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Appendix 4.3.1 Sewerage Infrastructure
A Overall PFD B Wastewater Stage 1 PFD
C Description of Proposed Sewerage Infrastructure
CATHERINE HILL BAY WATER UTILITY PTY LTD
PRIVATE WATER UTILITY:PROJECT:
CATHERINE HILL BAY RESIDENTIAL SUBDIVISIONMONTEFIORE STREET, CATHERINE HILL BAY
DRAWING TITLE:
PROCESS FLOW DIAGRAMOVERALL
IPART REFERENCE:
APPENDIX 4.1.1
CLIENT:
ROSE PROPERTY GROUP PTY LTD
PHASE:
IPART LICENSE APPLICATION
CONTROL ROOM
1.2 ML POTABLE WATER + FIRE STORAGE(0.5ML DEDICATED
FIRE STORAGE)
0.85 ML RECYCLED
WATER STORAGE
WYONG COUNCIL
KANANGRA DRIVE
RESERVOIR
CHEM
ICAL
S
10 ML WET WEATHER
STORAGEPUMP ROOM
AIR GAP
SOLO WATER
WYONG COUNCIL
POTABLE WATER
CLASS A+ RECYCLED WATER
MBR + UV PERMEATE
REVERSE OSMOSIS REJECT
PRESSURE SEWER
UF RETENATE
POTABLE WATER PRESSURE BOOSTER PUMP SET WITH VARIABLE SPEED DRIVE
NON-POTABLE WATER PRESSURE BOOSTER PUMP SET WITH VARIABLE SPEED DRIVE
PRESSURE SEWER NETWORK
CATHERINE HILL BAY DEVELOPMENT LOTS
470 ET
IRRIGATION OF OPEN SPACE AREAS
IRRIGATION AREA: 4.9 ha
UF RETENATE
RO REJECT
BULK POTABLE WATER TRANSFER SYSTEMTRANSFER PIPELINE
TOTAL PIPELINE 6.3 km x DN 200 mm HDPE4.2 km EXISTING HDPE MAIN IN NPWS/RFS CLASS 1 FIRE TRAIL1.5 km OF NEW HDPE MAIN TO CONNECT KANANGRA DR RESERVOIR TO THE EXISTING MAIN0.6 km OF NEW HDPE MAIN TO CONNECT THE EXISTING MAIN TO ONSITE POTABLE WATER STORAGE TANK (REFER TO BULK WATER MAIN LAYOUT PLAN IN APPENDIX 4.1.3)
NEW TRANSFER PUMP STATION LOCATED AT THE EXISTING WYONG COUNCIL KANANGRA DR RESERVOIR SITEVARIABLE SPEED DRIVE BOOSTER PUMP SET WITH BUILT IN STANDBY CAPACITYPEAK DESIGN FLOW 23.3 L/s
197.4 kL/day
15.8 kL/day
209.2 kL/d
MBR WASTE SLUDGE
MBR WASTE SLUDGE
4 kL/day
185.
7 kL
/d
7.7 kL/day4700 mg/L TDS
ADD: 151.3 kL/day
ADD: 118.4 kL/day
197.4 kL/day
213.2 kL/day
OFFSITE DISPOSAL TO APPROVED FACILITY USING
LICENSED WASTE TRANSPORT CONTRACTOR
AWTP(WWTP Stage 2)
RECYCLED WATERCLASS A+
PRODUCTION: 185.7 kL/d
MBR(WWTP Stage 1)
PEAK CAPACITY 300 kL/day)
209.
2 kL
/d
2000 m2
RO REJECTEVAPORATION
POND No. 1
2000 m2
RO REJECTEVAPORATION
POND No. 2
MISTING SPRAYERS MISTING SPRAYERS
6.2 kL/day5600 mg/L TDS
OFFSITE DISPOSAL OF SALT RESIDUE/SURPLUS BRINE TO APPROVED FACILITY USING
LICENSED WASTE CONTRACTOR
TOTAL WATER DEMAND: ADD: 337.1 kL/dPDD: 987.8 kL/dPDD FLOW: 12.5 L/s in 22 hoursFIRE FLOW: 10.0 L/sTOTAL PEAK FLOW 22.5 L/s
PDD: 179.0 kL/day
PDD: 472.4 kL/day
500 m2 RO REJECT EVAPO-TRANSPIRATION WETLAND.
SALT TOLERANT VETIVER GRASS
LEGEND
AIR GAP
DRAWING NUMBER:
H10052_P01C
POTABLEADD: 151.3 kL/dPDD: 179.0 kL/d2.3 L/s IN 22 hrs
FIRE:10 L/s
NON-POTABLEADD: 185.7 kL/dPDD: 808.8 kL/d
10.2 L/s IN 22 hrs
EMERGENCY BACKUP
RECYCLED WATER RETICULATION NETWORK
EMERGENCY STANDBY DEISEL PUMP WITH AUTOMATIC CHANGEOVER
EMERGENCY STANDBY DEISEL PUMP WITH AUTOMATIC CHANGEOVER
POTABLE WATER RETICULATION NETWORK
DATE:05/07/2013
PROCESS FLOW DIAGRAM OVERALL
IRRIGATION OF LANDSCAPED ROAD
BUFFERSIRRIGATION AREA: 3.5 ha
AVG: 39.2 kL/dayPEAK: 196.2 kL/day
AVG: 28.1 kL/dayPEAK: 140.2 kL/day
STAGE 1 TEMPORARY
IRRIGATION AREA(up to 240 lots or 100 kL/day)
IRRIGATION AREA: 10.8 ha
ADD: 185.7 kL/dayPDD: 808.8 kL/day
HIGH & LOW DEMAND
STAGE 1 TEMPORARY IRRIGATION
LS PSR LS PSR
EVAPORATIVE COOLER
LS DO SSpH
INLET BALANCE
TANKANAEROBIC
TANKANOXIC
TANKAERATION
TANKSUBMERGED MEMBRANE
TANKUV
INLETSCREEN
AUTO BAGGING
UNIT
WASTE SLUDGE
TANK
ACTIVATED CARBON FILTER
PASSIVE TANK VENTILATION
MEMBRANE PERMEATE
PUMP
CIP WAST
E
OFFSITE TO DISPOSAL TO
APPROVED LANDFILL FACILITY
OFFSITE DISPOSAL TO APPROVED FACILITY USING
LICENSED WASTE TRANSPORT CONTRACTOR
10 MLWET WEATHER
STORAGE
LOW PRESSURE SEWERAGE NETWORK – WELDED HDPE
MBR CIP WASTE TANK
AIR BLOWER
pH
MIXED LIQUOR SUSPENDED SOLIDS
DISSOLVED OXYGEN
WATER LEVEL
FLOW
TRANSMEMBRANE PRESSURE
TURBIDITY
UV INTENSITY
MBR PERMEATE
TANK
WAS
TE
SLU
DGE
MIXER
PRESSURE
FREE CHLORINE RESIDUAL
BUNDED CHEMICAL CONTAINERS AND DOSING PUMPS
SOLO WATER
SOLO WATER
HOME OWNER/BUILDER
GRAVITY COLLECTION SYSTEMS
PRIVATE WASTEWATER DRAINAGE SYSTEMS TO AS3500 BY LICENSED DOMESTIC PLUMBER
HOME OWNER/BUILDER
ELECTRICAL CONDUCTIVITY
CHEMICAL DELIVERY LINES
AACID
CCAUSTIC
ClCHLORINE
SMSODIUM METABI-SULPHITE
AlALUM
CBCARBON
CIP PREP TANK
Cl, C
, AC, A
, CB
C, A
, Al,
CB
SM, C
, A
C, A
, Cl
C, A
, Cl
PROCESS FLOW DIAGRAM STAGE 1 WASTEWATER TREATMENT PLANT
SUPE
RNAT
ENT
NU
ETRA
LISE
D
RETURN TO INLET BALANCE TANK
TO ADVANCED WATER TREATMENT PLANT IN STAGE 2 AFTER 240 LOTS DEVELOPED. REFER TO NON-POTABLE WATER PFD APPENDIX 4.2.1.
