RAND WATER

Date: Friday, 01 March 2013

Presentation by:

BULK SANITATION DEPARTMENT

• 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

About Rand Water: Snapshot

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

Inlet works Division

Box

Primary Settling Tanks x2 BNR

Secondary Settling Tanks x3 Chlorination

Primary Settling Tanks x2 Bio-filter x8

Humus Tanks x2 Humus effluent pumped to BNR

Vaal River

Anaerobic digesters X6 Sacrificial Land

Leeuwkuil Wastewater Treatment Plants

Inlet works Division

Box

Primary Settling Tanks x2 BNR

Secondary Settling Tanks x3 Chlorination

Primary Settling Tanks x2 Bio-filter x8

Humus Tanks x2 Humus effluent pumped to BNR

Vaal River

Anaerobic digesters X6 Sacrificial Land

INLET WORKS

• Removal of materials such as rags, plastics, sand, metal particles.

• Wastewater passes through mechanical screens where these particles are removed.

• 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 breakdowns

Leeuwkuil Wastewater Treatment Plants

Inlet works Division

Box

Primary Settling Tanks x2 BNR

Secondary Settling Tanks x3 Chlorination

Primary Settling Tanks x2 Bio-filter x8

Humus Tanks x2 Humus effluent pumped to BNR

Vaal River

Anaerobic digesters X6 Sacrificial Land

PRIMARY SETTLING TANKS (PST) • 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

sludge. • Organic and inorganic solids are removed

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 grease are removed.

Leeuwkuil Wastewater Treatment Plants

Inlet works Division

Box

Primary Settling Tanks x2 BNR

Secondary Settling Tanks x3 Chlorination

Primary Settling Tanks x2 Bio-filter x8

Humus Tanks x2 Humus effluent pumped to BNR

Vaal River

Anaerobic digesters X6 Sacrificial Land BIOLOGICAL NUTRIENT REMOVAL (BNR)

• 5-stage Bardenpho Configuration • Removes Nitrates, Ammonia &

phosphates • Oxygen introduced through surface

aeration • Amount of oxygen supplied is

controlled by SCADA system • Oxygen in aerobic zone is maintained

between 1.5 -4 mg/ℓ • Excess sludge is wasted to digesters

Activated sludge process

Leeuwkuil Wastewater Treatment Plants

Inlet works Division

Box

Primary Settling Tanks x2 BNR

Secondary Settling Tanks x3 Chlorination

Primary Settling Tanks x2 Bio-filter x8

Humus Tanks x2 Humus effluent pumped to BNR

Vaal River

Anaerobic digesters X6 Sacrificial Land

SECONDARY SEDIMENTATION TANKS(SST)

• Separation of solids and water takes place.

• Solids are returned back (RAS) to the process as part of treatment

• Clear water (supernatant) is disinfected before discharge into the river

Leeuwkuil Wastewater Treatment Plants

Inlet works Division

Box

Primary Settling Tanks x2 BNR

Secondary Settling Tanks x3 Chlorination

Primary Settling Tanks x2 Bio-filter x8

Humus Tanks x2 Humus effluent pumped to BNR

Vaal River

Anaerobic digesters X6 Sacrificial Land

BIOLOGICAL TRICKLING FILTERS

• Designed to treat up to 16Mℓ/day (mainly from Abattoir)

• Using natural process to treat sewage (

• Using stones with diameter ranging from 10mm – 20mm

• No electricity required to run these systems

• Only removed organic load and Ammonia from sewage

• More reliable to treat domestic sewage

Leeuwkuil Wastewater Treatment Plants

Inlet works Division

Box

Primary Settling Tanks x2 BNR

Secondary Settling Tanks x3 Chlorination

Primary Settling Tanks x2 Bio-filter x8

Humus Tanks x2 Humus effluent pumped to BNR

Vaal River

Anaerobic digesters X6 Sacrificial Land

DISINFECTION

• 1 ton chlorine liquid is used for disinfecting treated water

• Residual chlorine test is done every 8 hours (per shift)

• Weekly compliance monitoring of final water is done as per the plants license.

• Fortnightly toxicity test is done at RW Analytical Services

FINAL EFFLUENT As per license, the following parameters are analysed; pH, COD, SS, NH3, NO3,E-coli, Faecal coliforms, EC, SO4, Na, Toxicity (Bio-monitoring)

Anaerobic Digestion. • Primary & WAS

digested for 18 days • Gas generated is

released to the

atmosphere • Digested sludge is

sent to the lagoons

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