waste water risk abatement plan (w2rap) revision b waste... · drakenstein municipality currently...

DRAKENSTEIN MUNICIPALITY

WASTE WATER RISK ABATEMENT PLAN (W2RAP)

REVISION B

FEBRUARY 2013 Prepared by : Prepared for : LYNERS CONSULTING ENGINEERS

DRAKENSTEIN MUNICIPALITY

AND PROJECT MANAGERS P O BOX 1 P O BOX 79 MAIN STREET PAARL MAIN STREET PAARL 7622 7622 TEL : (021) 872 3564 TEL : (021) 807 4500 FAX : (021) 872 0619 FAX : (021) 872 8054

Revision History

Revision No.

Prepared by Description Date

Draft A Lyners Draft of W2RAP 7 October 2011

Draft B Lyners Draft of W2RAP 1 February 2013

Document Acceptance

Action Name Signed Date

Prepared by Lyners

Reviewed by R Brown

Approved by R Brown

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C:\Users\Bradley.DRAKENSTEIN\Desktop\IDP\Lyners Waste Water Risk Abatement Plan\2013-02-19 - W2RAP on CD submitted\0828 W2RAP Report Rev B Feb 2013.docx

Table of Contents

1 INTRODUCTION .................................................................................................................................. 1

2 DESCRIPTION OF W2RAP TEAM ....................................................................................................... 1

2.1 Duties of team and commitment ........................................................................................................... 1

3 DESCRIPTION OF VARIOUS WORKS ............................................................................................... 3

3.1 Paarl WWTW ........................................................................................................................................ 3

3.1.1 Catchment ............................................................................................................................................. 3

3.1.2 Collection .............................................................................................................................................. 3

3.1.3 Treatment .............................................................................................................................................. 3

3.2 Wellington WWTW ................................................................................................................................ 4

3.2.1 Catchment ............................................................................................................................................. 4

3.2.2 Collection .............................................................................................................................................. 4

3.2.3 Treatment .............................................................................................................................................. 5

3.3 Pearl Valley WWTW ............................................................................................................................. 5

3.3.1 Catchment ............................................................................................................................................. 5

3.3.2 Collection .............................................................................................................................................. 5

3.3.3 Treatment .............................................................................................................................................. 6

3.4 Saron WWTW ....................................................................................................................................... 6

3.4.1 Catchment ............................................................................................................................................. 6

3.4.2 Collection .............................................................................................................................................. 7

3.4.3 Treatment .............................................................................................................................................. 7

3.5 Hermon WWTW .................................................................................................................................... 7

3.5.1 Catchment ............................................................................................................................................. 7

3.5.2 Collection .............................................................................................................................................. 8

3.5.3 Treatment .............................................................................................................................................. 8

3.6 Gouda WWTW ...................................................................................................................................... 8

3.6.1 Catchment ............................................................................................................................................. 8

3.6.2 Collection .............................................................................................................................................. 8

3.6.3 Treatment .............................................................................................................................................. 8

4 HAZARD ASSESSMENT...................................................................................................................... 9

4.1 Risk Matrix used ................................................................................................................................... 9

4.2 Hazard Analysis of works ................................................................................................................... 11

4.3 Paarl WWTW ...................................................................................................................................... 11

4.4 Pearl Valley WWTW ........................................................................................................................... 15

4.5 Wellington WWTW .............................................................................................................................. 17

4.6 Hermon WWTW .................................................................................................................................. 21

4.7 Saron WWTW ..................................................................................................................................... 22

4.8 Gouda WWTW .................................................................................................................................... 26

5 CONTROL MEASUREMENTS ........................................................................................................... 29

6 MONITORING OF CONTROL MEASURES AND RESPONSE PROTOCOL ................................... 31

6.1 Operational Alert Levels...................................................................................................................... 32

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6.2 Verification of functioning of W2RAP .................................................................................................. 32

7 SUPPORT PROGRAMMES ............................................................................................................... 33

7.1 Process Controller Training Provided ................................................................................................. 33

7.2 Supervisors Forum .............................................................................................................................. 33

7.3 Career Pathing .................................................................................................................................... 33

7.4 Consultant Advisors ............................................................................................................................ 33

8 INCIDENT MANAGEMENT PLAN ...................................................................................................... 33

9 CONCLUSIONS .................................................................................................................................. 36

10 RECOMMENDATIONS....................................................................................................................... 36

10.1 Risks to be addressed ........................................................................................................................ 36

10.2 Way forward ........................................................................................................................................ 36

ANNEXURES : ANNEXURE A : CATCHMENTS

ANNEXURE B : FLOW DIAGRAMMES

ANNEXURE C : DRAKENSTEIN MUNICIPALITY : WWTW RISK ASSESSMENT

ANNEXURE D : DRAKENSTEIN MUNICIPALITY : WASTE WATER INCIDENT MANAGEMENT PROTOCOL

ANNEXURE E : HIGH AND MEDIUM RISK ITEMS FOR WWTW WITH MITIGATION MEASURES

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1 INTRODUCTION

Drakenstein Municipality currently (year 2013) provides Waste Water Treatment to six (6) communities within it’s municipal boundaries amounting to approximately 240 000 residents. Of the six Waste Water Treatment Works (WWTW), four are activated sludge works and two are evaporation pond systems. Drakenstein Municipality currently experiences challenges with regards to WWTW operation and maintenance which include :

Aging Infrastructure (Sections of Paarl WWTW were upgraded in the 1960’s)

Relatively low Operational & Maintenance Budgets for WWTW’s

Large funding shortfalls for upgrading of existing infrastructure and construction of new infrastructure or technologies.

Skill shortages in WWTW management and operations

Large increases in flow volumes due to increasing housing developments; and

Erratic power supply from national providers.

Given these challenges, it is imperative to follow a risk based management method to risks in the treatment process and identify priority risk areas for inclusion in limited Operational & Maintenance- and Capital upgrading budgets. To this end Drakenstein Municipality has developed a Waste Water Risk Abatement Plan (W

2RAP)

to identify potential risks and mitigation measures for each risk. This document is a living document which will be reviewed and amended constantly as and when the risk situation changes. This document provides an overview of the risks faced by the Drakenstein Municipality and must be considered in conjunction with the other reference documents such as the Green Wastewater Performance Audit Report (November 2012) and the Sewer Master Plan (December 2012).

2 DESCRIPTION OF W

2RAP TEAM

2.1 Duties of team and commitment

The W2RAP team is a multi disciplinary team consisting of team members with intimate knowledge

of the Waste Water Treatment system and the receiving environment. A diagramme showing the composition of this team is shown in figure 2.1 below.

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Figure 2.1 : Diagramme of W

2RAP Team

As the W2RAP is a living document, it is expected that the members of the team provide continual

feedback on the implementation of the system as well as potential improvement. The W

2RAP is a management tool designed to assist policy makers in decision making with regards

to Waste Water Treatment. Drakenstein Municipality owns and manages a total of six (6) WWTW’s and collection systems, namely:

Paarl Wastewater Treatment and Collection System

Wellington Wastewater Treatment and Collection System

Pearl Valley/Val de Vie Wastewater Treatment and Collection System (also known as the Kliprug Wastewater Treatment Plant)

Saron Wastewater Treatment and Collection System

Gouda Wastewater Treatment and Collection System

Hermon Wastewater Treatment and Collection System

Team Leader

Mr R Brown Head of Waste Services Drakenstein Municipality

Compilers

Mr H Mulder (Civil Engineer) and Mr M Filippi (Prof. Civil Engineer and Project Manager)

Private Entities

Berg River Irrigation Board

Information Sources

Mr C Morkel (Supervisor on all Drakenstein WWTW’s)

Various Process controllers for each WWTW

Department of Water Affairs (DWA)

Legislative Bodies

Consultants including WorleyParsons (Green Wastewater Performance Audit), Aurecon and Lyners (Various WWTW’s) AL Abbott Laboratories (Process Auditing) Virtual Consulting Engineers (Saron WWTW) Integral Laboratories (All WWTW’s)

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3 DESCRIPTION OF VARIOUS WORKS 3.1 Paarl WWTW 3.1.1 Catchment

The Paarl WWTW Services a vast section of the Paarl area, from the Bo-Dal Josafat Area to the Paarl South Area, including the areas of Mbekweni and Silvertown to the north. The WWTW is situated next to the Berg River, into which final effluent is discharged. The WWTW is a Class C WWTW under the DWA classifications and currently (2013) has a capacity of 27Mℓ/d, receives and Average Daily Dry Weather Flow (ADDWF) of approximately 22Mℓ/d and is licensed by a water usage permit (No 1222B). A layout of the Paarl WWTW catchment is shown in drawing no 0828/C/002 in Annexure A. The receiving environment is the Berg River. The final effluent must comply with the requirements of the Water Act and for Paarl WWTW these are General Standard. In the near future however the WWTW may need to comply with the Special Standards.

3.1.2 Collection

Influent is conveyed to the Paarl WWTW through various gravity bulk sewers mainly along the Berg River from South to North. The main sewers include the domestic outfall sewer and the industrial outfall sewer. The Bulk Sewer to Southern Paarl currently under construction will serve as a further domestic bulk sewer addressing capacity shortfalls in the existing domestic bulk sewer and providing for future developments in the south of Paarl. Furthermore there are several sewage pumping stations in the catchment that convey sewage via rising mains to the Paarl WWTW which include the following pumping stations shown in table 3.1 below.