SOIL MOISTURE PROBE
LOW PRESSURE SEWERAGE SYSTEM
- WASTEWATER WILL DRAIN THROUGH A GRAVITY SEWERAGE COLLECTION SYSTEMS TO A NUMBER OF DUPLEX LOW PRESSURE SEWAGE PUMP STATIONS THAT SERVICE 1 TO 4 LOTS EACH.- WASTEWATER IS PUMPED IN A CONTROLLED MANNER THROUGH THE LOW PRESSURE SEWERAGE NETWORK TO THE INLET BALANCE TANK AT THE WWTP. OPERATION OF THE PRESSURE SEWER NETWORK PUMPS IS CONTROLLED BY THE DIRECT DIGITAL CONTROL SYSTEM AT THE WWTP TO CONTROL PEAK INFLOWS TO THE MBR.- LOW PRESSURE SEWER NETWORK TO BE CONSTRUCTED WITH BROWN-STRIPED PN 16 HDPE PIPE WITH WELDED PIPE JOINTS AND FITTINGS.- EACH LOW PRESSURE SEWERAGE PUMP STATION WILL INCLUDE:
- PUMP HEAD AND FLOW CAPACITY TO SERVICE BETWEEN 1 AND 4 LOTS.- DUTY AND STANDBY PUMPS WITH ONLINE FAULT DETECTION AND ALARMS.- 24 HOURS EMERGENCY STORAGE CAPACITY IN THE WET WELL.- HARD WIRED COMMUNICATION CABLING BACK TO THE DIRECT DIGITAL CONTROL SYSTEM AT THE WWTP. - CONTINUOUS ONLINE WET WELL WATER LEVEL AND FLOW MONITORING WITH ALARMS.- AUTOMATED SYSTEM START-UP AND RECOVERY FOLLOWING POWER OUTAGE VIA THE DIRECT DIGITAL
CONTROL SYSTEM.- ABILITY TO INSTALL ADDITIONAL ONLINE WATER QUALITY MONITORING PROBES, E.G. PH, TDS, TOC, FOR
DETECTION OF INAPPROPRIATE CHEMICAL DISPOSAL OR TRADE WASTE PRACTICES, IF REQUIRED DURING OPERATION.
FOR FURTHER INFORMATION ON THE LOW PRESSURE SEWER NETWORK REFER TO PRESSURE SEWERAGE SOLUTIONS PTY LTD.
STAGE 1 WASTEWATER TREATMENT PLANT – MEMBRANE BIOREACTOR
- ALL WASTEWATER TREATED IN THE MEMBRANE BIOREACTOR TO PRODUCE “CLASS A” RECYCLED WATER SUITABLE FOR CONTROLLED IRRIGATION OF TEMPORARY IRRIGATION AREAS. MBR TARGET EFFLUENT QUALITY:
- BIOCHEMICAL OXYGEN DEMAND < 10 mg/L- SUSPENDED SOLIDS < 10 mg/L- TOTAL NITROGEN < 10 mg/L- TOTAL PHOSPHOROUS < 0.3 mg/L- pH 6.5 TO 8.5- FAECAL COLIFORMS < 10 cfu/100 mL- TURBIDITY < 2 NTU
- PEAK DESIGN CAPACITY OF MBR PROCESS TRAIN OF 300 kL/DAY WILL CATER FOR ULTIMATE DEVELOPMENT OF 470 LOTS WITH RESERVE CAPACITY. - THE ADVANCED WATER TREATMENT PLANT TO PRODUCE “CLASS A+ RECYCLED WATER” WILL BE OPERATIONAL ONCE 240 LOTS ARE CONNECTED TO THE SYSTEM, OR WHEN FLOWS REACH 100 kL/day.- OPERATION OF THE WWTP IS FULLY AUTOMATED AND INTEGRATED WITH OPERATION OF THE PRESSURE SEWER NETWORK TO CONTROL PEAK FLOWS INTO THE MBR USING THE DIRECT DIGITAL CONTROL SYSTEM.- ENERGY CONSUMPTION IN THE PROCESS IS MINIMISED THROUGH THE USE OF VARIABLE SPEED DRIVE CONTROLLERS ON ALL PROCESS PUMPS AND AIR BLOWERS.- ALL ONLINE MONITORING, CONTROL AND ALARM SYSTEM CAN BE REMOTELY ACCESSED THROUGH THE INTERNET. ALL DATA IS LOGGED FOR LATER REVIEW AND TROUBLE SHOOTING.- THE MBR IS LOCATED INSIDE THE WWTP SHED TO MINIMISE NOISE AND ODOUR IMPACTS. ALL TANKS ARE ENCLOSED WITH PASSIVE VENTILATION THROUGH ACTIVATED CARBON FILTERS. AMBIENT AIR QUALITY INSIDE THE WWTP BUILDING IS CONTINUOUSLY MONITORED WITH ALARMS FOR ELEVATED HYDROGEN SULPHIDE, METHANE & OXYGEN CONCENTRATIONS. AIR CONDITIONING UNITS AND DEODORISING SPRAYS OPERATE AUTOMATICALLY TO MAINTAIN INDOOR AIR QUALITY WITHIN APPROPRIATE LIMITS.
STAGE 1 TEMPORARY EFFLUENT MANAGEMENT SYSTEM
- THE STAGE 1 EFFLUENT MANAGEMENT SYSTEM WILL SERVICE UP TO 240 LOTS, OR UP TO APPROX 100 kL/day.- ALL MBR TREATED EFFLUENT IS STORED IN A HDPE LINED 10 ML WET WEATHER STORAGE DAM, WHICH PROVIDES APPROXIMATELY 100 DAYS STORAGE AT AVERAGE IRRIGATION FLOWS.- EFFLUENT MANAGEMENT IS VIA CONTROLLED, RESTRICTED ACCESS, NIGHT TIME IRRIGATION OF TEMPORARY IRRIGATION AREAS USING MBR EFFLUENT.-APPROXIMATELY 10.8 ha OF TEMPORARY, RESTRICTED ACCESS IRRIGATION AREAS WILL BE PROVIDED DURING STAGE 1 TO SERVICE UP TO 240 LOTS. AVERAGE IRRIGATION RATES DURING STAGE 1 ARE UP TO 1 mm/day.- ALL TEMPORARY IRRIGATION AREAS, LANDSCAPING AND IRRIGATION INFRASTRUCTURE WILL BE PROVIDED BY THE DEVELOPER DURING CONSTRUCTION OF EACH DEVELOPMENT STAGE.- DECOMMISSIONING OF THE TEMPORARY STAGE 1 IRRIGATION AREA WILL COMMENCE AFTER 240 LOTS ARE CONNECTED.- AN IRRIGATION MANAGEMENT PLAN WILL BE DEVELOPED FOR THE TEMPORARY SCHEME THAT WILL OUTLINE SITE SPECIFIC IRRIGATION, ENVIRONMENTAL AND PUBLIC HEALTH CONTROL MEASURES FOR EACH IRRIGATION AREA. TYPICAL IRRIGATION CONTROLS WILL INCLUDE:
- IRRIGATION SCHEDULING CONTROLS TO CONTROL THE TIME, FREQUENCY AND DURATION OF IRRIGATION EVENTS.
- SOIL MOISTURE PROBES AND WEATHER STATION OVERRIDE ON IRRIGATION CONTROLLERS TO PREVENT IRRIGATION DURING RAINFALL, HIGH WIND OR ELEVATED SOIL MOISTURE.
- SECURE, RESTRICTIVE ACCESS AREAS INCLUDING APPROPRIATE WARNING SIGNS, IDENTIFICATION AND LABELLING.
- SITE BASED STORM WATER, RUN OFF AND ENVIRONMENTAL CONTROLS.- SURFACE SPRINKLERS WITH SPRAY DRIFT CONTROL INCLUDING SPRINKLER NOZZLES THAT OPERATE UNDER LOW
PRESSURE WITH A LARGE DROPLET SIZE AND LOW THROW HEIGHT.
PUMP STARTS AND RUN HOURS
LEGENDPROCESS MONITORING
METHANE GAS
HYDROGEN SULPHIDE GAS
OXYGEN GAS
INLET SCREEN
SUBMERSIBLE PUMP
DRY-MOUNTED PUMP
MIXING PUMP
MOTORISED VALVE
HOUSEHOLD SEWERAGE CONNECTION POINT
EVAPORATIVE AIR CONDITIONING UNIT
CATHERINE HILL BAY WATER UTILITY PTY LTD
PRIVATE WATER UTILITY:PROJECT:
CATHERINE HILL BAY RESIDENTIAL SUBDIVISIONMONTEFIORE STREET, CATHERINE HILL BAY
DRAWING TITLE:
PROCESS FLOW DIAGRAMWASTEWATER TREATMENT
IPART REFERENCE:
APPENDIX 4.3.1
CLIENT:
ROSE PROPERTY GROUP PTY LTD
PHASE:
IPART LICENSE APPLICATION
CB ACETIC ACID (CARBON) DOSING AS SUPPLEMENTARY FOOD SOURCE
SM SODIUM METABISULPHIDE DOSING FOR DECHLORINATION
Al POLYALUMINIUM CHLORIDE DOSING FOR PHOSPHORUS REMOVALCl SODIUM HYPOCHLORITE FOR CHLORINATION
BUNDED CHEMICAL STORAGE AREA
C SODIUM HYDROXIDE (CAUSTIC) FOR pH CORRECTION AND MEMBRANE CLEANINGA HYDROCHLORIC ACID FOR pH CORRECTION AND MEMBRANE CLEANING
WWTP BUILDING
WWTP BUILDING
MEMBRANE BIOREACTOR PROCESS TANKS
PROCESS EQUIPMENT PROCESS CHEMICALS
NOTES1. PRELIMINARY PROCESS FLOW DIAGRAM FOR IPART APPLICATION ONLY. NOT FOR CONSTRUCTION2. NOT TO SCALE. FOR WWTP SITE LAYOUT PLANS REFER TO APPENDIX 4.3.2.3. SUBJECT TO MINOR CHANGES DURING DETAILED DESIGN
INLET PUMP
ANOXIC FEED
AERATION FEED
MEMBRANE FEEED
ACTIVATED CARBON FILTER
SAFETY SHOWER
DEODOURISING SPRAY SM STAGE 1 (0-240 Lots)
TEMPORARY OPEN SPACE IRRIGATION AREAS
Stage 1 effluent irrigation area: 10.8 haAverage flow: 100 kL/day
Average irrigation rate: 1 mm/day
IRRIGATION CONTROL PANELS
LS
NTU
UV INT
pH
P TMP
Cl
EC
FM
PSR
DO
SS CH
H2S
02
LS
LSLS LS LS LS
LS
LS
FM FM
FM
FM FM FM
FMFM
FM FM
FM
FM FM
P
P
H2S CH02
DO TMP
NTU UV INT
RS
ClpH
EC
ClpH
PP
DRAWING NUMBER:
H10052_P04CDATE:
05/07/2013
Membrane Bioreactor Peak Design Capacity 300 kL/day for 470 Lots.
