what to expect from sans 241:2015 rand water rietvlei indaba auditorium mapula mametja 18 february...
TRANSCRIPT
WHAT TO EXPECT FROM SANS 241:2015
RAND WATER RIETVLEI INDABA AUDITORIUM
Mapula Mametja18 February 2015
OVERVIEW WATER LAWS IN SA
CURRENT SANS (2006 OR 2011?)
COMPARISONS OF SANS, BLUE DROP LIMITS AND RAND WATER PRODUCTION SPEC
SANS 241: 2015
PRESCRIBED WATER QUALITY MONITORING PROGRAMME
CHANGING DETERMINANDS IN DISTRIBUTION
CONCLUSION
WaterTreatment
Distribution Use
What is “Water Services”?
Management and customer interface and services
Surface and ground water
Abstraction
Treated &untreateddischarges
Water use efficiency and demand management (No Drop)
Diffusepollution
Non-reticulated systems (e.g. on-site “dry” sanitation)
Re-use
WastewaterTreatment
Collection
= Key interfaces between the resource and the services
National Water Act, 36 of 1998
Water Services Act, 108 of 1997
Water Laws in South Africa-
WaterTreatment
Distribution Use
What is “Water Services”?
Management and customer interface and services
Surface and ground water
Abstraction
Treated &untreateddischarges
Water use efficiency and demand management (No Drop)
Diffusepollution
Non-reticulated systems (e.g. on-site “dry” sanitation)
Re-use
WastewaterTreatment
Collection
= Key interfaces between the resource and the services
National Water Act, 36 of 1998
Water Services Act, 108 of 1997
Water Laws in South Africa-
• Regulations under s9: Compulsory National Standards for Quality Water Services
basic water supply, interruption in provision of water services, disposal of grey water, repair of leaks, quality of potable water - refers National Standard for Drinking Water (SANS) 241)
SANS 241: 2006 vs SANS 241:2011 DWS assessed WSI using Blue Drop
Limits Developed from both SANS 241:2006
and 2011 Less stringent limit was considered -
2014 Blue Drop Limits 2014 Blue Drop limits – 2013 Audits 2015 Blue Drop limits – PAT assessment SANS 241:2015 (2016 Audit?)
Comparison between SANS 241 Limits and Blue Drop Limits
Comparison between SANS 241 Limits, Blue Drop Limits and Rand Water Production limits
SANS 241:2015Part 1: Definition of safe drinking water quality requirements for humans.
Part 2: Definition of water quality management system requirements (Application of SANS 241-1)
SANS 241-2Part 2: Application of SANS 241-1
Key elements for management actions1. water quality risk assessment – assessment of
risk from intake water to point of delivery
2. routine monitoring – establishment and implementation of operational & compliance (location of sampling points, frequency & determinands)
3. response monitoring – incident management / monitoring of DWQ following non-compliance
4. verification of water quality – calculate compliance with numerical limits; &
5. water safety planning – address outcomes of above
minimum requireme
nts
SANS 241-2: PRESCRIBED WATER QUALITY MONITORING PROGRAMME
Table 2 — Minimum sample numbers for E. coli (or faecal coliforms) in water supply systems
1 2
< 5 000 2
5 000 to 100 000 1 per 5 000 head of population + additional sample
100 000 to 500 000 1 per 10 000 head of population + 11 additional samples
≥ 500 000 1 per 20 000 head of population + 36 additional samples
Population served
a During the rainy season, sampling should be carried out more frequently to ensure that all spatial and temporal risksare identified.
Total number of samples per montha
Minimum
Annual risk assessment risk defined monitoring programme (table 3)
Table 1 SANS241-2 default risk determinands which will also form part of
risk defined monitoring programme
SANS 241-2WATER QUALITY MONITORING PROGRAMME
Table 3 — Frequency of analyses for determinands identified during the risk assessment exceeding the numerical limits in
SANS 241-1
1 2 3 4
Risk Raw Water Final Water Critical distribution System points
Acute health Bacteriological risk determinands
see table 1 see table 1 see table 2
Protozoan Parasite risk determinands Not applicable Monthly
Acute health Chemical risk determinands
Weekly Weekly Monthly
Chronic health risk determinands Monthly Monthly Monthly
Aesthetic risk determinands Monthly Monthly Quarterly
Operational risk determinands Weekly Weekly Monthly
Frequency
a Aluminium should be monitored on the final water in accordance with table 1 and monthly on distribution system
DETERMINANDS THAT CAN CHANGE IN THE DISTRIBUTION NETWORK
Reasons that can lead to the deterioration:– Addition of chemicals– Leaching from pipe lining– Leaks – Regrowth inside the pipe etc.
Deteminands that can change
Frequency of monitoring as per table 3
CONCLUSION
SANS 241:2015 determinands limits - relaxed/more stringent
Full SANS – annually ( 45 determinands)– Protozoa to be monitored if final water indicated
positive results– Total Microcystin to be monitored if there is algal
bloom in raw water New determinands = 18 Removed determinands = 9 Current monitoring to be aligned with SANS
241 requirements
THANK YOU