wastewater disposal and water supply preliminary report woodlane

WASTEWATER DISPOSAL AND WATER SUPPLY PRELIMINARY 

REPORT 

WOODLANE 

Prepared for 

RURAL CITY OF MURRAY BRIDGE 

by 

JANUARY 2008 

REVISION B 

Job No: C070250

CONTENTS 

1. PROJECT APPRECIATION 

1.1 INTRODUCTION 

1.2 BACKGROUND INVESTIGATION 

1.2.1 DOCUMENTATION REVIEW 

1.2.2 INVESTIGATION AND EXPLORATION 

1.2.3 INTERPRETATION OF FINDINGS 

2. SEWAGE DISPOSAL SCHEME 

2.1 SEWERAGE SCHEME 

2.1.1 ASSETS REGISTER 

2.1.2 CAPACITY ASSESSMENT 

2.2 EFFLUENT TREATMENT AND REUSE 

2.2.1 WASTEWATER TREATMENT PLANT 

2.2.2 IRRIGATION 

3. WATER SUPPLY SYSTEM 

3.1 GENERAL 

3.2 WATER TREATMENT PLANT 

3.3 ALTERNATIVE FUTURE WATER SUPPLY 

4. ISSUES AND RECOMENDATIONS 

4.1 SEWAGE SYSTEM 

4.2 WATER SUPPLY 

4.3 OPERATION AND MAINTENANCE 

Woodlane Wastewater Disposal and Water Supply Preliminary Report 

Wallbridge & Gilbert/070250rp002RevB/January 2008 Page 1

CONTENTS (continued) 

5. APPENDICES 

APPENDIX A – Secon Consulting Engineers Drawings List 

APPENDIX B – Aeroflo WWTP Layout 

APPENDIX C – Sewer Pump Curves 

Data Sheets and Performance Curves 

APPENDIX D – Sewer Assets Register 

APPENDIX E – Sewage Capacity Assessment 

APPENDIX F – DAC Approvals 

APPENDIX G – DH Approval December 1998 

APPENDIX H – DH Approval 21 August 1996 

APPENDIX I – DH Approval 17 December 1996 

APPENDIX J – GHD Water Treatment Plant Assessment 

APPENDIX K – Abtech WTP Specifications 

APPENDIX L – Abtech WTP Maintenance Schedule 

APPENDIX M – Abtech Plant Log Sheet 

APPENDIX N – SA Water Chemical Dosage Records 

APPENDIX O – SA Water Main Layout 

APPENDIX P – Photographs 



CONTENTS (continued) 

6. REFERENCES 

1. Secon Consulting Engineers Submitted Report 3, 

Woodlane and Mypolonga Shacks, Document No. 

91632 REP Rev 2, 29 July 1997. 

2. Norman Waterhouse Effluent Scheme Draft Agreement 

between Council and Secon Consulting Engineers, ref: 

227041/SDK0029, 24 December1999. 

3. United Water Woodlane STEDS Audit Report, April 

2006. 

4. Abtech Water Treatment Plant Specifications, 

Installation, Operation, Maintenance and Material 

Technical Data Booklet, 12 October 1998. 

5. SA Water Draft Agreement No 544. 

6. Australian Water Quality Centre Final Analytical Report 

issued to DIPA Consulting, Customer Service Request 

No. 140836-2007-CSR-1, Sample Date Range 11 Oct 

07 – 24 Oct 07. 

7. Department of Water, Land and Biodiversity 

Conservation Water Licence Nos. 943 & 2740 



1. PROJECT APPRECIATION 

1.1 INTRODUCTION 

The Woodlane wastewater disposal and water supply schemes were originally 

proposed to be constructed by Mr Desmond Murray and Pat Wynne as part of 

their residential sub-division development with development act approvals 

obtained from The Rural City of Murray Bridge in April 1997. The schemes 

were commissioned in 2001. The schemes were then handed over to The 

Rural City of Murray Bridge, serving 40 new residential properties and 19 preexisting 

shacks. The schemes were developed along the Murray River 

immediately above the 1956 flood level. The land was previously utilised as an 

orange orchard. 

