REC-19-030 4.4 Mapoon ASC DWQMP (2) · 18QU39-REC-19-030-4.4 4 June 2019 The capacity of the bores is regularly challenged by demand, and Council will be installing an additional

Drinking  Water  Quality  Management  Plan  

Service  Provider  No.  176  

Drinking  Water  Quality  Management  Plan    

Mapoon  ASC  Service  Provider  No.  176    

 Viridis Consultants Pty Ltd

PO Box 131

Bulimba Qld 4171

Australia

www.viridis.net.au

ABN: 49 129 185 271

Telephone: 1300 799 310

Date: 28 February 2019

Reference: 18QU39

Status: Final

© Viridis Consultants Pty Ltd 2019

Citation: Viridis Consultants 2019, Drinking Water Quality Management Plan - Mapoon ASC DWQMP, prepared for Mapoon ASC by Viridis Consultants Pty Ltd.

Drinking Water Quality Management Plan – Mapoon ASC

18QU39-REC-19-030-4.4 i June 2019

Contents  1.   Introduction  ...................................................................................................................................  1  

2.   Registered  service  details  .........................................................................................................  2  3.   Details  of  infrastructure  for  providing  the  service  ...........................................................  3  

3.1.   Schematic ....................................................................................................................................... 3  3.2.   Source ............................................................................................................................................. 3  3.3.   Treatment ....................................................................................................................................... 4  3.4.   Reservoirs ....................................................................................................................................... 4  3.5.   Distribution .................................................................................................................................... 5  3.6.   Key Stakeholders ........................................................................................................................... 7  

4.   Identify  hazards  and  hazardous  events  ................................................................................  8  4.1.   Catchment ...................................................................................................................................... 8  4.2.   Bores .............................................................................................................................................. 9  4.3.   Water Quality Assessment ........................................................................................................... 11  4.3.1.   Raw  Water  .....................................................................................................................................................  11  4.3.2.   Treated  Water  .............................................................................................................................................  13  4.3.3.   Customer  Complaints  ...............................................................................................................................  14  

4.4.   Hazard Identification .................................................................................................................... 15  4.4.1.   Hazard  Identification  and  Risk  Assessment  Team  ......................................................................  15  

5.   Assessment  of  risks  ...................................................................................................................  16  5.1.1.   Methodology  ................................................................................................................................................  16  5.1.2.   Acceptable  Risk  ...........................................................................................................................................  17  

6.   Managing  risks  ............................................................................................................................  18  6.1.   Risk management measures ......................................................................................................... 18  6.1.1.   Critical  Control  Points  ..............................................................................................................................  18  6.1.2.   Staff  Training  ...............................................................................................................................................  18  6.1.3.   Existing  preventative  measures  ..........................................................................................................  18  6.1.4.   Proposed  preventative  measures  .......................................................................................................  19  6.1.5.   Cybersecurity  ...............................................................................................................................................  19  

6.2.   Operation and maintenance procedures ....................................................................................... 19  6.3.   Management of incidents and emergencies ................................................................................. 21  6.3.1.   Alert  Levels  ...................................................................................................................................................  21  6.3.2.   Response  Actions  .......................................................................................................................................  21  6.3.3.   Process  for  incident  reporting  .............................................................................................................  24  6.3.4.   Notification  of  Alerts  about  water  quality  .......................................................................................  28  6.3.5.   Staff  Training  for  Incident  Response  .................................................................................................  28  

6.4.   Service Wide Support – Information Management ..................................................................... 29  6.5.   Customer Complaints ................................................................................................................... 30  

7.   Operational  and  verification  monitoring  programs  ......................................................  31  7.1.   Regular Checks ............................................................................................................................ 31  7.2.   Operational Monitoring ................................................................................................................ 31  7.3.   Verification Monitoring ............................................................................................................... 35  

 Appendices  Critical  Control  Points  .................................................................................................................................................................................  A  Boil  Water  Alert  ..............................................................................................................................................................................................  B  Do  Not  Drink  Alert  .........................................................................................................................................................................................  C  Drinking  Water  Alert  Lifted  ......................................................................................................................................................................  D  

Figures  Figure  1  Map  of  the  Mapoon  region  .......................................................................................................................................................  1  

