annual drinking water quality report - south east...

Annual Drinking Water Quality Report2011–12

Company statistics

1.6 millionpopulationserviced

8,951 km of watermains

669,953 watercustomers

39water samplinglocalities

80 pump stations

67 water storage facilities

21 secondary disinfection plants

ContentsManaging Director’s message ......................................................................................2

South East Water’s supply system ..............................................................................3

Characteristics of our water supply by locality .......................................................... 6

Managing our water supply ......................................................................................... 9

Water quality results 2011–12 ..................................................................................... 12

Section 1: Drinking water quality standards .......................................................... 13

Section 2: Other water quality parameter results ................................................22

Section 3: Aesthetic water quality results ........................................................... 30

Regulatory notifi cations to the Department of Health .............................................35

Other incidents and noteworthy events ...................................................................37

Responding to our customers ................................................................................... 38

Appendix - Certifi cate of Audit ................................................................................................40

Glossary/acronyms .................................................................................................... 41

Managing Director’s messageAt South East Water, our priority is to provide safe, reliable and high quality water to our customers. Each year, South East Water produces an Annual Drinking Water Quality Report, which details our performance against the requirements of the Safe Drinking Water Act 2003 (the Act), the Safe Drinking Water Regulations 2005 (the Regulations) and the Australian Drinking Water Guidelines 2011 (ADWG).

I am delighted to report that South East Water performed extremely well against all of the requirements during 2011–12. Our testing of Escherichia coli (E. coli) indicated that 99.95 per cent of samples contained no E. coli per 100 millilitres (mL). This figure is well within the regulatory requirement of 98 per cent of samples containing no E. coli per 100 mL. We also complied with the regulations for the six other drinking water quality standards, which include aluminium, turbidity and by-products of chlorine disinfection.

In 2011–12, customer complaints about water quality issues remained below the Essential Services Commission (ESC) target of 0.28 complaints per 100 customers. South East Water received only 0.2 complaints per 100 customers.

Major achievements for 2011–12:

> Passing the Risk Management Audit in accordance with the Safe Drinking Water Act 2003 and meeting all requirements.

> Successful completion of our Re-Certification Audit, securing our Hazard Analysis and Critical Control Points (HACCP) accreditation for the 13th consecutive year.

> Development of our water quality website, which allows customers to access the most recent testing results from our entire network, as well as provides information about treatment processes and the testing we perform to ensure our water is safe to drink.

> Effective management of water quality during a period of high rainfall after a prolonged drought.

> Preparing for the introduction of desalinated water from the Victorian Desalination Plant. This involved research into the impacts of desalinated water on water quality and the development of protocols, in conjunction with the Victorian Desalination Plant Joint Venture, to ensure water supplied in 2012–13 will meet South East Water’s stringent requirements.

This report highlights results from our water quality monitoring program and explains the processes we undertake to ensure our customers receive the best quality water possible. It also provides examples of our response to water quality challenges.

By continuing to improve our water quality management and providing our customers with new ways to learn more about their water supply, South East Water remains committed to providing our customers with healthy water for life.

Kevin Hutchings Managing Director October 2012

Page 2 Annual Drinking Water Quality Report 2011–12

South East Water’s supply systemSouth East Water provides water, sewerage and recycled water services to residential, commercial and industrial customers across Melbourne’s south east – from Port Melbourne to Portsea, and Parkdale to some 30 kilometres east of Pakenham.

We purchase our water from our wholesaler, Melbourne Water, which is responsible for harvesting, storing and treating water prior to its arrival in our system. Our distribution system is integrally linked with Melbourne Water’s transfer system and the transfer arrangements are formalised under a Bulk Water Supply Agreement.

After treatment, water is transported through a secure closed network to various covered storages. It is then delivered to our customers via the smaller reticulation water mains in the street. The distribution system operates 24 hours a day, on demand, and provides drinking water for more than 1.6 million South East Water customers.

A large proportion of our drinking water comes from protected or uninhabited mountain ash forests high in the Yarra Ranges east of Melbourne, where more than 157,000 hectares have been reserved for the primary purpose of harvesting water. These water supply catchments were set aside more than 100 years ago to supply high quality water that requires minimal treatment. The catchments are managed by Melbourne Water and Parks Victoria.

Melbourne is one of five major cities in the world that has such protected catchments.

From the uppermost catchments, water flows into the Thomson and Upper Yarra reservoirs, where water may be stored for many years before being used. Holding the water for a long period allows the sediments from the forests, washed in by the rain, to settle, providing natural purification.

Water from the upper reservoirs is then transferred to Silvan and Cardinia reservoirs. Upon leaving the reservoirs, it is disinfected using chlorine to kill potentially harmful micro-organisms, thereby maintaining public health. The water is also fluoridated to improve dental health – a requirement of the Health (Fluoridation) Act 1973 – and corrected for pH by the addition of lime to increase and maintain it at a neutral level of 7 to 7.5.

South East Water customers in South Melbourne and Caulfield are supplied with water from the Winneke Water Treatment Plant (WTP) located at Sugarloaf Reservoir. Water stored in Sugarloaf Reservoir is harvested from both the Yarra River at Yering Gorge as well as the Maroondah Aqueduct. It is then treated by filtration at Winneke WTP before undergoing the same treatment as water from Silvan and Cardinia reservoirs, as outlined above.

Towns from Bunyip to Lang Lang, the Mornington Peninsula and Cranbourne receive water from the Tarago Reservoir and Tarago WTP. The Tarago WTP is a state-of-the-art Dissolved Air Flotation and Filtration (DAFF) and ultraviolet (UV) disinfection water treatment plant. Water from the Tarago WTP is fed directly into South East Water’s supply system via the Tarago Westernport Pipeline.

The water treatment applicable for each water quality locality supplied by South East Water is shown on page 8.

To maintain the aesthetic quality of our water supply, South East Water has 21 secondary disinfection plants to provide a more balanced level of chlorine and minimise fluctuations that occur with changing demand and water temperature. The locations of these secondary disinfection plants are shown on the map of our water supply system on pages 4 and 5.

Localised secondary pH correction plants are available for use along the Tarago Westernport Pipeline at Koo Wee Rup, Tynong, Garfield and Bunyip for supply to the respective localities. These pH correction plants use carbon dioxide to lower the pH to neutral (pH 7). Correction is required only when these towns are being supplied by Cardinia Reservoir. The reason for this correction is that the large diameter pipeline used to supply these areas is lined with cement. The mortar and lime, which can leach out of the cement into the water when flows are low, can increase the pH level to near the upper guideline limit. No pH correction is required when the towns are supplied by Tarago WTP, however the secondary disinfection plants along this pipeline remain in operation all year round to maintain consistency for these customers.

Annual Drinking Water Quality Report 2011–12 Page 3

South East Water’s supply system


Characteristics of our water supply by localityOur water system is divided into 39 water sampling localities. Each locality is determined by the origin of the water and the treatment applied, including where the primary treatment is augmented by secondary disinfection and the associated delivery system. Supply-by-Agreement customers with private extensions are included in relevant localities, as the water supplied to the off-take point is guaranteed to meet the Safe Drinking Water Regulations 2005 (SDWR) requirements.

Localities Cora Lynn (No. 260) and Moorooduc (No. 710) are supplied from large transfer pipelines (the Tarago Westernport Pipeline for Cora Lynn and the Bittern Dromana Pipeline for Moorooduc). These large pipelines may be shut down for maintenance reasons for extended periods. As such, continuous access to water cannot be guaranteed. Customers in these localities are supplied via a private water service under Supply-by-Agreement arrangements.

South East Water has a number of customers who receive water from the Bunyip Main Race and Tarago Main Race. The water is supplied from an open channel system from the Bunyip and/or Tarago Rivers. The water is untreated and used for stock and domestic purposes. Each customer has an individual Supply Agreement with South East Water to provide them with water. The agreement specifically states that the water supplied is not fit for human consumption. In addition, South East Water notifies these properties when there is a change of owner or tenant that the quality of water is not fit for human consumption, and signs the new owner up to an individual agreement. A note that the water is ‘not fit for drinking’ is also included on the bill sent to these customers and there is a note to this effect on the Section 32 agreement for land transfer.

South East Water customers in Gembrook and on Old Menzies Creek Road, Selby, are supplied water directly from Yarra Valley Water mains and sources. South East Water notifies these properties individually on change of owner or tenant that their water is supplied directly from Yarra Valley Water mains and sources.

620

610

670

680

690640

660

630

580

570570

590

581700

310

311

290

260

280271

270

300

450

321

320

322

323

390

330

340

350

360

370

440

430

420

410

400

710

650

Port Phillip Bay

Bass Strait

Western Port

Page 6

Water sampling locality number

Water sampling locality name Towns/suburbs supplied Population

360 Balnarring Balnarring, Bittern, Merricks, Merricks Beach, Somers 6,248

570 Bayswater Bayswater, Boronia, Ferntree Gully, Knoxfield, The Basin, Upper Ferntree Gully, Wantirna, Wantirna South

64,891

680 Beaumaris Beaumaris, Black Rock, Cheltenham 27,075

581 Belgrave Belgrave, Belgrave Heights, Belgrave South, Selby, Upper Ferntree Gully, Tecoma, Upwey

16,219

310 Berwick Beaconsfield, Berwick, Nar Nar Goon, Narre Warren, Narre Warren South, Narre Warren North, Officer, Pakenham

68,085

350 Bittern Bittern, Bittern West, Crib Point, HMAS Cerberus 6,558

670 Brighton-Heatherton

Bentleigh, Bentleigh East, Brighton, Brighton East, Caulfield South, Cheltenham, Clarinda, Clayton South, Hampton, Heatherton, Highett, McKinnon, Mentone, Moorabbin, Oakleigh South, Ormond, Sandringham

202,947

270 Bunyip Bunyip, Longwarry 4,112

322 Carrum Downs Carrum Downs, Sandhurst, Skye 28,101

610 Caulfield Armadale, Carnegie, Caulfield, Caulfield North, Caulfield South, Clayton, Elsternwick, Elwood, Hughesdale, Huntingdale, Murrumbeena, Oakleigh, Oakleigh South, Ormond, Prahran, Ripponlea, South Yarra, Springvale, St Kilda, St Kilda East, Toorak, Windsor

169,065

650 Chelsea Aspendale, Aspendale Gardens, Bonbeach, Carrum, Chelsea, Chelsea Heights, Edithvale, Patterson Lakes

49,035

260 Cora Lynn Bunyip, Koo Wee Rup, Nar Nar Goon, Tooradin 103

320 Cranbourne Centreville, Cranbourne, Cranbourne East, Cranbourne North, Cranbourne South, Cranbourne West, Langwarrin, Pearcedale

