Domestic wastewater reuse overview and research in South Africa

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1 Domestic wastewater reuse overview and research in South Africa Chris Swartz DWA-WISA Session IFAT Africa 2017 Johannesburg Expo Centre 12 September 2017

2 Overview 1. Water scarcity worldwide 2. Severe water scarcity in South Africa 3. Status of reuse in South Africa 4. Key factors in water reuse 5. WRC reuse research projects 6. Health aspects of CECs in water reuse 7. De facto water reuse (unplanned reuse)

3 Water scarcity worldwide Water scarcity is recognized as a major challenge for countries on a world-wide basis in their endeavour towards sustainable life for humankind and the environment. Lazarova et al (2013) state the alarming fact that by 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world population could be under water-stress conditions.

4 Global demand for water... and in South Africa By 2050, the World population will be close to 9 billion people, and more regions of the world may be without freshwater, with a sharp decrease in the average water supply per person In South Africa, close to 5.7 million people do not have access to basic water while million lack access to adequate sanitary facilities Most effluent discharge and urban run off are not reused South Africa is already a water stressed nation Wastewater re-use is expected to offset more clean water resource and reduce discharged effluent

5 Critical water scarcity in South Africa Kroonstad June 2016

6 Water scarcity in the Southern Cape : Severe droughts! 1. Water demand management (water restrictions) 2. Desalination 3. Water reuse

7 Water scarcity in the Cape Town Metropole ?

8 Water reclamation and reuse as supplemental water source Water reclamation and reuse is a feasible and attractive alternative water source option, and is increasingly being used in South Africa. What is the current status?

9 Drivers for water reuse There are a number of drivers for water reuse, of which the most important are: rapid population growth urbanization unpredictability of conventional water source sustainability (due to climate change and source pollution) Water resource managers and planners are forced to look at other, unconventional water sources such as desalination (of seawater and brackish groundwater), water reuse and rainwater harvesting. 9

10 Reuse: Internationally Most of the development in water reuse has taken place in the following regions: California, USA Australia Middle East Southern Europe (Mediterranean countries) South West and Southern Africa China Singapore. 10

11 Some reuse timelines: Direct potable reuse 11

12 Status of water reuse in SA Reuse plants Windhoek (Goreangab) (DPR) Beaufort West (DPR) emahlhleni (Mine water)(dpr) Optimum Coal (Mine water)(dpr) George (Outeniqua)(IPR) Ballito, Darville, ethekwini... Feasibility studies Cape Town (feasibility study) Hermanus (DPR feasibility and tender) Port Elizabeth (NPR/IPR, feasibility study complete) East London.

13 Some DWS perceptions on reuse Used water can be treated to a standard fit for domestic use (drinking purposes) Treated water can be supplied directly or discharged back into fresh water resources In-direct water re-use schemes are well established throughout the world (and in South Africa) Direct re-use is the challenge Main Concerns: Presence of micro pollutants Cost of treatment (to produce potable water) Handling of waste / residue streams Risks associated with operations and management of the reclamation facilities Public perceptions and acceptance

14 Key factors in water reuse Key considerations for water reuse as an option for water supply and augmentation Water quality Water treatment technologies Cost Social and cultural perceptions (public acceptance) Environmental considerations Health impacts Microbiologic EDCs CECs By-products Never compromise health to reduce cost! Multi-barrier approach Engineered storage buffer Availability of financial and skill resources for O&M (esp. in developing countries) Capital cost Operating cost Maintenance cost Residuals disposal cost Surety (reliability) of supply makes reuse attractive Do life-cycle costing Reuse image very important Important where there are other options Terminology Role of the media Wastewater discharge to rivers Residuals disposal Energy consumption Environmental benefits

15 WRC reuse research projects

16 WRC reuse research projects Costing and decision support model (K5/2119) Excel based model for costing and decision support regarding various treatment configurations for potable water reclamation. Monitoring guidelines for reuse (K5/2212) The first proposed water quality guidelines for potable water reclamation in South Africa. Health aspects of CECs in water reuse (K5/2369) A detailed view of the human health implications of various micro pollutants typically found in South African wastewater.

17 WRC reuse research projects Costing of desalination and reuse plants (K5/2121) Costing and O&M of reuse and desalination plants in South Africa WW reclamation for potable use (K5/1894) Performance of various treatment configurations for potable reclamation of secondary treated waste water Implementation plan for DPR and IPR (K8/1029) Sector discussion document for the progressive implementation of the Water Reuse Strategy

18 WRC REPORT TT 641/15 MAIN OBJECTIVES Develop proposed water quality monitoring programmes and guidelines consisting of : Constituents and parameters that will require monitoring, Monitoring approaches to be used Analytical methods, time to obtain results, reliability of method, detection limits, frequency and costs of analyses.

