1. ACWA – RECYCLE RESEARCH
Presentation to the ACWA National Convention
August 2009

2. ACWA – RECYCLE RESEARCH
ACWA applied for a grant to study the risks associated with water recycling in car washes
Smart Water Fund of Victoria provided $240,000 for the research
Management Committee of ACWA members, government and environmental/biological scientists
Ecowise Environmental appointed technical consultant

3. EXPERIMENTAL OBJECTIVES
Characterisation of source water quality
Assessment of microbial risk in source water and final effluent
Evaluation of currently available treatment systems
Validation of a risk management protocol
Establish a guideline for water recycling systems

4. EXPERIMENTAL METHODOLOGY
Initial Screening of multiple sites for each system
Detailed monitoring of one site for each system
Source water sample collection and test
E. coli, total organic carbon, pH, turbidity, total petroleum hydrocarbons and total metals
Final effluent sample collection and test
Heterotrophic plate count, E. coli, Legionella, total organic carbon, pH, turbidity, total petroleum hydrocarbons and total metals
Questionnaire
Site characterisation / operation and maintenance

5. SITE SELECTION Found 12 recycle systems or system designs to test
Initial screening with random selection of 3 sites per system
34 sites tested
Urban, regional and all east coast states

6. METALS – SOURCE WATER
Initial Screening
Aluminium and Iron guidelines are aesthetic based only (not health based)

7. METALS – FINAL EFFLUENT
Initial Screening
Aluminium and Iron guidelines are aesthetic based only (not health based)

8. TURBIDITY Median turbidity removal was 34 % removal
Initial Screening
Median turbidity removal was 34 % removal
Some turbidity is being removed by the systems currently on the market

9. E COLI IN SOURCE WATER BY ORIGIN
Initial Screening
Auto median
170 org/100mL
Auto & SS median
1,650 org/100mL
Statistical analysis showed a significant increase in water sourced from Self Serve

10. E. COLI IN FINAL EFFLUENT DISINFECTION
Initial Screening
This graph shows the disinfection performance observed by comparing the E. Coli concentrations in various treated waters

11. QUALITATIVE RESULTS
Initial Screening
Qualitative data was obtained through questionnaires
Data will be useful for refinement of risk assessments

12. RISK ASSESSMENT Chemical contaminant risks acceptable
Initial Screening
Chemical contaminant risks acceptable
Largest risk are pathogens in treated water due to:
Source water
Treatment process
Operational quality – variations between the same system types due to operation and maintenance differences

13. CONCLUSIONS Metals concentrations acceptable
Initial Screening
Metals concentrations acceptable
Effective turbidity removal is occurring in some systems tested to a small degree.
TOC removal by most systems tested is minimal. Where ozone is used, high levels of TOC removal occur.

14. CONCLUSIONS
Initial Screening
E. coli in source water is more of a concern when the source water is drawn from self serve bays.
Pathogen risks need more investigation as the final effluent from many sites did not meet limits for E. coli in the ANZECC Guidelines;
No firm conclusions on effects of specific detergents used with the recycling system performance
Disinfection performance between similar systems was variable

15. RECOMMENDATIONS
Initial Screening
Develop a validation protocol against which to test the performance of recycle systems.
operation and maintenance
pathogens
set out the number of required validation sampling events and the frequency
Develop a risk-based management template to ensure that operation and maintenance issues are addressed
Develop a Guideline for car wash water recycling
Detailed monitoring with sites that represent each system type using all of the above processes

16. VALIDATION PROTOCOL Microbial Risk Assessment
Detailed Monitoring
Microbial Risk Assessment
Sewage E coli concentration 10 million org/100ml.
Greywater E coli concentration 1,000 org/100ml
Stormwater non human microbial indicators
Australian Guideline for Recycled Water
Stormwater with 10% sewage content
Required 92% reduction in E coli for safe recycled water

17. RISK MANAGEMENT TEMPLATE
Detailed Monitoring
Recycling system information including major technologies and support;
Sketch a process flow diagram of the system
Individual sections dedicated to the major critical control points
Operating procedures for start up, normal operation, shut down and emergency shut down of the system;
Maintenance procedures
Incident reporting procedures
Training log.