57,197

640 Dandenong Bangholme, Dandenong, Dandenong South, Dingley Village, Doveton, Keysborough, Noble Park, Springvale South

119,083

660 Dandenong North Clayton, Dandenong North, Noble Park North, Springvale 25,384

321 Devon Meadows Clyde, Fiveways, Blind Bight, Cannons Creek, Cranbourne, Tooradin, Warneet 6,016

430 Dromana Dromana, McCrae, Mt Martha, Safety Beach 23,421

580 Ferntree Gully Boronia, Ferntree Gully, The Basin, Upper Ferntree Gully 21,870

390 Frankston Baxter, Carrum Downs, Cranbourne, Frankston, Frankston North, Langwarrin, Seaford, Pearcedale

89,624

400 Frankston South Baxter, Frankston, Frankston South, Mt.Eliza 15,935

271 Garfield Garfield, Garfield North 1,278

630 Hallam Dandenong South, Doveton, Endeavour Hills, Eumemmerring, Hallam, Hampton Park, Lynbrook, Lyndhurst, Narre Warren North

97,370

340 Hastings Bittern, Hastings 11,552

323 Karingal Frankston 10,953

300 Koo Wee Rup Koo Wee Rup 2,513

450 Lang Lang Lang Lang 1,496

710 Moorooduc Dromana, Moorooduc, Tuerong 504

690 Mordialloc Braeside, Dingley Village, Mentone, Mordialloc, Parkdale, Waterways 31,740

410 Mornington Mt Eliza, Mornington, Mt Martha, Osborne 45,005

420 Mount Martha Mount Martha 8,559

290 Pakenham Pakenham 39,883

700 Rowville Lysterfield, Rowville 31,526

440 Rye Blairgowrie, Cape Schank, Fingal, McCrae, Portsea, Rosebud, Rosebud South, Rosebud West, Rye, Sorrento, St Andrews Beach, Tootgarook,

80,550

370 Shoreham Flinders, Point Leo, Shoreham 3,417

330 Somerville Pearcedale, Somerville, Tyabb 16,345

620 South Melbourne Albert Park, Balaclava, Middle Park, Port Melbourne, Prahran, South Melbourne, South Yarra, Southbank, St Kilda, St Kilda East, St Kilda West, Toorak, Windsor

196,789

280 Tynong Nar Nar Goon, Nar Nar Goon North, Tynong 657

311 Upper Beaconsfield Beaconsfield, Guys Hill, Officer, Upper Beaconsfield, 3,037

590 Wantirna Knoxfield, Scoresby, Wantirna, Wantirna South 22,797


Treatment processes across localities

Water sampling locality no. Source supply Treatment process Added substances

290, 311, 650 Cardinia Reservoir and WTP with localised secondary disinfection

Primary disinfection, fluoridation, pH correction, secondary disinfection

Gaseous, chlorine,fluoride, lime, sodium hypochlorite

310, 322, 630, 640, 680, 690, 700 Cardinia Reservoir and WTP Primary disinfection, fluoridation, pH correction

Gaseous chlorinefluoride, lime

320, 321, 323, 330, 390, 400 Cardinia Reservoir and WTP; Tarago Reservoir and WTP with localised secondary disinfection

Primary disinfection, fluoridation, pH correction,secondary disinfection

Alum, polyelectrolyte, gaseous chlorinefluoride, lime, sodium hypochlorite

260# Tarago Reservoir and WTP Primary disinfection, fluoridation, pH correction

Alum, polyelectrolyte,gaseous chlorinefluoride, lime

270, 271, 280, 300, 340, 350, 360, 370, 410, 420, 430, 440, 450, 710 *

Tarago Reservoir and WTP with localised pH correction and secondary disinfection


Alum, polyelectrolyte,gaseous chlorinefluoride, lime, sodium hypochlorite, carbon dioxide

580 Silvan Reservoir and WTP Primary disinfection, fluoridation, pH correction


610, 620^ Cardinia Reservoir and WTP; Silvan Reservoir and WTP; Sugarloaf Reservoir and Winneke WTP

Filtration,primary disinfection, fluoridation, pH correction

Alum, polyelectrolyte,gaseous chlorinefluoride, lime

570, 581, 590 Silvan Reservoir and WTP with localised secondary disinfection


Gaseous chlorinefluoride, lime, sodium hypochlorite

660 and 670 ** Cardinia Reservoir and WTP; Silvan Reservoir and WTP

Primary disinfection, fluoridation, pH correction


The water sampling localities are shown below:

Comments

# Locality 260 supplied from Tarago Westernport Pipeline. Customers supplied by private water services and Supply-by-Agreement conditions.

* Locality 710 supplied from Bittern Dromana Pipeline. Customers supplied by private water services and Supply-by-Agreement conditions.

^ Locality 620 has been receiving its water from all three water sources over the last year.

**Localities 660 and 670 have been receiving a mixture of these two sources. Cardinia Reservoir is expected to continue as the majority supply source.


Managing our water supplyWater quality risk managementWe continued to deliver on our Water Quality Risk Management Plan during the 2011–12 financial year. The plan is designed to ensure our approach for managing risks to water quality meets the requirements of the Safe Drinking Water Act 2003 and the Australian Drinking Water Guidelines 2011. The plan references our incident and emergency response program, our research program and the actions and outcomes for continual improvement of our water quality. A key component of this framework is our Hazard Analysis and Critical Control Points (HACCP) Plan, which details the specific procedures and corrective measures we use to protect our water quality. This year marks the 13th consecutive year that we have maintained our HACCP accreditation.

During the year we underwent our third Department of Health Regulatory Audit. A formal assessment of how South East Water implements the requirements in our Water Quality Risk Management Plan was conducted by an external auditor. The audit found that there were no critical, major or minor non-conformances, but four opportunities for improvement were identified, as listed below:

> The inspection checklist, which is filled out by operations employees at our water storage facilities during routine inspections, did not specifically detail that the roof must be inspected for damage or deterioration. South East Water has updated the checklist and work instruction to include the inspection of roof structures.

> Tank inspections are conducted by our operations employees after water quality incidents or severe weather events, but the relevant work instruction did not specify these requirements. South East Water has amended the work instruction accordingly.

> Telecommunications equipment on the tops of tanks posed an Occupational Health and Safety risk because the equipment made it difficult to inspect tank roof tops for small holes. Tests have been conducted to determine safe areas for inspections to be carried out in future.

> It was suggested that the South East Water HACCP Plan documented a link to the new Appendix 7 operations focussed audit elements that are controlled by South East Water. Reference to this document has been added to our HACCP Plan under Element 11: Evaluation & Audit.

A copy of the Certificate of Audit has been provided as an appendix to this report.

We also worked with Melbourne Water to optimise and integrate our HACCP Plans to ensure a seamless transition of risk management from the catchment to our customers.

Proactive management of our water supply South East Water maintains a proactive approach to managing the water supply through a number of supporting programs linked to our HACCP Plan. Some of these programs are outlined on the following two pages.

Metropolitan Water Industry Response PlanSouth East Water, in conjunction with Melbourne Water, Yarra Valley Water and City West Water, maintains a Metropolitan Water Industry Response Plan. This plan builds upon South East Water’s proven Incident Management Plan to ensure all incidents, from a localised incident through to a major event, are escalated promptly and appropriately. The Industry Response Plan is regularly tested for accuracy and effectiveness. Through this plan, a Melbourne-wide protocol has been established for all four companies to follow when an unauthorised entry or security breach occurs at a water asset.

Incident Management PlanIn the event there is a non-conformance or a complaint that is deemed to be significant, an incident is declared and the Incident Management Plan is applied.

South East Water’s Incident Management Plan details the procedures to follow in such circumstances, including who to contact and inform as well as escalation protocols and procedures for managing and controlling the incident.

Protocols for the management of water quality during drought and high rainfall periodsProcedures and protocols are in place for the management of water quality during extreme weather periods, such as times of drought or flood. Regular monitoring and trending of water quality variations in the reservoirs is carried out during these times. Changes to the operation of the reservoir and harvesting practices are implemented to ensure the quality of the water meets the requirements stipulated in the Bulk Water Supply Agreement


Zero and inadequate disinfection events documentThe zero and inadequate disinfection events document refers to primary disinfection plant failure at each of Melbourne Water’s primary disinfection plants. The protocol for plant failure follows a scientific approach based on quantitative microbial risk assessment. This statistical technique uses existing water quality data to confirm appropriate response times to chlorinator outages.

The Department of Health was involved in the development of this protocol and has endorsed the notification protocols pertaining to notifications under section 22 of the Act.

Water main renewal programThe water main renewal program was developed in-house as a dynamic mains renewal prioritisation system. It is updated weekly with the latest field information, such as burst main locations, to ensure repeat customer interruptions are reduced and capital expenditure is targeted appropriately and efficiently. This program not only improves water quality through a reduction in mains bursts, it is also designed so that customer complaints or water quality issues can feed into the system to allocate a higher priority to a renewal. During the 2011–12 financial year, we renewed more than 32.2 kilometres of water mains.

Backflow prevention programThe backflow prevention program requires all new properties connecting to our water supply system to install an appropriate backflow prevention device to prevent contaminants from entering the system. We also maintain a registration system for all industrial and commercial properties.

Hydrant permit systemSouth East Water operates a hydrant permit system where only registered users can access the water supply system at designated points. The hydrant permit system, HydroTrak, is installed on registered users’ vehicles and provides greater water security by tracking who is using water, where they are taking it from and how much they are taking. This system can be used to identify trends in relation to the use of hydrants in our system, as well as reduce the number of dirty water issues associated with illegal hydrant usage in our area. Registered hydrant users also have access to a web based application that shows suitable hydrants to use in their area.

Water quality alert agentThe water quality alert agent is a water quality complaints detection system. The system alerts key employees to activate an investigation in instances where we receive three or more dirty water complaints from customers over 24 hours within three kilometres of each other. The same system applies when we receive five or more taste and odour complaints across South East Water’s entire service region over a 24 hour period. Irrespective of this tool, each customer complaint is individually responded to, as detailed on page 38.

Continuous On-Line TestingThe analyser alert is a Continuous On-Line Testing (COLT) result alert system on Supervisory Control and Data Acquisition (SCADA). South East Water has numerous COLT units distributed throughout our system that continuously monitor water for pH, turbidity, chlorine, temperature and electrical conductivity. The data is assessed daily to confirm the results are within acceptable limits. Any abnormal trends are reported by an email alert to key employees.

Internal excursion notificationTo ensure our management and other key areas of the business are up-to-date on daily water quality events, we have implemented an internal excursion notification system. The rules for notification, which are based on tighter internal limits than those found in the ADWG, detect when a water quality parameter is not at optimal levels. This ensures we strive for excellence in water quality, rather than simply satisfying the ADWG criteria.

Non-drinking waterSouth East Water has a number of customers who receive non-drinking water from the Bunyip Main Race and Tarago Main Race. In consultation with the Department of Health, these customers are classified as receiving a non-drinking supply that does not need to be classified as regulated water under the Act.