Copies of the Development Act Approvals (development number 415/240/96) 

issued by Council are attached in Appendix F for reference. 

The consultant engaged to undertake the project was Secon Consulting 

Engineers (former Hutt Pike and Associates), with Robert C. Frazer and 

Associates Consulting Engineers as the Civil Engineer. Norman Waterhouse 

was engaged by Council to be their legal solicitor for this project. 

The Woodlane wastewater scheme consists of two separate collection 

networks. One services the new housing development along North Bokara 

Road and Woodlane Drive, which comprises a network of gravity drains with a 

connection point provided to each property within the scheme limits. There are 

no on-site septic tanks within the sub-division and all sewage gravitates directly 

to a single pump station at a low point in the system along North Bokara Road 

in front of Lot 34. It is then pumped through a rising main to a wastewater 

treatment plant approximately 1.3km south of the development at Lot 50 

Woodlane Drive Hd Mobilong at about 53m AHD. Treated effluent from the 

plant is then disposed of on a nearby woodlot. 

The other network services the existing (as at 1997) shacks closer to the river 

along Mathews Court with a connection point provided to each shack, 

bypassing the existing septic tanks. The effluent gravitates directly to a second 

pump station along Mathews Court near Lot 11, from where it is pumped 

through a separate rising main to the sub-division pump station. 



The water supply system draws water from the Murray River via two Councilowned 

screened positive displacement pumps (DAB Jet 100 MX) housed in a 

pump shed by the river bank. Raw water is then pumped to a water treatment 

plant located between the shack site and the sub-division along North Bokara 

Road, after which treated water is then reticulated through both the sub-division 

and the shack site. There are no water meters at each residential property and 

shack allotment. 

Both the wastewater disposal and water supply schemes are currently 

maintained by Council but due to the lack of associated as-constructed 

information, Council has been unable to have a complete appreciation for their 

operational requirements. 

Wallbridge and Gilbert (W&G) was engaged to prepare operational and 

maintenance manuals for both schemes. W&G proposed a 2 stage process to 

prepare the manuals, Stage 1 was an investigation into the system to 

determine the components of the system and their general condition. Stage 2 

was to prepare the operation and maintenance manuals. W&G have initially 

been engaged to complete stage 1 only. This report presents the findings of 

the stage 1 investigation. 

1.2 BACKGROUND INVESTIGATION 

1.2.1 Documentation Review 

From an initial review conducted of all the documentation provided by Council, 

information on the Woodlane wastewater and water schemes in general were 

found to be incomplete with several inconsistencies identified during the 

preliminary site investigations. Council lacks as-constructed drawings for the 

scheme, with the majority of their drawings being for tendering and design 

purposes only. 

A list of Secon drawings provided by Council has been attached in Appendix A 

for reference. Among the eleven drawings only the Water Services and the 

Water Treatment Plant layout are as-constructed, with the remaining as tender 

and design drawings and some of which do not conform to observations made 

on site. 



The key information deficiencies identified were: 

Actual layouts and as-constructed configurations of the sewer and 

water supply system. 

Capacities of the wastewater and water supply system. 

Relationship between the Woodlane reserve toilet block and the 

wastewater and water supply system. 

Process flow, performance and maintenance of the wastewater and 

water treatment plants. 

Approval status from the Department of Health (DH) and Environment 

Protection Authority (EPA). 

A summary of the documents provided by Council is presented below: 

1. Secon Consulting Engineers Submitted Report 3: Woodlane and 

Mypolonga Shacks, Document No, 91632 REP Rev 2, 29 July 1997 

It is not clear who this report was originally addressed to as details of the 

recipient were not found anywhere in the report. However, judging from its 

contents it is apparent that it was compiled to be submitted to the thendeveloper 

Des Murray and Pat Wynne, with all the proposed design and 

statutory application details attached. 

