By Kerry Larsen

Overwhelming community support to have the Douglas region's drinking water return to chlorine-free has the Friends Of Douglas Shire (FODS) demand Queensland Health become involved in the issue immediately.

Our Newsport Daily readers poll, asking readers "Do you support a chlorine free water trial?" shows a massive 87 per cent majority, or 133 votes, support a return to chlorine-free water, while 13 per cent said they did not support a chlorine-free water trial (Total votes to date 154).

It follows a deputation put to last Wednesday's Cairns Regional Council (CRC) meeting at the Mossman chambers, in which FODS asked the reasons behind the sudden cancellation of a chlorine free water trial and requested that CRC revert to the former Douglas Shire Council's water management micro-filtration drinking system, in which Council immediately voted 9-1 against the recommendation.

FODS spokesman, Michael Gabour, says FODS will continue to fight for the right to have a chlorine-free drinking water supply, despite the Council's decision.
"This issue is not going to go away," Mr Gabour said. "Adding chlorine to the water supply does not fix the current problems with our water, it masks it".

"The Newsport poll shows clearly that the vast majority of the community demand a return to chlorine-free water in the Douglas region.

"There is a responsibility that must be met to take care of the repairs and maintenance of our drinking water system as recommended by Professor Don Bursill and consultants, Black and Veatch".

"Cairns Water is not meeting their obligations as set out in the Australian Drinking Water Guidelines and we request the Queensland Health get involved immediately."

At last Wednesday's CRC general meeting in Mossman, Division 10 councillor, Julia Leu, proposed that Council require that the Douglas reticulated water supply be secured against contamination from vermin entry and the pipe network and reservoirs be maintained in a clean state free of sediment, in accordance with the risk based approach advocated in the National Health and Medical Research Council (NHMRC) guidelines.  For your interest The Newsport has been granted permission by Councillor Leu to set out the motion at the end of this article below that she presented to the Council meeting last Wednesday.

The motion also asked that a timeframe and budget be reported back to Council and that Council provides a financial account of income and expenditure of the reticulated water supply system in the Douglas region.

The motion was lost with Councillors Bonneau, Cochrane, Forsyth, Cooper, Blake, Lesina,Pyne, Lanskey and Gregory voting against, much to the surprise of the public forum which had earlier staged a demonstration outside the Mossman Council chambers.

The FODS deputation also demanded that Cairns Water showed transparencyin income figures since amalgamation, as well as full operational and expenditure figures, and if the information was not presented in a timely fashion, the information would be sought through the Right to Information (RTI) Act.

MOTION BY Cllr LEU REF DOUGLAS WATER SUPPLY

·         That Council require that the Douglas reticulated water supply be secured against contamination from vermin entry and the pipe network and reservoirs be maintained in a clean state free of sediment, in accordance with the risk based approach advocated in the National Health and Medical Research Council (NHMRC) guidelines.

·         That a timeframe and budget be reported back to Council

·         That Council provides a financial account of income and expenditure of the reticulated water supply system in the Douglas region. Expenditure should be separated into capital and operational expenses and document what is in the reserve fund from developer contributions for water head-works charges and other sources of capital works/upgrades. It should be laid out and presented in sufficient detail that the financial business of the water fund can be clearly understood

 Background:

Recently the CRC provided a report with costs of preparing the system for a chlorine free trial. That report required securing the system against contamination from vermin entry, cleaning pipes of sediment and improved monitoring. As a result of the cost CRC chose not to go ahead with a chlorine free trial on the basis it would cost too much

Douglas residents have since sought advice on this report from Professor Don Bursill, Chair of the National Health and Medical Research Council drinking water committee whose guidelines form the basis of Qld drinking water legislation. Professor Bursill agrees the NHMRC Guidelines use a risk based approach to ensure drinking water safety. This means maintaining the asset in a secure and clean state. The Guidelines do not endorse accepting contamination and fixing it with chlorine, rather it advocates reducing all known risk.