The Bunyip Main Race and Tarago Main Race are open channels owned and operated by Melbourne Water. The water is not disinfected or treated in any way and customers draw water into their properties for non-drinking uses (e.g. stock and domestic purposes). Furthermore, the prominent colour of the supply helps to make it clear that this water is not drinking water. In order to manage risks associated with supplying water that is not intended for drinking, all Bunyip Main Race and Tarago Main Race customers have an individual Supply Agreement with South East Water regarding the quality of the water that they receive.

Managing our water supply


Risk management procedures relating to non-drinking water from the Bunyip Main Race and Tarago Main Race are stated in South East Water’s HACCP Plan, which covers the potential physical, chemical and biological hazards, as well as the preventative measures in place to minimise these risks.

Routine monitoring and testing water qualityIn accordance with the Act and the Regulations, we collect water samples and have them tested by an approved laboratory for regulatory compliance reporting. The monitoring of compliance is conducted through the Drinking Water Regulatory Section of the Department of Health on a monthly basis, and annually through this report. South East Water has a contractual relationship for the collection and testing of all our samples with ALS Group, an independent National Association of Testing Authorities (NATA) accredited laboratory. During the financial year we collected more than 7,000 water quality samples from our customers’ properties, our water storages and our large water mains to ensure we have a clear picture and understanding of water quality across our whole system. These samples were tested for a range of parameters including E. coli, turbidity, pH, chlorine, disinfection by-products, temperature, hardness, fluoride and metals. More than 50 characteristics were measured, consistent with the requirements of the ADWG. The samples were collected across the whole system covering all areas within the 39 water sampling localities.

In 2011–12, there were no water quality issues arising from the disinfection or treatment of drinking water. Furthermore, over the same period South East Water did not have any undertakings, exemptions or variations under the Act.

Section 22 of the Act requires South East Water to notify the Department of Health in instances where we suspect contamination of our drinking water that may pose a possible health risk or cause widespread public complaint. There were seven events that required section 22 notifications to the Department of Health, which are detailed in the regulatory notifications section on page 35.


Water quality results for 2011–12The following tables summarise the results of South East Water’s monitoring program for each water sampling locality in accordance with the requirements of the Department of Health under the Act. The data in the following tables show results of routi ne samples taken at customer taps. It excludes any results from resamples and samples taken at water storage reservoirs, pressure reducing stati ons and large water mains.

Tables are provided for:

Page 13 Drinking water quality standards

Escherichia coli (E. coli), disinfecti on by-products – chloroaceti c acid, dichloroaceti c acid, trichloroaceti c acid and trihalomethanes – turbidity and aluminium.

Page 22 Other water quality parameter results

Including fl uoride, arsenic, copper, lead, manganese, inorganic parameters and organic parameters.

Page 30 Aestheti c water quality results

Colour, pH, iron and chlorine.


Water Quality Report 2011–12 Page 13

Drinking waterquality standardsEscherichia coli (E. coli), disinfection by-products – chloroacetic acid, dichloroacetic acid, trichloroacetic acid and trihalomethanes – turbidity and aluminium

The drinking water supplied by South East Water complied with the Department of Health requirement that at least 98 per cent of all samples for each locality be zero organisms per 100 mL (98 per cent < 1).

E. coli is a subgroup of total coliforms organisms that indicate a high probability of recent faecal contamination of the drinking water. E. coli is found in large numbers in the faeces of human and other warm-blooded animals, although only a few strains of E. coli are human pathogens.

Escherichia coli (E. coli) results

Water sampling localityFrequency

of samplingNo. of

samplesNo. of samples

containing E. coliMax. result

orgs/100mL

Percentage of samples with

no E. coli

Complying (yes/no)Locality no. Locality name

360 Balnarring Weekly 104 1 3 99.0% Yes

570 Bayswater Weekly 213 1 1 99.5% Yes

680 Beaumaris Weekly 121 0 0 100% Yes

581 Belgrave Weekly 104 0 0 100% Yes

310 Berwick Weekly 250 0 0 100% Yes

350 Bittern Weekly 104 0 0 100% Yes

670 Brighton / Heatherton Daily 470 0 0 100% Yes

270 Bunyip Weekly 104 0 0 100% Yes

322 Carrum Downs Weekly 105 0 0 100% Yes

610 Caulfield Daily 406 0 0 100% Yes

650 Chelsea Weekly 170 0 0 100% Yes

260 Cora Lynn Weekly 105 0 0 100% Yes

320 Cranbourne Weekly 131 0 0 100% Yes

640 Dandenong Daily 329 0 0 100% Yes

660 Dandenong North Weekly 104 0 0 100% Yes

321 Devon Meadows Weekly 104 0 0 100% Yes

430 Dromana Weekly 120 0 0 100% Yes

580 Ferntree Gully Weekly 104 0 0 100% Yes

390 Frankston Weekly 262 0 0 100% Yes

400 Frankston South Weekly 104 0 0 100% Yes

271 Garfield Weekly 104 0 0 100% Yes

630 Hallam Weekly 210 0 0 100% Yes

340 Hastings Weekly 104 0 0 100% Yes

323 Karingal Weekly 104 0 0 100% Yes

300 Koo Wee Rup Weekly 104 0 0 100% Yes

450 Lang Lang Weekly 104 0 0 100% Yes

710 Moorooduc Weekly 105 0 0 100% Yes

690 Mordialloc Weekly 118 0 0 100% Yes

410 Mornington Weekly 143 1 1 99.3% Yes

420 Mount Martha Weekly 104 0 0 100% Yes

290 Pakenham Weekly 106 0 0 100% Yes

700 Rowville Weekly 119 0 0 100% Yes

440 Rye Weekly 247 0 0 100% Yes

370 Shoreham Weekly 104 0 0 100% Yes

330 Somerville Weekly 104 0 0 100% Yes

620 South Melbourne Daily 392 0 0 100% Yes

280 Tynong Weekly 104 0 0 100% Yes

311 Upper Beaconsfield Weekly 104 0 0 100% Yes

590 Wantirna Weekly 106 0 0 100% Yes

Total 6100 3 3 99.95% Yes

Note: all samples where E. coli was detected were reported to the Department of Health. A summary of each report is provided on page 35. Sample numbers per locality are based on the population, with more samples required with greater population as per the ADWG recommendations.


Four of these chemicals must be tested – chloroacetic acid, dichloroacetic acid, trichloroacetic acid and trihalomethanes.These chemicals are produced in drinking water as by-products of the reaction between chlorine and the naturally occurring organic material that comes from decaying plant material in the source water.

Chlorine-based disinfection by-product chemicals

South East Water complied with the Department of Health requirement that chloroacetic acid levels must not exceed 0.15mg/L. All results were less than 0.005mg/L.

Chloroacetic acid results

Water sampling localityFrequency of

samplingNo. of

samples

No. of non-complying

samples

Maximum mg/L


360 Balnarring Monthly 12 0 <0.002 Yes

570 Bayswater Monthly 12 0 0.002 Yes

680 Beaumaris Monthly 12 0 <0.002 Yes

581 Belgrave Monthly 12 0 0.005 Yes

310 Berwick Monthly 12 0 <0.002 Yes

350 Bittern Monthly 12 0 <0.002 Yes

670 Brighton / Heatherton* Twice monthly 24 0 <0.002 Yes

270 Bunyip Monthly 12 0 0.002 Yes

322 Carrum Downs Monthly 12 0 <0.002 Yes

610 Caulfield Monthly 12 0 <0.002 Yes

650 Chelsea Monthly 12 0 <0.002 Yes

260 Cora Lynn Monthly 12 0 <0.002 Yes

320 Cranbourne Monthly 12 0 0.002 Yes

640 Dandenong Monthly 12 0 <0.002 Yes

660 Dandenong North Monthly 12 0 <0.002 Yes

321 Devon Meadows Monthly 12 0 <0.002 Yes

430 Dromana Monthly 12 0 0.007 Yes

580 Ferntree Gully Monthly 12 0 <0.002 Yes

390 Frankston* Twice monthly 24 0 0.002 Yes

400 Frankston South Monthly 12 0 0.002 Yes

271 Garfield Monthly 12 0 0.003 Yes

630 Hallam Monthly 12 0 0.007 Yes

340 Hastings Monthly 12 0 <0.002 Yes

323 Karingal Monthly 12 0 <0.002 Yes

300 Koo Wee Rup Monthly 12 0 <0.002 Yes

450 Lang Lang Monthly 12 0 <0.002 Yes

710 Moorooduc Monthly 12 0 0.003 Yes

690 Mordialloc Monthly 12 0 <0.002 Yes

410 Mornington Monthly 12 0 <0.002 Yes

420 Mount Martha Monthly 12 0 0.004 Yes

290 Pakenham Monthly 12 0 <0.002 Yes

700 Rowville Monthly 12 0 <0.002 Yes

440 Rye Monthly 12 0 <0.002 Yes

370 Shoreham Monthly 12 0 <0.002 Yes

330 Somerville Monthly 13 0 <0.002 Yes

620 South Melbourne Monthly 12 0 0.003 Yes

280 Tynong Monthly 12 0 <0.002 Yes

311 Upper Beaconsfield Monthly 12 0 0.009 Yes

590 Wantirna Monthly 12 0 <0.002 Yes

Total 493 0 0.009 Yes

* Double the samples were taken in the Brighton/Heatherton and Frankston localities because of their large size and greater population, as specified by the Department of Health.


South East Water complied with the Department of Health requirement that dichloroacetic acid levels must not exceed 0.1mg/L. All results were less than or equal to 0.029mg/L.

Dichloroacetic acid results


samplingNo. of

samples


samples

Maximum mg/L


360 Balnarring Monthly 12 0 0.013 Yes


680 Beaumaris Monthly 12 0 0.009 Yes


310 Berwick Monthly 12 0 0.025 Yes

350 Bittern Monthly 12 0 0.009 Yes

670 Brighton / Heatherton* Twice monthly 24 0 0.011 Yes


322 Carrum Downs Monthly 12 0 0.016 Yes

610 Caulfield Monthly 12 0 0.011 Yes

650 Chelsea Monthly 12 0 0.017 Yes

260 Cora Lynn Monthly 12 0 0.012 Yes


640 Dandenong Monthly 12 0 0.017 Yes

660 Dandenong North Monthly 12 0 0.010 Yes

321 Devon Meadows Monthly 12 0 0.011 Yes


580 Ferntree Gully Monthly 12 0 0.013 Yes





340 Hastings Monthly 12 0 0.045 Yes

323 Karingal Monthly 12 0 0.010 Yes

300 Koo Wee Rup Monthly 12 0 0.006 Yes

450 Lang Lang Monthly 12 0 0.006 Yes


690 Mordialloc Monthly 12 0 0.007 Yes

410 Mornington Monthly 12 0 0.030 Yes


290 Pakenham Monthly 12 0 0.017 Yes

700 Rowville Monthly 12 0 0.027 Yes

440 Rye Monthly 12 0 0.014 Yes

370 Shoreham Monthly 12 0 0.013 Yes

330 Somerville Monthly 13 0 0.013 Yes


280 Tynong Monthly 12 0 0.005 Yes


590 Wantirna Monthly 12 0 0.018 Yes

Total 493 0 0.045 Yes



South East Water complied with the Department of Health requirement that trichloroacetic acid levels must not exceed 0.1mg/L. All results were less than or equal to 0.073mg/L.