Temporary Effluent Management System Design Capacity 100 kL/day for 240 Lots.
SM
SM
WS
WEATHER STATIONWS
IPART License Application ‐ Network Operator and Retail Supplier Solo Water Catherine Hill Bay Water Utility
APPENDIX 4.3.1 P a g e | 1
Descriptionofproposedsewerageinfrastructure
Sewerage Infrastructure Description
Wastewater minimisation
Water demand management strategy involving mandatory water efficient fixtures, smart metering, customer awareness and education. Residential customer supply agreement and trade waste agreement will be entered with each customer to outline responsibilities for appropriate waste disposal practices to minimise disposal of inappropriate substances to the sewer. Water tight sewerage system to minimise infiltration of stormwater and groundwater to the sewerage system.
Low pressure sewerage network – Constructed in line with development build out
Low pressure sewerage network constructed using PN 16 HDPE pipe with welded joints and fittings to minimise infiltration. Low pressure duplex pump stations service up to 4 lots with duty/standby pumps and 24 hours storage capacity in each pump well (refer to Appendix 4.3.3). Automated operation of the low pressure sewerage network is integrated with operation of the wastewater treatment plant through the direct digital control system to minimise peak inflow rates. Peak diurnal flows into the wastewater treatment plant are controlled using buffer storage provided in each pump well and at the inlet balance tank and the direct digital control system. For a more detailed overview of the Pressure Sewer System refer to page 3.
Membrane bioreactor (MBR) + Ultraviolet disinfection (UV) – Constructed during Stage 1
All wastewater produced under the scheme is treated in a Membrane Bio‐Reactor with UV disinfection (MBR+UV) to produce “Class A” recycled water suitable for controlled irrigation of the stage 1 temporary irrigation areas. The full capacity of the MBR will be constructed upfront during stage 1 with the following target effluent quality:
Biochemical Oxygen Demand (BOD) < 10 mg/L Suspended Solids (SS) < 10 mg/L Total Nitrogen (TN) < 10 mg/L Total Phosphorous (TP) < 0.3 mg/L pH 6.5 to 8.5 Faecal Coliforms < 10 cfu/100 mL Turbidity < 2 NTU
No pathogen log reduction credits are being claimed for the MBR. The MBR will be validated based on effluent quality. The peak design capacity of the MBR process train will be 300 kL/day and is sized to provide treatment of average wastewater flows of 197.4 kL/day with spare capacity. The MBR will be located inside the WWTP shed to minimise noise and odour impacts. All tanks are enclosed with passive ventilation through activated carbon filters. Ambient air quality inside the WWTP building is continuously monitored with alarms for elevated hydrogen sulphide, methane & oxygen concentrations. Air conditioning units and deodorising sprays operate automatically to maintain indoor air quality within appropriate limits.
IPART License Application ‐ Network Operator and Retail Supplier Solo Water Catherine Hill Bay Water Utility
APPENDIX 4.3.1 P a g e | 2
Sewerage Infrastructure Description
10 ML Wet weather storage dam
A 10 ML HDPE lined wet weather storage dam will be constructed to receive “Class A” MBR+UV treated effluent. During stage 1 the MBR+UV effluent will be irrigated in temporary irrigation areas via a separate independent irrigation supply network. The wet weather storage dam will provide approximately 100 days storage at average irrigation flows. During stage 2, the MBR+UV treated effluent will be the source water to the AWTP and the wet weather storage will provide a buffer for non‐potable water demand providing additional source water to the AWTP during periods of high demand. Water sourced from the wet weather storage will be pre‐filtered to remove algae and suspended solids prior to undergoing treatment in the AWTP.
Stage 1 Temporary Effluent Irrigation Areas
Wastewater from the MBR+UV treatment process produced during stage 1 will be managed via controlled, restricted access, night time irrigation of approximately 10.8 ha of temporary irrigation areas. Stage 1 will service up to 240 Lots or flows up to 100 kL/day. Average irrigation rates during stage 1 will be up to 1 mm/day. All temporary irrigation areas, landscaping and irrigation infrastructure will be provided by the developer during construction of each development stage. An Irrigation Management Plan will be developed for the temporary scheme that will outline site specific irrigation measures to manage environmental and public health risks which will include:
Irrigation of high quality MBR+UV effluent with <10 faecal coliforms and <2 NTU. Approximately 100 days storage at average irrigation flows is provided by the 10 ML wet
weather storage dam. Irrigation scheduling controls to control the time, frequency and duration of irrigation
events with irrigation occurring at night time only. Soil moisture probes and weather station override on irrigation controllers to prevent
irrigation during rainfall, high wind or elevated soil moisture. Secure, restrictive access areas including appropriate warning signs, identification and
labelling. Site based storm water runoff and environmental controls. Surface sprinklers with spray drift control including sprinkler nozzles that operate under
low pressure with a large droplet size and low throw height. A minimum 30 m buffer distance between the edge of the temporary irrigation areas
and the closest dwelling. Non‐irrigated, vegetated buffer strips down gradient of the temporary irrigation areas. Monitoring to detect any potential impacts.
Decommissioning of the temporary stage 1 irrigation area will commence after 240 lots are connected or flows reach approximately 100 kL/day.
Stage 2 (Ultimate) Open Space Irrigation
Once the Advanced Water Treatment Plant (AWTP) is constructed in stage 2, 100% of MBR+UV effluent will be treated in the AWTP to “Class A+” and used in the non‐potable supply network including irrigation of open space areas. A description is included in Appendix 4.2.1.
Integrated online monitoring, control and alarm system
Continuous online monitoring, control and alarms for the sewerage infrastructure is centrally managed using the direct digital control system. The control system allows the infrastructure to operate unattended and automatically reports issues requiring operator attention. Online monitoring probes are manually calibrated and checked by operations staff on a routine basis to ensure all probes are recording accurate readings. All critical alarm system have a battery backup to ensure faults are reported during power failure. The control system is designed to automatically recover following power outage.
IPART License Application ‐ Network Operator and Retail Supplier Solo Water Catherine Hill Bay Water Utility
APPENDIX 4.3.1 P a g e | 3
OverviewofPressureSewerSystems
Pressure sewerage systems consist of a network of pressure pipes and grinder pumps, which integrate to form a collection system.
A pressure sewerage system comprises a two pump (duplex) Pressure Sewer Unit (PSU) installed to service up to four properties, depending upon the lot layout on occasions a single pump unit is installed at each property in the catchment. The pressure sewer unit will discharging to a common collection system.
The pump units macerate the sewerage into fine watery slurry for discharge through a small diameter pipeline. Being a pressure system, the network is not constrained by maintaining constant falls in most installation areas. Utilising shallower trenching and adopting trenchless technology where advantageous, the quantity of excavation and disruption to existing vegetation and ground surfaces is greatly reduced, providing environmental and social advantages to the community.
Energy savings are achieved when benchmarked against traditional gravity sewers installed in areas with topography requiring sewage pumping stations. The pressure sewer units selected by Solo Water are an EOne positive displacement type. The EOne units offer greater efficiency than traditional centrifugal type sewage pumping stations, and comparatively, the total nett energy used in a pressure sewerage system is less than a combined gravity / sewage pumping station solution.
An additional benefit of pressure sewerage systems when compared to traditional gravity systems is the reduction or elimination of wet weather flows. Wet weather flows significantly affect the performance of receiving Waste Water Treatment Plants, and can overload transfer pumping stations. Minimising wet weather flows has benefits in reduction of pumping energy, minimising environmental risk of overflow within the network and at receiving works, and removing the need for large wet weather storage structures normally associated with gravity collection systems.
Eliminating wet weather flows is achieved through a combination of quality control during design and installation of the property gravity collection systems and the ongoing monitoring and maintenance of the system to detect illegal connections to the sewer system.
Polyethylene pipe is proposed to be used for the pipe network, which is fully sealed by electrofusion welded joints. Depending on the topography, size of the system and planned rate of connection, other appurtenances will include isolation valves, flushing points, air release valves at significant high points, check and stop valves at the junction of each property connection with the pressure sewerage main.
