Status Quo Assessment of Wastewater Ponding

Systems

Presentation Road Map…Presentation Road Map…

1.1. BackgroundBackground

2.2. Study MethodologyStudy Methodology

3.3. Study FindingsStudy Findings

4.4. Why PondsWhy Ponds

Background…Background… Free StateFree State

Act. sludge, trick. filters, RBCs and PondsAct. sludge, trick. filters, RBCs and Ponds Complaints relating to the failure and/or poor Complaints relating to the failure and/or poor

condition condition Locality and operation – unacceptable and create Locality and operation – unacceptable and create

environmental and health risksenvironmental and health risks Insufficient information wrt operational status & Insufficient information wrt operational status &

effectiveness of management thereof by WSAseffectiveness of management thereof by WSAs Circumstances in other parts of SA???Circumstances in other parts of SA??? ID and understand status of pond systems ID and understand status of pond systems

in SAin SA Develop Practical GuidelinesDevelop Practical Guidelines

Study MethodologyStudy Methodology

Management Meetings…Management Meetings… Management questionnaireManagement questionnaire Included queries related to:Included queries related to:

Effluent sourceEffluent source Population served (size and status)Population served (size and status) Records of pond system designRecords of pond system design Understanding of the status of the pond Understanding of the status of the pond

systemsystem Safety aspects (e.g. fence, location, clothing)Safety aspects (e.g. fence, location, clothing) MonitoringMonitoring Staff Staff availability and skills, basic needs met availability and skills, basic needs met

(water) (water)

Site Visits…Site Visits… Assessment of pond system using modified/updated Assessment of pond system using modified/updated

questionnairequestionnaire Collection of GPS co-ordinates (location)Collection of GPS co-ordinates (location) Photographing the sitePhotographing the site Number of ponds, shape of ponds, type of ponds and flow Number of ponds, shape of ponds, type of ponds and flow

patternspatterns Location relevant to nearest housingLocation relevant to nearest housing Capacity – measured either by a measuring tape or the foot Capacity – measured either by a measuring tape or the foot

methodmethod Measurement of sludge depthMeasurement of sludge depth Maintenance aspects – screenings, grass on linings or within Maintenance aspects – screenings, grass on linings or within

pondsponds Safety aspects – enclosure, vandalism, etcSafety aspects – enclosure, vandalism, etc Origin of effluent – nightsoil: bucket washing, connectionOrigin of effluent – nightsoil: bucket washing, connection Final effluent – discharged, irrigated, recycled/re-usedFinal effluent – discharged, irrigated, recycled/re-used Water quality – systems discharging or irrigatingWater quality – systems discharging or irrigating

Wastewater Pond System Wastewater Pond System Assessment Tool…Assessment Tool…

WSAs WSAs Self Assessment of the Wastewater Self Assessment of the Wastewater Pond SystemPond System Assist in planning (short/medium or long term Assist in planning (short/medium or long term

needs)needs)

Identify areas of risks and needs (short/medium Identify areas of risks and needs (short/medium or long term needs) or long term needs)

Assist in identifying and tracking emergency Assist in identifying and tracking emergency issuesissues

Assist in understanding of required maintenanceAssist in understanding of required maintenance

Tool Components… Tool Components… General AssessmentGeneral Assessment

Standardized assessmentStandardized assessment Can be completed by range of people with same Can be completed by range of people with same

outcomeoutcome Allows for comparative assessmentsAllows for comparative assessments Guides proactive interventionGuides proactive intervention

Risk AssessmentRisk Assessment Looks at Key Areas of RiskLooks at Key Areas of Risk Guides attention to Proactive Intervention (i.e. prevent Guides attention to Proactive Intervention (i.e. prevent

incidents before they arise)incidents before they arise)

Tool has been modified to make easier to Tool has been modified to make easier to useuse

Allocation of Weights/Score…Allocation of Weights/Score…

WeightWeight ConsequencesConsequences

100100 Direct health threat to communities / Direct threat to proper functioning of environment.

5050 Environmental impacts i.e. degradation / Operational failure leads to environmental impact / Direct threat to individual or impacts on individual regularly.

