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

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Presentation on theme: "ACWA – RECYCLE RESEARCH Presentation to the ACWA National Convention August 2009."— Presentation transcript:

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 $244,000 for the research Management Committee of ACWA members, government and environmental/biological scientists Ecowise Environmental appointed technical consultant

3 Characterisation of source water quality Assessment of pathogen 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 EXPERIMENTAL OBJECTIVES

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 Aluminium and Iron guidelines are aesthetic based only (not health based) Initial Screening

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

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

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

10 E. COLI IN FINAL EFFLUENT DISINFECTION This graph shows the disinfection performance observed with regards to the E. Coli concentrations in treated water Initial Screening

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

12 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 RISK ASSESSMENT Initial Screening

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

14 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 CONCLUSIONS Initial Screening

15 RECOMMENDATIONS 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 Initial Screening

16 VALIDATION PROTOCOL Microbial Risk Assessment –Sewerage 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% sewerage content Required 92% reduction in E coli for safe recycled water Detailed Monitoring

17 RISK MANAGEMENT TEMPLATE 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. Detailed Monitoring

18 CHEMICAL PARAMETERS IN FINAL EFFLUENT Detailed Monitoring

19 DISINFECTION Detailed Monitoring

20 RECYCLING WATER TREATMENT SYSTEMS ASSESSED Detailed Monitoring

21 E COLI REMOVAL Influent Effluent Detailed Monitoring

22 CONCLUSIONS The source water E. coli 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. Detailed Monitoring

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

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 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? GUIDELINES FOR WATER RECYCLING IN COMMERCIAL CAR WASH FACILITIES Supplier Questions

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

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 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 ACWA – RECYCLE RESEARCH What have we learned

30 ACWA – RECYCLE RESEARCH © Australian Car Wash Association All rights reserved. No part of the material presented here may be used or reproduced in any form or by any means whatsoever without prior written permission from ACWA.


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