stellenbosch municipality drinking-water quality management: lessons learnt€¦ · ·...
TRANSCRIPT
A. Smit, G. Mackintosh, P. De Souza and A. Blanckenberg
Stellenbosch Municipality Drinking-Water Quality
Management: Lessons Learnt
Presentation Roadmap• Background
– South African Water Sector & DWQ requirements
– Stellenbosch Municipality• DWQ monitoring and management in
Stellenbosch Municipality– Operational monitoring– Compliance monitoring – Risk assessments
• On-going Challenges• Discussion and Conclusions
Background: SA WQM• Provision of safe drinking water and effective sanitation
most NB determinants of public health• DWAF water services sector leader & national
regulator• Water Services Authority (Municipality) responsible for
provision of acceptable water services• DWAF DWQM Framework and DWQ Standard (SANS
241) specifies requirements– Suitable DWQM programme, sample points,
frequency, determinants, etc• Electronic Water Quality Management System
(eWQMS) used by WSAs for identifying issues
Water Services ProviderBulk WSP
Water ServicesAuthority
Legal Requirements
GovernanceRequirements
Provincial Government
ID Chronic & Acute Issues
Technical &Financial
Assistance
DWAFDWAF
National regulator-technical-economic-contract
Background: STB Municipality
Stellenbosch Municipality Water Services Overview
• Function of Water Services Authority– Responsible for delivering Water Services– Appointment of Water Services Providers
• Water Treatment– Paradys Kloof WT Plant (conventional)– Idas Valley WT Plant (Slow sand filters)– Franschhoek (Disk filters)
• Water Distribution– 40 Reservoirs– 20 pump stations (Topography)– 461km distribution mains
• Waste Water Treatment Works– 7 Waste Water Treatment Works
Stellenbosch Raw Water Quality• Mostly surface water
sources• Very soft, acidic water • Moderately high in
dissolved humicsubstances (colour)
• Raised turbidity• Chemical concentrations
not high
Stellenbosch Initiatives• Approach is one of Integrated Water
Management• DWQM
– One of first to utilise internet-based eWQMS– Numerous awards for DWQM Best Practice by
a WSA– Driving DWQM in the W. Cape (Masibambane)
• River water quality monitoring and management– Successful initiation of Public-Private collaboration
• Improved Wastewater Management practices • Industrial effluent investigations (wineries)• Use of risk assessment tools (WRC Tools)• LGWSETA investigation – skills
Stellenbosch DWQM Programme
WSA commitment to Drinking Water Quality Management
System Analysis & Management
· Assessment of Drinking Water Supply System
· Risk Management measures· Operational Procedures &
process control· Verification of drinking water
quality· Management of Incidents &
emergencies· Water Safety & Security Plans· Communities not yet served
(backlogs)
Supporting Requirements
· Employees Awareness & training
· Community involvement & awareness
· Data management and information dissemination
· Research and Development· Documentation and reporting
Review
· Evaluation and Audit· Review and
continual improvement
Effective Municipal DWQ Management
DWQM ProceduresInitial familiarization with water
supply scheme
Preliminary water quality investigation
Define operations and management team and responsibilities
Implementation of monitoring process
Monthly sampling
Simplified Small Water Distribution System
Catchment/Source
Water Treatment Plant
Main Water Line
Elevated Service Reservoir
Loop
Branch
LoopG
F
D
B
A
C
H
E
Monthly DWQM CycleMonthly sampling
Review informationNo failure
Review/optimise managementand treatment procedures, e.g. free chlorine
Summary report
Failure (wrt SANS 241Specifications)
Investigatefailure
Re-sample
Failure
Notify consumerse.g. boil water
Implement temporary andmedium term solution
Monitoring Types• Operational monitoring
– Day-to-day at water treatment works (and reservoirs) (i.e. frequent)
– Monitor key operational parameters• pH, turbidity, free chlorine residual
– Trigger required short-term actions
• Compliance monitoring (verification)– At least monthly– From catchment to consumer– Comply with SANS 241
WTWs Operational Monitoring
chlorination & pH adjustment
• Paradyskloof • Idas Valley• Franschhoek
– Also receive water from City of Cape Town
– Need to ensure daily checks and corrective actions implemented
Network Disinfection Optimisation• Stellenbosch Municipality
reservoirs categorized– Daily monitoring– Monday/Thursday monitoring
• Distribution network diagrams (monitoring frequency, limits, sample points)
• FCR monitoring record sheets
• Emanti – “Consultative Audit” function • Collect samples throughout STB LM• Source treatment reservoirs network
taps• Analyse at SANAS Accredited Laboratory • Data loaded onto eWQMS• Failures management informed & actions
taken• Monthly summary reports, quarterly detailed
reports & management meeting – Way Forward
Compliance Monitoring
Compliance Monitoring
Key Component: eWQMS
eWQMS assists Stellenbosch Municipality with identifying and rectifying issues of concern
Examples of Protocols…• Bacteriological failures• Disinfection optimisation• Turbidity• DWQ complaints• Etc
• Appropriate Number of Samples
Strategic Analysis of WQM…
2006
2008
2007
WTW Risk Assessments
Receive immediate feedback
• Where are the major risks at our WTWs?
On-going Challenges• Automation of Chlorine stations • Online monitoring FCR -telemetry• Turbidity monitoring • Replace old infrastructure• Budget constraints• Growth
Utilise information to formulate strategies & implement actions to address issues of concern
Stabilisation
STB Wastewater
Responsible Development
• E.g. De Zalze Winelands Golf Estate• Commitment to environmental integrity• Water Quality Monitoring &
Management programme – Investigates quality of irrigation
water, drinking water, stormwater & Blouklip River
• Good example for other developments/industries
Blue Drop Certification Process
95% required for Blue Drop StatusTowns may also be awarded a RED DROP for continued, serious non-compliance
100100100
10100Drinking Water Asset Management9
550Publication of Drinking Water Quality Performance8
151520Management of Drinking Water Quality Failures7
303030Drinking Water Quality Compliance6
5510Submission of Drinking Water Quality Results5
5510Drinking Water Quality Sample Analysis4
101520Drinking Water Quality Monitoring Programme3
101010Process Controllers2
1050Water Safety and Security Plan1
YEAR 3+
YEAR 2
YEAR 1
Allocated Weight (%)Criterion
Conclusions• Excellent progressive improvement BUT…• Key challenges remain
– Ongoing raising of awareness of importance of safe DWQ
– Fast tracking the adherence to legislative compliance wrt monitoring and control
• Achieve and maintain Blue Drop status• Water Safety Plans
– Addressing Municipal engineering skill development / capacity requirements
– Managing Municipal wastewater discharge
So…Can I Drink the Tap Water in Stellenbosch?
ABSOLUTELY!!!!We are working very hard to
ensure you can!