Table 3.1 : Sewage Pumping Stations within Paarl

Name of Pumping Station Pumping station to/into

Paarl South Pumping Station No 1 & 2

Existing Domestic Outfall Sewer

Boschenmeer Existing Domestic Outfall Sewer

Roodeberg Existing Domestic Outfall Sewer

Carletta Collector Sewer draining to the Existing Domestic Outfall Sewer

Kaplan Street Collector Sewer draining to the Existing Domestic Outfall Sewer

Dal Josafat Directly to the inlet works of the WWTW

Mbekweni Directly to the inlet works of the WWTW

Silvertown Collection Sewer draining to Mbekweni Pumping Station

Most of the reticulation infrastructure is relatively old, but in good condition. The Asset Management Register of Drakenstein Municipality estimates that approximately 47,6% of the value (useful life) of the sewage network has been consumed. Not withstanding this, the network is continually refurbished/upgraded to replace old infrastructure.

3.1.3 Treatment

The Paarl WWTW comprises a combination of trickling filters (biofilters) and activated sludge processes, with maturation ponds for tertiary treatment. Normally all flow passes through the trickling filter works, after which it is further treated in the activated sludge works. During periods of high flow,

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excess flow that cannot be accommodated hydraulically in the trickling filter works, then bypasses this section and flows directly to the activated sludge works. In 2003, Drakenstein Municipality appointed Ninham Shand (now Aurecon) in association with Lyners to investigate and report on options for upgrading the existing WWTW to provide for nutrient removal, and in particular for phosphate removal (for a maximum ortho-phosphate level of 1 mg/L as PO4). Subsequent to this investigation, Drakenstein Municipality appointed Africon (now Aurecon) to compile a master plan which identified the preferred locations for future WWTW’s in the area. This investigation recommended that the existing Paarl WWTW be developed to a capacity of 35 Mℓ/d. The consulting engineers recommended the treatment of a blend of industrial humus tank effluent and settled and raw domestic sewage in a biological nutrient removal (BNR) activated sludge process. The process was achieved by converting the existing aerated lagoon to a BNR activated sludge system. Upgrading of the aerated lagoon was completed in March 2012.

A flow diagramme of the works is included in Annexure B.

3.2 Wellington WWTW 3.2.1 Catchment

The Wellington WWTW services the entire Wellington area, from the Newton- and Erf 8000 areas in the south to the Pentz Domestic area in the north as well as the Industrial Park Area in the west of Wellington. The WWTW is a Class C WWTW under the DWA classifications and currently has a capacity of 6Mℓ/d with a ADDWF of approximately 5.5Mℓ/d. Upgrading of this WWTW to a capacity of 16 Mℓ/d is currently underway. The WWTW is licensed by a water usage permit (No 918B). A layout of the Wellington WWTW catchment area is shown on drawing no 0828/C/003 in Annexure A. As with the Paarl WWTW, the receiving environment for the effluent from the Wellington WWTW is also the Berg River and the Wellington WWTW most also comply with the General Standard. In future the WWTW may also need to comply with the Special Standard.

3.2.2 Collection

Influent to the Wellington WWTW is from various Sewage Pumping Stations conveying sewage to the WWTW via rising mains. The various pumping stations in the Wellington area are shown in table 3.2 below.

Table 3.2 : Sewage Pumping Station within Wellington


Erf 8000 Newton Sewage Pumping Station

Newton Directly to the WWTW Inlet

Wellington Industries Directly to the WWTW Inlet *(1)

Pentz Street Industrial and Domestic Pumping Stations

Directly to the WWTW Inlet *(1)

Nywerheids Park Directly to the WWTW Inlet *(2)

Kromrivier Collector Sewers draining towards the Pentz Street Domestic Pumping Station

*(1)

These two pumping stations will be consolidated into one large pumping station (Pentz Street Sewage Pumping Station). Construction is estimated to be completed by June 2013.

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*(2)

This pumping station was recently upgraded.

Currently the influent to the WWTW is not separately treated with respect to industrial- and domestic influent.

Some of the pumping stations and rising mains such as the Pentz Street Domestic- and Industrial Pumping Stations are old or at capacity and require replacement or upgrading. However for the most part of the reticulation network is in good condition and have a remaining useful life similar to that of the Paarl. Some re-use of effluent is already implemented with the Wellington Golf Club receiving irrigation water from the works. This is on a relatively small scale and amount. Similarly to Paarl WWTW, it is envisioned that further re-use of effluent for irrigation or large industrial use must occur in future. This process is in the Planning Phase in conjunction with the Paarl WWTW.

3.2.3 Treatment

The Wellington WWTW combines the biological wastewater treatment systems of trickling filters and activated sludge. Raw wastewater (consisting of domestic sewage and industrial effluent) flows through an inlet works to two primary settling tanks and then to five trickling filters (biofilters) of which two are large biofilters supplemented by three smaller biofilters. The effluent from the biofilters is settled in two humus tanks and the settled water is then pumped to the activated sludge bioreactor and a secondary settling tank. The final effluent is chlorinated before receiving tertiary treatment in five maturation ponds in series. The effluent from the last maturation pond discharges to a natural stream which flows to the Berg River. Waste sludge is either treated in two anaerobic digesters and then in sludge drying beds, or in two sludge lagoons. The WWTW is in need of upgrading and extension of the treatment capacity. Aurecon in association with Lyners was appointed in 2010 to investigate options for the required upgrading and extensions. The project is currently (2013) in the in the Planning and Environmental Impact assessment Phase.

A flow diagramme of the works is included in Annexure B.

3.3 Pearl Valley WWTW 3.3.1 Catchment

The Pearl Valley WWTW services the Pearl Valley Golf Estate and the Val-de-Vie Developments to the south of Paarl. The WWTW is a Class D works under the DWA classifications and currently has a capacity of 1Mℓ/d with a ADDWF of approximately 0.2Mℓ/d. This WWTW is licensed under a General Authorization (Ref 16/2/7/G100/A/8). A layout of the Pearl Valley WWTW catchment area is included in Annexure A drawing no 0828/C/001. Again the receiving environment for final effluent is the Berg River and the WWTW must also currently comply with the General Standard. It may also have to comply with the Special Standard in future.

3.3.2 Collection

Influent to this WWTW is domestic in nature and is conveyed to the WWTW via various Sewage Pumping Stations and Rising mains which are shown below in table 3.3.

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Table 3.3 : Sewage Pumping Stations in the Pearl Valley WWTW Catchment


Pearl Valley Directly to the WWTW Inlet

Val-de-Vie 3 Directly to the WWTW Inlet

Val-de-Vie 1,2,5 and 6- and the Guardhouse Pumping Stations

Collector sewers ultimately draining to Val-de-Vie 3 Pumping Station

These pumping stations and reticulation networks are relatively new and in good condition. 3.3.3 Treatment

The Pearl Valley WWTW’s consists of two nearly identical activated sludge modules. The first module (“old section”) was provided to treat the wastewater from the Pearl Valley Golf Estate, while the second module (“new section”) was added later to treat wastewater from the more recently established Val-de-Vie Development. Raw domestic sewage from the two private developments both enter the WWTWs in an inflow sump at the head of the works, from where it flows through a communal inlet works (hand raked screen; grit channels) to two activated sludge reactors. The reactors have been designed for biological nutrient removal and therefore include anoxic zones for denitrification. After the removal of the biomass (sludge) in the secondary settling tanks, the settled water is chlorinated and then polished in large maturation ponds before discharging to a natural water course leading to the Berg River. Waste sludge is disposed of in sludge drying beds. However, the system currently operates on a low MLSS, resulting in low waste sludge volumes to be disposed of. A mechanical sludge dewatering facility has also been provided at the WWTW, but to date this has not been used. A flow diagramme of the works is included in Annexure B.

3.4 Saron WWTW 3.4.1 Catchment

The Saron WWTW services the rural town of Saron north of Gouda. The WWTW is a Class E works under the DWA classification and currently has a capacity of 1Mℓ/d with a ADDWF of approximately 0.8Mℓ/d. The WWTW is licensed by a General Authorization. A conditional assessment of the works was undertaken which recommended upgrading of various structures at the works which include construction of a new activated sludge reactor. The first phase of the upgrading project is currently in the construction phase with a second phase currently (2013) in the planning and EIA phase. A layout of the Saron WWTW catchment is included in drawing no 0828/C/006 in Annexure A.

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The receiving environment for this works is the Klein Berg River which ultimately drains to the Berg River. This works is also subject to the General Standard for effluent and may in future be subject to the Special Standard.

8


3.4.2 Collection

Influent to this WWTW is domestic in nature and is conveyed to the WWTW from a Sewage Pumping Station which was recently upgraded. There are only two Sewage Pumping Stations in Saron which operate as shown in the table 3.4 below.

Tabel 3.4 : Sewage pumping station in Saron.


Saron 1 Collector sewer draining towards Pumping Station

Saron 2 Directly into the Saron WWTW inlet works*

* Recently upgraded

Although most of the reticulation network is old it is still in good condition. As stated above the Saron 2 Sewage Pumping Station and Rising main was recently upgraded. The conditional assessment of the works found that the structures in the WWTW with the exception of the Secondary Settling tank (Clarifier) and the chlorination channel were not in a good condition. Therefore refurbishment and upgrading of the works was proposed.