2020 Aesthetic conditions / Inadequate maintenance leads to aesthetic conditions

1010 Medium / Long term sustainability may be affected by this parameter

If the issue may/will lead to:

Risk Orientated Weighting…Risk Orientated Weighting… Weighting scores Weighting scores

Wei

ghtin

g S

core

Consequence of the Risk

Wastewater Pond Assessment Wastewater Pond Assessment Tool…Tool…

Design

Maintenance Safety

Supervision and Management

Water Quality Monitoring

Effective & Sustainable

Wastewater Pond Systems

Operation and Performance

Assessment Categories…Assessment Categories…

1.1. DesignDesign (lining, depth, etc) (lining, depth, etc)2.2. MaintenanceMaintenance (screenings (screenings

removal/handling, removal/handling, housekeeping, etc)housekeeping, etc)

3.3. Operation and PerformanceOperation and Performance (flow rates, population served, (flow rates, population served, etc) etc)

4.4. Water Quality MonitoringWater Quality Monitoring (parameters, frequency, effluent (parameters, frequency, effluent standards, etc)standards, etc)

5.5. Supervision and ManagementSupervision and Management (assigning responsibilities, (assigning responsibilities, checks, etc)checks, etc)

6.6. SafetySafety (fencing, “no entry” signs, (fencing, “no entry” signs, etc)etc)

Scoring Tool Example…1. Design (Max Score = )1. Design (Max Score = ) Yes/No (Score)Yes/No (Score) WeightWeight

1.1 Are the ponds lined/ fully covered 1.1 Are the ponds lined/ fully covered

1.2 What kind of lining is used1.2 What kind of lining is used

1.3 Is the anaerobic pond depth within the recommended 1.3 Is the anaerobic pond depth within the recommended (recommended 3m for anaerobic)(recommended 3m for anaerobic)

1.4 Is the oxidation ponds depth within the recommended 1.4 Is the oxidation ponds depth within the recommended depthdepth

(recommended 1.0-1.5m for oxidation)(recommended 1.0-1.5m for oxidation)

1.5 What are the sizes of ponds (volume)1.5 What are the sizes of ponds (volume)

1.6 What size population is served (estimation)1.6 What size population is served (estimation)

1.7 Is the population served low/middle or upper class1.7 Is the population served low/middle or upper class

1.8 Is there a meter at the inlet 1.8 Is there a meter at the inlet

1.9 Is there space available for future upgrade1.9 Is there space available for future upgrade

Tool Users…Tool Users…

Likely to be completed by:Likely to be completed by: SupervisorSupervisor Superintendent Superintendent

Could be completed by Could be completed by

process controller process controller BUTBUT may not be may not be

able to read/write (can still able to read/write (can still

provide info to supervisor/superintendent)provide info to supervisor/superintendent)

Responsibility ultimately lies with Head Responsibility ultimately lies with Head of Water/Water Quality Manager or of Water/Water Quality Manager or Technical ManagerTechnical Manager

Study FindingsStudy Findings

DesignDesign Systems well designedSystems well designed Lack of knowledge regarding upgrading optionsLack of knowledge regarding upgrading options

Operation and PerformanceOperation and Performance Desludging not done Desludging not done poor performance poor performance Some systems discharging to Some systems discharging to

rivers and/or environmentrivers and/or environment

MaintenanceMaintenance PoorPoor

General Findings…General Findings…

General Findings (cont)…General Findings (cont)…

• Water Quality MonitoringWater Quality Monitoring• No monitoringNo monitoring

• Supervision and ManagementSupervision and Management• No recordsNo records

• SafetySafety• Not well secured, vandalismNot well secured, vandalism• Community awareness problematicCommunity awareness problematic• Operator basic need (e.g. drinking water, Operator basic need (e.g. drinking water,

shelter) and sanitary facilitiesshelter) and sanitary facilities

Final Effluent flowing to a dam

Sludge layer measurement

Animals drowning within ponds

Pond near dwellings

Why Ponds?Why Ponds?

Discharge to environmentDischarge to environment

Impact on riversImpact on rivers

ChallengesChallenges

UrbanisationUrbanisation Bucket eradicationBucket eradication

More capacity required More capacity required More possible overflow More possible overflow pollution pollution More protection costsMore protection costs More management costsMore management costs

Remove organic matter and solids Remove organic matter and solids Simple construction with relatively Simple construction with relatively

low capitallow capital High level of disinfection achievableHigh level of disinfection achievable Simple process operation – an Simple process operation – an

appropriate technologyappropriate technology Solar powered aeration/disinfectionSolar powered aeration/disinfection

Why consider Ponds?Why consider Ponds?

Minimal (or nil) mechanical/electrical Minimal (or nil) mechanical/electrical equipmentequipment

Minimal labour requirement without Minimal labour requirement without requirement for sophisticated requirement for sophisticated technical trainingtechnical training

Simple process operation – an Simple process operation – an appropriate technologyappropriate technology

Why consider PondsWhy consider Ponds