Trichloroacetic acid results


samplingNo. of

samples


samples

Maximum mg/L









































Total 493 0 0.064 Yes



South East Water complied with the Department of Health requirement that trihalomethane levels must not exceed 0.25mg/L. All results were less than or equal to 0.170mg/L.

Trihalomethane results


samplingNo. of

samples


samples

Maximum mg/L









































Total 493 0 0.160 Yes



South East Water complied with the Department of Health requirement for turbidity, which sets the 95 per cent upper confidence limit (UCL) of the mean for drinking water samples collected in the last 12 months to be less than or equal to 5.0 Nephelometric Turbidity Units (NTU).

Turbidity is caused by the presence of fine suspended matter such as silt, clay, plankton, and other organisms in the water. High turbidity can give the water a cloudy or muddy appearance and can lessen the effectiveness of disinfection.

Turbidity results

Water sampling locality Frequency of sampling

No. of samples

Maximum NTU

95% UCL of mean

Complying (yes/no)

Locality no. Locality name

360 Balnarring Weekly 52 1.4 0.8 Yes

570 Bayswater Weekly 52 1.3 0.8 Yes

680 Beaumaris Weekly 52 1.3 0.8 Yes

581 Belgrave Weekly 52 2.0 0.8 Yes

310 Berwick Weekly 53 1.2 0.8 Yes

350 Bittern Weekly 52 4.2 1.0 Yes

670 Brighton / Heatherton Weekly 52 1.4 0.9 Yes

270 Bunyip Weekly 52 1.2 0.4 Yes

322 Carrum Downs Weekly 52 1.4 0.9 Yes

610 Caulfield Weekly 52 1.6 0.8 Yes

650 Chelsea Weekly 52 3.7 1.0 Yes

260 Cora Lynn Weekly 52 1.4 0.4 Yes

320 Cranbourne Weekly 52 1.6 0.9 Yes

640 Dandenong Weekly 52 1.9 0.9 Yes

660 Dandenong North Weekly 52 2.0 0.9 Yes

321 Devon Meadows Weekly 52 1.7 0.8 Yes

430 Dromana Weekly 53 1.0 0.6 Yes

580 Ferntree Gully Weekly 52 1.4 0.8 Yes

390 Frankston Weekly 52 1.5 0.9 Yes

400 Frankston South Weekly 55 1.7 0.9 Yes

271 Garfield Weekly 52 1.6 0.4 Yes

630 Hallam Weekly 52 1.6 0.9 Yes

340 Hastings Weekly 52 18.0 1.7 Yes

323 Karingal Weekly 52 1.6 0.9 Yes

300 Koo Wee Rup Weekly 52 1.0 0.4 Yes

450 Lang Lang Weekly 52 3.2 0.5 Yes

710 Moorooduc Weekly 53 1.5 0.7 Yes

690 Mordialloc Weekly 52 1.3 0.8 Yes

410 Mornington Weekly 53 1.3 0.6 Yes

420 Mount Martha Weekly 52 1.3 0.6 Yes

290 Pakenham Weekly 52 1.4 0.9 Yes

700 Rowville Weekly 52 2.4 0.9 Yes

440 Rye Weekly 53 1.2 0.6 Yes

370 Shoreham Weekly 52 1.3 0.8 Yes

330 Somerville Weekly 52 1.2 0.9 Yes

620 South Melbourne Weekly 52 2.3 1.0 Yes

280 Tynong Weekly 52 1.1 0.3 Yes

311 Upper Beaconsfield Weekly 52 1.0 0.7 Yes

590 Wantirna Weekly 52 1.6 0.9 Yes

Total 2036 18.0 0.7 Yes


South East Water complied with the Department of Health requirement that aluminium levels must not exceed 0.2mg/L. All results were less than or equal to 0.07mg/L.

Aluminium is only required to be monitored on a monthly basis in the water sampling localities supplied from a WTP that uses aluminium in the treatment process. The Winneke WTP and Tarago WTP are the only WTPs that use aluminium to help remove suspended particles and contaminants from the water. Melbourne Water carries out the treatment and has a Risk Management Plan (HACCP Plan) in place to ensure the treatment complies with the Act.

The localities listed in the following table are either supplied by the Winneke WTP or the Tarago WTP and hence water from these localities was monitored for aluminium.

For all the remaining localities, the supply is from Silvan or Cardinia reservoirs where aluminium is not used in the treatment process.

Aluminium results


samplingNo. of

samples


samples

Maximum mg/L





670 Brighton / Heatherton Monthly 12 0 0.02 Yes







390 Frankston Monthly 13 0 0.02 Yes
















Total 315 0 0.06 Yes


The chemicals derived from disinfection or treatment using ozone (bromate or formaldehyde) are not tested in our system considering that ozone is not used in any processes within our supply region.

Ozone-based disinfection by-products chemical results

Compliance summary for drinking water quality standardsThe drinking water supplied by South East Water was compliant with the requirements of the Act in 2011–12 and the previous two years for all the water sampling localities and all parameters, as indicated in the summary table below.

Parameter Percentage of localities supplied with compliant water

Percentage of customers supplied with compliant water

2011–12 2010–11 2009–10 2011–12 2010–11 2009–10

Escherichia coli 100 100 100 100 100 100

Chloroacetic acid 100 100 100 100 100 100

Dichloroaecetic acid 100 100 100 100 100 100

Trichloroacetic acid 100 100 100 100 100 100

Trihalomethanes 100 100 100 100 100 100

Turbidity 100 100 100 100 100 100

Aluminium 100 100 100 100 100 100


Other water quality parameter resultsFluoride, arsenic, copper, lead, manganese, inorganic parameters, organic parametersThe following tables summarise the results of all the other parameters in our monitoring program that could pose a risk to human health. These parameters are measured against the ADWG criteria. Many of these parameters only require infrequent sampling because the results do not vary signifi cantly from year to year or from locality to locality for the same source water.

Specifi c results for arsenic, copper, lead and manganese have been shown not to change in Melbourne’s water. As such, South East Water has only taken random samples in groups of localiti es with similar source water to achieve the monitoring spread across our distributi on system in 2011–12.

Page 22 Water Quality Report 2011–12

South East Water att ained the Department of Health requirement for fl uoride that all individual results must not exceed 1.5mg/L and that the annual mean for each supply must not exceed 1.0 mg/L.

Fluoride is added to the water to improve dental health – a requirement of the Health (Fluoridati on) Act 1973.

Sampling frequency for fl uoride monitoring should be twice per week per fl uoridati on treatment plant. There are a number of fl uoridati on plants supplying water to South East Water’s area. Localiti es supplied from each fl uoridati on plant are listed in the table on page 8.

Fluoride results

Water sampling locality No. samples tested

Maximum mg/L

Minimum mg/L

Average mg/L

Complying (yes / no)


360 Balnarring 12 0.92 0.16 0.80 Yes

570 Bayswater 12 1.00 0.82 0.93 Yes

680 Beaumaris 12 0.88 0.74 0.84 Yes

581 Belgrave 12 1.00 0.77 0.93 Yes

310 Berwick 12 0.90 0.09 0.80 Yes

350 Bittern 12 0.87 0.52 0.82 Yes

670 Brighton / Heatherton 12 0.90 0.83 0.86 Yes

270 Bunyip 12 0.94 0.87 0.90 Yes

322 Carrum Downs 13 0.92 0.75 0.86 Yes

610 Caulfi eld 12 0.95 0.82 0.88 Yes

650 Chelsea 12 0.90 0.82 0.85 Yes

260 Cora Lynn 12 0.99 0.87 0.91 Yes

320 Cranbourne 12 0.91 0.07 0.79 Yes

640 Dandenong 12 0.91 0.58 0.83 Yes

660 Dandenong North 12 0.98 0.81 0.91 Yes

321 Devon Meadows 12 0.91 0.64 0.84 Yes

430 Dromana 12 0.96 0.84 0.88 Yes

580 Ferntree Gully 13 1.10 0.79 0.94 Yes

390 Frankston 12 0.93 0.69 0.85 Yes

400 Frankston South 12 0.88 0.75 0.84 Yes

271 Garfi eld 13 1.00 0.83 0.90 Yes

630 Hallam 12 0.97 0.55 0.84 Yes

340 Hastings 12 0.91 0.83 0.87 Yes

323 Karingal 12 0.88 0.55 0.81 Yes

300 Koo Wee Rup 11 0.92 0.81 0.88 Yes

450 Lang Lang 12 0.91 0.86 0.88 Yes

710 Moorooduc 13 0.90 0.83 0.86 Yes

690 Mordialloc 12 0.87 0.78 0.85 Yes

410 Mornington 13 0.88 0.83 0.86 Yes

420 Mount Martha 12 0.94 0.80 0.86 Yes

290 Pakenham 13 0.89 0.66 0.83 Yes

700 Rowville 13 0.96 0.79 0.87 Yes

440 Rye 12 0.90 0.82 0.86 Yes

370 Shoreham 12 0.99 0.82 0.86 Yes

330 Somerville 14 0.93 0.68 0.83 Yes

620 South Melbourne 13 0.94 0.84 0.87 Yes

280 Tynong 12 0.99 0.87 0.90 Yes

311 Upper Beaconsfi eld 12 0.89 0.60 0.84 Yes

590 Wantirna 12 1.00 0.11 0.86 Yes

Total 477 1.10 0.07 0.86 Yes


Drinking water supplied by South East Water complied with the ADWG health-related guideline value for arsenic of 0.01mg/L.

Arsenic is a naturally occurring element that can be introduced into water through the dissolution of minerals and ores (where it exists mainly in the sulphide form), or from industrial effluent and atmospheric deposition (through the burning of fossil fuels and waste incineration).

Arsenic

Water sampling locality No. samples

tested


results

Minimum mg/L

Average mg/L

Maximum mg/L



640 Dandenong 1 0 <0.001 <0.001 <0.001 Yes

321 Devon Meadows 1 0 <0.001 <0.001 <0.001 Yes

271 Garfield 1 0 <0.001 <0.001 <0.001 Yes

340 Hastings 1 0 <0.001 <0.001 <0.001 Yes

710 Moorooduc 1 0 <0.001 <0.001 <0.001 Yes

590 Wantirna 1 0 <0.001 <0.001 <0.001 Yes

Total 6 0 <0.001 <0.001 <0.001 Yes


Drinking water supplied by South East Water complied with the ADWG health-related guideline value for copper of 2mg/L.