3.4.3 Treatment

The Saron WWTW is also an activated sludge treatment works, but unlike the Paarl and Wellington WWTW, it is a relatively small plant with open ponds converted to an activated sludge reactor, with an aerobic zone and an anoxic zone. Raw sewage from Saron enters the works via the inlet works (hand raked screen followed by grit channels) to the anoxic zone of the activated sludge reactor. It overflows to the aeration section (with floating aerators) and then to a secondary settling tank. Return activated sludge is recycled to the anoxic zone, and waste activated sludge discharged to the sludge drying beds from time to time (daily sludge wasting is recommended). The settled wastewater from the secondary settling tank is firstly disinfected through chlorination and then normally flows to a series of maturation ponds, located some distance from the works. These ponds have become redundant and are in the process of being upgraded. As stated above this WWTW must be upgraded and refurbished. A flow diagramme of the works is included in Annexure B.

3.5 Hermon WWTW 3.5.1 Catchment

The Hermon WWTW services the small rural town of Hermon which is only partly serviced by gravity sewers with a Sewage Pumping Station. The other section of Hermon has conservancy tanks which are emptied by tanker trucks at regular intervals and the sewage from the tankers is then taken to the WWTW. The WWTW is a Class E works, under the DWA classification and currently has a capacity of 0.3Mℓ/d and a ADDWF of approximately 0.1Mℓ/d. This plant operates under a General Authorization from DWA (Ref 16/2/7/G/10F). A layout of the Hermon WWTW catchment is shown on drawing no 0828/C/004 in Annexure A. As the works is and evaporation pond system there is no effluent outflow.

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3.5.2 Collection

As stated above Hermon is only partially serviced with gravity sewers draining to the Hermon Sewage Pumping Station which conveys sewage to the WWTW. The other section of Hermon has conservancy tanks which are emptied by tanker truck at regular intervals and taken to the WWTW.

It is envisioned that in future the conservancy tanks will be made redundant by the installation of gravity sewers and a new Sewage Pumping Station.

The existing reticulation system is relatively old but still in good condition.

3.5.3 Treatment

The treatment system for Hermon is an evaporation pond system, consisting of two large, unlined evaporation ponds. Provision has been made for using the pond overflow for irrigation purposes (an irrigation pump has been installed for this purpose), but currently both the ponds are empty due to evaporation and possible seepage.

A flow diagramme of the works is included in Annexure A.

3.6 Gouda WWTW 3.6.1 Catchment

The Gouda WWTW services the rural town of Gouda to the north of Hermon. The WWTW is a Class E works under the DWA classification currently having a capacity of 0.64Mℓ/d and a ADDWF of approximately 0.4Mℓ/d. The works is currently licensed by a water use permit (No 1331B). As this works is also an evaporation pond system there is no effluent outflow. A layout of the Gouda WWTW catchment is included in Annexure A drawing no 0828/C/005.

3.6.2 Collection

In the past Gouda was divided into two sections Gouda north (north of the R45) was serviced by gravity sewers draining towards the Gouda Sewage Pumping Station which conveyed sewage to the WWTW. The Gouda South section was serviced by conservancy tanks with tanker trucks removing sewage to the WWTW regularly. Construction of a gravity sewer reticulation network for the Gouda South section is currently underway. This new reticulation network will drain to the Gouda North network, onto the Gouda Sewage Pumping Station and ultimately the Gouda WWTW. The Gouda North reticulation network is relatively old but still in good condition. A new Gouda Sewage Pumping Station and reticulation network for Gouda South was recently completed and are at the start of their service life.

3.6.3 Treatment

The Gouda WWTW is a waste stabilisation pond system (evaporation ponds) consisting of two primary ponds, followed by four secondary oxidation ponds. The final effluent overflowing from the last pond is used as irrigation water on the rugby field in town. Upgrading and rehabilitation of the pond system was recently completed, which included upgrading of the pump station in the town. A flow diagramme of the works is included in Annexure B.

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4 HAZARD ASSESSMENT

In 2011 DWA promoted the use of a W2RAP to identify risks at WWTW’s in detail and to this end all

of Drakenstein Municipality’s WWTW were analysed and a W2RAP drafted.

The W

2RAP is based on a risk factor which is obtained as a product of the perceived probability of

occurrence and the significance or consequence. A risk matrix must be set up to classify risks as low, medium or high.

4.1 Risk Matrix used

As stated above the risk factor is calculated as follows :

Risk factor = Probability of occurrence X significance or consequence

Based on this equation the following risk matrix and factors were used as shown in Figure 4.1 below.

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Figure 4.1 : Risk Matrix used for Hazard Assessment

Min Risk

2 7 8 13 14 19 20 24 25 26 30

Max Risk

Low Risk 2 to 13 Medium Risk 14 to 25 High Risk 25 to 30

Probability Score (Probability of Occurrence)

Severity Score

(Consequence of failure)

1 Rare

(1 in 5 years)

2 Insignificant (No Impact)

2 Unlikely

(once per annum)

3 Minor

(Minor Impact to a large population)

3 Moderately Likely (once per month)

4 Moderate

(Moderate Impact to a large population)

4 Likely

(once per week)

5 Major

(Population exposed to significant illness)

5 Almost Certain

(Once a day or permanent feature)

6 Catastrophic

(Death expected from exposure)

Risk Matrix

Severity

Risk Matrix

Severity

2 3 4 5 6

2 3 4 5 6

Probability

1 2 3 4 5 6

Probability

1 2 3 4 5 6

2 4 6 8 10 12

2 4 6 8 10 12

3 6 9 12 15 18

3 6 9 12 15 18

4 8 12 16 20 24

4 8 12 16 20 24

5 10 15 20 25 30

5 10 15 20 25 30

Based on this risk matrix all risks are classified on their probability (score between 2 and 5) and severity (score between 2 and 6) and ranked as Low, Medium or High.

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This formed the basis for the Hazard Assessment undertaken for each WWTW below.

4.2 Hazard Analysis of works

A Hazard Assessment was undertaken for each WWTW taking into account, among others, the following.

The catchment Surface water Ground water Collector systems Treatment Other factors

The risk analysis further also differentiated between four district risk categories for each section of the works namely :

Electrical failure (including motor failure, power failure, etc.)

Mechanical failure (eg gearboxes, sluices, gate valves, pumps, etc.)

Structural failure (eg structures needing replacement/refurbishment or upgrading)

Process failure (non-compliance with DWA Standards, Operational monitoring etc.)

Risk scores were allocated based mostly on the effect on the receiving environment and the end user. The risk assessment is also only a high level risk assessment and may be elaborated on in future revisions of this document.

4.3 Paarl WWTW The full risk matrix for the Paarl WWTW is included in Annexure C. The risk classified as Medium or High Risks are shown in table 4.1 below.

Table 4.1 : Paarl WWTW : Medium to High Risk Items Item no

System Hazard/Risk Description

Could this issue result in a risk?

Likelihood Consequence Inherent Risk Score (before

consideration of any controls)

Process Failure

11 Domestic Pumping

Station Influent compliance Y 4 5 20 Medium

12 Domestic Pumping

Station Design Capacity Y 4 5 20 Medium

Mechanical Failure

20 Industrial Inlet

Works Hand Raked Screens Y 5 3 15 Medium

Process Failure

21 Industrial Inlet

Works Influent compliance Y 4 5 20 Medium

Process Failure

27 Flocculator Operational Monitoring

Y 4 4 16 Medium

Electrical Failure

28 Flocculator Power failure to

bridge Y 3 5 15 Medium

Structural Failure

30 Domestic

splitterbox Tower Y 3 5 15 Medium

Process Failure

33 Domestic PST's Operational Monitoring

Y 4 4 16 Medium

Structural Failure

38 Biofilters Old Biofilter walls Y 5 5 25 High

Process Failure

39 Biofilters Operational Monitoring

Y 4 4 16 Medium

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Item no





Process Failure

43 Humus Tanks Operational Monitoring

Y 4 4 16 Medium

Process Failure

60 Aerobic Zone Operational Monitoring

Y 4 5 20 Medium

Process Failure

66 Clarifier Operational Monitoring

Y 4 5 20 Medium

Structural Failure

67 New Clarifier Clarifier Structure too

low Y 4 4 16 Medium

Structural Failure

77 Tanks Dome structure on

Tanks Y 5 5 25 High

Structural Failure

78 Digester Structure of digester Y 5 5 25 High

General

80 Digester Deep Structure Y 5 5 25 High

General

81 Incinerators Incinerators very old Y 4 4 16 Medium

Process Failure

84 Maturation Ponds Operational Monitoring

Y 4 5 20 Medium

Electrical Failure

85 Chlorination Store

Room Warning Lights outside building

Y 4 6 24 Medium


Room Dosing Electronics Y 4 6 24 Medium

Process Failure

89 Chlorination

Channel Compliance Monitoring

Y 5 5 25 High

Electrical Failure

91 Transformer Transformers on site

(4 No) Y 5 5 25 High

92 Genset Switch Over Board Y 4 5 20 Medium

General

94 General Site Lighting Y 3 5 15 Medium

95 General Telemetry at works Y 5 4 20 Medium

The risks mainly include operational- and compliance monitoring, replacement or upgrading of structures and dangerous installations such as chlorination storage. These risk are or can be mitigated by employing risk mitigation measures which are shown in table 4.2 below.

