RAND WATER Presentation by: BULK SANITATION DEPARTMENT Date: Friday, 01 March 2013
About Rand Water: Snapshot • Provide water services to other water services institutions: • Bulk Potable Water • Bulk Sanitation • Leaders in growing capacity, skills and knowledge • Product Quality - Rand Water consistently maintained delivery to customers on the SANS 0241 Class 1 and 2 specification • Corporate ISO 9001:2000 accredited and All plants ISO 14001 accredited • SANAS Accredited Analytical Laboratory
Rand Water Bulk Sanitation Rand Water partnered with Emfuleni Local Municipality since September 2009 on the following aspects: • Operation and Maintenance of three wastewater treatment plants and pump stations viz; Leeuwkuil, Rietspruit and Sebokeng WWTW • Maintenance of works – repair electrical, mechanical and civil structures • Refurbishment and Upgrade wastewater treatment plants • Analytical services • Industrial Effluent Monitoring Programme • Capacity building • Bio-monitoring programme
EMFULENI LOCAL MUNICIPALITY • Located along the southern boundary of the Gauteng Province in area known as Vaal Triangle. • Falls under Sedibeng District Municipality, a large district extending along the southern section of Gauteng Province between the adjacent provinces of Free State, North West and Mpumalanga • The Vaal River forms the southern boundary of Emfuleni and this river is also a boundary with Free State Province
Leeuwkuil Wastewater Treatment Plants • Design capacity of 36 Mℓ/day ( 20 Mℓ/day - Activated Sludge Plant, 16 Mℓ/day – Trickling Filters) • Constructed and commissioned in 1954 • Registered as Class B Plant with DWA • Staff compliment 22 • On-site Analytical laboratories for samples analysis • Treats sewage from Vereeniging Sharpville and Kwaggastroom • Final effluent discharges into the Vaal River
Leeuwkuil Wastewater Treatment Plants Sacrificial Land Anaerobic digesters X6 Primary Settling Division Tanks x2 Bio-filter x8 Inlet works Box Primary Settling Humus effluent Humus Tanks x2 Tanks x2 BNR pumped to BNR Secondary Settling Tanks x3 Chlorination Vaal River
Leeuwkuil Wastewater Treatment Plants Sacrificial Land Anaerobic digesters X6 Primary Settling Division Tanks x2 Bio-filter x8 Inlet works Box INLET WORKS • Removal of materials such as rags, plastics, sand, metal particles. • Wastewater passes through mechanical Primary Settling screens where these particles are Humus effluent Humus Tanks x2 Tanks x2 removed. BNR pumped to BNR • Approximately 95% of sand and grit are removed mechanically by Grit Removing system • The plant has 24 hrs -10 Ml storage capacity in-case of emergency Secondary Settling breakdowns Tanks x3 Chlorination Vaal River
Leeuwkuil Wastewater Treatment Plants Sacrificial Land Anaerobic digesters X6 Primary Settling Division Tanks x2 Bio-filter x8 Inlet works PRIMARY SETTLING TANKS (PST) Box • A primary sedimentation tank is defined as a tank in which wastewater is retained long enough to bring about sedimentation of suspended matter but short enough to prevent anaerobic decomposition of the Primary Settling sludge. Humus effluent Humus Tanks x2 Tanks x2 • Organic and inorganic solids are removed BNR pumped to BNR by sedimentation, and floatable material are removed by skimming • Typically, a COD reduction of 25% to 50% is achieved and 50% to 70% of the SS (suspended solids), and 65% of the oil and Secondary Settling grease are removed. Tanks x3 Chlorination Vaal River
Leeuwkuil Wastewater Treatment Plants Sacrificial Land BIOLOGICAL NUTRIENT REMOVAL (BNR) Anaerobic digesters X6 • 5-stage Bardenpho Configuration • Removes Nitrates, Ammonia & phosphates • Oxygen introduced through surface Primary Settling aeration Division Tanks x2 Bio-filter x8 Inlet works • Amount of oxygen supplied is Box controlled by SCADA system • Oxygen in aerobic zone is maintained between 1.5 - 4 mg/ℓ • Excess sludge is wasted to digesters Primary Settling Humus effluent Humus Tanks x2 Tanks x2 BNR pumped to BNR Secondary Settling Tanks x3 Chlorination Vaal River Activated sludge process