A diagrammatic map (91632SK9) showing the entire water supply and 

wastewater system for the sub-division and shacks was attached to the report. 

This drawing was a concept and does not reflect the as-constructed scheme. 

In contrast the other diagrammatic key plan (Item 1 in Appendix A) without any 

plot date appears to be a reasonable representation of the system as it is 

consistent with other information obtained. 

Drawing Plan 91632/ST1 (Sewer Treatment Plant Enclosure) does not show 

the as-built scenario of the wastewater treatment plant. 

Section 2 of the report states that there is to be only one 22kL water storage 

tank at the water treatment plant, but there are two of them on site. Section 7 

describes three Grundfos CR4-60 vertical multistage water pumps in the water 

treatment plant, but there are only two. 



Section 8 indicates that there was to be auto paging systems incorporated into 

both sewer pump stations, but this is not the case, as verified by ITT Flygt 

Limited who had installed the pump stations. 

Section 9 of the report indicated that WPS were initially to be engaged to 

undertake the work due to their successful disinfection trials conducted with SA 

Water Corporation. However it appears that the works were undertaken and 

commissioned by Abtech Environmental Services Pty Ltd (Abtech). The reason 

for this change could not be determined. 

An application was lodged with the SA Health Commission for the WWTP, 

however the application was based on the outdated drawing 91632/ST1 as 

described earlier and there is not any response letter from the Commission 

attached in the report. 

The above inconsistencies indicate that there were a number of changes made 

to the installation after the compilation of this report. It is clear that the Secon 

report was preliminary in nature and a number of changes were made and not 

registered. 

2. Health Commission (DH) 

The proposed scheme for the installation of the wastewater collection and 

treatment system for the Woodlane sub-division and Mypolonga shacks was 

approved by the Department of Health (DH) (refer Appendix G), however due 

to the lack of an EPA license the DH approval is considered invalid, as 

bounded by one of its conditions of approval. 

The United Water audit report identified that the scheme was within the Murray 

River Water Protection zone. This means that the threshold for requiring an 

EPA license is lowered from 1000EP schemes to 100 EP schemes. This 

scheme has an EP greater than 100 and therefore if it is in a water protection 

zone should be licensed by the EPA. 

Other DH conditions of approval not met are (refer Appendix G): 

- There is a lack of an automatic telemetry notification system for both pump 

stations in the event of alarms. 

- There is no formal management agreement between the then-developer, 

the Mypolonga shacks owners and Council for the continued 



esponsibilities of each party required to connect to the scheme, the 

individual requirements to connect to the scheme, and the on-going 

operation and maintenance of the wastewater collection, treatment and 

irrigation scheme. A draft effluent scheme agreement between Council and 

Secon was drawn up by Norman Waterhouse, ref 227041/SDK0006, dated 

15 May 1997 but it wasn’t formalised. 

- There is a lack of evidence to indicate that Shack Lot 19 as shown on 

Drawing 96210/P01 is connected to the scheme by pumping, as required 

in the management agreement described above. Interviews with Council 

staff has also revealed that only 18 out of a total 19 pre-existing shacks are 

connected to both the wastewater treatment and water supply schemes. 

Nonetheless it is understood that Council is currently in the process of 

establishing the connection of Lot 19 to the scheme. 

- Non availability of any operation and maintenance manuals for the 

wastewater treatment system and the irrigation scheme. 

Attached in Appendices H and I are the letters of pre-approvals from the South 

Australian Health Commission (SAHC) for the development of the wastewater 

treatment and water supply system respectively, both dated 1996. 

1.2.2 Investigation and Exploration 

In addition to meetings and interviews with Council staff, W&G explored other 

means of obtaining any available updated information outside Council’s 

network. This was done to achieve the most accurate and reliable database on 

which to base the scheme assessment. 