Copper can occur naturally in catchments as it is widely distributed in rocks and soils as carbonate and sulphide minerals. Copper can cause the water to appear blue or green, which may stain appliances and clothing.

Copper


tested


results

Minimum mg/L

Average mg/L

Maximum mg/L



360 Balnarring 1 0 0.008 0.008 0.008 Yes

570 Bayswater 2 0 0.005 0.008 0.011 Yes

581 Belgrave 2 0 <0.001 0.002 0.004 Yes

310 Berwick 1 0 0.004 0.004 0.004 Yes

350 Bittern 1 0 0.004 0.004 0.004 Yes

610 Caulfield 1 0 0.011 0.011 0.011 Yes

650 Chelsea 1 0 0.007 0.007 0.007 Yes

260 Cora Lynn 1 0 0.023 0.023 0.023 Yes

640 Dandenong 1 0 0.008 0.008 0.008 Yes

660 Dandenong North 1 0 0.003 0.003 0.003 Yes

321 Devon Meadows 1 0 0.024 0.024 0.024 Yes

430 Dromana 1 0 0.005 0.005 0.005 Yes

580 Ferntree Gully 2 0 0.004 0.010 0.016 Yes

271 Garfield 1 0 0.004 0.004 0.004 Yes

340 Hastings 1 0 0.011 0.011 0.011 Yes

323 Karingal 1 0 0.023 0.023 0.023 Yes

300 Koo Wee Rup 1 0 0.004 0.004 0.004 Yes

450 Lang Lang 1 0 0.083 0.083 0.083 Yes

710 Moorooduc 1 0 0.033 0.033 0.033 Yes

690 Mordialloc 1 0 0.008 0.008 0.008 Yes

420 Mount Martha 1 0 0.006 0.006 0.006 Yes

440 Rye 1 0 0.002 0.002 0.002 Yes

370 Shoreham 1 0 0.002 0.002 0.002 Yes

330 Somerville 1 0 0.001 0.001 0.001 Yes

620 South Melbourne 2 0 0.011 0.025 0.039 Yes

590 Wantirna 3 0 0.003 0.004 0.005 Yes

Total 32 0 <0.001 0.012 0.083 Yes


Drinking water supplied by South East Water complied with the ADWG health-related guideline value for lead of 0.01mg/L.

Lead can be present in drinking water as a result of dissolution from natural sources or from household plumbing systems containing lead. The amount of lead dissolved will depend on a number of factors including pH, water hardness and the standing time of the water.

Lead


tested


results

Minimum mg/L

Average mg/L

Maximum mg/L



360 Balnarring 1 0 <0.001 <0.001 <0.001 Yes

570 Bayswater 2 0 <0.001 <0.001 <0.001 Yes

581 Belgrave 2 0 <0.001 <0.001 <0.001 Yes

310 Berwick 1 0 <0.001 <0.001 <0.001 Yes

350 Bittern 1 0 <0.001 <0.001 <0.001 Yes

610 Caulfield 1 0 <0.001 <0.001 <0.001 Yes

650 Chelsea 1 0 <0.001 <0.001 <0.001 Yes

260 Cora Lynn 1 0 0.002 0.002 0.002 Yes

640 Dandenong 1 0 <0.001 <0.001 <0.001 Yes

660 Dandenong North 1 0 <0.001 <0.001 <0.001 Yes

321 Devon Meadows 1 0 <0.001 <0.001 <0.001 Yes

430 Dromana 1 0 <0.001 <0.001 <0.001 Yes

580 Ferntree Gully 2 0 <0.001 <0.001 <0.001 Yes

271 Garfield 1 0 <0.001 <0.001 <0.001 Yes

340 Hastings 1 0 <0.001 <0.001 <0.001 Yes

323 Karingal 1 0 <0.001 <0.001 <0.001 Yes

300 Koo Wee Rup 1 0 <0.001 <0.001 <0.001 Yes

450 Lang Lang 1 0 <0.001 <0.001 <0.001 Yes

710 Moorooduc 1 0 0.003 0.003 0.003 Yes

690 Mordialloc 1 0 <0.001 <0.001 <0.001 Yes

420 Mount Martha 1 0 <0.001 <0.001 <0.001 Yes

440 Rye 1 0 <0.001 <0.001 <0.001 Yes

370 Shoreham 1 0 <0.001 <0.001 <0.001 Yes

330 Somerville 1 0 <0.001 <0.001 <0.001 Yes

620 South Melbourne 2 0 <0.001 <0.001 <0.001 Yes

590 Wantirna 3 0 <0.001 <0.001 <0.001 Yes

Total 32 0 <0.001 <0.001 0.003 Yes


Drinking water supplied by South East Water complied with the ADWG health-related guideline value for manganese of 0.5mg/L.

Manganese is naturally present in the environment in various states which are soluble in water. At concentrations exceeding 0.1mg/L, manganese imparts an undesirable taste to water and stains plumbing fixtures and laundry. All sample results were well below the ADWG limits.

Manganese


tested


results

Minimum mg/L

Average mg/L

Maximum mg/L



360 Balnarring 1 0 0.002 0.002 0.002 Yes

570 Bayswater 2 0 0.004 0.005 0.005 Yes

581 Belgrave 2 0 0.004 0.004 0.004 Yes

310 Berwick 1 0 0.007 0.007 0.007 Yes

350 Bittern 1 0 0.003 0.003 0.003 Yes

610 Caulfield 1 0 0.006 0.006 0.006 Yes

650 Chelsea 1 0 0.004 0.004 0.004 Yes

260 Cora Lynn 1 0 0.002 0.002 0.002 Yes

640 Dandenong 1 0 0.005 0.005 0.005 Yes

660 Dandenong North 1 0 0.005 0.005 0.005 Yes

321 Devon Meadows 1 0 0.007 0.007 0.007 Yes

430 Dromana 1 0 0.003 0.003 0.003 Yes

580 Ferntree Gully 2 0 0.004 0.005 0.006 Yes

271 Garfield 1 0 0.004 0.004 0.004 Yes

340 Hastings 1 0 0.006 0.006 0.006 Yes

323 Karingal 1 0 0.003 0.003 0.003 Yes

300 Koo Wee Rup 1 0 <0.001 <0.001 <0.001 Yes

450 Lang Lang 1 0 0.002 0.002 0.002 Yes

710 Moorooduc 1 0 0.008 0.008 0.008 Yes

690 Mordialloc 1 0 0.002 0.002 0.002 Yes

420 Mount Martha 1 0 0.002 0.002 0.002 Yes

440 Rye 1 0 0.002 0.002 0.002 Yes

370 Shoreham 1 0 0.002 0.002 0.002 Yes

330 Somerville 1 0 0.003 0.003 0.003 Yes

620 South Melbourne 2 0 0.004 0.006 0.007 Yes

590 Wantirna 3 0 0.005 0.006 0.006 Yes

Total 32 0 <0.001 0.004 0.008 Yes


The following tables summarise the results of all the other parameters in our monitoring program that could pose a risk to human health.

These parameters are measured against the ADWG criteria – if available (N/A indicates that a guideline value has not been set). For these parameters, the samples are taken randomly in groups of localities, rather than within each locality, to achieve the monitoring spread. All results are in mg/L unless otherwise indicated after the parameter name.