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Table 4.2 : Paarl WWTW : Risk Mitigation Measures for Medium to High Risks

Item no


Inherent Risk Score (before consideration

of any controls) Existing controls

Control Effectiveness

(%)

Residual Risk Score

Comment Recommended mitigation/

improvement plan

Process Failure

11 Domestic Pumping

Station Influent

compliance 20 Medium

Operational Monitoring through on site Mini Lab.,

weekly verification at Paarl WWTW lab. and Monthly Audit by Independent Lab.

(A.L. Abbott)

80 4 Low Operational monitoring is to occur to

operational monitoring alert level Ensure monitoring occurs as

scheduled

12 Domestic Pumping

Station Design Capacity 20 Medium - 0 20 Medium

The existing Pumping Station has a lower capacity than newly

constructed sewer

Investigate New pumping station with higher capacity

Mechanical

Failure

20 Industrial Inlet

Works Hand Raked

Screens 15 Medium

Permanent Cleaning of Screen throughout the day

70 4.5 Low Permanently posted staff clean hand

raked screen Investigate installation of

mechanical screens in future

Process Failure

21 Industrial Inlet

Works Influent




(A.L. Abbott)

80 4 Low Operational monitoring is to occur to

operational monitoring alert level Ensure monitoring occurs as

scheduled

Process Failure

27 Flocculator Operational Monitoring

16 Medium



(A.L. Abbott)

80 3.2 Low Operational monitoring to occur to

alert levels with corrective actions as per Alert Level

Ensure Monitoring occurs as scheduled and incident

management protocol is followed

Electrical Failure

28 Flocculator Power failure to

bridge 15 Medium - 0 15 Medium

No power to the bridge at present and process is being affected

Power to be provided to bridge immediately

Structural

Failure

30 Domestic

splitterbox Tower 15 Medium - 0 15 Medium Tower must be investigated

Investigate structure of tower and gratings

Process Failure

33 Domestic PST's Operational Monitoring

16 Medium



(A.L. Abbott)

80 3.2 Low Operational monitoring needed with

Actions as per Alert Level Follow Alert Level actions

Structural

Failure

38 Biofilters Old Biofilter

walls 25 High Structure strapping 10 22.5 Medium

currently strapping is used to reinforce broken brickwork outer

walls

Refurbish walls as part of future upgrade

Process Failure

39 Biofilters Operational Monitoring

16 Medium



(A.L. Abbott)





Process Failure

43 Humus Tanks Operational Monitoring

16 Medium



(A.L. Abbott)





Process Failure


20 Medium



(A.L. Abbott)

80 4 Low Operational Monitoring to determine

sludge wasting

Operational Monitoring as scheduled with process

adjustments at alert levels as necessary

Process Failure


20 Medium



(A.L. Abbott)

80 4 Low Operational monitoring to occur to




Structural

Failure

67 New Clarifier Clarifier

Structure too low

16 Medium - 0 16 Medium

The clarifier structure was constructed low in the ground and

the possibility exists for someone to fall into the clarifier as there is no

handrail around the clarifier

Construct handrail around clarifier with apron

Structural

Failure

77 Tanks Dome structure

on Tanks 25 High

Signage, Gas traps and 24h monitoring

80 5 Low

Inspection of the dome must occur at regular interval as determined by a structural

Engineer

Structural

Failure

78 Digester Structure of

digester 25 High

Signage, Gas traps and 24h monitoring

80 5 Low

Inspection of the dome must occur at regular interval as determined by a structural

Engineer

General

80 Digester Deep Structure 25 High - 0 25 High No life buoy or safety ropes in a very

deep structure Provide life buoys and safety

ropes for structure

General

81 Incinerators Incinerators

very old 16 Medium - 0 16 Medium

The incinerators are very old and parts have become hard to source

Upgrade of the incinerators must be investigated as part of future

upgrade

15


Item no



of any controls) Existing controls


(%)

Residual Risk Score

Comment Recommended mitigation/

improvement plan

Process Failure

84 Maturation Ponds Operational Monitoring

20 Medium



(A.L. Abbott)

80 4 Low Operational monitoring to occur to




Electrical Failure



24 Medium

Warning lights checked daily, with Reactive Maintenance and Standby Generator on

Site

100 0 None Weekly inspection of

Component


Room Dosing

Electronics 24 Medium

Reactive Maintenance and Standby Generator on Site

80 4.8 Low Weekly inspection of

Component

Process Failure

89 Chlorination

Channel Compliance Monitoring

25 High 24h Compliance Monitoring

with on site lab. Newly refurbished

90 2.5 Low Compliance Monitoring to occur to




Electrical Failure

91 Transformer Transformers on

site (4 No) 25 High

Operation and Maintenance from Drakenstein Electrical

Department 0 25 High

Drakenstein Electrical Department is laboring under capacity constraints and maintenance cannot always be

effected in time

Maintenance schedule for all transformers which MUST be

adhered to and additional staffing in the Electrical

Department

92 Genset Switch Over

Board 20 Medium - 0 20 Medium

The existing switch board is old and is in need of upgrading with new

switchgear, etc.

Investigate upgrading of switch board as part of future upgrade

of works

General

94 General Site Lighting 15 Medium Existing high mast lighting 50 7.5 Low Investigate additional high mast

lighting when required

95 General Telemetry at

works 20 Medium 0 20 Medium

Contractor appointed to upgrade entire telemetry network

Monitor contractor performance and telemetry performance after

commissioning

16


If these mitigation measures are implemented the overall risk classification of the works may be regarded as low. 4.4 Pearl Valley WWTW

The full risk matrix for the Pearl Valley WWTW is included in Annexure C. The risk classified as Medium or High Risks are shown in table 4.3 below.

Table 4.3 : Pearl Valley WWTW : Medium to High Risk Items Item no





Electrical Failure



Y 4 6 24 Medium


Room Dosing Electronics Y 4 6 24 Medium

Process Failure

38 Maturation Ponds Compliance Monitoring

Y 5 5 25 High

Electrical Failure

42 Pumping Station Power failure Y 5 4 20 Medium

43 Pumping Station Telemetry Y 4 5 20 Medium

Mechanical Failure

44 Sludge Drying

Beds Drainage Pump Y 4 4 16 Medium

General

45 General Security at works Y 4 6 24 Medium

46 General Office Facilities Y 5 6 30 High

The risks mainly include operational- and compliance monitoring, upgrading of structures and dangerous installations such as chlorination storage.

These risk are or can be mitigated by employing risk mitigation measures which are shown in table

4.4 below. Table 4.4 : Pearl Valley WWTW : Risk Mitigation Measures for Medium to High Risks

Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment

Recommended mitigation/

improvement plan

Electrical Failure

33 Chlorination Store Room

Warning Lights

outside building

24 Medium

Reactive Maintenance and Standby Generator on

Site

80 4.8 Low

An audit has been

performed and corrective

measures have been

identified.

Weekly inspection of Component


Dosing Electronics

24 Medium

Reactive Maintenance and Standby Generator on

Site

80 4.8 Low

An audit has been

performed and corrective

measures have been

identified.

Weekly inspection of Component

Process Failure

17


Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment


improvement plan

38 Maturation

Ponds Compliance Monitoring

25 High

Compliance Monitoring

through on site Mini Lab.,

weekly verification at Paarl WWTW

lab. and Monthly Audit

by Independent Lab. (A.L.

Abbott) and Maturation

Pond Maintenance

80 5 Low

Compliance monitoring to occur to alert

levels with corrective

actions as per Alert Level,

Algal problems occurred in

retention pond and retention

time was reduced, however sediment transport remains

problematic

Ensure Monitoring occurs as

scheduled and incident


Electrical Failure

42 Pumping Station

Power failure

20 Medium

Standby generator on

site & Overflow pond

90 2 Low -

Pro-Active Maintenance Required & servicing of

standby generator required

43 Pumping Station

Telemetry 20 Medium - 0 20 Medium

Contractor appointed to

upgrade entire telemetry network

Monitor contractor

performance and telemetry performance

after commissioning

Mechanical

Failure

44 Sludge

Drying Beds Drainage

Pump 16 Medium

Reactive Maintenance

100 0 None New Pump Currently sourced

Monitor supplier

performance and pump

performance after

commissioning

General

45 General Security at

works 24 Medium - 0 24 Medium

No Security on site

Provide security guard and

facilities as part of the future

upgrade

46 General Office

Facilities 30 High - 0 30 High

No office on site. Non-

Compliance with OSH Act

Provide office facilities as part

of the future upgrade

18


If these mitigation measures are implemented the overall risk classification of the works may be regarded as low 4.5 Wellington WWTW The full risk matrix for the Wellington WWTW is included in Annexure C. The risk classified as Medium or High Risks are shown in table 4.5 below.

Table 4.5 : Wellington WWTW : Medium to High Risk Items Item no

System Hazard/Risk Description Could this issue result in a risk?