The organisations contacted and the relevant findings are summarised below: 

1. Secon Consulting Engineers (Secon) 

Based on the initials printed on the Secon drawings, Mr Ken Hutt was traced 

and contacted, who had been the project manager and main liaison person 

representing the developer in the project. At the time of contact he had left 

Secon but verified that the available drawings provided by Council are all that 

are available. A similar enquiry to Secon directly had drawn the same 

conclusion. 



Although not critical, it may be worth mentioning that unlike the other drawings, 

91632/P06 – Eco Trap on Stormwater was issued by Hutt Pike and Associates 

and from its much earlier plot date (Oct 1995), it seemed that there had been a 

transition from Hutt Pike to Secon during the design phase. This was later 

verified by Ken himself. 

With regard to the Woodlane reserve toilet block Ken recalled that it was 

connected to the sewerage and water supply system only after the handover of 

the completed project to Council. This connection is not shown anywhere on 

the drawings, although subsequent liaison with SA Water confirms that the 

toilet block is connected to a nearby SA Water 100mm main approximately 

170m away on North Bokara Road. 

2. SA Water 

Contact with the SA Water Chemical Dosing Department at Murray Bridge 

suggests that the two raw water pumps by the river do not belong to SA Water 

but to Council, although they do sometimes maintain the pumps when required, 

despite the lack of any formal agreement for them to do so. The pumps are 

model DAB Jet 100 MX, located within a screened shed together with two other 

operating irrigation pumps (Hydro Titan) that irrigate the reserves within the 

development. SA Water believes that these irrigation pumps are owned and 

maintained by the local residents. 

3. Department of Water, Land and Biodiversity Conservation (DWLBC) 

Feedback from the DWLBC has indicated that Council does possess a water 

licence (Licence no. 2740) taking 20,000kL of water per annum for the 

Woodlane sub-division for domestic purposes. DWLBC however also indicated 

that no water licence has been issued for the shacks. 

A water meter (meter no. 30125494) was also present in the water treatment 

plant located along the river water intake pipe and is owned by Council, but 

monitored by DWLBC for the river water intake amount. 

Another water licence issued to Council is for the Woodlane public reserves 

under licence no. 943 and measured off water meter no. 12273. The Woodlane 

reserves together with several other reserves are allocated a total of 249,560kL 

of water per annum for recreational purposes from the Murray River. 



4. Aquatec-Maxcon Pty Ltd (Aquatec) 

Known as Aeroflo during the project construction stage, and formerly as Copa 

Water, Aeroflo later traded as Eimco Water Technologies and was recently 

bought out by Aquatec. Contact established with Phil Mercer, Eimco’s previous 

Regional Manager, who had been involved in the maintenance of the 

wastewater treatment plant, has provided us with an as-built layout plan of the 

plant, dated May 2003 (refer Appendix B). For reference purposes this plan 

should supersede the Secon Drawing Plan 91632/ST1 (Sewer Treatment Plant 

Enclosure) as described earlier in Section 1.2.1. 

It can be seen from the as-built layout that drying ponds were originally 

installed just outside the fenced area to receive backwash waste from the sand 

filter and sludge from the waste activated pump, but these sludge beds have 

since been decommissioned. 

Based on the audit report submitted by United Water, April 2006, due to OHS 

infringement and odour events, backwash waste from the sand filter was 

pumped back into the treatment plant under the approval of Copa Water, this 

being the case at least up to the time of submission of the audit report. This is 

quite evident from the site investigation conducted, where the backwash pipe 

was observed to eventually fall into the intermittent aeration tank (IAT) (see 

Appendix P Photos 12, 15 and 16). However, a deliberate disconnection of the 

backwash pipe was also noticed a few metres away from the irrigation pump 

shed (see Appendix P Photo 13), hence suggesting that backwash did not 

reach the IAT. We believe that the disconnection occurred only within the last 

two years. 