Drinking Water Quality Management Plan – Mapoon ASC

18QU39-REC-19-030-4.4 ii June 2019

Figure  2  Schematic  for  the  Mapoon  scheme  .......................................................................................................................................  3  Figure  3  Mapoon  reticulation  schematic  ..............................................................................................................................................  6  Figure  4  Map  of  the  Wenlock  catchment  ..............................................................................................................................................  9  Figure  5  Mapoon  supply  scheme  bore  locations  ............................................................................................................................  10  Figure  6  Typical  bore  compound  construction  (RN  92522)  .....................................................................................................  10  Figure  7  Treated  Water  Free  Chlorine  (November  2017  –  November  2018)  ..................................................................  13  Figure  8  Treated  Water  pH  (November  2017  –  November  2018)  .........................................................................................  13  Figure  9  Preliminary  Incident/Emergency  Flow  Chart  ..............................................................................................................  22  Figure  10  Actions  and  Reporting  for  Detection  of  E.  coli  ...........................................................................................................  25  Figure  11  Actions  and  Reporting  for  Detection  of  Chemical  Parameters  above  ADWG  Health  Guideline  Values

 ...................................................................................................................................................................................................................  26  Figure  12  Actions  and  Reporting  during  a  Disaster  .....................................................................................................................  27  

Tables  Table  1  Registered  service  details  ...........................................................................................................................................................  2  Table  2  Details  of  bores  ................................................................................................................................................................................  4  Table  3  Treatment  details  ...........................................................................................................................................................................  4  Table  4  Reservoir  details  .............................................................................................................................................................................  5  Table  5  Summary  of  the  reticulation  system  ......................................................................................................................................  5  Table  6  Mapoon  drinking  water  supply  key  stakeholders  ...........................................................................................................  7  Table  7  Summary  of  catchment  characteristics  ................................................................................................................................  8  Table  8  Raw  water  quality  .......................................................................................................................................................................  11  Table  9  Summary  of  treated  water  verification  results  (November  2017-­‐  July  2018)  .................................................  14  Table  10  Risk  review  team  (January  2019  Review)  .....................................................................................................................  15  Table  11  Risk  review  team  (Initial  assessment  in  2016)  ...........................................................................................................  15  Table  12  Risk  assessment  likelihood  descriptions  .......................................................................................................................  16  Table  13  Risk  assessment  consequence  descriptions  .................................................................................................................  16  Table  14  Likelihood-­‐consequence  matrix  used  for  the  assessment  ......................................................................................  17  Table  15  Risk  assessment  uncertainty  descriptions  ....................................................................................................................  17  Table  16  Critical  control  points  for  the  Mapoon  drinking  water  supply  system.  ............................................................  18  Table  17  Mapoon  water  supply  procedures  ....................................................................................................................................  20  Table  18  Overview  of  alert  levels  .........................................................................................................................................................  21  Table  19  Summary  of  actions  for  each  alert  level  .........................................................................................................................  23  Table  20  Incident  reporting  requirements  .......................................................................................................................................  24  Table  21  Vulnerable  consumers  ...........................................................................................................................................................  28  Table  22  Information  Management  Activities/Document  Summary  ...................................................................................  29  Table  23  Regular  checks  and  inspections  .........................................................................................................................................  31  Table  24  Operational  monitoring  locations  .....................................................................................................................................  31  Table  25  Operational  monitoring  details  ..........................................................................................................................................  33  Table  26  Verification  monitoring  sampling  sites  ..........................................................................................................................  35  Table  27  Verification  monitoring  program  ......................................................................................................................................  35    

Drinking Water Quality Management Plan – Mapoon ASC

18QU39-REC-19-030-4.4 iii June 2019

Document  History  and  Status  Revision Date Approved by Initials Details

4.1 22.02.19 Tasleem Hasan TH Internal Review

4.2 28.02.19 Tom Smith TS MASC Review

4.3 31.05.19 Tom Smith TS Updated based on DNRME comments.

4.4 3.06.19 Tom Smith TS Updated based on DNRME comments.