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20 Chemicals of Emerging Concern What should we focus on (priority list for South Africa) Industrial chemicals Pesticides, biocides and herbicides Natural chemicals Pharmaceuticals and metabolites Personal care products Household chemicals and food additives Transformation products Flame retardants, TDCPP and TCEP X-ray contract fluid, Iopromide PAH, Benzo(a)pyrene Atrazine, Terbutylazine, Imidacloprid and Simazine Caffeine, 17 beta estradiol Antiretroviral drugs Lamivudine and Stavudine Anti-epileptic, Carbamazepine Anti-malarial drugs Cinchonidine and Cinchonine Analgesic, Paracetamol Antibiotic, Sulfamethoxazole Anti-microbial, Triclosan Plasticiser, Bisphenol-A By-product, N-Nitrosodimethylamine (NMDA)

21 Chemicals of Emerging Concern Removal of CECs Reverse Osmosis Nanofiltration Ozonation + BAC + GAC Advanced oxidation

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23 Reverse Osmosis BAC Activated Carbon Nanofiltration Biodegradation Advanced Oxidation Photodegradation Activated Sludge UV Cl2/CLO2 Softening Coaf/Floc Percent removal of EDCs, PHACs and PCPs by AWT unit treatment processes (Charla, 2011) Group Classification EDCs Pesticides E E E G v L-E E v E v G P Industrial Chemicals E E E E G-E G- G v v E P P-L P-L Steroids E E E G L-E E v v E E P-L P Metal E G G G P P v E P P F-G Inorganics E F P-L G P-L P P-L P-L P P G P F- G Organometallics E G-E G-E G-E L-E L-E L-E L-E F-G P-F P-L P-L Antibiotics E E F-G E E L-E G-E v F-G P-G P-L P-L Anti-depressants E G-E G-E G-E G-E L-E G-E G-E F-G P-F P-L P-L PHACs Anti-inflammatory E G-E E G-E E E v v E P-F P-L P Lipid regulators E E E G-E P E v v F-G P-F P-L P X-ray contrast media E G-E G-E G-E E L-E E v F-G P-F P-L P-L Phsychiatric control E G-E G-E G-E G-E L-E G-E G-E F-G P-F P-L P-L Synthetic musks E G-E G-E G-E E L-E v v E P-F P-L P-L PCPs Sunscreens E G-E G-E G-E G-E L-E G-E G-E F-G P-F P-L P-L Antimicrobials E G-E G-E G-E v L-E F v F-G P-F P-L P-L Detergents E E E E L-E F-G v v F-G P P-L P-L E = excellent (>90%); G = good (70-90%); F = fair (40-70%); L = low (20-40%); P = poor (<20%) v variable 23

24 Focus areas in water reuse Three main focus areas: 1. Addressing De Facto (unplanned) potable reuse 1. Validation of reuse processes and technologies 1. National laboratory for advanced analyses

25 What is unintended (de facto) reuse? It is an unplanned or incidental presence of treated or untreated waste water in a drinking water supply source, i.e when a substantial portion of this water contributes to source water of drinking water treatment plant. De facto reuse is much more pronounced during dry periods, when natural supply water are reduced and waste water makes up a larger portion of the water flow.

26 Dam WTW Aquifer Town 1 Intentional IPR Intentional DPR Intentional IPR River De facto (unplanned) reuse Water Reclamation Plant WWTW Irrigation Industries NPR Town 2 Discharge to river (return flow) WTW Unintentional IPR (de facto reuse) DPR = Direct Potable Reuse IPR = Indirect Potable Reuse NPR = Non-Potable Reuse WTW = Water Treatment Works WWTW = Wastewater Treatment Works

27 Status in South Africa: rivers Major rivers Orange River Vaal River (upper/mid/lower) Olifants River (also AMD) Komati River Tugela River Msunduzi River (serious) Jukskei River Crocodile River Berg River

28 Status in South Africa: dams Dams Hartebeespoort Dam (hypertrophic) Roodeplaat Dam (eutrophic) Rietvei Dam (eutrophic) Vaalkop Dam (eutrophic) Shongweni (eutrophic) Hammersdale (eutrophic) Nagle (serious eutrophication potential) Inanda (serious eutrophication potential) Laing Dam (eutrophic) Nahoon Dam (serious eutrophication potential)

29 Concerns about de facto reuse There are many concerns regarding de facto reuse that should be regarded: Cost to water treatment plants Need to upgrade technology, or over utilize existing technology beyond practical and economically feasible operational limits Health risk Many WTPs do not realize that they ought to be treating the water for contaminants that are present (only due to reuse) Cost to health sector Many water related diseases are caused by de facto reuse that could have been avoided if the presence of wastewater in the source water was correctly identified and managed, or treated.

30 Need for a National Laboratory Flow of information from decentralized laboratories to the proposed National Laboratory For Advanced Water Quality Analysis (NLAWQA) NLAWQA

31 Challenges for direct potable reuse in SA Improved regulatory environment Independence, stability and leadership in public water bodies Acceptance that DPR is safe and reliable Reducing the cost of technology and water quality monitoring Improved efficiency of monitoring processes Alternative energy sources (solar/wind) Need for public and political education and acceptance

32 Thank you for your attention