18. CHEMICAL PARAMETERS IN FINAL EFFLUENT
Detailed Monitoring

19. DISINFECTION
Detailed Monitoring

20. RECYCLING WATER TREATMENT SYSTEMS ASSESSED
Detailed Monitoring

21. E COLI REMOVAL
Detailed Monitoring
Influent
Effluent

22. CONCLUSIONS
Detailed Monitoring
The source water E. coli levels were comparable to those obtained in initial screening
Operation and maintenance of the recycling systems is an important factor in reducing risks
Site specific risk management plans were effective
engage car wash owners and operators with risk management
improve operations and maintenance;
Microbial re-growth in stored treated water is a concern if a disinfection residual cannot be maintained
Water quality monitoring is highly variable making a test protocol with a “pass/fail” outcome difficult.

23. RECOMMENDATIONS
Detailed Monitoring
Move away from testing system performance against chemical and pathogen targets and produce a guideline document outlining best practice in management of recycle systems.
A risk management plan template
A non-mandatory, indicative Water Quality Testing Guideline;
Evaluate which systems performed consistently against the Water Quality Testing Guidelines,

24. GUIDELINES FOR WATER RECYCLING IN COMMERCIAL CAR WASH FACILITIES
Regulatory requirements for water recycling in Australia
Relevant questions to ask in selecting a recycle system
Parameters for risk management
Monitoring and performance expectations
Risk management plan template
Non-mandatory indicative water quality guidelines
Sampling guide.

25. GUIDELINES FOR WATER RECYCLING IN COMMERCIAL CAR WASH FACILITIES
Supplier Questions
Does the system incorporate a disinfection stage?
Is treated water stored prior to use or is it continually recirculated without any final storage? If it is stored, is a disinfectant residual maintained in the final storage tank to reduce the risk of microbial re-growth?
Does the system incorporate any monitoring equipment and/or alarms to help assess disinfection performance? If not, how is disinfection performance monitored?
Are there any alarms to indicate failure of the disinfection process?
Does the system utilise any online turbidity monitoring to indicate that there is a shock load, or one of the system barriers has failed (filters etc)?
Does the system have processes that remove BOD, Suspended Solids and turbidity? Is there any monitoring data to prove this?
Does the system have pH correction? How does it maintain a safe and workable pH in the final effluent given the varying input pH’s from car wash chemicals?

26. GUIDELINES FOR WATER RECYCLING IN COMMERCIAL CAR WASH FACILITIES
Risk Management Plan
Site Characteristics
System diagram with explanations
Manufacturer maintenance contact details
Critical control points
Template for each element in each system type
Points of system control that may fail with how risks should be managed
Operation and maintenance plan
Incident Reporting
Training

27. GUIDELINES FOR WATER RECYCLING IN COMMERCIAL CAR WASH FACILITIES
Risk Management Plan

28. GUIDELINES FOR WATER RECYCLING IN COMMERCIAL CAR WASH FACILITIES
Analysis Parameters and Results Interpretation

29. ACWA – RECYCLE RESEARCH
What have we learned
Human health risks associated with car wash water are more akin to risks in stormwater than sewerage and grey water
Combined auto and self serve feed is higher risk than auto alone
Recycling to self serve is higher risk – not recommended
Generally chlorine does a more satisfactory job at removing microbes than ozone or UV
Storage of recycled water is higher risk
Testing water to defined parameters is useful but not exacting
Creating and following a Risk Management Plan is the most essential element in controlling risks from recycling car wash water
We now have a tool kit which will be on the ACWA web site
Guideline for Water Recycling in Commercial Car Wash Facilities
Risk Management Plan template

30. ACWA – RECYCLE RESEARCH
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