Annual Drinking Water Quality Report

Annual Drinking Water Quality Report 2011–12

Company statistics 1.6 million population serviced

39 water sampling localities

669,953 water customers

67 water storage facilities

8,951 km of water mains

21 secondary disinfection plants

80 pump stations

Contents Managing 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 notifications to the Department of Health .............................................35 Other incidents and noteworthy events ...................................................................37 Responding to our customers................................................................................... 38 Appendix - Certificate of Audit ................................................................................................40 Glossary/acronyms .................................................................................................... 41

Managing Director’s message At 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:

>> 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.

>> 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.

Page 2 Annual Drinking Water Quality Report 2011–12

Kevin Hutchings Managing Director October 2012

South East Water’s supply system South 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-ofthe-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 locality Our 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

570

570 580

590

610

581

700 670

660

680 690

311

640 630 650

310 280 271

290 322

Port Phillip Bay

270 320 260

323

400

321

390

300 330

410

Western Port 420

340

710 430

350 360

440 370

Page 6

Bass Strait

450

Water sampling locality number

Water sampling locality name

Towns/suburbs supplied

360

Balnarring

Balnarring, Bittern, Merricks, Merricks Beach, Somers

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

Population 6,248

68,085

350

Bittern

Bittern, Bittern West, Crib Point, HMAS Cerberus

670

BrightonHeatherton

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

6,558

270

Bunyip

Bunyip, Longwarry

322

Carrum Downs

Carrum Downs, Sandhurst, Skye

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

650

Chelsea

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

260

Cora Lynn

Bunyip, Koo Wee Rup, Nar Nar Goon, Tooradin

320

Cranbourne

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

640

Dandenong

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

119,083 25,384

202,947

4,112 28,101

660

Dandenong North

Clayton, Dandenong North, Noble Park North, Springvale

321

Devon Meadows

Clyde, Fiveways, Blind Bight, Cannons Creek, Cranbourne, Tooradin, Warneet

430

Dromana

Dromana, McCrae, Mt Martha, Safety Beach

169,065

49,035 103 57,197

6,016 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 15,935

400

Frankston South

Baxter, Frankston, Frankston South, Mt.Eliza

271

Garfield

Garfield, Garfield North

630

Hallam

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

340

Hastings

Bittern, Hastings

11,552

323

Karingal

Frankston

10,953

1,278 97,370

300

Koo Wee Rup

Koo Wee Rup

2,513

450

Lang Lang

Lang Lang

1,496

710

Moorooduc

Dromana, Moorooduc, Tuerong

690

Mordialloc

Braeside, Dingley Village, Mentone, Mordialloc, Parkdale, Waterways

31,740

504

410

Mornington

Mt Eliza, Mornington, Mt Martha, Osborne

45,005

420

Mount Martha

Mount Martha

290

Pakenham

Pakenham

8,559 39,883

700

Rowville

Lysterfield, Rowville

440

Rye

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

31,526

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

280

Tynong

Nar Nar Goon, Nar Nar Goon North, Tynong

311

Upper Beaconsfield

Beaconsfield, Guys Hill, Officer, Upper Beaconsfield,

590

Wantirna

Knoxfield, Scoresby, Wantirna, Wantirna South

80,550

196,789 657 3,037 22,797


Treatment processes across localities The water sampling localities are shown below:

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 chlorine fluoride, lime

320, 321, 323, 330, 390, 400

Cardinia Reservoir and WTP; Tarago Reservoir and WTP with localised secondary disinfection


Alum, polyelectrolyte, gaseous chlorine fluoride, lime, sodium hypochlorite

260#

Tarago Reservoir and WTP


Alum, polyelectrolyte, gaseous chlorine fluoride, 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 chlorine fluoride, lime, sodium hypochlorite, carbon dioxide

580

Silvan Reservoir and WTP



610, 620^

Cardinia Reservoir and WTP; Silvan Reservoir and WTP; Sugarloaf Reservoir and Winneke WTP

Filtration, primary disinfection, fluoridation, pH correction

Alum, polyelectrolyte, gaseous chlorine fluoride, lime

570, 581, 590

Silvan Reservoir and WTP with localised secondary disinfection


Gaseous chlorine fluoride, lime, sodium hypochlorite

660 and 670 **

Cardinia Reservoir and WTP; Silvan Reservoir and WTP



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 supply Water quality risk management We 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.

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 Plan South 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 Plan In 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 periods Procedures 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

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.


Managing our water supply Zero and inadequate disinfection events document The 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 program The water main renewal program was developed inhouse 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 program The 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 system South 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 agent The 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 Testing The 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 notification To 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 water South 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.

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 quality In 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 2011–12 The 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 routine samples taken at customer taps. It excludes any results from resamples and samples taken at water storage reservoirs, pressure reducing stations and large water mains. Tables are provided for:

Page 13

Drinking water quality standards

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

Page 22

Other water quality parameter results

Including fluoride, arsenic, copper, lead, manganese, inorganic parameters and organic parameters.

Page 30

Aesthetic water quality results

Colour, pH, iron and chlorine.


Drinking water quality standards Escherichia coli (E. coli), disinfection by-products – chloroacetic acid, dichloroacetic acid, trichloroacetic acid and trihalomethanes – turbidity and aluminium

Water Quality Report 2011–12 Page 13

Escherichia coli (E. coli) results 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. Water sampling locality

Frequency of sampling

No. of samples

No. of samples containing E. coli

Max. 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.


Chlorine-based disinfection by-product chemicals 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.

Chloroacetic acid results

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. Water sampling locality

Frequency of sampling

No. of samples

No. of noncomplying samples

Maximum mg/L

Complying (yes/no)

Locality no.

Locality name

360

Balnarring

Monthly

12

0