DRAFT CLIENT: Department of Water and Sanitation – Construction West By- e-mail MASTERPLAN FOR THE CONSOLIDATION OF THE MATJABENG WASTE WATER TREATMENT PLANTS: REV 0 JULY 2016 COMPILED BY: WaterGroup (Pty) Ltd Tel: 011 950 0242 CSVwater Consulting Engineers (Pty) Ltd Tel: 012 667 6260 Master Plan for the Consolidation of the Matjabeng WWTW’s – Revision 0 DRAFT Compiled by : WaterGroup (Pty) Ltd Tel: 011 950 0242 CSVwater Consulting Engineers (Pty) Ltd Tel: 012 667 6260 Project Manager : Charl van der Walt [email protected] // 082 374 1581 Date : July 2016 TABLE OF REVISIONS Rev No. Date Nature of Revision 0 July 2016 First DRAFT Submission Compiled by Watergroup and CSVwater Consulting Engineers Page | i Master Plan for the Consolidation of the Matjabeng WWTW’s – Revision 0 DRAFT EXECUTIVE SUMMARY The Watergroup/CSV consortium presented the DWS Construction Unit North West with a report on 14 January 2016 in which the short term interventions for the Theronia and Witpan waste water treatment works (WWTW’s) were set out. These interventions have in the meantime been implemented. The objective of this second report is to provide the Matjabeng LM with a view on the eventual layout of its water treatment facilities, in particular the three large facilities of Thabong (currently 18 Mℓ/d), Witpan (currently being upgraded to 12 Mℓ/d) and Theronia (25 Mℓ/d). For the masterplan determination, a time horizon of 20 years has been used. Information regarding growth forecasts, existing sewer infrastructure as well as the status of the sewage pump stations has been obtained from the municipality. This information has been used to build a model in SWMM (a This report is the second of two reports where the first report described the current status and recommends immediate interventions required. For the sake of completion, these recommended interventions proposed were to: (a) Fast Track the implementation of the changes currently being done at the Witpan WWTW – no more than 6 months should be allowed for these changes to be implemented. (b) Start immediately with restoring the unit processes at the Theronia WWTW – as an interim measurement, flow must be diverted after the inlet works to the existing maturation ponds. (c) Investigate the feasibility of implementing a regional waste water work at a suitable point where land is available and the typography encourages feed by gravity. Use of existing infrastructure should be utilised as far as possible (Report 2 to expand more on this). (d) Investigate the viability of the sewage pump stations in maintaining their functionality regarding delivery of raw sewage to the two plants (Report 2 to expand on this) (e) Resume with monitoring as soon as processes are restored (staff has monitoring equipment Green Drop kits for onsite analysis). Weekly reports to DWS must be done in the meantime. Progress on points a) and b) above is that the completion of the Witpan construction changes are scheduled for completion in May 2016. As far as Theronia WWTW is concerned, the sewage flow after the inlet works has been intercepted and diverted to the maturation ponds. No feedback on the restoration of the existing plant has been made. Report 2 (this report) concluded with the following: (i) Repair all defunct mechanical and electrical equipment at Theronia WWTW; (ii) Limited refurbishment at Thabong WWTW. Provide for an additional 15 Mℓ/d new activated sludge treatment plant at Thabong WWTW immediately, with another 15 Mℓ/d module by the time the Witpan WWTW is decommissioned; (iii) Finalise the current work at the Witpan WWTW to prevent further pollution of the Witpan lake; (iv) Existing pump stations should be brought back to optimal operation. This includes upgrading security, maintaining equipment and ensuring the safety measures are taken and in place. Compiled by Watergroup and CSVwater Consulting Engineers Page | 2 Master Plan for the Consolidation of the Matjabeng WWTW’s – Revision 0 DRAFT (v) Construction of new transfer pump station at Witpan WWTW. This will collect current flows to Witpan WWTW and transfer to Thabong WWTW. The current structures could be utilized to provide emergency storage. New Bronville pump station to transport waste water to Thabong WWTW (Option to upgrade and divert current Bronville pump stations will also be considered) (vi) New rising mains to be installed at two new pump stations as stated above. (vii) Repair and lining of current Mostert canal, as well as the installation of a new canal at Theronia WWTW. (viii) A funding option entailing the implementation of a Public Private Partnership (PPP) option to exploit water reclamation has been provided for consideration. Compiled by Watergroup and CSVwater Consulting Engineers Page | 3 Master Plan for the Consolidation of the Matjabeng WWTW’s – Revision 0 DRAFT TABLE OF CONTENTS DESCRIPTION PAGE NO. EXECUTIVE SUMMARY ..................................................................................................................................... i 1. INTRODUCTION ...................................................................................................................................... 7 1.1 Background ............................................................................................................................................ 7 1.2 Purpose and Context of this Report ..................................................................................................... 9 2. NEEDS ANALYSES .............................................................................................................................. 10 2.1 Population ............................................................................................................................................. 10 2.1.1 RSA Census 2011 .................................................................................................................. 10 2.1.2 Aerial Counting ....................................................................................................................... 11 2.2 Existing Network .................................................................................................................................. 13 2.3 Status of the Sewage Pumping Station ............................................................................................. 17 2.4 Status of the Current Sewage Treatment Plants ............................................................................... 23 2.5 Required Effluent Standards ............................................................................................................... 25 2.5.1 Background: ............................................................................................................................ 25 2.5.2 Current WULA status: ............................................................................................................. 27 2.5.3 Future Effluent Quality Expectations ...................................................................................... 27 2.5.4 Other Stakeholders ................................................................................................................. 28 2.5.5 Conclusion and Recommendation .......................................................................................... 28 2.5.6 Thabong WWTW .................................................................................................................... 29 2.5.7 Witpan WWTW ....................................................................................................................... 34 2.5.8 Theronia WWTW .................................................................................................................... 37 2.6 Summary of the Needs Analyses ....................................................................................................... 41 3. OPTION ANALYSES ............................................................................................................................. 42 3.1 Identifications of Options .................................................................................................................... 43 3.1.1 Option 1A: Upgrade both Thabong and Theronia .................................................................. 44 3.1.2 Option 1B: Extension of the Thabong WWTW ....................................................................... 44 3.1.3 Option 2: Extension of the Theronia WWTW and Decommissioning of the Thabong WWTW and Witpan WWTW ................................................................................................................ 45 3.1.4 Option 3: New Regional Works at Extension of the Theronia WWTW and Decommissioning of the Thabong WWTW and Witpan WWTW ......................................................................... 46 3.2 Pricing of Options ................................................................................................................................ 47 4. SEWAGE NETWORK BULK INFRASTRUCTURE - DESIGN BASIS ................................................. 50 4.1 General Design Considerations .......................................................................................................... 50 4.2 Sewage Reticulation ............................................................................................................................ 50 4.3 Sewage Pumping Station .................................................................................................................... 52 4.3.1 Structural Design