Electrical Failure

1 Pumping Station Power failure Y 5 5 25 High

Process Failure

2 Pumping Station Flow meter Y 3 5 15 Medium

Mechanical Failure

3 Pumping Station Screening of Sewage Y 4 5 20 Medium

General

6 Pumping Station No permanent

supervision Y 5 5 25 High

General

11 Pumping Station Security Y 5 5 25 High

General

12 Pumping Station Design Capacity

Exceedance Y 3 5 15 Medium

Mechanical Failure

14 Pumping Station Screening of Sewage Y 3 5 15 Medium

General

17 Pumping Station Security Y 5 5 25 High

18 Pumping Station Telemetry at pumping

Station Y 3 5 15 Medium

General

21 General Plant Design Capacity

Exceedance Y 5 5 25 High

Electrical Failure

22 Inlet Works Power failure Y 5 5 25 High

Process Failure

26 Inlet Works Influent compliance Y 4 5 20 Medium

Process Failure

31 PST's Operational Monitoring Y 4 4 16 Medium

Process Failure

37 Biofilters Operational Monitoring Y 4 4 16 Medium

Process Failure

43 Humus Tanks Operational Monitoring Y 4 4 16 Medium

Process Failure

55 Aerobic Zone Operational Monitoring Y 4 5 20 Medium

Process Failure

59 Clarifier Operational Monitoring Y 4 5 20 Medium

Electrical Failure


Room Warning Lights outside

building Y 5 5 25 High


Room Dosing Electronics Y 5 5 25 High

Process Failure

70 Maturation Ponds Compliance Monitoring Y 5 5 25 High

General

71 Sludge Drying

Beds Design Capacity

Exceedance Y 5 5 25 High

General

72 Digester No Gas Tank Y 4 5 20 Medium

General

73 Incinerator No incinerator on site

for screenings Y 4 5 20 Medium

19


Item no




General

74 Personnel Facilities

Offices Y 4 5 20 Medium



77 General Security Y 5 5 25 High

78 General Signage Y 5 5 25 High

The risks mainly include operational- and compliance monitoring, upgrading of structures, inadequate capacity, no standby electricity generation and dangerous installations such as chlorination storage. These risk are or can be mitigated by employing risk mitigation measures which are shown in table

4.6 below.

20


Table 4.6 : Wellington WWTW : Risk Mitigation Measures for Medium to High Risks

Item no


Inherent Risk Score (before consideration of any controls)

Existing controls Control

Effectiveness (%) Residual Risk

Score Comment Recommended mitigation/ improvement plan

Electrical Failure

1 Pumping Station Power failure 25 High - 0 25 High No Standby Generator on site, Urgently required as this is the closest

pumping station to the Berg River

Process Failure

2 Pumping Station Flow meter 15 Medium - 0 15 Medium Flow meter has not been commissioned

Mechanical Failure

3 Pumping Station Screening of Sewage 20 Medium Basket screen, inspected daily according to pumping station checklist 90 2 Low -

General

6 Pumping Station No permanent

supervision 25 High Daily inspections only 0 25 High Supervision required as pumping station is closest to Berg River

General

11 Pumping Station Security 25 High 3m high wall with barbed wire, fencing, security lights and Armed response 80 5 Low High vandalism rate at this pumping station forced extreme security

measures

General

12 Pumping Station Design Capacity

Exceedance 15 Medium - 0 15 Medium Capacity problems observed in past

Mechanical Failure

14 Pumping Station Screening of Sewage 15 Medium - 0 15 Medium Contract has been issued for provision of a mechanical screen

General

17 Pumping Station Security 25 High Broken fencing and Armed response 25 18.75 Medium High vandalism rate at this pumping station requires security measures

18 Pumping Station Telemetry at pumping

Station 15 Medium - 0 15 Medium

Telemetry required as pumping station is closest to Berg River, Contractor appointed to upgrade entire telemetry network

General

21 General Plant Design Capacity

Exceedance 25 High 0 25 High

Upgrading of Plant Required, All flows pumped to WWTW therefor also may need a balancing dam

Electrical Failure

22 Inlet Works Power failure 25 High No Standby Generator on site - 0 25 High No Standby Generator on Site

Process Failure

26 Inlet Works Influent compliance 20 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) - 80 4 Low Operational monitoring is to occur to operational monitoring alert level

Process Failure

31 PST's Operational Monitoring 16 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) - 80 3.2 Low Operational monitoring needed with Actions as per Alert Level

Process Failure

37 Biofilters Operational Monitoring 16 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 3.2 Low

Operational monitoring to occur to alert levels with corrective actions as per Alert Level

Process Failure

43 Humus Tanks Operational Monitoring 16 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 3.2 Low


Process Failure

55 Aerobic Zone Operational Monitoring 20 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 4 Low Operational Monitoring to determine sludge wasting

Process Failure

59 Clarifier Operational Monitoring 20 Medium Operational Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 4 Low


Electrical Failure


Room Warning Lights outside

building 25 High

Reactive Maintenance and No Standby Generator on Site, Inspection completed and Certificate for compliance obtained

90 2.5 Low A Standby Generator on site is imperative


Room Dosing Electronics 25 High

Reactive Maintenance and No Standby Generator on Site, Inspection completed and Certificate for compliance obtained

90 2.5 Low A Standby Generator on site is imperative

Process Failure

70 Maturation Ponds Compliance Monitoring 25 High Compliance Monitoring through on site Mini Lab., weekly verification at Paarl

WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott) 80 5 Low

Compliance monitoring to occur to alert levels with corrective actions as per Alert Level

General

71 Sludge Drying

Beds Design Capacity

Exceedance 25 High - 0 25 High 2 Waste ponds, Large Sludge Volume coming into works.

General

72 Digester No Gas Tank 20 Medium - 0 20 Medium The plant has Gas Digesters but no gas tank. A waste to energy project

has been initiated which could utilize the gas

General

73 Incinerator No incinerator on site for

screenings 20 Medium Screenings conveyed to Paarl WWTW for Incineration 50 10 Low -

21


Item no






General

74 Personnel Facilities

Offices 20 Medium Some office space provided with limited ablution facilities 10 18 Medium Existing facilities do not comply with OSH Act

75 General Telemetry at works 20 Medium 0 20 Medium Contractor appointed to upgrade entire telemetry network

76 General Site Lighting 20 Medium Existing Lighting on site 50 10 Low Site lighting may be insufficient

77 General Security 25 High Existing Fence 25 18.75 Medium Contract for a new security fence has been issued and is underway

78 General Signage 25 High - 0 25 High Signage is required on site to comply with various statutory regulations

including the OSH Act

If these mitigation measures are implemented the overall risk classification of the works may be regarded as low

22


4.6 Hermon WWTW

The full risk matrix for the Hermon WWTW is included in Annexure C.

The risk classified as Medium or High Risks are shown in table 4.7 below

Table 4.7 : Hermon WWTW : Medium to High Risk Items

Item no




Process Failure

1 Inlet Influent compliance Y 4 5 20 Medium

Process Failure

6 Evaporation

pond 3 Operational Monitoring

Y 4 5 20 Medium

7 Evaporation

Ponds Ground Water

Monitoring Wells Y 4 5 20 Medium

Structural Failure

8 Sump Structure Sump Structure Size Y 3 5 15 Medium

Mechanical Failure

9 Pumps Pump Failure Y 3 5 15 Medium

Electrical Failure

10 Pumps No Standby Power Y 5 5 25 High

General

11 General Telemetry at Pumping

Station Y 5 4 20 Medium

The risks mainly consist only of operational- and compliance monitoring as the ponds are oxidation ponds and do not have any mechanical equipment. These risk are or can be mitigated by employing risk mitigation measures which are shown in table

4.8 below. Table 4.8 : Hermon WWTW : Risk Mitigation Measures for Medium to High Risks

Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment


improvement plan

Process Failure

1 Inlet Influent


Operational monitoring

i.e. Laboratory

testing

80 4 Low

Operational monitoring is

to occur to operational monitoring alert level

Ensure monitoring occurs as scheduled

Process Failure

6 Evaporation

pond 3 Operational Monitoring

20 Medium

Operational Monitoring

weekly sampling with

monthly audits by

independent lab. (A.L. Abbott)