What is proposed is in accordance with the report prepared by Prof Bursill (as below). The Black and Veitch recommendations are supported and principally matters that should be addressed as a matter of course

Attachment 1

An assessment of the Former Douglas Shire water supply systems

The Potential for Chemical Free Operation

 By

Don Bursill AM

August 2009

Introduction

Some 5-6 years ago the then Douglas Shire Council made a decision to provide ultra-filtration treatment to the source waters to Port Douglas, Mossman, Daintree and associated communities and that the distribution systems would be free of a disinfectant residual – the so called chemical free option.  This approach was apparently taken after community consultation, including community support for increased water charges to support this approach.  At the time this decision was taken the technology employed was very new, in terms of implementation in actual public water supplies.  It was rather adventurous at that time, especially for a small community system somewhat remote from capital cities where the specialized technical support for this emerging technology might be more readily available.

 Recent action by the Cairns Regional Council (which is now responsible for these systems) to control contamination has caused concern from the affected community.  In particular the recent implementation of chlorination is not well supported by the Douglas Shire residents.

The issues with these related water systems were discussed with the author and a visit was subsequently agreed for the period 15 – 25 August to evaluate the available information, make inspections of system elements and make comment on the feasibility of the Douglas Shire water systems operating without a disinfectant residual.  The visit was agreed after discussion with CRC Water and Waste established that this proposed input was welcome and well supported by CRC W & W.  Copies and the two recent consultants’ reports and some additional monitoring data were made available prior to 15 August to assist the evaluation.  An invitation was also extended to attend the proposed meeting of the Water Reference Group meeting scheduled for Thursday 20 August at Mossman.

 A pubic meeting was arranged by local community leaders for Saturday 22 August at Pt Douglas to provide an opportunity to discus the issues with interested community members.  A presentation was given at that meeting which included an explanation of the key principles of water quality management for public water supply systems appropriate to the Douglas Shire systems.  This was done to provide a basis for a better understanding of the logic being applied in the formulation of the opinions being expressed by the author.  A summary of these points is given in this report to assist the reader.

Possible way forward.

1. A more detailed and systematic examination of the former Douglas Shire systems needs to be undertaken which ensures that every opportunity is closed off for cross connections, or ingress of contaminating material containing faecal matter from animal or human origin. 
2. The investigation needs to be supported by investigative monitoring designed to verify the integrity of the various parts of the system, including issues such as why regular faecal indicator organisms seem to be entering the systems between filtration and UV disinfection.  These features of the system are all in close proximity to the treatment plants and no such contamination should occur. 
3. In addition to the integrity testing of the distribution system, there needs to be a quality assurance audit of the monitoring system from sampling through analysis to verification of results, reporting and the maintenance of the data base.
4. Whilst chlorination is still in use and after the above operations are successfully completed and the security (with respect to the ingress of pollution) of the systems is confirmed, flushing should be undertaken.  If there is evidence of strong biofilm growth in the mains then swabbing or air scouring may be required.   The system could then be returned to chlorine free operation on a trial basis, whilst undertaking regular and detailed monitoring for HTP counts.  Some monitoring of opportunistic pathogens such as those suggested by Water Futures would be desirable. 
5. A more rigorous monitoring system is required for residual disinfection free systems, with an emphasis on HTP counts for operational control, with some opportunistic pathogen sampling for system verification.  This additional; monitoring would probably cost less than the cost of chlorination.

 Summary of Key Principles and Terms

Safe Water Systems:

•          Are the single most important feature of our public health system at the population level.  The provision of safe water supply and sewerage systems have contributed more to the improvement of population life spans in wealthy countries over the past 100 years than any other factor.

•          The safety of public water supplies is vital for the protection of public health and should never be compromised.

•          The Australian Drinking Water Guidelines are Worlds best practice – The risk based Water Quality Management Framework that is being applied across most of the Australian water industry is an Australian development that is being applied internationally  as a result of WHO effectively picking up the Framework (as Water Safety Plans) for their current International Guidelines for Drinking Water.  The principles being explained here are part of that Framework.

•          The ADWG are not legally enforceable but are generally called in to force through State legislation or operating licenses.  The new water legislation being implemented in Queensland is based on the ADWG.

 The Multiple Barrier Concept:

•          Calls for multiple barriers between potential sources of pollution and the customer tap because no available management measures are absolutely 100% effective.    Although some barriers are highly effective some poor source waters require very high removal efficiencies for 24 hours a day, 7 days a week for the life of the water scheme – which is usually many decades.

