WATER QUALITY INFORMATION

Product Quality: 2013-2014

Management Approach

Umgeni Water is committed to providing all its customers with safe drinking (potable) water that is suitable for lifetime consumption. This commitment is realised through the implementation of water safety plans. The implementation of water safety plans involves a rigorous and system-wide water quality management programme. It includes but not limited to continuous review of the water quality risks (associated with abstraction, conveyance, treatment and bulk distribution), implementation of risk based monitoring programmes, auditing, compliance reporting and a drinking water quality incident management protocol. Furthermore, sampling and analysis are undertaken in accordance with an ISO 9001 certified monitoring programme and SANAS 17025 accredited laboratory methods, respectively.

In addition to ensuring safe drinking water, Umgeni Water is also responsible for ensuring that wastewater discharges are not harmful to the environment and downstream users. This is achieved through development and implementation of wastewater risk abatement plans. This process includes but not limited to comprehensive and site specific risk assessments and implementation of the respective mitigations plans. Site specific wastewater incident management protocols have also been developed and implemented in the management of wastewater incidents and non-compliances.

In line with our stakeholder communication plan, information on water quality performance is conveyed to all customers, stakeholders and legislative decision makers.  The entity also remains committed to providing customer support toward ensuring progressive achievement of full system (i.e. including distribution) Blue and Green Drop Certifications.

Potable Water Quality Performance

South African National Drinking Water Specification (SANS 241:2015) dictates compliance requirements for potable water systems and requires the performance to be reported against the following five risk categories (as per the classification tabulated further below):

(1) Acute Microbiological Health, 
(2) Acute Chemical Health,
(3) Chronic Chemical Health,
(4) Aesthetic, and
(5) Operational categories.

Key to classification of the performance of drinking water supply systems according to SANS 241: 2015

  Population up to 100 000
Proportion of samples compliant
Population > 100 000
Proportion of samples compliant
  Excellent Good Unacceptable Excellent Good Unacceptable
Acute Microbiological Health ≥97% ≥95% <95% ≥99% ≥97% <97%
Acute Chemical Health ≥97% ≥95% <95% ≥99% ≥97% <97%
Chronic Chemical Health ≥95% ≥93% <93% ≥97% ≥95% <95%
Operational ≥93% ≥90% <90% ≥95% ≥93% <93%
Aesthetic ≥93% ≥90% <90% ≥95% ≥93% <93%

Overall compliance of bulk potable water supply systems was excellent for the reporting period. Compliance per SANS 241:2015 risk category is shown in Figure 1 and the more detailed potable water quality compliance per water supply system is shown in Table 1.

Table 1: 2016/2017 Potable Water Quality Compliance (%) with SANS 241:2015 per Water Supply System

      Percentage Compliance with SANS 241:2015
Water Treatment Works Average daily volume treated (Ml/d) Volume % Acute Microbiological Health Acute Chemical Health Chronic Chemical Health Operational Aesthetic
1 Durban Heights 447.28 37.12 99.82 100 100 99.95 100
2 Wiggins 252.04 20.92 99.73 100 100 99.79 100
3 Midmar 218.41 18.13 100 100 100 99.40 99.94
4 DV Harris 83.56 6.94 99.79 100 100 99.72 100
5 Amanzimtoti 77.01 6.39 100 100 100 99.12 99.91
6 Hazelmere 53.55 4.44 100 100 99.90 99.73 100
7 Maphumulo 21.35 1.77 98.92 100 98.73 96.99 98.40
8 Umzinto 12.67 1.05 100 100 100 100 100
9 Mvoti 12.26 1.02 100 100 99.85 96.68 99.69
10 Mtwalume 10.78 0.89 100 100 100 100 100
11 Mpofana 6.45 0.54 100 100 100 98.57 99.60
12 Mhlabatshane 3.53 0.29 100 100 100 98.51 100
13 Maphephethwa 3.32 0.28 100   100 99.38 100
14 Ixopo 1.99 0.17 100 100 99.65 99.12 98.33
15 Appelsbosch 0.28 0.02 100 100 100 94.87 99.15
16 Rosetta 0.21 0.02 100 100 97.92 99.62 96.27
17 Lidgetton 0.14 0.01 100 100 98.92 91.21 95.45

Compliance per System

Sixteen (16) bulk water supply systems complied with the excellent requirements for all risk categories specified in SANS 241:2015 Drinking Water Specification. The Lidgetton system reported excellent compliance, except for the operational risk category which was classified as good.

Wastewater Quality Performance

Table 2 shows bulk wastewater quality compliance per system, assessed against the relevant licence or General Authorisation General Limits prescribed by the Department of Water and Sanitation (DWS).

Table 2: Wastewater compliance per treatment works

Wastewater Treatment Works System Volume (Ml/d) Volume (%) 2013 2014 2015 2016 2017 Target 2017 Actual
1 Darvill 72.6 80% 87% 78% 85% 82% ≥ 80% 72%
2 Mpofana 10.3 11% - - - 65% ≥ 60% 72%
3 Howick 5.6 6.20% 83% 87% 87% 89% ≥ 85% 86%
4 Richmond 1.2 1.30% - - - 89% ≥ 85% 87%
5 Cool Air 0.5 0.60% - - - 90% ≥ 85% 98%
6 Ixopo 0.3 0.30% 88% 95% 96% 93% ≥ 85% 94%
7 Lynnfield Park 0.2 0.20% - 66% 87% 86% ≥ 85% 96%
8 Camperdown 0.1 0.20% - - - 91% ≥ 85% 97%
9 Applesbosch 0.1 0.10% - - - 94% ≥ 85% 91%
  • Umgeni Water was not managing these sites at the time.

Bulk Wastewater Supply Systems

Overall effluent compliance for the reporting period was 79% (Figure 2). One works, Darvill WWTW, did not meet the set target, achieving 72.4% against the target of 80%.

The non-compliance recorded at Darvill WWTW was mainly due to process overloading, accentuated by the following:

  • Power outages and construction related activities,
  • The intermittent spilling of the storm dam in particular caused the E. coli failures,
  • Sludge related problems resulted in elevated suspended solids, phosphate solubilisation and COD overloading,
  • Total chlorine non-compliances were due to increasing the chlorine dosage in order to improve disinfection, particularly, when the storm dam was spilling, and
  • Aluminium non-compliance remains a long term problem at the site due to industrial inputs.  

Supply Graph

The completion of the works upgrade project, which is significantly advanced, will increase capacity and enable compliance related improvement. The proposed constructed wetland, for detention of some storm dam spills, will also have a significant benefit once completed.