Author: Glen Luscombe

Project manager: Glen Luscombe

Name of client: Mapoon ASC

Name of project: Drinking Water Quality Management Plan

Name of document: Mapoon ASC DWQMP Document number REC-19-030

Document version: 4.4

Project number: 18QU39

The Mapoon Aboriginal Shire Council considers this document contains matters relating to the business and financial affairs of Mapoon Aboriginal Shire Council and its disclosure may be contrary to the public interest under section 49 and Schedule 4 of the Right to Information Act 2009 (RTI Act). Mapoon Aboriginal Shire Council would therefore be substantially concerned if this document was to be released publicly. Given this, Mapoon Aboriginal Shire Council provides this copy of the Drinking Water Quality Management Plan to the recipient agency on the understanding that if the agency receives a Right to Information (RTI) request that captures this document; it will formally consult with Mapoon Aboriginal Shire Council under section 37 of the RTI Act before a decision is made on the RTI request.

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1. Introduction  

This Drinking Water Quality Management Plan (DWQMP or plan) documents the risk management approach taken by Mapoon Aboriginal Shire Council (MASC) to maintain and improve the safety of the Mapoon drinking water supply scheme. The document is a ‘living document’, representative of current practice and must be regularly reviewed and updated.

The DWQMP has been developed to meet the requirements of the Water Supply (Safety and Reliability) Act 2008 (the Act). The structure and content of this plan was based on the Drinking Water Quality Management Plan Guideline (DNRME, 2018).

This plan contains or references the relevant documentation which underpins the drinking water quality management for the Mapoon water supply scheme. The following documents make up the DWQMP:

• Main DWQMP Document (this document) • Risk Register and Risk Management Improvement Plan (RMIP) • Critical Control Point (CCP) Procedures

The Mapoon Aboriginal Shire Council Local Government area is situated in a coastal area of far north Queensland approximately 80 km north of Weipa and is the land described as lots 4 and 6 on Crown Plan WP53 and lot 2 on Crown Plan WP839186 and is comprised of an area of about 183,960 hectares (refer Figure 1).

Figure 1 Map of the Mapoon region  

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2. Registered  service  details  

Details for the water supply service are provided in Table 1.

Table 1 Registered service details

Service description Details

Service Provider Identification Number (SPID) 176

Council Name and Contact Details Mapoon Aboriginal Shire Council Red Beach Road Mapoon 4874 ABN: 15 093 924 706 Phone: 07 4082 5203 Technical Services E-Mail: [email protected] CEO E-Mail: [email protected] Website: http://www.mapoon.qld.gov.au

Communities serviced Mapoon

Current population (2019)* 325

Current connections (2019) 126

Current demand (2019) ML/day 0.9

Projected population (2029)* 342

Future connections (2029) 132

Future demand (2029) ML/day 0.95

*Note, population projected from 2016 census data using an annual growth rate of 0.58% based on similar localities published in the Queensland Government Projected Population (medium series) 2016.

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3. Details  of  infrastructure  for  providing  the  service  

3.1. Schematic  

A schematic for the supply system is provided in Figure 2.

Figure 2 Schematic for the Mapoon scheme

3.2. Source  

Source water for the Mapoon supply scheme is provided by four bores drawing water from the aquifer (refer Table 2). Bores are operated on a duty/duty/duty/standby basis. The bore field includes a fifth bore, however this is used for irrigation supply.

The bores are protected are secured in a fenced compound and sealed to prevent surface water infiltration. During power outages, power to the borefield is supplied through a backup generator.

18QU39-REC-19-030-4.4 4 June 2019

The capacity of the bores is regularly challenged by demand, and Council will be installing an additional bore in 2020. This will help to ensure water security during peak periods and provide redundancy where equipment failure or water quality issues arise from a bore.