Appendix 4.3.3 Location of Sewerage infrastructure
A – WWTP Site Layout P10C B – Example MBR AWTP Building Plan F0101A
C – Draft Open Space Irrigation P09.1C D – Stage 2 Irrigation Areas P09.2C
E – Pressure Sewer Masterplan SK001 F – Duplex Installation Details SK101
G – Property Connection Details SK102 H – Property Connection Details SK103 I – Property Connection Details SK104
arvest~~ -.ha-.c:om.au
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OLO WA lER - CA lHERINE HILL BAY WA lER UlllllY
A lHERINE HILL BAY ESIDENllAL SUBDIVISION OSE GROUP
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ON1EF10RE ROAD A lHERINE HILL BAY sw c
EXAMPLE W
WTP LA
YOUT WITH
2-TRAIN
MBR (6
60 kL
/d) &
AW
TP
LEGEND
A
B
c
D
E
2 3
l.OML POTA8LE WATER
STORAGE
4
F A PRELIMINARY
Rev No Revision no te
This drawing, or any part thereof, remains the property of Solo Water and is confidential. It is provided in confidence and must not be loaned, copied or reproduced in part or in total for manufacturing or any other purpose without the written permission of Solo Water and is not to be used in any way detrimental to the interests of Solo Water.
2 3
l.OML RECYCLE WATER
STORAGE
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0.5 ML RECYCLE WATER
STORAGE
6
STAGE 2 M6R
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A
B
c
D
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Drawn by Approved by - date Date Scale
~TR~~~~-~----~LJ_A_N_2_0L13~---_J~~---LJ=A~N~2=0~13~--~N~.T~.S~.-~ F 1/19 Hill Street Sunshine Beach QLD 4567 P: 07 5447 4403 F: 07 5447 4403 E:
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water m an age m en t cons u It a n t s p t y It d ABN: 1!41411944047
INE HILL BAY llAL. SUBDIVISION
GROUP
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Rd Buffer
Buffer
Site
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water management consultants pty ltd AB11tli414llB44047
l..'1So lo Water -
CLARKE ST
R.O.W. 3m WIDE
MONTEFIORE STREET
CLARKE STREET
MONTEFIORE STREET
MONTEFIORE STREET
EXISTING ROAD RESERVE (OLD PACIFIC HIGHWAY)
ROAD 10
ROAD 12
ROAD
28
ROAD 3
1 SEC KD
.P.163
2 SEC I
D.P.163
ROAD 22
SUBJECT TOFUTURE DA
(F)
3
12
4
5
7
6
1
3
12
4
5
7
6
1
HERITAGEPRECINCT
1465.4m²
5038
625.6m²
7007
3672.6m²
1112
991.6m²
1079
747.6m²
1061
851.9m²
5019
650.4m²
6006
186.8m²
10
1632.2m²
6083
1190.7m²
6021
705.9m²
2066730.4
m²1030
647.5m²
3024
653.4m²
2072
552.2m²
3009
709.8m²
5046
685.6m²
5024
980.2m²
2026
958.6m²
4045
685.7m²
2114
725.9m²
2102
763.9m²
7019
1043.5m²
3036
5436.4m²Pt 3041
3063.3m²
3040
11322.6m
²101
962.4m²
3004
18198.4m
²Pt 3041
1202.4m²
3031
877.6m²
1109
909.6m²
1088
465.5m²
1006
1219.9m²
5036
603.8m²
2052
560.8m²
2060
753.3m²
2065
574.1m²
2082
620.9m²
2085
629.5m²
2084
638.0m²
2083
841.8m²
2080
702.0m²
3032
580.0m²
2008
1084.7m²
2015
3310.6m²
3001
1198.1m²
30061008
.8m²3005
1908.0m²
3002
700.8m²
3033
755.0m²
1087
598.7m²
3026
656.9m²
3025
652.7m²
3021
639.3m²
3023
702.2m²
3016
554.5m²
3017
563.2m²
3018
666.7m²
3019
651.7m²
3020
670.8m²
3022
621.8m²
3012
550.0m²
3014
580.2m²
3011
590.5m²
3010
567.9m²
3008
550.4m²
3013
581.0m²
3015
582.2m²
3007
656.8m²
3028
700.0m²
3027
791.6m²
3034
746.8m²
1096
607.8m²
4063
664.2m²
1052
806.8m²
2040
832.1m²
2035
640.1m²
4071
684.9m²
4082
1055.0m²
1104
834.1m²
1103
976.1m²
1106
3210.5m²
1113
908.0m²
1110
938.4m²
1111
748.8m²
2119
698.1m²
2096
730.1m²
2118
722.3m²
2097
720.4m²
1072
632.7m²
1071
716.3m²
2117
740.8m²
2098
700.8m²
2116
736.2m²
2099
801.9m²
2108
781.0m²
2107
712.4m²
2109
725.5m²
2106
701.7m²
2111
725.7m²
2104
707.0m²
2110
725.6m²
2105
736.0m²
2100
696.4m²
2112
706.5m²
2115
726.0m²
2101
691.0m²
2113
725.8m²
2103
872.1m²
2032
811.5m²
2033
816.8m²
2034
885.2m²
2037 846.2m²
2036
935.1m²
2039 911.9m²
2038
798.4m²
2022
658.6m²
2092 705.2m²
2093725.9
m²2094
872.8m²
2095
567.7m²
2091
622.0m²
1054
652.2m²
1053
806.6m²
1050
752.9m²
1051
699.8m²
1023542.8
m²1022
496.7m²
1015
511.5m²
1021
477.3m²
1016621.5
m²1018
500.8m²
1014
572.9m²
1046
710.9m²
4081
717.5m²
4080
720.1m²
4079
671.8m²
4078
581.0m²
4076
633.8m²
4077
574.5m²
4074
545.2m²
4075
607.3m²
4073
662.8m²
4072
924.4m²
4070
820.3m²
4069
643.7m²
4032 670.2m²
4068
642.9m²
4067
645.3m²
4066608.6m²
4065
586.6m²
4064
804.1m²
4055
709.2m²
4062
584.2m²
4061
554.0m²
4060
471.8m²
4059
538.6m²
4058
592.1m²
4057
645.7m²
4056
615.8m²
4053
688.9m²
4051
620.7m²
4054
631.0m²
4052
611.9m²
6013
589.8m²
6015600.8
m²6014
623.0m²
6012627.5
m²6011
578.9m²
6016
562.8m²
6017
587.9m²
6018
668.4m²
6001
625.7m²
6002
648.5m²
6008646.8
m²6004
650.6m²
6005 638.3m²
6003
640.0m²
6010647.6
m²6009 649.5
m²6007
1139.7m²
6020602.7
m²6019
721.6m²
7005
729.2m²
7004
702.4m²
7003
630.0m²
6076
630.0m²
6075
630.0m²
6074
675.2m²
7001
649.1m²
6079 630.0m²
6078629.9
m²6077
745.3m²
7008
635.4m²
7006
662.8m²
7002
684.8m²
6058
620.5m²
6057
629.6m²
6059
624.9m²
6060
602.0m²
6055661.2
m²6053
600.0m²
6054
630.6m²
6056
601.7m²
6052
747.6m²
6024
658.7m²
7046
633.5m²
7045
673.9m²
7042558.0
m²7040
587.8m²
7041
651.0m²
7043
654.1m²
7044
799.5m²
7037
1352.2m²
7032
1128.8m²
7031
1031.5m²
7034
1122.8m²
7033
776.8m²
7026
739.0m²
7022670.0m²
7023660.0m²
7024717.1
m²7025
859.9m²
7028
778.6m²
7027
873.5m²
7030
855.8m²
7035893.7
m²7036
744.0m²
7038
634.6m²
7039
791.0m²
7029
559.0m²
6072
708.0m²
7017760.7
m²7018
763.9m²
7021
763.9m²
7020
650.9m²
7016
641.7m²
7015
632.4m²
7014
623.1m²
7013
613.8m²
7012
604.4m²
7011
591.8m²
7010
572.5m²
7009
581.6m²
6063
555.8m²
6073
1389.6m²
6080
578.1m²
6068
478.4m²
6070502.5
m²6069
482.3m²
6071 874.2m²
6067
545.0m²
6066
1149.3m²
6061
589.6m²
6062
526.7m²
6065
553.5m²
6064
850.1m²
6041
756.5m²
6043
599.9m²
6039
599.9m²
6044
599.9m²
6038
599.9m²
6045
599.9m²
6037
599.9m²
6046
6413.0m²
6081
599.9m²
6036
721.5m²
6042
760.8m²
6040
685.7m²
6047
688.1m²
6034
688.4m²
6048
600.1m²
6050
600.0m²
6032
600.1m²
6049
610.9m²
6033
600.0m²
6031
1020.0m²
6030
1032.2m²
6051
893.6m²
6023
7342.9m²
6082
600.0m²
6027
707.3m²
6028600.0m²
6026
599.9m²
6025
705.6m²
6029
1303.6m²
6022
592.5m²
5033
647.9m²
5029
659.6m²
5031587.5
m²5030
706.4m²
5032
645.6m²
5034
858.2m²
5013
758.1m²
5010
700.2m²
5009719.3
m²5011
559.1m²
5012
711.1m²
5008
846.7m²
5014
761.3m²
5007
662.0m²
5005683.6
m²4010852.8
m²5006
581.8m²
4005
647.9m²
5028
657.3m²
5025
648.1m²
5026
647.9m²
5027
541.3m²
5015610.5
m²5016
726.7m²
5017 810.8m²
5018
634.2m²
5021
683.9m²
4008
645.4m²
4009
873.0m²
5020
652.5m²
4007
676.2m²
5023 621.2m²
5022622.2
m²4006
571.7m²
4003
584.5m²
4004 573.0m²
4002577.8
m²4001
758.1m²
50351600.0m²
5037
1318.3m²
5039
1531.7m²
5040
844.3m²
5041
820.2m²
5042
859.1m²
5043
711.9m²
5044
706.1m²