90 2 Low

Operational monitoring to occur to alert


actions as per Alert Level



management protocol is followed,

Investigate need for Mini Lab. On

site

7 Evaporation

Ponds

Ground Water

Monitoring Wells

20 Medium



monthly audits by


90 2 Low







23


Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment


improvement plan

Structural

Failure

8 Sump

Structure

Sump Structure

Size 15 Medium

Daily inspection of

sump according to

Pumping Station

checklist

25 11.25 Low

Current sump structure to

large and has overflow

walls and no Mechanical

screen. Screenings

accumulate in first chamber and must be

manually removed

Investigate upgrade of

pumping station and installation of Mechanical

Screen

Mechanical

Failure

9 Pumps Pump Failure

15 Medium

Reactive maintenance with 24h turn around time

50 7.5 Low

Pumps may experience

problems due to screenings clogging the

pumps

In the interm continue daily

inspections and Investigate upgrade of

pumping station and installation of Mechanical

Screen in future

Electrical Failure

10 Pumps No Standby

Power 25 High - 0 25 High

At the moment no

Standby Power at the

pumping station

Investigate supply of

standby power generator at

pumping station

General

11 General Telemetry

at Pumping Station

20 Medium 0 20 Medium


upgrade entire

telemetry network

Monitor contractor

performance and telemetry performance

after commissioning


4.7 Saron WWTW The full risk matrix for the Saron WWTW is included in Annexure C.

The risk classified as Medium or High Risks are shown in table 4.9 below

Table 4.9 : Saron WWTW : Medium to High Risk Items

Item no





Electrical Failure

1 Inlet Works Power failure Y 5 5 25 High

Mechanical Failure

4 Inlet Works Hand Raked Screens Y 5 3 15 Medium

Process Failure

6 Inlet Works Influent compliance Y 4 5 20 Medium

7 Inlet Works Design Capacity N 4 5 20 Medium

Structural Failure

8 Inlet Works Inlet Works Structure Y 3 5 15 Medium

Electrical Failure

24


Item no





9 Anaerobic Zone Mixer Motors Y 4 4 16 Medium

Mechanical Failure

10 Anaerobic Zone Mixer Gearbox Y 4 4 16 Medium

Structural Failure

11 Anaerobic Zone Zone Structure Y 4 4 16 Medium

Electrical Failure

12 Aerobic Zone Aerator Motors Y 4 4 16 Medium

Mechanical Failure

13 Aerobic Zone Aerator Gearbox Y 4 4 16 Medium

Process Failure


Y 4 5 20 Medium

Structural Failure

17 Clarifier Clarifier Structure Y 3 5 15 Medium

Process Failure


Y 4 5 20 Medium

Mechanical Failure

20 Pumping Station Pumps Y 5 5 25 High

Electrical Failure



Y 5 5 25 High


Room Dosing Electronics Y 5 5 25 High

Structural Failure


Room Store Room Structure Y 5 5 25 High

Structural Failure

25 Maturation Ponds Structures across river Y 4 4 16 Medium

Process Failure

26 Maturation Ponds Compliance Monitoring

Y 4 5 20 Medium

Structural Failure

27 Sludge Drying

Beds Bed Structures Y 4 6 24 Medium

Process Failure

28 Sludge Drying

Beds Filter Medium Y 5 3 15 Medium

General


30 General Security Guard at

works Y 5 4 20 Medium


The risks mainly include operational- and compliance monitoring, upgrading of structures, inadequate capacity, no standby electricity generation and dangerous installations such as chlorination storage. As stated earlier in the document Saron WWTW required upgrading and it is therefore expected to identify so many risks These risks however, can be mitigated by employing risk mitigation measures which are shown in table 4.10 below.

25


Table 4.10 : Saron WWTW : Risk Mitigation Measures for Medium to High Risks Item no






Electrical Failure

1 Inlet Works Power failure 25 High No Standby generator on site 0 25 High No Standby Generator on site Install Standby Generator as part of WWTW upgrade.

Contractor appointed and supply of generator imminent

Mechanical Failure

4 Inlet Works Hand Raked

Screens 15 Medium Permanent Cleaning of Screen throughout the day 70 4.5 Low

Permanently posted staff clean hand raked screen and a new Mechanical screen will be provided at the Saron Sewage pumping

station in new contract

Monitor screenings amount after commissioning of mechanical screen at Saron Sewage pumping station

Process Failure

6 Inlet Works Influent


Operational Monitoring through on site Mini Lab., weekly verification at Paarl WWTW lab. and Monthly Audit by

Independent Lab. (A.L. Abbott) 90 2 Low

Operational monitoring is to occur to operational monitoring alert level


7 Inlet Works Design Capacity 20 Medium 0 20 Medium Upgrade needed of inlet works Upgrade inlet Works as part of WWTW upgrade

Structural Failure

8 Inlet Works Inlet Works Structure

15 Medium Inspection of Structure 0 15 Medium Upgrade needed of inlet works Upgrade inlet Works as part of WWTW upgrade

Electrical Failure

9 Anaerobic Zone Mixer Motors 16 Medium Reactive Maintenance 90 1.6 None Reactive maintenance at the present with 24h turn around time Replaced Mixer and now Pro-Active Maintenance and

Servicing

Mechanical Failure

10 Anaerobic Zone Mixer Gearbox 16 Medium Reactive Maintenance 90 1.6 None Reactive maintenance at the present with 24h turn around time Replaced Mixer and now Pro-Active Maintenance and

Servicing

Structural Failure

11 Anaerobic Zone Zone Structure 16 Medium 0 16 Medium New Reactor must be constructed as part of WWTW upgrade Construct new Reactor as part of WWTW upgrade

Electrical Failure

12 Aerobic Zone Aerator Motors 16 Medium Reactive Maintenance 90 1.6 None Reactive maintenance at the present with 24h turn around time Hour Logging, Pro-Active Maintenance and Servicing or possible standby Aerator. Also investigate timer for low

flow periods

Mechanical Failure

13 Aerobic Zone Aerator Gearbox 16 Medium Reactive Maintenance 90 1.6 None Reactive maintenance at the present with 24h turn around time Hour Logging, Pro-Active Maintenance and Servicing or possible standby Aerator. Also investigate timer for low

flow periods

Process Failure


20 Medium Operational Monitoring through on site Mini Lab., weekly

verification at Paarl WWTW lab. and Monthly Audit by Independent Lab. (A.L. Abbott)

90 2 Low Operational Monitoring to determine sludge wasting Operational Monitoring as scheduled with process

adjustments at alert levels as necessary

Structural Failure

17 Clarifier Clarifier Structure 15 Medium Inspection of Structure 0 15 Medium Inspection must occur during cleaning, Cracks observed on outside. Inspect structure during cleaning, perform structural

investigation with report

Process Failure




90 2 Low Operational monitoring to occur to alert levels with corrective

actions as per Alert Level Ensure Monitoring occurs as scheduled and incident


Mechanical Failure

20 Pumping Station Pumps 25 High Standby Pump Available but not in sump 25 18.75 Medium Standby pump on site but not installed in sump Investigate installation of standby pump in sum as part of

future upgrade

Electrical Failure


Warning Lights outside building

25 High Reactive Maintenance and No Standby Generator on Site 50 12.5 Low Entire system will be replaced with Chlorine tablet system until

future upgrade is completed Coordinate a new disinfection system with future upgrade

of works


Dosing Electronics 25 High Reactive Maintenance and No Standby Generator on Site 50 12.5 Low Entire system will be replaced with Chlorine tablet system until


of works

Structural Failure


Store Room Structure

25 High Inspection of Structure 50 12.5 Low Entire system will be replaced with Chlorine tablet system until


of works

Structural Failure

25 Maturation

Ponds Structures across

river 16 Medium 0 16 Medium

Structure across river may have leakages in crossing, relining of 1st pond currently (2012) underway

Construct new Maturation ponds closer to the WWTW as part of upgrading of WWTW

Process Failure

26 Maturation

Ponds Compliance Monitoring



90 2 Low Compliance monitoring to occur to alert levels with corrective

actions as per Alert Level Ensure Monitoring occurs as scheduled and incident


Structural Failure

27 Sludge Drying

Beds Bed Structures 24 Medium 0 24 Medium Contractor appointed to refurbish the beds All beds to be refurbished

Process Failure

28 Sludge Drying

Beds Filter Medium 15 Medium 0 15 Medium

Water does not filter through quick enough, Contractor appointed to refurbish the beds

All beds to be refurbished, monitor speed of water filtration after refurbishments are complete

General

29 General Telemetry at works 20 Medium 0 20 Medium Contractor appointed to upgrade entire telemetry network Monitor contractor performance and telemetry

performance after commissioning

26


Item no







works 20 Medium 0 20 Medium No security guard at the works.

Provide security guard and facilities as part of the future upgrade

31 General Site Lighting 20 Medium 0 20 Medium Minimal site lighting Additional site lighting must be provided as part of future

upgrade

If these mitigation measures are implemented the overall risk classification of the works may be regarded as Medium and therefore motivates the upgrades currently in progress.

27


4.8 Gouda WWTW

The full risk matrix for the Gouda WWTW is included in Annexure C. The risk classified as Medium or High Risks are shown in table 4.11 below

Table 4.11 : Gouda WWTW : Medium to High Risk Items Item no




Electrical Failure

2 Pumping Station

Standby power Y 5 5 25 High

Process Failure

4 Inlet Influent compliance Y 4 5 20 Medium

Mechanical Failure

5 Inlet Hand Raked Screens Y 5 3 15 Medium

Process Failure

1 Inlet Spetic tank influent

compliance Y 4 5 20 Medium

Process Failure

10 Primary Pond 1 Operational Monitoring

Y 4 5 20 Medium

11 Primary Pond 2 Operational Monitoring

Y 4 5 20 Medium

12 Secondary

Pond 3 Operational Monitoring

Y 4 5 20 Medium

13 Secondary


Y 4 5 20 Medium

14 Secondary


Y 4 5 20 Medium

15 Secondary

Pond 6 Compliance Monitoring Y 5 5 25 High

16 Evaporation

Ponds Ground Water

Monitoring Wells Y 4 5 20 Medium

General



works Y 5 4 20 Medium


The risks mainly consist only of operational- and compliance monitoring as the ponds are oxidation ponds and do not have much mechanical equipment.

These risks however, can be mitigated by employing risk mitigation measures which are shown in table 4.12 below.

28


Table 4.12 : Gouda WWTW : Risk Mitigation Measures for Medium to High Risks

Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment


improvement plan

Electrical Failure

2 Pumping Station

Standby power

25 High - 0 25 High

No Standby Power

generator available on

site

A standby power generator must be provided for

the pumping station

Process Failure

4 Inlet Influent


Operational monitoring

through weekly testing as there is no

effluent outflow from

this evaporation pond system

90 2 Low

Operational monitoring is

to occur to operational monitoring alert level


Mechanical

Failure

5 Inlet Hand Raked

Screens 15 Medium

Permanent Cleaning of

Screen throughout

the day

90 1.5 None

Permanently posted staff clean hand

raked screen, however low

screenings volume due to

mechnical screen at

Gouda Sewage Pumping Station

Clean Screen Daily

Process Failure

1 Inlet Spetic tank

influent compliance

20 Medium - 0 20 Medium

No monitoring of farms septic tank loadings

(e.g. COD, etc.)