Leeuwkuil Wastewater Treatment Plants Sacrificial Land Anaerobic digesters X6 Primary Settling Division Tanks x2 Bio-filter x8 Inlet works Box SECONDARY SEDIMENTATION TANKS(SST) • Separation of solids and water takes place. • Solids are returned back (RAS) to the process as part of treatment Primary Settling • Humus effluent Humus Tanks x2 Clear water (supernatant) is Tanks x2 BNR disinfected before discharge into pumped to BNR the river Secondary Settling Tanks x3 Chlorination Vaal River
Leeuwkuil Wastewater Treatment Plants Sacrificial Land Anaerobic digesters X6 BIOLOGICAL TRICKLING FILTERS Primary Settling Division Tanks x2 Bio-filter x8 Inlet works • Box Designed to treat up to 16Mℓ/day (mainly from Abattoir) • Using natural process to treat sewage ( • Using stones with diameter ranging from 10mm – 20mm Primary Settling • No electricity required to run these Humus effluent Humus Tanks x2 Tanks x2 BNR systems pumped to BNR • Only removed organic load and Ammonia from sewage • More reliable to treat domestic sewage Secondary Settling Tanks x3 Chlorination Vaal River
Leeuwkuil Wastewater Treatment Plants Sacrificial Land Anaerobic digesters X6 FINAL EFFLUENT Primary Settling As per license, the Division Tanks x2 Bio-filter x8 Inlet works following parameters are Box DISINFECTION analysed; pH, COD, SS, • NH3, NO3,E-coli, Faecal 1 ton chlorine liquid is used for Anaerobic Digestion. disinfecting treated water • Primary & WAS coliforms, EC, SO4, Na, • Residual chlorine test is done every 8 digested for 18 days Toxicity (Bio-monitoring) hours (per shift) • Gas generated is • Weekly compliance monitoring of released to the Primary Settling final water is done as per the plants atmosphere Humus effluent Humus Tanks x2 Tanks x2 license. BNR • pumped to BNR Digested sludge is • Fortnightly toxicity test is done at RW sent to the lagoons Analytical Services Secondary Settling Tanks x3 Chlorination Vaal River
Plant Management Process : • The plant operates on three shift system (8 hours/shift) • Inflows/outflows are recorded twice a day (i.e. 06h00 and 20h00). • Plant inspections are done every shift by qualified Process Controllers • Check sheets are used for inspection of the plant which include: flows, sludge withdrawal, process equipment running time etc. Chlorine dosage is monitored every shift and consumption recorded daily . • Maintenance : • Scheduled maintenance are done on weekly basis and job cards are generated using maintenance management system (PlantMan) • There are site based maintenance team • There are rotational standby maintenance team to react on breakdowns after hours/weekends • Weekly maintenance meetings are held for feedback on the outstanding issues
Achievements • Improved the effluent quality within 6 months from 60 % to above 90 % compliance with legislation • Minimized sewage spillage and repairs turn around time • The municipality was ranked position 7 out 12 with the respect to Green Drop certification of 2012 in Gauteng Province. • Training of Process Controllers ( including lab staff) • All Process Controllers are registered with DWA as per regulation R2384 • Revamping of the Leeuwkuil water laboratory
Achievements • Processes control: Effective continuous monitoring and process control • Implemented Industrial Effluent Monitoring Programme • Implemented Bio- monitoring Programme • Implemented sampling and analysis schedule • Maintenance : Implementation of preventative maintenance schedule • Health & safety :Implementation Medical Check-up & vaccination of staff
Thank you
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