Interestingly, a subsequent visit on the 13 Dec 2007 showed that the backwash 

pipe had been connected (see Appendix P Photo 14), although it is not clear 

how and when exactly this had happened. 

As a result of the re-routing of the backwash waste, the drying ponds had since 

been abandoned (see Appendix P Photo 17) and the waste activated pump is 

no longer in service. A 60mm dia. transfer pipe from the submersible pump to 

the drying ponds is still clearly visible (see Appendix P Photo 8), and a metal 

label plate by the side of the IAT indicates that it is a Flygt pump. Feedback 

from ITT Flygt reveals that they no longer have any records of this pump. 



It is understood that Aquatec has declined their last service renewal with 

Council, with their last service conducted in March 07 and DIPA Consulting has 

since been engaged to undertake this work as at July 07. 

5. ITT Flygt Limited 

Details of the two pump stations was obtained from ITT Flygt and are attached 

in Appendix C. 

Both stations are generally in good condition, as outlined on the provided data 

sheets, dated in April 2004 and April 2006 for the sub-division station and 

shack station respectively. The valve chamber lid for the sub-division pump 

station is reported to be very tight, as also verified from the site investigation. 

Interestingly feedback from ITT confirmed that both stations together with the 

pumps were installed in 1995, much earlier than the completion of the 

wastewater disposal scheme which was around 1998. 

1.2.3 Interpretation of Findings 

Other than the as-constructed drawings for the water supply network (Appendix 

A Items 3 and 8), site investigations, interviews with Council staff, liaisons with 

relevant organisations and review of provided documents have shown that the 

remaining of the Secon drawings are generally reliable with the following 

exceptions: 

 

 

 

 

An additional connection for the Woodlane reserve toilet block to be 

allowed for the wastewater disposal system, based on the assumption 

of direct connection to the nearest sewage manhole. 

Layout and details of Shack Pump Station shown on Drawing 

96210/P02 is not accurate. Refer to ITT Flygt’s data sheet instead 

(refer Appendix C). 

Layout of the wastewater treatment plant shown on Drawings 

91632/P01 and 91632/ST1 are to be replaced by the as-built layout 

provided by Aquatec (refer Appendix B). 

Stormwater plans (91632/P05 and 91632/P06) are not considered for 

the compilation of this report and hence have not been verified for 

accuracy. 



2. SEWAGE DISPOSAL SCHEME 

2.1 Sewerage Scheme 

2.1.1 Assets Register 

An asset register was compiled for the Woodlane sewerage scheme based on 

the interpretation of findings outlined earlier in Section 1.2.3 and is attached in 

Appendix D. 

In summary the system consists of the following major components: 

 

985m of 150 mm diameter uPVC gravity drains 

 

 

 

 

 

 

 

220m of 50mm diameter uPVC CL12 rising main 

1,290m of 100mm diameter uPVC CL9 rising main 

2 effluent pump stations 

59 connections 

14 manholes 

15 inspection openings 

1 wastewater treatment plant with reuse irrigation scheme 

There are two separate rising mains in the network, a 50mm main from the 

shack pump station to the sub-division pump station, and a 150mm main 

pumping from the sub-division station to the wastewater treatment plant. 

Reinforced concrete manholes are generally located on drain junctions and at 

end of drains, with a control manhole situated on the drains just before entry 

into the pumping chambers. Inspection openings are generally situated along 

the drains. 

A general description of the pump stations is presented in Table 1 and a 

summary of the pump technical data is presented in Table 2. 