Inorganic parameters

Parameter No. samples tested

Minimum mg/L

Average mg/L

Maximum mg/L

ADWG value Complied with ADWG

Alkalinity 24 10 17 30 N/A N/A

Aluminium 315 <0.01 0.013 0.06 0.2 Yes

Ammonia 32 <0.002 0.003 0.007 0.5 Yes

Antinomy 14 <0.001 <0.001 <0.001 0.003 Yes

Arsenic 6 <0.001 <0.001 <0.001 0.01 Yes

Asbestos (fibres/mL) 14 <50 <50 <50 N/A N/A

Barium 6 0.008 0.011 0.014 2 Yes

Beryllium 6 <0.001 <0.001 <0.001 0.06 Yes

Boron 6 <0.02 <0.02 <0.02 4 Yes

Cadmium 9 <0.0002 <0.0002 <0.0002 0.002 Yes

Calcium 24 2.3 7.1 16 N/A N/A

Chloride 9 7 8 10 250 Yes

Chromium 9 <0.001 <0.001 <0.001 0.05 Yes

Copper 32 <0.001 0.012 0.083 2 Yes

Cyanide 6 <0.005 <0.005 0.009 0.08 Yes

Dissolved oxygen 32 5 9 11 N/A N/A

Electrical conductivity (uS/cm) 33 55 85 180 ~780 Yes

Hardness 24 9 23 49 200 Yes

Lead 32 <0.001 <0.001 0.003 0.01 Yes

Magnesium 24 0.7 1.3 2.4 N/A N/A

Manganese 32 <0.001 0.004 0.008 0.5 Yes

Mercury 6 <0.0001 <0.0001 <0.0001 <0.001 Yes

Molybdenum 6 <0.001 <0.001 <0.001 0.05 Yes

Nickel 9 <0.001 <0.001 <0.001 0.02 Yes

Nitrate 32 0.21 0.29 0.53 50 Yes

Nitrite 32 <0.002 <0.002 <0.002 3 Yes

Potassium 9 0.6 0.7 0.9 N/A N/A

Selenium 6 <0.001 <0.001 <0.001 0.01 Yes

Silica 9 5.8 6.4 7.1 80 Yes

Sodium 9 4.5 5.1 6.0 180 Yes

Sulphate 9 1.0 1.5 2.2 N/A N/A

Suspended solids 14 <2 <2 2 N/A N/A

Total dissolved solids 14 25 50 92 600 Yes

Total organic carbon 9 2 2 3 N/A N/A

Total phosphorus 9 <0.005 0.008 0.02 N/A N/A

Zinc 32 <0.001 0.005 0.051 3 Yes


Organic parametersParameter No. samples

testedMinimum

mg/LAverage

mg/LMaximum

mg/LADWG value Complied

with ADWG

Trihalomethanes

Dibromochloromethane 493 <0.001 0.002 0.013 0.25 mg/L Yes

Bromoform 493 <0.001 <0.001 <0.001 0.25 mg/L Yes

Dichlorobromomethane 493 0.005 0.013 0.037 0.25 mg/L Yes

Chloroform 493 0.024 0.055 0.13 0.25 mg/L Yes

Chlorophenols

2 chlorophenol 26 < 0.001 < 0.001 < 0.001 0.3 mg/L Yes

2,4 dichlorophenol 26 < 0.001 < 0.001 < 0.001 0.2 mg/L Yes

2,4,6 trichlorophenol 26 < 0.001 < 0.001 < 0.001 0.02 mg/L Yes

Pentachlorophenol 26 < 0.001 < 0.001 < 0.001 0.01 mg/L Yes

Pesticides

Aldrin 7 < 0.00001 < 0.00001 < 0.00001 0.0003 mg/L Yes

cis-Chlordane 7 < 0.00001 < 0.00001 < 0.00001 0.002 mg/L Yes

trans-Chlordane 7 < 0.00001 < 0.00001 < 0.00001 0.002 mg/L Yes

Dieldrin 7 < 0.00001 < 0.00001 < 0.00001 0.0003 mg/L Yes

Heptachlor epoxide 7 < 0.00005 < 0.00005 < 0.00005 0.0003 mg/L Yes

Heptachlor 7 < 0.00005 < 0.00005 < 0.00005 0.0003 mg/L Yes

Lindane 7 < 0.00005 < 0.00005 < 0.00005 0.01 mg/L Yes

Atrazine 7 < 0.01 < 0.01 < 0.01 0.02 mg/L Yes

DDT 7 < 0.00006 < 0.00006 < 0.00006 0.009 mg/L Yes

2,4-D 7 < 0.01 < 0.01 < 0.01 0.03 mg/L Yes

Volatile organic compounds

Benzene 26 <0.001 <0.001 <0.001 0.001 mg/L Yes

Carbon Tetrachloride 26 <0.001 <0.001 <0.001 0.003 mg/L Yes

Chlorobenzene 26 <0.001 <0.001 <0.001 0.3 mg/L Yes

1,2-dichlorobenzene 26 <0.001 <0.001 <0.001 1.5 mg/L Yes



1,1-dichloroethane 26 <0.001 <0.001 <0.001 N/A N/A

1,2-dichloroethane 26 <0.001 <0.001 <0.001 0.003 mg/L Yes

1,1-dichloroethene 26 <0.001 <0.001 <0.001 0.03 mg/L Yes

1,2-dichloroethene 26 <0.001 <0.001 <0.001 0.06 mg/L Yes

Methylene chloride 26 <0.001 <0.001 <0.001 0.004 mg/L Yes

Ethylbenzene 26 <0.001 <0.001 0.006 0.3 mg/L Yes

Styrene 26 <0.001 <0.001 <0.001 0.03 mg/L Yes

Tetrachloroethene 26 <0.001 <0.001 <0.001 0.05 mg/L Yes

Toluene 26 <0.001 <0.001 <0.001 0.8 mg/L Yes

Trichlorobenzenes 26 <0.001 <0.001 <0.001 0.03 mg/L Yes

Xylene 26 <0.002 <0.002 <0.005 0.6 mg/L Yes

Polycyclic aromatic hydrocarbons

Benzo(a)pyrene 11 <0.000002 <0.000002 <0.000002 0.00001 mg/L Yes


Aesthetic water quality resultsColour, pH, iron and chlorineAestheti c quality of the drinking water supplied by South East Water is assessed against the criteria in the ADWG.


South East Water met the ADWG criteria for colour, which suggests a ‘true’ colour of 15 Hazen Units (HU), with an upper limit of 25 HU permissible so long as eff ecti ve disinfecti on can be maintained.

Colour is caused by dissolved organic matt er (humic and fulvic acids), which originate from the soils and decaying vegetati on from the catchments. There are two ways to measure colour: ‘true’ colour is measured aft er fi ltering the water to remove the parti culate matt er (turbidity), and ‘apparent’ colour is measured without fi ltrati on and is more like what our customers see. South East Water uses apparent colour with 25 HU as the limit.

Colour (apparent) results


sampling

No. samples

tested

Minimum HU

Average HU

Maximum HU

Complying* (yes / no)Locality no. Locality name

360 Balnarring Fortnightly 26 2 4 8 Yes

570 Bayswater Fortnightly 26 4 7 12 Yes

680 Beaumaris Fortnightly 26 4 5 8 Yes

581 Belgrave Fortnightly 26 4 7 16 Yes

310 Berwick Fortnightly 26 2 5 8 Yes

350 Bittern Fortnightly 26 2 5 8 Yes

670 Brighton / Heatherton Fortnightly 26 2 7 66 Yes

270 Bunyip Fortnightly 26 <2 2 6 Yes

322 Carrum Downs Fortnightly 26 2 5 8 Yes

610 Caulfi eld Fortnightly 26 4 7 10 Yes

650 Chelsea Fortnightly 26 4 5 8 Yes

260 Cora Lynn Fortnightly 26 <2 3 8 Yes

320 Cranbourne Fortnightly 26 2 8 80 Yes

640 Dandenong Fortnightly 26 2 5 10 Yes

660 Dandenong North Fortnightly 26 4 8 14 Yes

321 Devon Meadows Fortnightly 26 2 5 8 Yes

430 Dromana Fortnightly 26 <2 3 6 Yes

580 Ferntree Gully Fortnightly 26 4 8 10 Yes

390 Frankston Fortnightly 26 2 5 10 Yes

400 Frankston South Fortnightly 26 2 4 8 Yes

271 Garfi eld Fortnightly 26 <2 2 6 Yes

630 Hallam Fortnightly 26 2 5 8 Yes

340 Hastings Fortnightly 26 <2 4 8 Yes

323 Karingal Fortnightly 26 2 5 8 Yes

300 Koo Wee Rup Fortnightly 26 <2 2 6 Yes

450 Lang Lang Fortnightly 26 <2 3 24 Yes

710 Moorooduc Fortnightly 26 <2 3 8 Yes

690 Mordialloc Fortnightly 26 4 5 8 Yes

410 Mornington Fortnightly 26 <2 3 8 Yes

420 Mount Martha Fortnightly 26 <2 3 8 Yes

290 Pakenham Fortnightly 26 2 5 10 Yes

700 Rowville Fortnightly 26 2 5 10 Yes

440 Rye Fortnightly 26 <2 3 6 Yes

370 Shoreham Fortnightly 26 2 5 8 Yes

330 Somerville Fortnightly 26 2 5 10 Yes

620 South Melbourne Fortnightly 26 4 7 10 Yes

280 Tynong Fortnightly 26 <2 2 6 Yes

311 Upper Beaconsfi eld Fortnightly 26 4 5 10 Yes

590 Wantirna Fortnightly 26 4 7 10 Yes

Total 1014 <2 5 80 Yes

*Compliance with the ADWG means the upper bound of the 95 per cent confi dence interval of the mean is less than the guideline value.


South East Water met the ADWG criteria for pH, which suggests a pH range of 6.5 to 8.5 and up to 9.2 for areas where new cement-lined pipes are present. Cement-lined pipes are common in our service area.

pH is a measure of the acidic or alkaline nature of the water.

pH results


No. samples

tested

Minimum (units)

Average (units)

Maximum (units)

Complying* (yes / no)


360 Balnarring Fortnightly 26 7.2 7.8 9.3 Yes

570 Bayswater Fortnightly 26 7.0 7.6 9.2 Yes

680 Beaumaris Fortnightly 26 7.0 7.2 7.5 Yes

581 Belgrave Fortnightly 26 6.7 7.8 9.4 Yes

310 Berwick Fortnightly 26 6.9 7.3 8.8 Yes

350 Bittern Fortnightly 26 7.2 7.8 9.0 Yes

670 Brighton / Heatherton Fortnightly 26 7.0 7.2 7.5 Yes

270 Bunyip Fortnightly 26 7.1 7.4 7.6 Yes

322 Carrum Downs Fortnightly 26 7.0 7.2 7.5 Yes

610 Caulfield Fortnightly 26 7.0 7.3 7.4 Yes

650 Chelsea Fortnightly 26 6.8 7.4 9.0 Yes

260 Cora Lynn Fortnightly 26 7.1 7.4 7.6 Yes

320 Cranbourne Fortnightly 26 6.7 7.2 8.0 Yes

640 Dandenong Fortnightly 26 7.0 7.3 8.0 Yes

660 Dandenong North Fortnightly 26 7.1 7.6 8.6 Yes

321 Devon Meadows Fortnightly 26 7.0 7.3 7.7 Yes

430 Dromana Fortnightly 26 7.2 7.6 8.1 Yes

580 Ferntree Gully Fortnightly 26 7.3 7.6 8.6 Yes

390 Frankston Fortnightly 26 6.8 7.3 8.1 Yes

400 Frankston South Fortnightly 26 7.0 7.4 7.7 Yes

271 Garfield Fortnightly 26 7.2 7.4 7.5 Yes

630 Hallam Fortnightly 26 7.0 7.6 9.4 Yes

340 Hastings Fortnightly 26 7.1 7.4 8 Yes

323 Karingal Fortnightly 26 7.1 7.3 7.6 Yes

300 Koo Wee Rup Fortnightly 26 6.9 7.5 8.1 Yes

450 Lang Lang Fortnightly 26 7.0 7.5 7.7 Yes

710 Moorooduc Fortnightly 26 6.9 7.4 7.6 Yes

690 Mordialloc Fortnightly 26 7.0 7.4 7.9 Yes

410 Mornington Fortnightly 26 7.2 7.5 7.9 Yes

420 Mount Martha Fortnightly 26 7.4 7.9 9.3 Yes

290 Pakenham Fortnightly 26 6.8 7.3 8.6 Yes

700 Rowville Fortnightly 26 6.9 7.4 7.9 Yes

440 Rye Fortnightly 26 7.4 8.2 9.3 Yes

370 Shoreham Fortnightly 26 7.5 8.6 9.4 Yes

330 Somerville Fortnightly 26 6.9 7.2 7.5 Yes

620 South Melbourne Fortnightly 26 6.9 7.2 7.7 Yes

280 Tynong Fortnightly 26 7.3 7.4 7.6 Yes

311 Upper Beaconsfield Fortnightly 26 7.3 7.8 8.9 Yes

590 Wantirna Fortnightly 26 7.1 7.6 9.0 Yes

Total 1014 6.7 7.5 9.4 Yes

* Compliance with the ADWG means the upper bound of the 95 per cent confidence interval of the mean is less than the guideline value.


South East Water met the ADWG criteria for iron, which suggests an aesthetic limit of 0.3mg/L.

Iron can occur naturally in the water from the catchment area soils. Iron can discolour the water and cause staining problems for plumbing fixtures and laundry.