5045
862.8m²
5049
713.6m²
5047
837.7m²
5048
1796.2m²
5052848.3m²
5050
752.7m²
5051
672.4m²
4029
593.7m²
4030
593.6m²
4031
624.2m²
4033
649.6m²
4035
641.3m²
4034
636.8m²
4037
654.9m²
4038
624.1m²
4039
666.3m²
4036
676.2m²
4040
704.6m²
4041
697.6m²
4043
748.7m²
4044
693.1m²
4042
827.5m²
4050
720.8m²
4048
814.3m²
4047
904.3m²
4046
720.8m²
4049
802.8m²
2016
790.7m²
2017
662.0m²
2019
745.4m²
2021
821.6m²
2024
1001.6m²
2025
848.3m²
2030
729.3m²
2027 728.9m²
2028 726.6m²
2029
847.2m²
2023
506.4m²
2081
691.4m²
2018
642.1m²
2020
663.1m²
2013
693.3m²
2014
661.4m²
1001
554.7m²
2001
591.0m²
2002
559.2m²
2003
586.5m²
2004
586.5m²
2005
593.7m²
2006
580.5m²
2007
588.1m²
2012 533.1m²
2011 554.4m²
2010 569.0m²
2009
1033.5m²
2031
541.0m²
2069
653.9m²
2086
597.7m²
2089
785.8m²
2087
696.2m²
2068
536.6m²
2090
750.9m²
1055
750.9m²
1057
750.9m²
1056
728.0m²
1068 791.3m²
1083
955.4m²
1081
820.2m²
1084
1105.0m²
1078
920.3m²
1080
841.1m²
1082
820.2m²
1085
820.2m²
1086
750.9m²
1077
461.1m²
1017
478.6m²
1020
580.5m²
1019
884.8m²
1107
847.2m²
1108
902.2m²
1105
701.4m²
1102
703.9m²
1101
703.9m²
1100
715.8m²
1099
710.0m²
1098
720.5m²
1097
585.4m²
1092
733.0m²
1095
710.0m²
1094
605.5m²
1093
627.5m²
1089
571.1m²
1090
565.3m²
1091
502.2m²
1010
465.5m²
1009501.3
m²1008
465.5m²
1007
501.3m²
1003465.5
m²1005
465.5m²
1004
636.3m²
1002916.1
m²3003
680.4m²
3038
1149.0m²
3035
846.6m²
3037996.3
m²3039
868.1m²
3030
670.7m²
3029
630.1m²
1040649.2
m²1039
572.9m²
1041
666.4m²
1035
688.6m²
1038
572.9m²
1042
811.0m²
1032
572.9m²
1043
572.9m²
1045
610.8m²
1048
616.3m²
1025
572.9m²
1047
764.1m²
1049
589.2m²
1026
706.6m²
1024
568.7m²
1027
667.6m²
1031
639.0m²
1029
581.1m²
1028
572.9m²
1044
670.6m²
2042
770.0m²
2067
544.9m²
2046
599.7m²
2043
548.9m²
2044
715.4m²
2064
540.7m²
2045
576.3m²
2047
587.8m²
2062
558.2m²
2061
561.7m²
2048
610.7m²
2054 523.1m²
2053
591.2m²
2050
570.0m²
2051
689.4m²
2055 625.6m²
2056 579.5m²
2057 555.9m²
2058 569.7m²
2059
579.5m²
2049
5475.6m²
2137
719.8m²
4027
841.8m²
4012
759.7m²
4020
725.4m²
4026
837.6m²
4013
783.4m²
4021
727.6m²
4025
636.2m²
4014
817.6m²
4022
795.8m²
5004
646.4m²
4015
841.7m²
4023
727.4m²
5003
642.9m²
4016
723.3m²
4024
734.0m²
5002
646.9m²
4017
735.4m²
5001
707.5m²
4018
931.1m²
4028
843.8m²
4011
713.6m²
4019
759.0m²
2133
618.3m²
2125
808.7m²
2132
630.9m²
2124
849.0m²
2131
767.0m²
2123
871.5m²
2130
855.5m²
2122
858.2m²
2129
767.0m²
2121
943.8m²
2136
800.0m²
2128
927.8m²
2120
722.7m²
2135
746.6m²
2127
729.0m²
2134
664.7m²
2126
688.8m²
2079487.2
m²2077 488.3
m²2076 573.6
m²2075
614.0m²
2073
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2074
605.8m²
2071
586.5m²
2070
577.4m²
1036
573.7m²
1034
479.3m²
1033
844.0m²
1063
777.1m²
1064
774.3m²
1065
761.8m²
1066
776.8m²
1062
747.2m²
1067
740.8m²
1070
747.6m²
1059
736.8m²
1069
777.7m²
1076
586.5m²
1037
747.6m²
1060
446.4m²
2078
867.2m²
2088
628.3m²
4083
668.4m²
4084
680.5m²
2041
615.4m²
2063
599.9m²
6035
610.8m²
1012
494.4m²
1011
596.5m²
1013
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1058
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1073720.0
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1075
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Appendix 4.3.9 Sewerage Preliminary Risk Assessment
Project: Catherine Hill Bay Water UtilityClient: Rose GroupTitle: Sewerage Preliminary Risk Assessment for IPART ApplicationAuthor: BIDate (Revision): 10/07/2013 (Revision B)Risk Criteria: As per Tables 2.5, 2.6 & 2.7: Australian Guidelines for Water Recycling: Managing Health and Environmental Risks‐phase 1 (2006)
Risk RiskTrace contaminants in domestic wastewater
Poor household chemical use and disposal practices resulting in excessive contaminant levels in recycled water
Potential environmental impacts on effluent irrigation areas
C Possible 2 Minor Moderate 1. Customer supply contracts and recycled water use agreement will be developed with each customer and will include obligations and education regarding appropriate substances to be disposed of to sewerage and substances that should be avoided.2. Ongoing customer awareness campaigns and information provided with each water bill and through the CHB Water Utility website.
B Unlikely 2 Minor Low
Trace contaminants in commercial wastewater
Poor trade waste management practices resulting in excessive contaminant levels in recycled water
Potential environmental impacts on effluent irrigation areas
D Likely 2 Minor Moderate 1. Predominately residential sewerage catchment with non‐residential customers account for less than 1% of all wastewater generated. 2. Trade waste agreement will be developed with each non‐residential customers to ensure wastewater is pretreated to domestic standards before discharge into the sewerage system.3. Each non‐residential customer will have its own low pressure sewage pump station to enable monitoring compliance of trade waste agreements.
B Unlikely 2 Minor Low
Shock load of chemical
Poor chemical or trade waste management practices resulting in shock load of contaminants on MBR
Potential biomass die off and reduction in MBR effluent quality.Chemicals may also be an OHS hazard.
A Rare 2 Minor Low 1. Continuous online monitoring of MLSS, DO, pH, EC and other process parameters to detect potential impacts on the treatment process. 2. Investigation will be undertaken into the source of contamination. This may involve review of Pressure Sewer Unit (PSU) operational data, water usage data, trade waste agreement etc.3. Additional online water quality monitoring probes can be installed into suspect PSUs for tracing persistent sources of contamination if required.4. Road tanker pump out of contaminated water from the inlet balance tank if required.
B Unlikely 1 Insignificant Low
Gross pollutants in raw wastewater
Poor solid waste management practices resulting sewer blockage and overflow.
Potential sewer blockage and overflow
E Almost certain
2 Minor Moderate 1. Low pressure sewerage system with grinder pumps will macerate sewage prior to entering the pipe network.2. Appropriately designed network with self cleansing velocities and high head pumps will minimise the potential for network blockage.3. Sewer/pump blockage Emergency Response Plan will be developed for the scheme and will include step for identification of route cause and preventative actions. Where multiple blockages have occurred on the same pump station, specific customer awareness/education will be implemented or compliance notices issued.4. Flushing and maintenance regime will be developed for the pressure sewer network.
