uthukela Water (Pty) Ltd

Transcription

1 Hannelie Hickley - RCM Bulk Water & Scientific Services Milne Cronwright RCM Waste Water Treatment Plants Zenzele Ndlovu - Trainee Waste Water Treatment Plant Manager uthukela Water (Pty) Ltd Developing and Implementation of uthukela Water W2RAP Osizweni WWTP Wednesday 11 July 2012 Figure 1: Osizweni aerial photo July 2012 Water Master Class #2 1 Figure 2: Newcastle Geographical Layout INTRODUCTION Newcastle is situated in the Northwest KZN at the foot of the Northern Drakensburg Mountains. Newcastle Municipality is classified as a Water Service Authority. uthukela Water is the WSP Population being served is approximately (2007 survey). Average growth of 3.5%. Waste Water Treatment plants within the Newcastle LM area of jurisdiction are: Newcastle WWTP 25 ML/day Osizweni WWTP 14.7 ML/day Madadeni WWTP 12 ML/day Kilbarchan WWTP ML/day Charlestown ponds ML/day July 2012 Water Master Class #2 2 1

2 CHALLENGES AND INTERVENTIONS Water Conservation and Demand Management Hydraulic overload of WWTP Newcastle WWTP 25 Megs/day (Stormwater ingress > 78 Megs/day) Osizweni WWTP 14.7 Megs/day (Stormwater ingress > 30 Megs/day) Madadeni WWTP 12 Megs/day ( Megs/day due to water loss, also storm water ingress > 30 Megs/day). Kilbarchan WWTP 0.5 Megs/day - old infrastructure. These WWTP s are all serviced by aging sewer networks resulting in large volumes of storm water ingress during summer months, this is exacerbated by the severe water loss being experienced in the reticulation system. General Effluent standards compliance Planned maintenance insufficient qualified manpower and systems to record and schedule the maintenance. Staff compliment qualifications and certification. Asset Management No risk abatement plans or process audits in place O & M manuals July 2012 Water Master Class #2 3 GOAL Newcastle WSA and uthukela Water wishes to address all the requirements of the DWA Green Drop Certification programme Development and use of Wastewater Risk Abatement Plans (W 2 RAPs) to plan and manage towards safe and complying municipal wastewater collection and treatment. INTERVENTIONS TO MEET GOALS Appoint service provider to co-ordinate and facilitate Risk Abatement plans. Plant audit of all failing infrastructure. Set action plan to prioritise the highest risk effluent quality failures to meet general compliance standard. Appoint service provider to implement plant man. Reshuffling of available staff and motivation to uthukela Water Board for additional key posts. Updating of existing Process O & M manuals and compilation of documentation where none existed. Osizweni W2RAP development and implementation Service provider EMANTI July 2012 Water Master Class #2 4 2

3 METHODOLOGY AND APPROACH FOLLOWED - W 2 RAP To mitigate potential risks associated with wastewater systems. The primary objectives of a W 2 RAP are to: Prevent contamination during transport of wastewater / storage / disposal of sludge. Reduce or remove contamination through the treatment processes. Minimise contamination of the resource to which the treated effluent is returned to. W 2 RAP contains the following three key components: System assessment (effluent quality) Identifying control measures (i.e. what is in place to prevent an incident occurring?) Management plans (i.e. Normal operation and/or incident conditions, monitoring plans, communication plans, supporting programmes) July 2012 Water Master Class #2 5 APPROACH WHEN DEVELOPING A W 2 RAP COMPRISES THE FOLLOWING STEPS: Assemble project team/ key stakeholders Document and describe the present wastewater treatment system Assess the wastewater treatment system Undertake a hazard/risk assessment Identify hazards, control measures and preventative actions Workshop the risk and control measure with the project team/ key stakeholders Monitoring of control measures and wastewater quality Verify that the W 2 RAP is operational Develop and or review management procedures and supporting programmes Establish documentation and communication procedures Review of the W 2 RAP A site visit was conducted, where after a detailed assessment was drafted using the water services sector tools provided for on the ewqms July 2012 Water Master Class #2 6 3

4 Pollution Sites What is a risk? The likelihood that a hazard could cause harm and the consequences. RISK MATRIX: The following Risk Assessment Matrix was used to calculate the likelihood of a risk occurring and consequences of the hazard. RISK RATING = LIKELIHOOD x CONSEQUENCES Table 2: Risk Matrix Risk Rating Range Low 0-10 Medium High July 2012 Water Master Class # ASSEMBLING THE TEAM: Team members included: WSP: RCM WWTP, Senior Process Controllers, Superintendants, Safety Officer, Specialist Technical Input, Specialist Water Quality and WSA: WSA Manager and Technical Specialist. 2. SYSTEM DESCRIPTION: 2.1 Waste Water Plant Class C Activated Sludge system Design capacity of 15 ML/day Hydraulically overloaded - ingress of storm water and poor WCDM System units: Inlet works Primary Sedimentation Tanks 3 Bio filters Primary Sludge Pump Station Activated Sludge Reactor Figure 3: Process Flow Diagram July 2012 Water Master Class #2 8 4