•          Selecting the best source water possible in the area is important.  Having protected catchments from a World Heritage area is excellent and would allow less rigorous treatment to be applied

•          Ultra filtration is an excellent treatment – accredited for 3 logs removal (ie 99.9%) of bacterial and protozoan pathogens

•          UV disinfection gives further protection – additional 3.5 logs (ie 99.97%) removal for bacteria and protozoans.  Only 1 log (ie 10%) removal would be credited for viruses under the current radiation intensity, but the source of the water supply does not require any higher treatment for viruses and the ultra-filtration process would remove some – in the unlikely event of them being present.

•          Total removal of pathogens is 6.5 logs or 99.9997%  - or to put it another way - even if there was 1 000 000 bugs per L, none should get past the treatment plant.

E coli are Indicator Organisms

 •          They indicate that the water has been contaminated recently by faecal matter from warm blooded animals or humans

•          They don’t grow – or even survive for very long in water

•          If present there may be viable human pathogens in the water  - but not necessarily. 

 Opportunistic Pathogens

•          Are a concern in systems without disinfectant residuals – eg chlorine

•          They are organisms that grow naturally in water – given the right environmental conditions of temperature, nutrients and time

•          Biofilms and other free living organisms that are not harmful to humans may also grow in water. Some can have adverse aesthetic effects – eg taste and smell.  HTP and coliforms are indicators of these free living organisms in water systems.  Some HTP counts are inevitable in any water supply system, even with a chlorine residual as these systems cannot be kept completely sterile.  Increasing HTP counts in a contamination free system may indicate that conditions within the system are favourable for opportunistic pathogen growth and operator attention may be required to return the system to a more stable microbiological status (eg flushing or other system cleaning options).

 Disinfectant Free Water Supply Systems:

 •          Have been operating successfully in Europe for more than 20 years.

•          Their main characteristics are good quality source water, excellent and appropriate treatment, small distribution systems (<10 days detention) and cold water temps. (usually <10C but some operate up to 18 C).

•          These systems need intensive and strategic monitoring so that any system failures can be rapidly and effectively dealt with.

•          Any potential ingress of contamination in residual free systems from pipe failures, operator errors or cross connections are usually more readily located and identified than in chlorinated systems – where the indicators may be eliminated by residual chlorine.  The elimination of indicators does not necessarily mean there is no risk from any human pathogens that may have been present with the contamination.  This was the main issue that caused The Netherlands to adopt a disinfectant free distribution management philosophy.

•          Water systems with moderate and higher organic nutrient content, long detention times and high water temperatures are not likely to be able to operate without a disinfectant residual.

 Comments and observations on the Douglas Shire systems

·         My comments are based on an examination of the two reports commissioned by CRC (ie Hunter Water and Water Futures) and the monitoring data supplied by the CRC via email to Mike Berwick.  The data covers the period from 28 October 2003 to 14 May 2009.  The author was given a site visit by Bruce Gardiner on 18 August and issues were discussed with him and an area supervisor who joined us on the inspections.

·         The author has seen no data from the system for the period since 14 May 2009, except the two positive results reported at the Reference Group meeting on 20 August 2009, which related to recent monitoring.  It is understood that chlorination commenced in mid May and that this action has reduced the incidence of positive detections – but not yet fully eliminated them.

·         Although the monitoring frequency prior to the merger was inadequate, from the information supplied, the collective data from distribution taps indicates that the system as a whole failed to comply in only one year in the past five years (ie 2006/07).  If the reservoir samples are included then the overall level of positives falls from 98.5% free of positives to only 74.2% free of positives.  This seems to indicate persistent contamination events at a number of the reservoirs, with Rocky Point and Craiglie – Reef Park being the worst of these.  Interestingly, this contamination does not seem to have had a marked influence on the distribution system samples – with the possible exception of Rex Smeal Park which has recorded a number of low level positive E. coli counts.

·         There are some confusing results in the data that warrant further investigation.  This mainly relates to samples labeled Pre UV and Post UV for each of the plants.  There are a number of instances where contamination seems evident in the Pre UV samples – which are mostly absent from the Post UV samples. 