C Possible 2 Minor Moderate
Excessive wastewater generation
Peak tourist population or excessive water usage
Build up of raw wastewater in the inlet balance tank and PSUs. Potential overflow to the environment.
C Possible 2 Minor Moderate 1. Water demand management strategy including mandatory best practice water efficient fixtures, smart water metres, customer awareness.2. MBR capacity based on treatment of average daily flows plus 10% contingency at 2.8 EP/ET.3. Flow and level monitoring at each pump unit to detect sources of inflow.4. Road tanker pumpout from individual PSUs if required.
B Unlikely 1 Insignificant Low
Inflow and infiltration to the sewerage network
Inflow and infiltration to the sewerage network
Potential overflow from PSU or inlet balance tank if combined inflows exceed capacity of MBR
D Likely 2 Minor Moderate 1. Low pressure sewerage system constructed with PN16 HDPE with welded joints and fittings.2. Contractor induction and education. 3. Inspection and quality assurance during construction. 4. Flow and level monitoring at each pump unit to detect sources of inflow.5. PSU pump operation centrally controlled by the Direct Digital Control System. PSUs with high water level are given pumping priority.6. Road tanker pumpout from individual pump units if required.
C Possible 2 Minor Moderate
Inflow and infiltration upstream
of Pressure Sewer Unit (PSU)
Inflow and infiltration upstream of Pressure Sewer Unit (PSU)
Potential overflow from PSU or inlet balance tank if combined inflows exceed capacity of MBR
E Almost certain
2 Minor Moderate 1. Plumbing inspection of all household plumbing installation prior to connection.2. Induction and awareness training for all domestic plumbing contractors working in the scheme.3. Flow and level monitoring at each PSU to identify sources of inflow. Customer education and rectification notices will be provided if required.4. Road tanker pumpout from individual PSUs if required.
C Possible 2 Minor Moderate
High peak diurnal flows
Excessive peak inflows Potential overflow from PSU or inlet balance tank if combined inflows exceed capacity of MBR
C Possible 2 Minor Moderate 1. Inlet balance tank at WWTP provides buffer storage for diurnal flows.2. Storage capacity in each PSU provides buffer storage for diurnal flows.3. PSU pump operation centrally controlled by the Direct Digital Control System. PSUs with high water level are given pumping priority in the control system.4. Road tanker pumpout from individual pump units if required.
A Rare 2 Minor Low
Pressure main break Pressure main failure or breakage due to unapproved excavation activity
Discharge of raw sewage to the environment
C Possible 3 Moderate High 1. All mains constructed with PN16 HDPE pipe with welded joints and fittings.2. All mains are pressure tested and certified during construction. 3. Pressure sewer mains are generally located at the bottom of a common services trench, hence other pipes will be damaged from poor excavation practices before the pressure sewer.4. Signage and identification tape to be installed above all pressure mains.5. All sewer pipe locations registered with dial before you dig service.6. Flow monitoring at the WWTP will identify major variations in daily flow.7. Customer Service Centre and fault reporting with maximum response times for operations staff.8. Sewer spill Emergency Response Plan and cleanup procedures will be developed.9. Pressure and flow monitoring in the pressure sewer network.
B Unlikely 2 Minor Low
Mitigated RiskLikelihood Consequence Likelihood Consequence
Control StrategyUnmitigated Risk
Hazardous Event Impact
Wastewater generation
Scheme Component
Hazard
Low Pressure Sewerage Collection System
APPENDIX 4.3.9 Page | 1
Project: Catherine Hill Bay Water UtilityClient: Rose GroupTitle: Sewerage Preliminary Risk Assessment for IPART ApplicationAuthor: BIDate (Revision): 10/07/2013 (Revision B)Risk Criteria: As per Tables 2.5, 2.6 & 2.7: Australian Guidelines for Water Recycling: Managing Health and Environmental Risks‐phase 1 (2006)
Risk RiskMitigated Risk
Likelihood Consequence Likelihood ConsequenceControl Strategy
Unmitigated RiskHazardous Event Impact
Scheme Component
Hazard
Leakage from PSU wet well
Failure of PSU wet well resulting in subsurface leakage
Discharge of raw sewage to groundwater
C Possible 2 Minor Moderate 1. Clean water static pressure test of each wet well during construction. 2. Wet well designed to include allowances for all structural loads including hydrostatic and soil pressures.3. Timber bollards or fencing around all PSUs to prevent vehicle access.4. Water level and flow monitoring at each PSU.
B Unlikely 2 Minor Low
Pump Failure Pump failure by power surge, blockage, loss of suction etc
Potential discharge of raw
sewage to the environmentD Likely 3 Moderate High 1. Duty and standby pumps in each PSU.
2. Fail safe in electrical system so pump can operate with failed network connections.3. High quality robust pumps with long design life. Likely supplier is E‐One.4. Standard pumps with spare pumps maintained onsite for quick changeover if required.
B Unlikely 3 Moderate Moderate
Power failure Extended power failure across pressure sewer network
Potential discharge of raw
sewage to the environmentE Almost
certain 3 Moderate High 1. 24 hours emergency storage is provided in all PSUs.
2. Low pressure sewer network start up and recovery process is included in Direct Digital Control System logic to avoid excessive simultaneous pump operation.3. Road tanker pump out from individual PSUs if required.
B Unlikely 2 Minor Low
Structural failures of tanks and pipes
Tank failure Discharge of process water to environment
C Possible 3 Moderate High 1. Stainless steel tanks with appropriately designed footings.2. Quality assurance during tank manufacture and installation.
A Rare 3 Moderate Low
Process tank overflows
Blockage or fault causing overflow of process tanks
Discharge of process water to environment
C Possible 2 Minor Moderate 1. All process tanks gravity overflow back to inlet balance tank.2. Screening system on inlet to MBR to remove gross solids.
B Unlikely 2 Minor Low
Mechanical/ electrical items
Failure of mechanical electrical items
Non‐compliant recycled water E Almost certain
3 Moderate High 1. Fault detection on all critical mechanical electrical components.2. Continuous online water quality monitoring of critical process parameters, e.g. DO, pH, MLSS, transmembrane pressure, turbidity, UV intensity
C Possible 2 Minor Moderate
Power blackouts Extended power blackout Loss of treatment capacity E Almost certain
3 Moderate High 1. No sewage inflow to MBR during power blackout as pressure sewer system will also be down2. Wastewater will build up in 24 hours emergency storage at each PSU.3. Road tanker pump out from each PSU if required.4. Electrical connection point for mobile power generator to power MBR if required.
C Possible 2 Minor Moderate
Blockage of inlet screening unit
Blockage of screening unit caused by excessive solids in raw wastewater
Carryover of solids to MBR with reduced treatment performance and increased risk of membrane failure
C Possible 2 Minor Moderate 1. Only grinder pump macerated sewage will enter the plant.2. Water level monitoring and high level alarm in screening unit.3. If screening blockage occurs undertake investigation into source of gross solids and implement preventative actions.
B Unlikely 2 Minor Low
Hydraulic overload during diurnal peak flows
Excessive sewerage flows Build up of raw wastewater in the inlet balance tank and PSUs. Potential overflow to the environment.
C Possible 2 Minor Moderate 1. When peak capacity of the MBR is exceeded the inlet balance tank provides buffer storage for diurnal flows.2. 24 hour storage capacity in each PSU can also provide buffer storage in extreme events.3. PSU pump operation centrally controlled by the Direct Digital Control System. PSUs with high water level are given pumping priority through the control system logic.4. Road tanker pump out from individual PSUs if required during operation.
B Unlikely 2 Minor Low
Pollutant overload Excessive BOD or ammonia load
Non‐compliant recycled water C Possible 3 Moderate High 1. Continuous online monitoring of MBR process DO, MLSS, pH with alarms.2. Variable speed drive aeration system to match air supply with inflow. Reserve capacity is designed into the aeration system.3. If process impacts due to high pollutant loads are observed a source control investigation will be undertaken using raw wastewater and trade waste data.
B Unlikely 3 Moderate Moderate
Membrane CIP waste
Return of chemical laden CIP waste through MBR
Potential upset of treatment process and biomass die off
D Likely 3 Moderate High 1. MBR CIP waste is stored and neutralised prior to return to the inlet balance tank.2. If operational problems are experienced MBR CIP waste will be trucked off site to nearest approved facility.
B Unlikely 3 Moderate Moderate
Process chemicals Spillage of process chemicals Potential release of chemicals to the environmentPotential OH&S impacts.
C Possible 3 Moderate High 1. Appropriate bunding and separation of chemicals in chemical storage and delivery area.2. Standard operating procedures for the transport, receipt and use of chemicals.
A Rare 2 Minor Low
Waste activated sludge
Inadequate sludge wastage rates
High MLSS in MBR, decline in effluent quality & increased membrane fouling.
E Almost certain
3 Moderate High 1. Continuous online monitoring of MLSS, DO and TMP with alarms.2. When MLSS reaches maximum set point sludge is pumped from the bottom of the MBR tank to a sludge holding tank before offsite disposal to approved facility.