Iron results


No. samples

tested

Minimum mg/L

Average mg/L

Maximum mg/L



360 Balnarring Fortnightly 26 0.03 0.06 0.11 Yes

570 Bayswater Fortnightly 26 <0.01 0.07 0.09 Yes

680 Beaumaris Fortnightly 26 0.04 0.07 0.12 Yes

581 Belgrave Fortnightly 26 0.06 0.07 0.14 Yes

310 Berwick Fortnightly 26 0.04 0.07 0.10 Yes

350 Bittern Fortnightly 26 0.04 0.07 0.11 Yes

670 Brighton / Heatherton Fortnightly 26 0.04 0.07 0.12 Yes

270 Bunyip Fortnightly 26 <0.01 0.02 0.09 Yes

322 Carrum Downs Fortnightly 26 0.04 0.07 0.10 Yes

610 Caulfield Fortnightly 26 0.05 0.07 0.10 Yes

650 Chelsea Fortnightly 26 <0.01 0.07 0.12 Yes

260 Cora Lynn Fortnightly 26 <0.01 0.03 0.12 Yes

320 Cranbourne Fortnightly 26 0.02 0.10 0.84 Yes

640 Dandenong Fortnightly 26 0.04 0.07 0.11 Yes

660 Dandenong North Fortnightly 26 0.05 0.07 0.16 Yes

321 Devon Meadows Fortnightly 26 0.02 0.07 0.12 Yes

430 Dromana Fortnightly 26 0.02 0.05 0.10 Yes

580 Ferntree Gully Fortnightly 26 0.06 0.07 0.09 Yes

390 Frankston Fortnightly 26 0.03 0.08 0.28 Yes

400 Frankston South Fortnightly 26 0.04 0.07 0.11 Yes

271 Garfield Fortnightly 26 <0.01 0.02 0.08 Yes

630 Hallam Fortnightly 26 0.04 0.07 0.10 Yes

340 Hastings Fortnightly 26 0.03 0.06 0.11 Yes

323 Karingal Fortnightly 26 0.04 0.07 0.11 Yes

300 Koo Wee Rup Fortnightly 26 <0.01 0.03 0.10 Yes

450 Lang Lang Fortnightly 26 <0.01 0.04 0.23 Yes

710 Moorooduc Fortnightly 26 0.02 0.05 0.11 Yes

690 Mordialloc Fortnightly 26 0.04 0.07 0.10 Yes

410 Mornington Fortnightly 26 0.02 0.05 0.10 Yes

420 Mount Martha Fortnightly 26 0.02 0.05 0.11 Yes

290 Pakenham Fortnightly 26 0.04 0.07 0.11 Yes

700 Rowville Fortnightly 26 0.03 0.07 0.10 Yes

440 Rye Fortnightly 26 0.01 0.05 0.11 Yes

370 Shoreham Fortnightly 26 0.04 0.07 0.11 Yes

330 Somerville Fortnightly 26 0.04 0.07 0.11 Yes

620 South Melbourne Fortnightly 26 0.05 0.07 0.10 Yes

280 Tynong Fortnightly 26 <0.01 0.02 0.09 Yes

311 Upper Beaconsfield Fortnightly 26 <0.01 0.07 0.11 Yes

590 Wantirna Fortnightly 26 0.05 0.07 0.09 Yes

Total 1014 <0.01 0.06 0.84 Yes


South East Water met the ADWG criteria for chlorine, which suggests a health limit of 5 mg/L. Less than 2 mg/L is added to drinking water at any point in our network. The fundamental requirement is to maintain effective disinfection. Chlorine levels are higher in the water sampling localities that are closer to where the treatment occurs as chlorine levels gradually decline over time.

Chorine is the primary disinfectant used in Melbourne’s water supply. Chlorine is added to destroy any harmful micro-organisms, such as pathogenic bacteria. It is measured as ‘free chlorine residual’.

Chlorine results


No. samples

tested

Minimum mg/L

Average mg/L

Maximum mg/L



360 Balnarring Weekly 104 <0.01 0.19 0.59 Yes

570 Bayswater Weekly 213 <0.01 0.09 0.52 Yes

680 Beaumaris Weekly 121 0.01 0.11 0.39 Yes

581 Belgrave Weekly 104 <0.01 0.13 0.73 Yes

310 Berwick Weekly 250 <0.01 0.42 1.20 Yes

350 Bittern Weekly 104 <0.01 0.16 1.00 Yes

670 Brighton / Heatherton Daily 470 <0.01 0.13 0.53 Yes

270 Bunyip Weekly 104 0.01 0.17 0.56 Yes

322 Carrum Downs Weekly 105 <0.01 0.28 0.71 Yes

610 Caulfield Daily 406 <0.01 0.07 0.72 Yes

650 Chelsea Weekly 170 0.01 0.21 0.55 Yes

260 Cora Lynn Weekly 105 <0.01 0.04 0.35 Yes

320 Cranbourne Weekly 131 0.01 0.26 0.65 Yes

640 Dandenong Daily 329 <0.01 0.18 0.61 Yes

660 Dandenong North Weekly 104 <0.01 0.04 0.17 Yes

321 Devon Meadows Weekly 104 <0.01 0.15 0.51 Yes

430 Dromana Weekly 120 <0.01 0.34 0.79 Yes

580 Ferntree Gully Weekly 104 <0.01 0.09 0.50 Yes

390 Frankston Weekly 262 <0.01 0.32 0.70 Yes

400 Frankston South Weekly 104 <0.01 0.24 0.78 Yes

271 Garfield Weekly 104 0.02 0.38 0.72 Yes

630 Hallam Weekly 210 <0.01 0.28 0.99 Yes

340 Hastings Weekly 104 <0.01 0.32 1.20 Yes

323 Karingal Weekly 104 0.01 0.16 0.66 Yes

300 Koo Wee Rup Weekly 104 <0.01 0.35 0.78 Yes

450 Lang Lang Weekly 104 <0.01 0.23 0.59 Yes

710 Moorooduc Weekly 105 0.01 0.50 0.91 Yes

690 Mordialloc Weekly 118 <0.01 0.04 0.25 Yes

410 Mornington Weekly 143 0.01 0.20 0.57 Yes

420 Mount Martha Weekly 104 <0.01 0.16 0.69 Yes

290 Pakenham Weekly 106 0.01 0.27 0.61 Yes

700 Rowville Weekly 119 <0.01 0.42 0.88 Yes

440 Rye Weekly 247 <0.01 0.44 0.87 Yes

370 Shoreham Weekly 104 <0.01 0.19 0.57 Yes

330 Somerville Weekly 104 <0.01 0.14 0.72 Yes

620 South Melbourne Daily 392 0.01 0.10 0.37 Yes

280 Tynong Weekly 104 0.01 0.22 0.59 Yes

311 Upper Beaconsfield Weekly 104 <0.01 0.06 0.34 Yes

590 Wantirna Weekly 106 <0.01 0.16 0.56 Yes

Total 6100 <0.01 0.21 1.20 Yes


Section 22 of the Act requires South East Water to notify the Department of Health in instances where we suspect contamination of our drinking water that may pose possible health risks. This includes non-compliant laboratory test results related to any Department of Health standards or reporting requirements or events where there are widespread customer complaints about water quality.

This financial year we had seven events where the Department of Health was notified in relation to Section 22 of the Act. Four of these events involved the detection of E. coli – an organism that may not directly represent a hazard to human health but can indicate the presence of recent faecal contamination. The three remaining events involved: the failure of a backflow device causing potential for contaminated water; a non-routine sample returning an elevated nickel level, which breached the ADWG limit due to a corroded meter; and potential contaminated water due to a spill of hydrocarbons on the soil surrounding a customer’s service and water main. South East Water was not required to issue a boiled water notice for any of these events.

In all cases where E. coli is detected, the standard response involves:

1. Check primary and secondary disinfection plants.

2. Check for changes in source water.

3. Confirm the integrity of the reticulation system to point of detection.

4. Check for any changes to upstream system operation.

5. Check for any water mains works such as bursts in neighbouring streets.

6. Resample at the same site and another nearby site and take a sample at an upstream source, if appropriate.

7. If the resample is clear, take no further action.

8. If the resample is not clear of E. coli, undertake further investigation.

The first event was due to failure of a backflow device at a property in Macgregor Avenue, Portsea, which was detected by South East Water’s plumbing group on 1 October 2011. The property in question was connected to a pumped bore that was cross-connected into the potable water system. The backflow device on the meter had failed, causing the meter to go backwards. The bore was disconnected immediately. Field testing and hydraulic investigation confirmed the possible contamination would be restricted to the street. Pipes in the street were flushed

and samples were then taken from nearby routine sample taps, from garden taps at the start of the street and from a hydrant at the end of the street near the property in question. A positive detection for E. coli and coliforms was returned from the sample at the end of the street, while all others were free of E. coli and coliforms. It is believed the positive detection may have been due to sampling from a hydrant, which is not standard sampling practice. Irrespective of this, pipes in the street were flushed again and resampled. All resamples were free of E. coli and coliforms.

The second event was a detection of E. coli from a routine sample taken in Separation Street, Mornington on 2 December 2011. 1 organism per 100mL was detected, and the free chlorine residual at the site of the detection was 0.01 mg/L. This sample tap falls in the Mornington locality. Another sample taken in Mornington on the same day was free of E. coli. The area was flushed and all system checks were clear. Resamples were taken the following day from the sample tap in question and two nearby sample taps. All follow-up samples were free from E. coli.

The third event was a detection of E. coli from a routine sample taken in Claude Street, Bayswater on 21 March 2012. 1 organism per 100mL was detected, and the free chlorine residual at the site of the detection was 0.24 mg/L. This sample tap falls within the Bayswater locality and is supplied by the Boronia tank. The area was flushed and all system checks were clear. Resamples were taken the following day from the sample tap in question and two nearby sample taps, and all were free of E. coli.

The fourth event was a detection of E. coli from a routine sample taken in Banksia Square in Somers on 26 March 2012. 3 organisms per 100mL were detected, and the free chlorine residual at the site of the detection was <0.01 mg/L. This sample tap falls within the Balnarring locality and is supplied by the Somers tank, which provides backup supply to a small area. The area was chlorinated and flushed and all system checks were clear. The Somers tank was left offline as it was suspected that the tank was the cause of the detection due to the very low turnover in the tank. Resamples were taken the following day from the sample tap in question and two nearby sample taps and all were free of E. coli. The Somers tank was also sampled and it returned a positive detection, showing the contamination was from the tank. The tank was subsequently drained, cleaned and chlorinated. The tank was left offline, although it continued to be sampled routinely to ensure its safe use in case of emergency.

The fifth event was a detection of E. coli from a routine sample taken in Willow Road, East Frankston on 3 May 2012. 5 organisms per 100mL were detected, and the free chlorine residual at the site of the detection was 0.47 mg/L. This sample tap falls in the Karingal locality. The sample tap is the detention point from the East

Regulatory notifications to the Department of Health


Frankston secondary chlorinator on the outlet of the East Frankston tank. The area was flushed and all system checks were clear, including the chlorinator operation. Resamples were taken the following day from the sample tap in question, two nearby sample taps and the East Frankston tank, and all were free from E. coli.