Sampling of farm septic tanks

inffluent must be performed to

gauge impact on process

Process Failure

10 Primary Pond 1


20 Medium



monthly audits by


90 2 Low







investigate feasibility of Mini

lab. On site

11 Primary Pond 2


20 Medium



monthly audits by


90 2 Low








lab. On site

29


Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment


improvement plan

12 Secondary


20 Medium



monthly audits by


90 2 Low








lab. On site

13 Secondary


20 Medium



monthly audits by


90 2 Low








lab. On site

14 Secondary


20 Medium



monthly audits by


90 2 Low








lab. On site

15 Secondary

Pond 6 Compliance Monitoring

25 High

Compliance Monitoring


monthly audits by


90 2.5 Low

Compliance monitoring to occur to alert







lab. On site

16 Evaporation

Ponds

Ground Water

Monitoring Wells

20 Medium



monthly audits by


90 2 Low








lab. On site

General

17 General Telemetry at works

20 Medium 0 20 Medium


upgrade entire telemetry network

Monitor contractor

performance and telemetry

performance after

commissioning


works 20 Medium 0 20 Medium

No security guard at the

works.

Provide security guard and

facilities as part of the future

upgrade

30


Item no



of any controls)

Existing controls


(%)

Residual Risk Score

Comment


improvement plan

19 General Site Lighting 20 Medium 0 20 Medium Minimal site

lighting

Additional site lighting must be provided as part

of future upgrade


5 CONTROL MEASUREMENTS

The municipality conducts operational control of the WWTW’s according to a comprehensive operational monitoring program, which meets the minimum requirement of DWA as stipulated in the Green Drop certification criteria. Sampling is done on a frequent basis by the treatment plant personnel at the various WWTW’s, and analysed in a well-equipped laboratory situated at the Paarl WWTW. The operational monitoring programme of Drakenstein Municipality is summarised in the table 5.1 below:

Table 5.1 : Drakenstein Municipality’s Operational Monitoring Programme

Industries (Monitoring Intervals) WWTWs (Monitoring Intervals)

Paarl Weekly Paarl Weekly, 24 hrs Tuesday to Wednesday. Final

effluent weekly

Wellington Two Weekly Wellington

Two Weekly, 24 hrs Wednesday to Thursday. Final effluent weekly

Smaller WWTW’s Final effluent twice per week

Industries (Analysis) WWTW’s (Analysis)

pH, Electrical Conductivity, COD, Phosphates See Table 5.2

WWTW’s Sampling Points

Paarl

Industrial raw inlet, Industrial raw settled, Domestic raw inlet, Domestic raw settled, Biofilters (5 sets) inlet and outlet, Humus settling tanks (5) outlet, Combined humus tank effluent (to activated sludge), Clarifiers (2) outlet, Maturation (aeration) pond, Final effluent to the Berg River (chlorinated), Activated sludge MLSS

Wellington Raw inlet, Raw inlet settled (3 Primary settling tanks), Biofilters (5 sets) inlet and outlet, Humus settling tanks (2) outlet, Clarifiers (2) outlet, Retention pond, Final effluent to the Berg River (chlorinated), Activated sludge MLSS

Pearl Valley Raw inlet, Clarifier, Final effluent, Activated sludge MLSS

Saron Raw inlet, Clarifier, Final effluent, Activated sludge MLSS

Gouda Oxidation ponds outlets (7)

Hermon Raw inlet, Final effluent

31


Table 5.2: Drakenstein Municipality’s Sample Analysis Details

WWTW Sampling point Frequency of

sampling Analyses performed on the samples

Paarl

Industrial raw inlet Weekly COD, pH, EC, tot.alk., settleable solids, ammonia, phosphate, Cd, Cr, Cu, Ni, Zn K, Na, Pb

Industrial raw settled Weekly COD, pH, EC, ammonia, phosphate

Domestic raw inlet Weekly COD, pH, EC, tot.alk., settleable solids, ammonia, phosphate, Cd, Cr, Cu, Ni, Zn K, Na, Pb

Domestic raw settled Weekly COD, pH, EC, ammonia, phosphate

Biofilters (5 sets) inlet and outlet)

Weekly COD, pH, EC

Humus settling tanks (5) outlet Weekly COD, pH, EC

Combined humus tank effluent (to activated sludge)

Weekly COD, pH, EC

Clarifiers (2) outlet Weekly COD, pH, EC

Maturation (aeration) pond Weekly COD, pH, EC, dissolved oxygen, temp, ammonia, phosphate

Final effluent to Berg river (chlorinated)

Daily COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp, Cl

-,

Cd, Cr, Cu, Ni, Zn K, Na, Pb, tot.Cl2

Activated sludge MLSS Daily suspended solids

Wellington

Raw inlet Daily COD, pH, EC, tot.alk., settleable solids, ammonia, phosphate, Cd, Cr, Cu, Ni, Zn K, Na, Pb

Raw inlet settled

(3 primary settling tanks) Weekly COD, pH, EC, tot.alk., ammonia, phosphate

Biofilters (5 sets) inlet and outlet

Weekly COD, pH, EC

Humus Settling tanks (2) outlet Weekly COD, pH, EC

Clarifiers (2) outlet Daily COD, pH, EC

Retention pond Weekly COD, pH, EC

Final effluent to Berg river (chlorinated)

Daily COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp, Cl

-,


Activated sludge MLSS Daily suspended solids

Pearl Valley

Raw inlet 2/week COD, pH, EC, ammonia, phosphate, Cd, Cr, Cu, Ni, Zn K, Na, Pb

Clarifier 2/week COD, pH, EC

Final effluent 2/week COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp, Cl

-,


Activated sludge MLSS 2/week suspended solids

Saron

Raw inlet 2/week COD, pH, EC, tot.alk., ammonia, phosphate

Clarifier 2/week COD, pH, EC

Final effluent 2/week COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp, Cl-,


Activated sludge MLSS 2/week suspended solids

Gouda

Oxidation pond 1 raw 2/week COD, pH, EC, ammonia, phosphate, tot.alk

Oxidation pond 2 raw Weekly COD, pH, EC, ammonia, phosphate, tot.alk

Oxidation pond 3 outlet Weekly COD, pH, EC




Oxidation pond 7 outlet 2/week COD, pH, EC

Oxidation pond 8 (final effluent) COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp.

Hermon Raw inlet 2/week COD, pH, EC, ammonia, phosphate

Final effluent 2/week COD, pH, EC, ammonia, tot.alk., dissolved oxygen, temp.

The sampling (location; frequency) performed at the various treatment plants is in accordance with

the minimum requirements of the Green Drop programme of DWA.

The critical monitoring points for all the Activated Sludge WWTW’s is the discharge points from where problems in the process can be identified through the other monitoring points.

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6 MONITORING OF CONTROL MEASURES AND RESPONSE PROTOCOL

The Drakenstein Municipality Wastewater Section has implemented an incident response protocol, in which certain reactive procedures are followed when an incident occurs (normally when a malfunction of the treatment processes occur due to power failures, faulty equipment, adverse weather conditions, human error, etc). There are two levels of incident management, firstly when a final effluent is discharged that does not meet the requirements of the Water Act, and secondly when an event takes place causing a major pollution event for which emergency response is required. Currently, these requirements are the General Standard for the Paarl, Wellington-, Pearl Valley- and Saron WWTW, and Irrigation Standards for the Gouda and Hermon Pond Systems. After the recent upgrading of the Paarl WWTW and upgrading of the Wellington WWTW in the near future, both of these plants will have to comply with the Special Standard for discharging into the Berg River. The Pearl Valley WWTW will also be required to meet the Special Standard requirements. A set of Compliance Alert Levels, corresponding to the requirements of the General Standard (at present), has been drawn up as part of a Wastewater Incident Management Protocol for Drakenstein Municipality, and is shown in the table 6.1 below. Table 6.1 : Compliance Alert Levels

Table 6.1: WWTW’s Compliance Alert Levels

Compliance Monitoring Sample

Alert Levels requiring action Response Protocol

Paarl WWTW

Final Effluent

COD > 75 mg/L

TSS > 25 mg/L

5.5 > pH > 9.5

EC > 150 mS/m

Ammonia > 6 mg/L as N

Nitrate > 15 mg/L as N

Ortho- P > 10 mg/L as P

Total Cl2 < 0.3 mg/L

E. Coli > 100 #/100 mL

Temp > 300 C

Cd > 0.005 mg/L

Cr > 0.05 mg/L

Cu > 0.01 mg/L

Zn > 0.1 mg/L

Pb > 0.01mg/L

Laboratory personnel to notify:

- Mr. Frans van Rooyen

- Mr. Cecil Paulse

- Mr. Cedric Morkel

Mr. Morkel to notify Mr. Brown, and then Response Protocol to be followed

Wellington WWTW

Final Effluent

COD > 75 mg/L

TSS > 25 mg/L

5.5 > pH > 9.5

EC > 150 mS/m



Ortho- P > 10 mg/L as P


E. Coli > 100 #/100 mL

Temp > 300 C

Cd > 0.005 mg/L

Cr > 0.05 mg/L

Cu > 0.01 mg/L

Zn > 0.1 mg/L

Pb > 0.01mg/L


- Mr. Adam van Wyk

- Mr. Cecil Paulse

- Mr. Cedric Morkel


Pearl Valley WWTW

Final Effluent

COD > 75 mg/L

TSS > 25 mg/L

5.5 > pH > 9.5

EC > 150 mS/m



Ortho- P > 10 mg/L as


E. Coli > 100 #/100 mL

Temp > 300 C

Cd > 0.005 mg/L

Cr > 0.05 mg/L

Cu > 0.01 mg/L

Zn > 0.1 mg/L

Pb > 0.01mg/L


- Mr. Shane Gardner

- Mr. Cecil Paulse

- Mr. Cedric Morkel


Saron WWTW

Final Effluent

COD > 75 mg/L

TSS > 25 mg/L

5.5 > pH > 9.5

EC > 150 mS/m



Ortho- P > 10 mg/L as


E. Coli > 100 #/100 mL

Temp > 300 C

Cd > 0.005 mg/L

Cr > 0.05 mg/L

Cu > 0.01 mg/L

Zn > 0.1 mg/L

Pb > 0.01mg/L


- Ms. Tanya Simons

- Mr. Cecil Paulse

- Mr. Cedric Morkel


When the Compliance Alert Levels are exceeded, the actions stipulated in the Wastewater Incident Management Protocol of the municipality are followed. The Protocol is included in Annexure D.