(On two occasions the Post UV samples at Daintree had E. coli detections when the equivalent Pre UV samples did not.  This is highly unlikely and is clearly the result of sample error.  This error at Daintree has been recognized and better labeling of the sample points has been undertaken).

From the information supplied, the Pre UV samples are taken from a point after ultra-filtration but prior to UV disinfection.  The UV units are installed after the filtered water storages and so this would tend to suggest that there has been relatively frequent contamination of the treated water between ultra-filtration and UV treatment. 

Sampling from pre UV points seemed to have ceased from about mid November 2008 and there were no further results for these locations listed in the data provided by CRC.  In talking to the area supervisor just prior to the meeting in Mossman this issue was raised with him and the author was assured that the pre UV samples continue to be part of the on going weekly monitoring program.  It is not clear why these data were missing from the data set provided to the author.  It is not known if these data were also absent from the information examined by Water Futures.  The information supplied in Water Futures report seems consistent with the data the author has seen. 

·         At the meeting in Mossman, it was reported that there has been just two positive E. coli detects from 1 June to the current date.  Both were from distribution sample points.  One was reported as 1 E. coli/100ml and the other (from a Mossman town location) was reported on the overhead screen as >100 E. coli/ 100 ml.  (An almost inconceivable level of contamination from such a location – and without any other positive tests for the system at that particular time).  It was indicated that this second result was incorrect and that it should read >1 E. coli/100ml.  It was further suggested that if it had been the larger figure CRC would have been highly concerned about it.  This may seem a minor matter however, it raises an important issue.  If it was a reporting error, then it is important to know where in the monitoring and reporting chain the error was made so that this source of error can be eliminated. 

 If the reported (ie very high) result is not correct, there is also no possibility of it being >1 E. coli/100ml.  No water laboratory would report such a result.  It is nonsense.  The true figure has to be <1, 1, 2, 3, …. or > the upper bound of quantitation – which is determined essentially by the sub sample volume taken for analysis in the laboratory.  In the data seen by the author for this region it seems to be either >80 or >100 E. coli/100ml. 

The significance of this and some other unusual results in the data set made available is that there must be some concerns about the reliability of the data and the processes of quality assurance involved from sampling through analysis to verification and reporting of results.  It is stressed that this is not likely to be the total answer to the persistent contamination issues, but it may be contributing to the difficulties in tracking down the source(s) of contamination through throwing up confusing data among the accurate data being collected.  This needs to be resolved as a matter of priority.  It is not sufficient to just fall back on the fact that the laboratory is NATA registered.  NATA inspections are too infrequent and not sufficiently rigorous to guarantee detection of relatively few errors in a large data record.  Sampling processes are often not included in NATA registration, yet this is a significant possibility for the introduction of errors.  An audit and attention to any associated recommendations from an expert in quality assurance for large water laboratories would be advised.

 It is not known what the view of Queensland Health is of the recent high result for Mossman but it is worth pointing out that if it was to accept the explanation of the result being >1 E. coli, as presented to the meeting, then it would bring in to question the understanding of the underlying issues by the relevant officers of that agency.

·         The community served by the systems under review wants to return to a chemical free operation – ie not with a chlorine residual in distribution.  This is not feasible until the source or sources of persistent contamination are located and corrective action taken.  CRC has taken a number of steps to improve the standard of the reservoirs, their maintenance and monitoring with respect to the possible influx of contamination.  There also seems to have been significant improvement made to the operation and maintenance of the treatment facilities.  However, these actions appear not yet to have been sufficiently successful.  Consequently, chlorination of the system has been implemented to eliminate E coli detections.  This is an understandable action to take, especially given the need to comply with the regulations for public water supply safety.  However, this is not a desirable end point.  Best practice would require these contamination sources to be found and eliminated.

·         The presentations by the consultants at the Water Reference Group meeting included advice that it is very difficult and perhaps impossible to keep faecal contamination out of water distribution systems and consequently it is necessary to apply a disinfectant residual to control any such ingress of contaminated material.  This is not the reason disinfectant residuals are maintained in distribution as indicated earlier.  It is true that water distribution systems can never be made sterile as they are necessarily open to the atmosphere.  However, accepting the view that faecal contamination is inevitable, as indicated by E coli detections, brings with it some implications with respect to the underlying logic and philosophy of water quality management for public water systems. 