The sixth event was a high nickel result of 0.036mg/L from a non-routine sample on 31 May 2012 from a sample tap at McDonalds Drain Road at the off-take meter for a private extension. This sample tap is located in the Cora Lynn water quality locality. The sample tap was located on the meter and the customer had not been taking water for several months. The lack of turnover of water through the meter caused corrosion, which subsequently resulted in elevated metal concentrations. The elevated concentrations were restricted to the small volume of water contained in the meter. Nickel was the only result that exceeded ADWG. The elevated metals were reduced by flushing, but to prevent this from occurring in the future, the meter was replaced. The sample tap was also relocated to a more suitable location as this location did not allow for representative sampling of the water in the main due to low turnover.

The seventh event involved potentially contaminated water in Narre Warren, in the Berwick locality. On 19 June 2012, a customer from Wombat Court, Narre Warren complained of a slight petrochemical odour to the water. The issue was investigated on 20 June 2012 and it was determined that the odour was due to new polyethylene piping that was supplying the service. The customer was immediately connected to a temporary water supply. The service was scheduled for replacement on 22 June 2012. On excavating the PVC main and service it was found that a large volume of hydrocarbons had been illegally spilt on the nature strip, and had leached down to the water main and service. The customer’s service was replaced in copper and all contaminated soil was removed and disposed of. Testing of the soil determined the contaminant was likely to be mineral turpentine. Plastic pipe work used in water mains are not designed for use in environments with elevated hydrocarbons as it causes degradation of the plastic and the hydrocarbon may leach through the piping.


South East Water’s drinking water network was not significantly affected by the floods that occurred in the 2011–12 reporting year. Although some areas received significant rainfall during 2011–12, none of our assets were compromised and the water quality throughout our network was maintained. The catchments, which are managed by Melbourne Water, received significant rainfall and storage levels increased considerably. Melbourne Water managed the increased storage levels well and there were no impacts on the quality of the water in our network.

South East Water had two events that did not require notification to the Department of Health but the Department was kept informed.

The first event occurred on 4 November 2011. A sample taken from a routine sample tap in Boormani Court in Koo Wee Rup returned a positive E. coli result of 50 organisms per 100 mL, and the free chlorine residual at the site of the detection was 0.01mg/L. The court was flushed as per the normal E. coli response procedure and all resamples were free from E. coli with the event being reported as a Section 22 notification. When the rest of the results were submitted later that month, it was discovered the chemical results did not match the water quality in the Koo Wee Rup network. Fluoride was very low and disinfection by-products were also unusually low.

Given the fact that all water that is supplied to customers is disinfected, low levels of disinfection by-products are always present. Further investigation revealed the backflow device in the meter had failed and allowed the sample tap to be supplied from the customer’s rain water tank. The tank had been improperly connected, via a pump, to the customer’s internal drinking water. The stop tap at this site was shut, preventing the rainwater from entering South East Water’s system. As it could be proven the sample was not taken from the water supplied by South East Water, the results from the sample taken on 4 November 2011, including the E. coli detection and subsequent Section 22 notification, were dismissed by the Department of Health. This resulted in one less aluminium result being reported in the table on page 23 for the Koo Wee Rup locality in 2011–12.

As a result of this event and the backflow failure event in Portsea that required a Section 22 notification, South East Water, in collaboration with the Plumbing Industry Commission and the Department of Health, communicated with customers, the public and the plumbing industry to ensure they understood the risks

and requirements for installing rain water and bore water supplies. South East Water also conducted audits on low risk backflow devices on customers’ meters and audits on tank installations to determine the number that meet the requirements of the plumbing code.

The second event involved the contamination of a private extension by sewage from a private sewer main. On 11 April 2012, a contractor working on a customer’s property in Keysborough damaged a private extension. The burst was called in to South East Water. The asset did not belong to South East Water and South East Water was not responsible for the quality of water in the main. Despite this, it was determined South East Water was in the best position to repair the main. During the repair, it became clear that the private pressure sewer was also damaged when the excavation began filling with sewage after the sewer pump was turned on. All customers were immediately disconnected from the private extension by removing the meters and the private extension was also isolated from South East Water’s supplying main. Customers requiring potable water were supplied with potable water tanks. The private sewer and the private extension were repaired. The main was then flushed extensively and super-chlorinated. Samples were taken for testing to ensure there were no microbial contaminants in the water main and that chlorine was present but within the required limits. Once the results confirmed the water in the main was safe for consumption, the customers were reconnected to the private extension.

Other incidents and noteworthy events


Our water quality complaints remained below the ESC target (0.28 per 100 properties), with our yearly result being 0.20 per 100 properties. This result is the same as for 2010 –11, but it is higher than historical results due to an increase in discoloured water complaints. All other complaints have remained at similar levels.A summary of all water quality complaints is shown in the table below.

Type of complaint No. of complaints

No. of complaints per 100 customers supplied

Discoloured water 1076 0.16

Taste and odour 136 0.02

Blue water 13 0.002

Air in water 46 0.007

Alleged Illness 10 0.001

Other 49 0.007

Total 1330 0.20

We managed complaints by:

> preventing and responding to water quality complaints in a timely manner

> maintaining a fully closed system

> working closely with our wholesaler, Melbourne Water, to ensure all major construction works had minimal impact on water quality

> using secondary chlorinators for low level secondary disinfection to improve taste and odour and overall system maintenance

> using COLT units at key locations around our system, along with an automatic alerting system and analyser to determine a drift in trends

> using a water quality alert system to provide early warnings of potential incidents

> ensuring all new mains are swabbed, flushed and chlorinated where required, and tested for a number of key water quality parameters by an independent laboratory so that we start with a clean asset before connections are made.

South East Water is committed to ensuring all complaints are dealt with in an appropriate and timely manner. As such, all customer complaints about water quality are handled by dedicated and highly trained call centre employees. In all instances, the nature of the complaint determines our response, ranging from detailed investigative work to providing technical information. Our trained field employees can respond to customer complaints with appropriate knowledge and skills to ensure customer satisfaction.

Discoloured water complaintsThe majority of water quality complaints received during 2011–12 for discoloured water were attributed to an increase in the flow of water through the main, or a reversal of the flow direction within the main. This can disturb the fine sediment material from the source water, which can settle in the main during periods of low flow. A change of the flow in the main can then resuspend sediment and cause discoloured water. Low demand and slightly higher sediment loads entering the system, coupled with the suspension of routine mains cleaning during the drought to conserve water, have resulted in increased levels of settled sediment in the system. The majority of discoloured water complaints are due to emergency works and it is anticipated that this level of complaints may continue in the near future.

South East Water works hard to meet the needs and expectations of our customers and engage with our community. When we receive complaints relating to a burst or damaged water main, we respond by communicating why the water is dirty and how we will fix the problem. We also record the customers’ details and ask that they please be patient while we repair the burst and allow the suspended sediment to resettle in the main. If the water does not resettle overnight, we respond by flushing the water that still remains discoloured, usually targeting dead end streets.

Taste and odour complaintsThe taste and odour complaints we receive are usually related to chlorine and can vary with seasonal water demands and the location of the customer’s property in relation to the disinfection plant. The chlorination process can lead to objectionable, yet harmless, tastes and odours. This can occur with colder water temperatures in winter, which allows the chlorine residual to persist for longer periods, or with high flows in summer, which allows the chlorine to reach the customer sooner. Very low levels of chlorine can also cause noticeable tastes and odours if it reacts with organic matter present in the pipe.

Chlorine has been used effectively around the world for more than one hundred years as part of the water treatment process and the amount of chlorine added is minimal. It is not yet possible to accurately predict the occurrence of taste and odour problems, but once reported by customers, or detected by our employees, we investigate the issue to devise a prompt resolution.

Responding to our customers


Blue waterBlue water is caused by the release of high concentrations of copper into water passing through copper pipe, resulting in the water becoming a blue colour. Virtually all blue water related complaints received in 2011–12 were associated with corrosion of the copper pipe within a customer’s property. South East Water undertakes investigation of these complaints where necessary, and we provide our customers with up-to-date information on this issue.

Alleged illness complaintsAlleged illness complaints are received from customers who suspect their water may be associated with an illness they are experiencing. We investigate each complaint relating to alleged illness from our water quality with care and concern, inviting the Department of Health to assist where appropriate.

During 2011–12 there were no confirmed cases of illness arising from our water supply system.

Other complaintsOther water quality complaints received were either from industrial customers seeking information on water quality issues that could affect their processes (e.g. pH and conductivity), or residential customers with enquiries about water quality such as blackening of kettles and issues with aquariums. We produce a number of information sheets that cover numerous topics to help our customers understand water quality. This information, along with commonly asked questions, is now available on our website for customers to access.

Water quality websiteThis year, South East Water developed a water quality website that details the most recent results from all of the sampling taps throughout our network. These results are usually published within 24 hours after South East Water receives them.

The website uses a map-based program where customers can search for an address and access the most recent result from sample taps in the area. It also provides a rolling 12 month summary of the data for the entire South East Water network and each water quality locality, and it shows the parameter’s compliance against the Australian Drinking Water Guidelines.

Customers can also use the website to easily determine where their water is supplied from, what chemicals it has been treated with and the treatment process the water has undergone. An informative water quality glossary on the parameters that are tested, the limits for those parameters, why they are tested and if they are required to comply with the regulations is also available.

Customers can view the water quality website at sew.com.au/waterquality


Appendix - Certifi cate of Audit


Glossary/acronymsADWG Australian Drinking Water Guidelines 2011*

COLT Continuous On-Line Testing

E. coli Escherichia coli

ESC Essential Services Commission

HACCP Hazard Analysis and Critical Control Point

HU Hazen Units

mg/L Milligrams per litre

mL Millilitres

NTU Nephelometric Turbidity Units

PIC Plumbing Industry Commission

SDWA Safe Drinking Water Act 2003 (the Act)

SDWR Safe Drinking Water Regulations 2005 (the Regulations)

UCL Upper Confidence Limit

WTP Water Treatment Plant

Primary disinfection refers to the initial disinfection treatment before water is supplied to customers, usually when water leaves an open storage such as Cardinia Reservoir.

Secondary disinfection refers to additional, or booster, disinfection treatment within the distribution system, usually a long time after primary disinfection. For example, secondary disinfection occurs towards the end of the distribution system where the residual from the primary disinfection has diminished.

* The Australian Drinking Water Guidelines 2011 is freely available at the following webpage: www.nhmrc.gov.au/publications/synopses/eh19syn.htm

This report has been printed on 100% and 70% (cover) recycled, carbon neutral paper by a waterless printer.

20 Corporate Drive Heatherton VIC 3202 Locked Bag 1 Moorabbin VIC 3189 Australia

Telephone (03) 9552 3000 Facsimile (03) 9552 3001 [email protected] southeastwater.com.au/enquiries

For a full suite of South East Water’s corporate reports, visit southeastwater.com.au

South East Water Corporation ABN 89 066 902 547

annual drinking water quality report - south east...

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