5 Final Clarifiers RAS and WAS Pump Station Chlorination Tank Maturation ponds Sludge Screening and Building Digester Feed Pump Station and Pumps Sludge drying beds Emergency ponds 2.2 Pump Station and Infrastructure Site visits at selected pump stations to identify risks. Risk assessment findings were presented and work shopped with the WWRAP team July 2012 Water Master Class # Average Daily Dry Weather Flows July 2012 Water Master Class #2 10 5

6 3. HAZARDOUS ASSESSMENT The hazard assessment entailed; Site investigations of wastewater treatment works, pump stations, wastewater related infrastructure. Populating of Wastewater Risk Abatement Plan on the electronic Water Quality Management System (ewqms) Findings were workshoped to determine user defined risks. Proposed corrective actions were discussed and tabled indicating the person responsible, targeted time and the estimated cost. Figure 4: A screenshot of the risk assessment tool as seen on ewqms is shown below July 2012 Water Master Class # Risk Assessment Summary Photo Diary July 2012 Water Master Class #2 12 6

7 3.2 Cumulative Risk Rating (CRR) CRR = A*B+C+D A - Design Capacity B - Receiving Flow C - Technical Skills (required vs. actual) D - Effluent quality compliance CRR for Osizweni WWTP calculated using DWA Progress Assessment Tool, as per screenshot from Green Drop Progress Report 2012 is shown on the right. CRR: 45.5 % - Low Risk July 2012 Water Master Class # Critical Control Points The critical control points as indicated in red on the flow diagrams of Plant 1 & 2 below, is for present and future monitoring purposes. Figure 5. Osizweni Plant 1: Critical Control points July 2012 Water Master Class #2 14 7

8 Figure 6. Osizweni Plant 2: Critical Control Points July 2012 Water Master Class # Risk Assessment Findings Figure 7. Snapshot of findings July 2012 Water Master Class #2 16 8

9 4. CONTROL MEASURES VALIDATION AND ACTION The outcomes of the hazard risk assessment and workshops with the WSA, the following key aspects were highlighted Appropriateness of control measures. Responsible person for the control measures. Budget implication for the control measure where available. Time implication for the control measure where available. Figure 8. Snapshot of Control measures and actions July 2012 Water Master Class #2 17 Osizweni Old Head of works Manual screens and grit removal 5. IMPACTS AND RESULTS 5.1 Infrastructure refurbishment program New Head of works: Consisting of automated mechanical screen, washer and compactor July 2012 Water Master Class #2 18 9

10 Infrastructure refurbishment program Maturation ponds Before After Cleaning of maturation ponds and installing a temporary chlorine contact tank July 2012 Water Master Class #2 19 Infrastructure refurbishment program Staff quarters - Electrical panel upgrade July 2012 Water Master Class #

11 Palisade fencing erected around plant for safety purposes Infrastructure refurbishment program. Foreground: Refurbished Sludge drying beds July 2012 Water Master Class # Water quality performance indicators Ammonia results from Suspended solids results from July 2012 Water Master Class #

12 5.3 Staff : - Registration of all Process Staff and Plants - NQF 2 Training of Process Staff July 2012 Water Master Class # CONCLUSION The compilation of a W2RAP is a time-consuming process. But the benefits gained from a management point allows an in-depth control and management tool for the efficient operation of a WWTP. The efficiency of the W2RAP requires continues maintenance and updating to ensure effective management. The implementation and up keeping of the system is a team effort and involves all personnel from Assistant Process Controller level to Management. What we learned / What was working? What you don t measure you cant manage Remaining Challenges WCDM Infrastructure refurbishment and upgrading Maintenance of our W2RAP Effluent microbiological compliance July 2012 Water Master Class #

13 CHALLENGES STILL TO BE ADRESSED Digesters need to be cleaned Sludge Drying beds need repairing July 2012 Water Master Class #2 25 Water quality performance indicators challenge E. coli results from July 2012 Water Master Class #

14 6. RECOMMENDATIONS Obtain an experienced Service provider to assist and lead the compilation of an effective W2RAP Get all Staff and Stakeholder motivated to buy into the system. 7. ACKNOWLEDGEMENT emanti Newcastle WSA uthukela Water Staff July 2012 Water Master Class #