 The object of good water management practice is to source the best quality water that is possible and practical, provide appropriate treatment to that water source consistent with the risk assessments made for that source and then maintain that quality as much as possible in distribution.  The multiple barrier concept requires more than one barrier to be available between a potential contamination source and the customer tap as explained earlier.  Collection of the water from protected catchments in a World Heritage rainforest area provides one natural barrier and effectively allows regulators to accept that human infective viruses are unlikely to be a significant risk in these systems.  (The UV disinfection step would need to provide more intensive radiation than is currently the case if human viruses were likely to be present.  Human infective viruses are only really likely from domestic sewage contamination.) 

 The treatment systems are providing excellent barriers that would gain credit for 6.5 logs removal of pathogenic bacteria and protozoans (3 logs from ultra-filtration operated within the accredited limits discussed in the Hunter Water report and a further 3.5 logs from the UV system).  Accepting the inevitability of faecal contamination in the distribution system means that all of the credit obtained through high status catchments and excellent treatment amounts to nothing if the system is placed at risk through distribution system insecurity where the only barrier left is a low residual of chlorine, which may (or may not) deal with the indicators (ie E. coli).

 There are many potential human pathogens that are less easily controlled by low levels of chlorine residuals in distribution than are E coli.  The protozoan pathogen, cryptosporidium cannot be controlled by chlorination.  One might suggest that it is pointless to bother with treatment if the distribution issues are not meticulously pursued until adequately resolved.  Obviously this is not a sensible suggestion and it is only made to emphasise this important point.

 The Dutch water industry has actually taken the view that maintenance of chorine residuals does not provide protection against distribution ingress and that it only makes it harder to trace system failures if and when they occur.  They prefer to employ well structured and systematic monitoring programs that allow quick and effective identification of potential issues so that action can be taken to eliminate any system failures before they impact on the community.  This approach has been operating successfully in The Netherlands for more than 20 years. 

·         Once the re-contamination issues are resolved, then it would be possible to establish if the systems under review can be successfully managed without disinfectant residuals.  Under this scenario the concept is to take the benefit of high source water quality and excellent treatment, which collectively leads to low nutrient levels that make it less likely for opportunistic microbiological growth to occur at levels that may cause concern.  Success of this option is not determined by faecal related pathogens that do not grow under the conditions present in water. 

 Systems such as Adelaide has in place rely on chlorine in distribution for the control of opportunistic free living micro organisms.  It is not cost effective or practical to provide the level of treatment required to reduce microbial nutrient levels to a sufficient degree that would allow a disinfectant free distribution operation.  This is essentially due to the very poor source water quality available for the Adelaide region.  The provision of a distribution residual in Adelaide’s systems is not designed for the control of persistent faecal related contamination.  The structural integrity of the distribution system is maintained to a high standard to provide this system security. 

 Furthermore, disinfectant residual maintenance in South Australian country systems is often related to the potential for the growth of Naeglaria fowleri, which has the capacity to multiply in distribution when water temperatures are high (>28 C).  This organism is a free living protozoan that is not at all related to faecal sources (human or animal).  Water supply systems can be readily tested for this organism and warm water temperatures are not sufficient reason to require disinfectant residual maintenance in distribution.   These organisms do not exist in all catchment areas.

·         The Douglas distribution systems are relatively small, with low detention times – estimated at generally less than 1 day from treatment to customer tap, with the Whyanbeel system probably the longest at up to 5-7 days. 

·         In the absence of persistent contamination in distribution, the ability of these systems to be operated successfully without chlorine residual maintenance would depend on the growth of opportunistic organisms, particularly pathogens such as legionella species and pseudomonas species.  No testing for these types of problem organisms has been undertaken, according to the Water Futures report.  There seems to be no other evidence to suggest that there have been any problems in this regard.

·         There are many examples in Europe, particularly in Germany and The Netherlands where water supplies have been operated successfully without the use of disinfectant residuals in distribution.  The key characteristics of these systems include:

§         High quality source waters or very specialized treatment systems

§         Low detention times in distribution – usually less than 10 days.

§         Low water temperatures generally less than 10 C, but some examples exist where temperatures rise to about 18 C.