Table 2 Details of bores

Item Bore 1 Bore 2 Bore 3 Bore 4 Bore 5

Bore Number RN 92524 RN 92522 RN 92525 RN 92523 RN 72882

Service Drinking Water Supply

Drinking Water Supply

Drinking Water Supply

Drinking Water Supply Irrigation

Constructed 1996 1996 1996 1996 1989

Aquifer Type Unconfined Unconfined Unconfined Unconfined Unconfined

% of Supply 30% - 3L/s 30% - 3L/s 30% - 3L/s 10% - 1L/s 3L/s

Reliability Good – 100% Good – 100% Good – 100% Good – 100% Good – 100%

Pump Submersible Pump Grundfos SP8A-12

Submersible Pump Grundfos SP8A-12

Submersible Pump Grundfos SP8A-12

Submersible Pump Grundfos SP8A-12

Submersible Pump Grundfos SP8A-12

Capacity 8m3/hr 8m3/hr 8m3/hr 3m3/hr 8m3/hr

Bore Depth 30m 30m 30m 30m 30m

Bore Head Details Raised and sealed Raised and sealed Raised and sealed Raised and sealed Raised and sealed

Casing and Materials PVC, Cased PVC, cased PVC, Cased PVC PVC, Cased

Water Quality Issues Low pH Low pH Low pH Low pH Low pH

3.3. Treatment  

Raw water supplied from the bores is pumped to Mapoon WTP for treatment. The plant is operated manually by operators based on reservoir level, including start-stop of the plant. At Mapoon WTP, the following treatment processes are undertaken:

• pH Correction using soda ash • Disinfection using chlorine gas.

Soda ash dosing and chlorination systems are activated on start-up of the plant. Operators adjust dosing levels manually based on grab sampling results. No online instruments are installed in the plant. Further details on the treatment system are available in Table 3.

Table 3 Treatment details

Parameter Details

Process Soda Ash Dosing Gas Chlorination

Design capacity (20-hour operation) 0.9 ML/d

Daily flow range 0.4-0.9 ML/d

Chemicals added Soda Ash Chlorine

Standby chemical dosing facilities (Y/N) No

Bypasses/variations No

Alarms No PLC/SCADA installed for process alarms

3.4. Reservoirs  

Treated water is stored in a ground level reservoir and is delivered to the reticulation system by a town water pump station. During power outages, the ground level reservoir is isolated and treated water is pumped to the

18QU39-REC-19-030-4.4 5 June 2019

elevated reservoir, using gravity distribution to the reticulation network. Details of the reservoirs are available in Table 4.

A replacement reservoir is planned to replace the ground level reservoir in 2020. This renewal will increase the storage capacity to approximately 1.2ML, providing an increased buffer for equipment or treatment failure.

Table 4 Reservoir details

Parameter Reservoir 1 Reservoir 2

Capacity 0.22ML 50kL

Location Mapoon WTP Mapoon WTP

Type Reinforced concrete, ground level tank. Steel tank, elevated approximately 20m from ground level.

Roofing Sloped corrugated steel roof, runoff directed off tank.

Sloped corrugated steel roof, runoff directed off tank.

Vermin-proofing Openings covered in vermin-proof mesh. Openings covered in vermin-proof mesh.

Cleaning schedule Tank inspections on a five-year basis. Tank drained while not in use.

Filling Manual filling control using a float and slug indicator on the tank. Manual filling control.

3.5. Distribution  

Water from the ground level reservoir is pumped into the reticulation using a town water supply pump station. During a power outage, the reticulation system is gravity fed from the elevated storage tanks.

The distribution and reticulation of water services is largely fed from PVC and HDPE pipework, although some legacy asbestos cement remains. There is no copper or steel pipework in the council reticulation system, although copper and steel may be used in customer piping. A summary of the reticulation system is available in Table 5.

A monthly flushing program is conducted to maintain chlorination at dead ends.

Table 5 Summary of the reticulation system

Parameter Details

Pipe materials PVC HDPE Asbestos Cement

Age range Some areas installed in 2002, with areas renewed as required.

Length of mains 20km

Dead ends and high detention period areas

Cullen Point End Cullen Point Valve 2 Thungoo End 1 Thungoo End 2 Central Valve All dead ends are flushed on a monthly basis to maintain chlorine levels.

Areas of low pressure None.

A schematic of the reticulation system, noting sampling and hydrant locations, is provided in Figure 3. Sampling points are used for operational and verification sampling. For more information on operational and verification monitoring, refer to section 7.

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Figure 3 Mapoon reticulation schematic

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3.6. Key  Stakeholders  

Key stakeholders for the Mapoon drinking water supply scheme are noted in Table 6.