B Unlikely 3 Moderate Moderate
Membrane failure Membrane failure resulting in carryover of human pathogens
Non‐compliant recycled water D Likely 4 Major Very high 1. Continuous online monitoring of membrane permeate turbidity and transmembrane pressure.2. If event occurs, identify and isolate failed membrane module and if required replace failed membrane module.3. Shut off irrigation supply pump and undertake monitoring of pond water quality to ensure compliance.4. Chemical treatment of pond water can be undertaken if necessary.5. An Emergency Response Plan will be developed for MBR membrane failure.
B Unlikely 4 Major High
Low Pressure Sewerage Collection System
continued..
Wastewater Treatment ‐ Membrane Bioreactor + UV Disinfection
APPENDIX 4.3.9 Page | 2
Project: Catherine Hill Bay Water UtilityClient: Rose GroupTitle: Sewerage Preliminary Risk Assessment for IPART ApplicationAuthor: BIDate (Revision): 10/07/2013 (Revision B)Risk Criteria: As per Tables 2.5, 2.6 & 2.7: Australian Guidelines for Water Recycling: Managing Health and Environmental Risks‐phase 1 (2006)
Risk RiskMitigated Risk
Likelihood Consequence Likelihood ConsequenceControl Strategy
Unmitigated RiskHazardous Event Impact
Scheme Component
Hazard
UV failure Inadequate UV dose due to lamp failure, reactor fouling, high flow or high turbidity
Non‐compliant recycled water E Almost certain
3 Moderate High 1. Continuous online monitoring UV intensity, flow, upstream permeate turbidity and lamp failure.2. If Low UV dose is recorded investigate and rectify.3. Shut off irrigation supply pump and undertake monitoring of pond water quality to ensure compliance.4. Chemical treatment of pond water can be undertaken if necessary.5. An Emergency Response Plan will be developed for UV lamp failure.
C Possible 3 Moderate High
Sabotage/ vandalism
Sabotage/vandalism Potential loss of treatment function
C Possible 4 Major Very high 1. Lockable site with 6‐foot secure fencing.2. Lockable shed for all treatment equipment.3. Remotely accessible CCTV system at WWTP site.4. Community awareness and involvement in the local water scheme.
B Unlikely 3 Moderate Moderate
Noise Excessive noise generation Noise complaints for nearby residents
C Possible 2 Minor Moderate 1. All treatment equipment is located inside the WWTP building.2. 100 metre buffer to the nearest residential dwelling.3. Noisy equipment items will be enclosed in purpose built noise enclosures or insulated plant room. 4. Equipment specification and design will ensure compliance with NSW Industrial Noise Policy of 5 dBA above background noise level at the nearest residential dwelling.5. WWTP building located on Montefiore Road, which is impacted by background traffic noise.6. Noise complaint management system through customer service processes.
A Rare 2 Minor Low
Odour Excessive odour generation Odour complaints by nearby residents
C Possible 2 Minor Moderate 1. All treatment tanks are located inside the WWTP building.2. 100 metre buffer to the nearest residential dwelling.3. All treatment tanks are sealed with passive ventilation through Mcberns activated carbon filters located on the roof of the WWTP building.4. WWTP building includes deodorising sprayers for use if required.5. Odour complaint management system through customer service processes.
A Rare 2 Minor Low
Aesthetics Excessive visual impacts Complaints from nearby residents
C Possible 2 Minor Moderate 1. All treatment equipment is located inside the WWTP building.2. 100 metre buffer to the nearest residential dwelling.3. Vegetation screening around the WWTP site.
A Rare 2 Minor Low
Indoor air quality inside MBR shed
Contamination of indoor air with harmful sewer gases
OH&S impacts B Unlikely 4 Major High 1. All treatment tanks are sealed and externally ventilated.2. Continuous online monitoring of indoor air quality for oxygen, hydrogen sulphide and methane gas inside the WWTP building, with automated air conditioner/ventilation system operation and alarm systems.
B Unlikely 3 Moderate Moderate
Vector borne diseases
Vermin/mosquito invasion of wet weather storage
Potential spread of diseases D Likely 3 Moderate High 1. Steep batters to minimise potential for mosquito growth.2. Regular inspection for evidence vermin access, e.g. mosquito larvae, bird nests etc.
C Possible 3 Moderate High
Unintended contact with recycled water
Human access into storage Potential spread of disease. Potential drowning.
D Likely 2 Minor Moderate 1. Wet weather storage is fenced with appropriate warning signage.2. Remote CCTV system used at WWTP site.3. Safe egress point from storage.
A Rare 3 Moderate Low
Blue green algae Blue green algae outbreak in storage
Inhalation or contact with blue green algae toxins
D Likely 3 Moderate High 1. Low nutrient concentrations in MBR effluent (TP< 0.3 mg/L, TN < 10 mg/L)2. Ongoing monitoring for early detection of algae outbreaks. Algae speciation will be undertaken if outbreak occurs.3. Chemical treatment and/or aeration/mixing of pond will be undertaken if algae outbreak occurs.4. If frequent outbreaks occur a permanent aeration/mixer will be installed into the pond.
B Unlikely 2 Minor Low
Leakage to groundwater
Leakage to groundwater Contamination of groundwater C Possible 3 Moderate High 1. HDPE lined storage.2. Continuous online monitoring of pond water level to detect leaks.3. Groundwater monitoring
B Unlikely 3 Moderate Moderate
Stormwater inputs Stormwater runoff into storage during rain events
Increased potential for overflow
D Likely 2 Minor Moderate 1. Turkey nested dam to avoid inputs from stormwater runoff. A Rare 1 Insignificant Low
Uncontrolled overflow
Uncontrolled overflow from
the wet weather storage during extended wet weather
Stormwater contamination D Likely 3 Moderate High 1. MEDLI modelling indicates the 10 ML did not overflow based on 100‐years of historic climate data.2. Continuous online monitoring of storage water level with automatic scheduling of emergency irrigation events to irrigation areas will be undertaken as required to avoid uncontrolled overflow.3. Removal of excess water by road tanker pump out if required.
A Rare 2 Minor Low
Dam wall failure Dam wall failure Surface runoff and flooding C Possible 4 Major Very high 1. Design of dam walls with scour protection in the unlikely event of uncontrolled overflow.2. MEDLI modelling predicts the storage will not overflow based on historic rainfall data.3. Continuous online monitoring of storage water level with automatic scheduling of emergency irrigation events as required to avoid uncontrolled overflow.
B Unlikely 2 Minor Low
Wet Weather Storage
Wastewater Treatment ‐ Membrane Bioreactor + UV Disinfection continued…
APPENDIX 4.3.9 Page | 3
Project: Catherine Hill Bay Water UtilityClient: Rose GroupTitle: Sewerage Preliminary Risk Assessment for IPART ApplicationAuthor: BIDate (Revision): 10/07/2013 (Revision B)Risk Criteria: As per Tables 2.5, 2.6 & 2.7: Australian Guidelines for Water Recycling: Managing Health and Environmental Risks‐phase 1 (2006)
Risk RiskMitigated Risk
Likelihood Consequence Likelihood ConsequenceControl Strategy
Unmitigated RiskHazardous Event Impact
Scheme Component
Hazard
Cross connection with potable or non‐potable water networks
Cross connection between temporary irrigation network and other water networks
Contamination of other water supplies
C Possible 5 Catastrophic Very high Temporary irrigation management plan will be developed for the scheme and will include the following cross connection controls:1. Temporary irrigation system to operate under low pressure.2. Unique pipe materials. Temporary Irrigation Network is to use Lilac striped HDPE pipe.3. Temporary Irrigation Network pipes to be laid in their own separate trench with identification tape and above ground signage.4. Only approved, trained and supervised plumbing contractors are permitted to work on reticulation systems.
B Unlikely 3 Moderate Moderate
Unintended uses or human contact with recycled water
Unintended uses or human contact with recycled water
Potential health impacts D Likely 3 Moderate High Log reduction targets for the temporary irrigation system will be achieved with the following site based controls:1. Secure, restrictive access temporary irrigation areas including warning signs, identification and labelling.2. Surface sprinklers with spray drift control including sprinkler nozzles that operate under low pressure with a large droplet size and low throw height.3. A minimum 30 m buffer distance between the edge of the temporary irrigation areas and the closest dwelling.4. No above ground taps or fixtures in temporary irrigation areas.5. Lockable irrigation valves pits and controllers etc.6. Soil moisture probes and weather station override on irrigation controllers to prevent irrigation during rainfall, high wind or elevated soil moisture.7. Irrigation at night time only under normal conditions.8. Non‐irrigated, vegetated buffer strips down gradient of the temporary irrigation areas.
A Rare 3 Moderate Low
Spray drift during irrigation
Spray drift onto sensitive receptor
Potential ingestion of recycled water
E Almost certain
3 Moderate High 1. Weather station override on irrigation controllers to prevent irrigation during high wind.2. Surface sprinklers with spray drift control including sprinkler nozzles that operate under low pressure with a large droplet size and low throw height.3. A minimum 30 m buffer distance between the edge of the temporary irrigation areas and the closest dwelling.