Table 1 – Pump Stations Description 

Pump 

Station 

1 

2 

Location Pump Well No. of Inlets 

No. Allotments 

Serviced 

North Bokara 

2000mm x 4000mm 

Road in front of 

depth, precast 

Lot 34 

2 59 

Mathews Court 2000mm x 3000mm 

near Lot 11 depth, precast 

1 18 

Table 2 – Pump Technical Data 

Pump 

Station 

Pump 

Model 

Duty 

Flow 

Pump 

Head 

Motor 

Operating 

Speed 

Installation 

1 – 

Pump 1 

Flygt 

CP3152.181 

submersible 

4.0 

L/s 

64.5m 

415V, 26A, 

3Ph, 15kW 

1400 rpm 1995 

1 – 

Pump 2 

Flygt 

CP3152.181 

submersible 

4.0 

L/s 

64.5m 

415V, 26A, 

3Ph, 15kW 

1400 rpm 1995 

2 – 

Pump 1 

Flygt 

CP3057.180 

submersible 

5.0 

L/s 

15.7m 

415V, 3.5A, 

3Ph, 1.5kW 

1400 rpm 1995 

2 – 

Pump 2 

Flygt 

CP3057.180 

submersible 

5.0 

L/s 

15.7m 

415V, 3.5A, 

3Ph, 1.5kW 

1400 rpm 1995 

The details of both pumps have been based on information provided by ITT 

Flygt Limited as attached in Appendix C. Pump Station 1 (see Appendix P 

Photo 1) pumps effluent generated from both the sub-division (40 lots) and 

shacks area (18 lots), including the toilet block located on the nearby reserve to 

the treatment plant. Pump Station 2 (see Appendix P Photo 2) pumps only the 

effluent from the shacks to Pump Station 1, and with the exclusion of Lot 19 

there are only 18 connections out of total 19 shacks. 

For further details of the system layout, refer to Secon drawings as listed in 

Appendix A. 



2.1.2 Capacity Assessment 

To determine the current system load and its capacity for future expansion, a 

stand-alone assessment of the Woodlane sewerage was computed and is 

attached in Appendix E. Some assumed parameters of the assessment are as 

follows: 

Peak factor 3 

Average daily flow 490 L/connection/day 

The calculated flows for the pump stations are summarised below in Table 3. 

Table 3 – Pump Stations Summary 

Pump 

* Storage 

ADF Peak Flow Pump 

Time to Overflow Time to Overflow 

Station 

Capacity 

(L/d) (L/s) duty (L/s) 

(Local catchment) (System) 

No. 

(m 3 ) 

1 28,910 1.004 4.00 12.79 15.28 hrs 10.62 hrs 

2 8,820 0.306 5.00 6.90 18.77 hrs 18.77 hrs 

* Total emergency storage consisting of both the pump sump (storage above high level 

alarm) and incoming drains (storage between inlet inverts and overflow levels). 

Note that for Pump Station 1, the time to overflow for the local catchment is 

greater than for the system. The reason for this is that if PS2 is operating then it 

will pump into pump station 1 reducing its storage time. If PS2 is not working 

i.e. a complete area wide power failure, then PS 1 only receives effluent from 

the gravity connections directly connected to the pump station catchment. This 

means that the storage time will be greater than if PS2 is pumping effluent into 

PS1. 

As there is no other contributing effluent into Pump Station 2 its storage time 

remains constant at 18.77 hrs. 

Table 4 presents the emergency storages available for the pump sumps only 

and could be considered the worst case scenario with no line storage included. 



Table 4 – Pump Stations Sump Overview 

Inlet-1 Inlet-2 Sump 

High Low + Emerg. 

Pump Sump 

Pump Pump 

Invert Invert Floor 

Alarm Alarm Storage 

Station Top RL 

On RL Off RL 

RL RL RL 

RL RL (hrs) 

1 5.080 3.280 

Unknown 

1.080 3.580 4.280 2.880 nil 5.74 

2 2.500 1.000 nil -0.500 1.300 2.000 0.700 nil 15.39 

+ Emergency storage consisting of only the pump sump (storage above HL alarm) with no 

assumed drainline storage. 

Based on the data provided by ITT Flygt Limited there appears to be a 

significant volume between the pump on and pump off levels, with a level 

variance of 700mm for both stations. Given the flow rate of Pump Station 1 this 

is likely to result in significant standing times in the pump well which is highly 

likely to lead to H 2 S generation and hence unpleasant odour. This also impacts 

on the efficiency of the WWTP as it is an aerobic plant. It also reduces the 

available response time to an alarm situation. 