Table 6 Mapoon drinking water supply key stakeholders

Organisation Contact details Relevance to management of drinking water quality

How the stakeholder is engaged in the DWQMP

Mapoon Community Various - Contacted via letter drops, posters, door knocking and word of mouth.

Consumers Informed of water quality issues as they arise.

Ixom Enquiries: 1300 559 262 Emergencies: 1800 033 111

Provides chlorine Chlorine is ordered as required.

Northern Chemicals, Cairns Phone: 4035 4622 [email protected]

Provides soda ash Soda ash is ordered as required.

DNRME, WSR

Water Supply Regulation Incident Hotline: 1300 596 709 (24/7) Email: [email protected]

Regulator

Report incidents on 1300 596 709 when detection of E. coli and chemical parameters above health guideline value in ADWG in potable water supply; Report an event likely to affect drinking water quality in potable water supply. Approval of the DWQMP.

Queensland Health, Public Health Unit

Director Environmental Health Ph.: 4226 5604

Point of contact for assistance with public health issues related to water supply.

Provides advice during public health incidents.

Cairns Regional Council Water Laboratory

Laboratory Manager Ph.: 4044 8344

NATA certified laboratory where water samples are sent for analysis.

Scheduled water samples from the drinking water supply are collected and sent to this laboratory for analysis.

CEO and Elected Council As per Council directory Overall management, budget and finance

Kept up to date and informed of water operations. Submits Overall responsibility for DWQMP.

Mapoon Primary Health Care Centre

Ph.: 4082 9400 Address: Red Beach Road, Mapoon QLD 4874

Vulnerable consumer Informed during water quality incidents.

School Ph.: 4082 9333 Address: Red Beach Road, Mapoon QLD 4874

Vulnerable consumer Informed during water quality incidents.

A new aged care centre is being constructed in Mapoon and will be contacted for inclusion/engagement in the DWQMP process as the centre opens.

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4. Identify  hazards  and  hazardous  events  

4.1. Catchment  

Mapoon township is situated at the mouth of the Wenlock River, which is fed by its associated tributaries (refer Figure 4) of the Wenlock River. The reach of the catchment extends back to the Iron Range approximately over 240Km. The main water source is derived from aquifers in the Mapoon Peninsula, fed from the Wenlock catchment.

The Wenlock River catchment is heavily forested, containing dense bushland and swamps. The soil in the region predominantly consists of bauxite in the top layers with sandy, loamy soils in the lower layers. The area does not support agriculture or pasture for grazing, the main industry is bauxite mining which is 30 km away, and unlikely to impact the aquifer.

Mapoon experiences two distinct seasons, wet and dry. The wet season runs from late November to late March and the dry season for the remainder of the year. Mapoon receives most of its annual rainfall in the form of heavy thunderstorms and/or cyclonic weather conditions. The area suffers occasional flooding and bushfires, both of which do not interfere with the water supply aquifer. There have been no occasions where water supply from the aquifer has been limited.

Table 7 Summary of catchment characteristics

Characteristic Details

Area 7435 km²

Topography Flat

Soil type Sand (Bauxite) and soil

Monthly rainfall (min, max, average) Min: 1400mm per annum Max: 2600mm per annum Average: 2200mm per annum

Incidence of flooding and bushfires Occasional flooding, bushfires (dry season only)

Land use Low density rural and residential Swamps, forest and bushland

Agriculture, industry, mining Bauxite mining

18QU39-REC-19-030-4.4 9 June 2019

Figure 4 Map of the Wenlock catchment  

4.2. Bores  

The water supply system is fed from four bores located in a single borefield located near the Mapoon township. The bores are located within a 1km zone (refer Figure 5). The bores used to feed the drinking water supply system are:

• RN 92522 • RN 92523 • RN 92524 • RN 92525

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Figure 5 Mapoon supply scheme bore locations

The bores are protected are secured in a fenced compound and sealed to prevent surface water infiltration. Bore heads are raised above the pad surface to reduce the likelihood of surface water infiltration (refer Figure 6), and bores are fenced to prevent vandalism or damage from wildlife. For further information about bore infrastructure, refer to section 3.2.

Figure 6 Typical bore compound construction (RN 92522)

.