33


For serious incidents or emergency situations, additional actions and notifications are required, including notification of DWA and the media/public. The protocol to be followed in these situations is included in the Wastewater Incident Management Protocol.

6.1 Operational Alert Levels

For continuously improving the performance of the various WWTW’s, a set of operational alert levels has also been drawn up and followed by the operating personnel. The Operational Alert Levels are tabled below.

Table 6.2.1: WWTW’s Operational Alert Levels

ALL ACTIVATED SLUDGE WASTEWATER TREATMENT WORKS

(Paarl / Wellington / Pearl Valley / Saron)

Operational Samples Alert Levels Actions to be taken

Raw inlet

COD > 1000 mg/L


5.5 > pH > 9.5

EC > 150 mS/m

Settl. solids > 20 mL/L

Cd > 0.005 mg/L

Cr > 0.05 mg/L

Cu > 0.01 mg/L

Zn > 0.1 mg/L

Pb > 0.01 mg/L

Check for possible illegal industrial effluent discharge

Do more frequent measurements of DO levels, pH and MLSS in the activated sludge reactor

Raw inlet settled COD > 400 mg/L

Check operation of PST (faulty scrapers; blockages)

Check for oils and fats on the water surface

Activated sludge reactor

DO < 0.5 mg/L Increase aeration capacity or cycles

MLSS < 2000 mg/L Reduce discharge of WAS and allow MLSS –

levels to increase to 4000 mg/L

MLSS > 6000 mg/L Gradually waste more sludge on a daily basis

to reduce the MLSS to 4000 mg/L

pH < 7.0

Add lime to the inlet works to maintain the pH in the reactor at 7.0 or slightly above

Secondary settling tanks

COD > 75 mg/L

Check for sludge carry – over from secondary settling tanks

Check RAS recycle rates

Check for bulking sludge

Check for rising sludge

Take actions to rectify as appropriate

6.2 Verification of functioning of W2RAP

It is imperative that the functioning of the W2RAP can be monitored. If the W

2RAP is functioning

correctly there should be a decrease in risk and consequently better Wastewater treatment. There are various legislative requirements which will monitor the functioning of the W

2RAP indirectly,

such as the Green Drop Certification process and the RPMS system implemented by DWA. A well functioning W

2RAP will show improved scores in these processes.

Internal monitoring will also show improvement from well functioning W

2RAP. Comparisons of

internal monitoring results such as final effluent compliance over time will provide an indication of W

2RAP effectiveness.

Furthermore the W

2RAP is to be used inter alia with other Municipal Systems such as the Asset

Management Plan and the Operational and Maintenance Plans and the risk mitigation measures employed or identified in the W

2RAP must be aligned with these plans.

As stated above the W

2RAP must be reviewed at least once a year. A well functioning W

2RAP will

show a reduction in risk, year on year, due to implementation of mitigation measures.

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7 SUPPORT PROGRAMMES

Drakenstein Municipality provides various training projects and supporting programmes to educate their staff.

7.1 Process Controller Training Provided

On request of the Engineer: Waste Services (Mr R Brown), an on-site short course in wastewater treatment was presented to the process controllers and plant managers of the Drakenstein Municipality Wastewater Section by Water Training Africa in association with Seboka Manyabolo Management Solutions. The three-day course was presented on 3-5 May 2010 at the Training Centre of the Drakenstein Municipality and included practical training on site at the Paarl, Wellington, Pearl Valley and Saron wastewater treatment plants.

The course covered all aspects of municipal wastewater treatment, with an emphasis on practical aspects, and monitoring requirements. Evaluation of the candidates was done by means of a written-test, and certificates were presented to the course attendees on completion of the course.

7.2 Supervisors Forum

Drakenstein Municipality in conjunction with the University of Stellenbosch have partnered with other Municipalities within the Western Cape to be part of a WWTW Supervisors forum, where supervisors come together for training events and knowledge sharing.

Through this initiative valuable knowledge and problems solving skills are imparted on WWTW Supervisors. This type of support will provide valuable knowledge for incident situations. 7.3 Career Pathing

Professor Lagardien of the Cape Peninsula University of Technology has been approached to perform a Human Capital Development Audit which will inform the Municipality on career pathing and training priorities for its staff. Through this initiative risks associated with staffing problems can be addressed.

7.4 Consultant Advisors

The Municipality currently also employs several consultants, such as AL Abbott Laboratories and Integral Laboratories, to assist the Municipality with process audits.

These consultants form an integral part of the monitoring and verification processes which unfortunately, the Municipality does not always have the capacity to perform at the moment. 8 INCIDENT MANAGEMENT PLAN

Drakenstein Municipality has implemented an Incident Management Protocol (Annexure D) for all of their WWTW. The protocol differentiates between three alert levels based on the severity of the incident. These alert levels are shown in figure 8.1 below.

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Figure 8.1 Alert Levels and Reporting Implementation of these alert levels and the actions will occur as shown in the flowchart in figure 8.2 below.

Alert Level III:

Definite risk to health

or possible death

Inform : All stated for alert level two and Disaster and Emergency Management, Head of Department : Civil Engineering Services, Executive Director : Infrastructure and Planning, Municipal Manager, DWA, General Public Action : As per protocol

Alert Level II:

Potential risk to health

Inform : Senior Laboratory Chemist, Process Controllers, Plant Supervisor, District Supervisor, Head of Waste Services

Action : As per protocol

Alert Level I :

No significant risk to health

Inform : Senior Laboratory Chemist, Process Controllers, Plant Supervisor

Action : As per protocol

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Figure 8.2 Flow Chart of Incident Protocol

Incident

Senior Chemist or Process Controller : Report incident to Plant Supervisor

Plant Supervisor : Can Problem be Solved ?

Yes

Plant Supervisor to implement corrective action and report to District Supervisor

No

District Supervisor : Can Problem be Solved ?

Yes

District Supervisor to implement Incident Management Protocol and report to Head of Waste Services

No

Head of Waste Services: Can Problem be Solved ?

Yes

Head of Waste Services to implement Incident Management Protocol and report to Head of Department : Civil Engineering Services

No

Head of Waste Services to report and provide ongoing updates to :

Implement Incident Management Protocol

Disaster Management and Environmental Management

Head of Department : Civil Engineering Services

Executive Director : Infrastructure and Planning

Municipal Manager

Press, Public and DWA

Alert Level I

Alert Level II

Alert Level III

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9 CONCLUSIONS

The Hazard- or Risk Assessments of the various works show that Drakenstein Municipality have or are implementing various methods which mitigate their risks in terms of wastewater treatment. Saron WWTW is the highest risk and is therefore currently upgraded. The next phase of the upgrade also needs to be implemented as a matter of urgency. Initiatives include various training programmes for staff as well as cooperative governance. Furthermore the municipality also has implemented various management plans which include Incident Management Protocols, Asset Management and Operation and Maintenance Plans. Various risks have been identified for each works and mitigation measures have been proposed.

10 RECOMMENDATIONS 10.1 Risks to be addressed

The various high to medium risk items which must be addressed are shown in Annexure E along with the proposed mitigation measures. The most urgent risks are those associated with the Saron- and Wellington WWTW’s of which emergency funding for Saron WWTW is being applied for and the Wellington WWTW upgrading is in the planning and EIA phase.

10.2 Way forward

Priority must be given to the high risk items at each WWTW and allocations must be made through either staffing, operation and maintenance- or capital project budgets. An internal W²RAP workshop with all WWTW staff must be conducted to familiarize them with the W²RAP and the principle of risk management A yearly review of the W²RAP must be scheduled. It is proposed that the W²RAP must be updated in February every year.


ANNEXURE A :

CATCHMENTS


ANNEXURE B :

FLOW DIAGRAMMES


ANNEXURE C :

DRAKENSTEIN MUNICIPALITY : WWTW RISK ASSESSMENT


ANNEXURE D :

DRAKENSTEIN MUNICIPALITY : WASTE WATER INCIDENT MANAGEMENT PROTOCOL


ANNEXURE E :

HIGH AND MEDIUM RISK ITEMS FOR WWTW WITH MITIGATION MEASURES

waste water risk abatement plan (w2rap) revision b waste... · drakenstein municipality currently...

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