4.00% R4,403,835.52 Total Project Value (exc VAT) R129,379,743.82 Total Project Value (Inc VAT) R147,500,000.00