A Rare 2 Minor Low
Irrigation during wet weather
Irrigation during wet weather resulting in surface runoff or deep percolation of effluent
Contamination of surface and/or groundwaters
E Almost certain
3 Moderate High 1. 10 ML wet weather storage provides approximately 100 days storage at average irrigation rates.2. Soil moisture probes and weather station override on irrigation controllers to prevent irrigation during rainfall, high wind or elevated soil moisture.3. Non‐irrigated, vegetated buffer strips down gradient of the temporary irrigation areas.
A Rare 2 Minor Low
Irrigation rates and scheduling
Inappropriate irrigation scheduling
Increased risk of surface and ground water contamination
C Possible 2 Minor Moderate 1. Irrigation scheduling will use programmable irrigation controllers to control irrigation frequency, time and duration. Irrigation rates will be calibrated to ensure no ponding.2. Irrigation rates will be seasonally adjusted in the irrigation controller to match seasonal irrigation demand.
B Unlikely 2 Minor Low
Recycled water Surface runoff during irrigation Potential contamination of surface water
C Possible 3 Moderate High 1. All temporary irrigation areas to use irrigation scheduling controls to control the time, frequency and duration of irrigation events.2. Soil moisture probes and weather station override on irrigation controllers to prevent irrigation during rainfall or elevated soil moisture.3. Site based storm water run off and environmental controls.4. Non‐irrigated, vegetated buffer strips down gradient of the temporary irrigation areas.
B Unlikely 2 Minor Low
Nitrogen Excessive nitrogen load resulting in leaching of nitrate from irrigation areas
Contamination of groundwater C Possible 3 Moderate High 1. Irrigation of "Class A" recycled water with total nitrogen concentration of 10 mg/L and low average irrigation rates of around 0.9 mm/day.2. MEDLI modelling indicates all nitrogen applied in irrigation is taken up by vegetation.3. MEDLI modelling indicates negligible nitrate concentration in deep drainage.
B Unlikely 2 Minor Low
Phosphorus Excessive phosphorous load resulting in leaching of phosphate from irrigation area
Contamination of groundwater C Possible 3 Moderate High 1. Irrigation of "Class A" recycled water with total phosphorus concentration of 0.3 mg/L and low average irrigation rates of around 0.9 mm/day.2. MEDLI modelling indicates the majority of phosphorus applied in irrigation is taken up by vegetation.3. MEDLI modelling indicates negligible phosphate concentration in deep drainage.4. MEDLI modelling predicted Phosphorus adsorption into soil at a low rate of 0.3 kg/ha/year.5. Critical P‐sorption life of the soil is conservatively estimated to be >166 years based on P‐sorption capacity of holocene sand.
B Unlikely 2 Minor Low
Effluent Salinity Impacts on plant growth due to salinity
Reduction in plant growth and water and nutrient uptake rates
C Possible 2 Minor Moderate 1. MEDLI modelling indicated no impacts on plant growth due to salinity based on a conservative effluent TDS of 1500 mg/L.2. Landscape design processes will ensure appropriate vegetation is selected in temporary irrigation areas that can tolerate the required salt concentrations.3. The natural sandy top soil profile and relatively high rainfall at the site will assist with flushing of salt through the soil profile to minimise potential salinity impacts on vegetation.
B Unlikely 3 Moderate Moderate
Stage 1 temporary, restricted access Irrigation System
APPENDIX 4.3.9 Page | 4
Project: Catherine Hill Bay Water UtilityClient: Rose GroupTitle: Sewerage Preliminary Risk Assessment for IPART ApplicationAuthor: BIDate (Revision): 10/07/2013 (Revision B)Risk Criteria: As per Tables 2.5, 2.6 & 2.7: Australian Guidelines for Water Recycling: Managing Health and Environmental Risks‐phase 1 (2006)
Risk RiskMitigated Risk
Likelihood Consequence Likelihood ConsequenceControl Strategy
Unmitigated RiskHazardous Event Impact
Scheme Component
Hazard
Effluent SAR Long term sodicity impacts on soil
Soil dispersion, reduction in permeability
C Possible 2 Minor Moderate 1. Topsoil profile is dominated by sand, hence the likelihood of sodicity impacts is low.2. Detail geotechnical testing to be undertaken for each development stage will avoid areas with high clay content and Exchangeable Sodium Percentage (ESP).3. Ongoing monitoring of soil cations will detect changes in soil ESP over time.4. If required gypsum/lime application to irrigation areas will be undertaken. 5. If required the irrigation water SAR will be adjusted through addition of calcium/magnesium or reduction in sodium inputs to maintain effluent SAR<5.
B Unlikely 2 Minor Low
Metals and trace contaminants
Trace contaminants in irrigation supply resulting in long term accumulation in irrigation area
Contamination of soil and groundwater
C Possible 2 Minor Moderate 1. Source catchment is >99% domestic wastewater hence the likelihood of trace contaminants is low.2. Customer awareness campaigns, supply contracts, trade waste agreements and recycled water use agreements will further reduce the likelihood of events occurring.3. Detailed monitoring of effluent quality for trace contaminant will be undertaken annually using a NATA accredited laboratory.4. Soil monitoring in temporary irrigation area will identify any build up or increase in contaminants. 5. If contaminants are detected then an investigation into the likely source will be undertaken and trade waste/source controls implemented.6. If required additional treatment processes can be installed, e.g. BAC, ion exchange.
B Unlikely 2 Minor Low
Recycled water Pipe breakage Potential contamination of surface or groundwater
C Possible 2 Minor Moderate 1. Flow and pressure monitoring in the temporary irrigation supply system.2. Visual inspection to identify boggy areas or erosion etc.
B Unlikely 2 Minor Low
Odour Odour released during irrigation
Odour impacts on nearby residents
B Unlikely 2 Minor Low 1. Irrigation of high quality "Class A" recycled water with low BOD2. Algae control in the wet weather storage3. Irrigation at night time only.4. A minimum 30 m buffer distance between the edge of the temporary irrigation areas and the closest dwelling.
A Rare 2 Minor Low
Stormwater runon Stormwater running onto irrigation areas from
upgradient
Water logging of irrigation area D Likely 2 Minor Moderate 1. Stormwater diversion drains to divert all upgradient stormwater runoff around temporary effluent irrigation areas.2. Appropriate buffers to waterways, ponds, stormwater drains and SEPP14 wetlands
A Rare 2 Minor Low
Percolation to groundwater
Excessive percolation of effluent to groundwater
Contamination of groundwater C Possible 3 Moderate High 1. Low long term average irrigation rate of approximately 0.9 mm/day, hence low risk of groundwater contamination.2. Minimal presence of groundwater within 3 metres of ground surface in geotechnical investigation.3. Irrigation of high quality "Class A" recycled water with low nutrients.4. MEDLI modelling indicates negligible concentrations of nutrients in deep drainage for conservative sandy soil profile.5. A minimum of 600mm sandy loam topsoil cover will be provided on irrigation areas if there is potential for seasonal high water table.
B Unlikely 2 Minor Low
Stage 1 temporary, restricted access Irrigation System
continued…
APPENDIX 4.3.9 Page | 5
Qualitative measures of likelihood
Level Descriptor
A Rare
B Unlikely
C Possible
D Likely
E Almost certain
Qualitative measures of consequence or impact
Level Descriptor
1 Insignificant
Qualitative risk analysis matrix: Level of risk
1 2 3 4 5
Insignificant Minor Moderate Major Catastrophic
A Rare Low Low Low High High
B Unlikely Low Low Moderate High Very high
C Possible Low Moderate High Very high Very high
D Likely Low Moderate High Very high Very high
E Almost certain Low Moderate High Very high Very high
Health — Major impact for large population Environment — Potentially lethal to regional ecosystem or threatened species; widespread on‐site and off‐site impacts
Consequences
Likelihood
Example Description from AGWR May occur only in exceptional circumstances. May occur once in 100 years
Could occur within 20 years or in unusual circumstances
Might occur or should be expected to occur within a 5‐ to 10‐year period
From tables 2.5, 2.6 and 2.7 on Page 39 of the Australian Guidelines for Water Recycling Managing Health & Environmental Risks Phase 1 (2006)
QUALITATIVE ENVIRONMENTAL AND PUBLIC HEALTH RISK ASSESSMENT CRITERIA SEWERAGE
5 Catastrophic
3 Moderate
4 Major
Health — Minor impact for large population Environment — Potentially harmful to regional ecosystem with local impacts primarily contained to on‐site Health — Major impact for small population Environment — Potentially lethal to local ecosystem; predominantly local, but potential for off‐site impacts
2 Minor
Is expected to occur with a probability of multiple occurrences within a year
Example Description from AGWR
Insignificant impact or not detectable
Health — Minor impact for small population Environment — Potentially harmful to local ecosystem with local impacts contained to site
Will probably occur within a 1‐to 5‐year period
APPENDIX 4.3.9 Page | 6