§         Well maintained distribution systems with good monitoring regimes that provide early alert of any system breaks or other likely challenges to the operation.  Regular mains and tank cleaning programs are employed.

·         The Douglas systems seem to have good source water quality, excellent treatment and low detention.  There is a possible issue with high water temperatures.  However, there is no evidence to suggest that the treated water involved here is biologically unstable – ie will readily develop and support opportunistic bacterial development.  This cannot be assessed while the system is subject to persistent contamination events (which would include the influx of nutrients) and there apparently has been no monitoring for opportunistic pathogens of potential concern. The very high quality of the treated water means that there is little food source available for bacterial re growth in the absence of subsequent contamination.

Conclusions

 ·         The current chlorination of the water systems in the former Douglas Shire is supported whilst faecal related contamination is still occurring.

·         There has been substantial improvement in the maintenance and prevention of access by unauthorized persons to reservoirs.  However, opportunities for faecal related contamination must still exist.  It seems most likely that this contamination is associated with the reservoirs. 

·         There are some data in the data set examined that would indicate some work needs to be done to improve quality assurance from sampling through analysis to data verification and reporting.  The absence of the pre UV sample data after mid November 2008 to 14 May 2009 from data sent to the author raises some concern about the way data sets are maintained.  These issues are important but are unlikely to be the answer to the contamination issue.  The occasional incorrect result may be making the resolution of the contamination issue more difficult.

·         It is not possible to say whether or not these systems can be definitely run without a disinfectant residual.  This cannot be resolved until the contamination issue is resolved.   However, the low level of microbiological nutrients in the treated water, the general high standard of the distribution pipe work and the low system detention times would suggest that an optimistic outcome is likely.  The lack of issues in the Mossman system (which doesn’t have a reservoir in the system after the UV disinfection process) and the relatively good record for the Whyanbeel system (which has the longest detention times) tends to support an optimistic view being adopted.

 Possible way forward.

 A more detailed and systematic examination of the former Douglas Shire systems needs to be undertaken which ensures that every opportunity is closed off for cross connections, or ingress of contaminating material containing faecal matter from animal or human origin.

1. The investigation needs to be supported by investigative monitoring designed to verify the integrity of the various parts of the system, including issues such as why regular faecal indicator organisms seem to be entering the systems between filtration and UV disinfection.  These features of the system are all in close proximity to the treatment plants and no such contamination should occur.
2. In addition to the integrity testing of the distribution system, there needs to be a quality assurance audit of the monitoring system from sampling through analysis to verification of results, reporting and the maintenance of the data base.
3. Whilst chlorination is still in use and after the above operations are successfully completed and the security (with respect to the ingress of pollution) of the systems is confirmed, flushing should be undertaken.  If there is evidence of strong biofilm growth in the mains then swabbing or air scouring may be required.   The system could then be returned to chlorine free operation on a trial basis, whilst undertaking regular and detailed monitoring for HTP counts.  Some monitoring of opportunistic pathogens such as those suggested by Water Futures would be desirable.
4. A more rigorous monitoring system is required for residual disinfection free systems, with an emphasis on HTP counts for operational control, with some opportunistic pathogen sampling for system verification.  This additional; monitoring would probably cost less than the cost of chlorination.

 The possible outcomes of such a trial would likely be:

 ·         The re-occurrence of E. coli contamination would indicate that the work done to secure the system was still inadequate.  Hopefully, this would not occur.

·         A rapid and consistent build up in HTP counts would indicate the potential for undesirable bacterial re growth in the system notwithstanding the low nutrient status of these water supplies.  This seems unlikely, but if it did occur then close monitoring for opportunistic pathogens would be important. 

·         In the absence of recontamination sources it is likely that the HTP counts will be able to be maintained at levels generally below 250 CFU/ml and that opportunistic pathogens such as legionella sp. and aeromonas sp. will not be found. 

·         HTP detections above 250 CFU/ml and/or detections of opportunistic pathogens does not necessarily mean that full time chlorination needs to be re-instated.  A possible compromise may be that the system can be safely operated for some time (eg several weeks) followed by one or two days of chlorination and then a return to chlorine free operation until HTP counts rise again.

Prof Don Bursill - 28/08/2009