From the assessment it was derived that the pump duties of 4.0L/s and 5.0L/s 

are sufficient to cater for the estimated peak inflows of 1L/s and 0.3L/s for 

Pump Stations 1and 2 respectively, with their total available time to overflow 

and even their storage time of the pump sumps alone (minimum available 

storage) greater than the minimum of 5 hours required under current DH 

standards. 

In addition the emergency storages can be further increased by simply 

changing the pump set levels. A recommended setting will be 200-300mm 

between the pump stop and pump start level. 

W&G completed a capacity assessment of the drainlines and none of the 

gravity drains operates at over 5% capacity (refer Appendix E). For a better 

appreciation of the capacity of the current sewerage scheme, a breakdown of 

the individual capacity and adequacy of both pump and storage components is 

presented in Table 5 below: 



Table 5 – System Capacity Breakdown 

System 

Components 

Pump Station 1 

Pump 


Total Emerg. Storage 


Pump 


Total Emerg. Storage 

Duty / 

Current Additional 

Equivalent 

Capacity 

Connections Capacity Available 

4.00 L/s 235 connections 59 176 

12.79 m3 131 connections 59 72 

5.00 L/s 294 connections 18 276 

6.90 m3 70 connections 18 52 

From the table it can be seen that the pumps component is able to deal with an 

additional 176 and 276 new connections for Stations 1 and 2 respectively as 

governed by their Flygt pump duties. 

However, based on the estimated governing total emergency storage 

capacities (see Table 3), both pump stations are only able to accommodate not 

more than an additional 72 and 52 connections respectively. 

As such the sewerage system could only be increased by a further 72 total 

connections combined from both the sub-division and shack area without any 

upgrade to the collection network, with the number of additional connections at 

the shack area restricted to a maximum of 52. 

2.2 EFFLUENT TREATMENT AND REUSE 

2.2.1 Wastewater Treatment Plant 

Based on the Secon design and tender drawings the Woodlane wastewater 

treatment plant is believed to be installed in around 1998 by Aeroflo (presently 

Aquatec). Document review has shown that the plant was originally planned to 

be a fully automated WPS non-biological, non-chemical system that utilises 

electrolysis as the treatment device. 

Based on the Aeroflo layout (Appendix B) and site investigations, the Woodlane 

wastewater treatment plant comprises the following key components: 



1 x intermittent aeration tank (IAT) with 1 x 300 Sinkair QF2 4kW 

aerator and 1 x decant assembly 

1 x chlorine dosing pump in the IAT 

1 x Waste Activated Sludge (WAS) Flygt submersible pump in the IAT 

(deactivated) 

1 x 22kL treated effluent storage tank, 3.2m diameter 

1 x pump shed with 2 x Grundfos NM 50.32.200.SKW irrigation pumps 

and 1 x sand filter 

Some photographs of the above items have been attached in Appendix P 

Photos 3 – 7 and 9 – 11 for references. 

Generally the plant is functional but it is not achieving a Class B output as 

required by the DH approval. Overflow of the system was also observed during 

the initial site visits. 

As described earlier in Section 1.2.2, there appears to be no sludge removal 

program currently in place, with the evaporation ponds already abolished and 

the WAS pump and line deactivated. This needs to be rectified for the plant to 

work effectively. An estimated 8000L sludge thickening tank would aid in the 

management of the sludge. 

It was also noted that sludge from the water treatment plant which includes 

coagulants and PH adjustment is released into the sewer. This coupled with 

the fact that there appears to be no sludge wastage indicates that the current 

sludge age would be much greater than desirable. 

Based on a Council-provided final analytical report issued by the Australian 

Water Quality Centre to DIPA Consulting (Customer Service Request ref. no. 

140836-2007-CSR-1), it was noticed that the results for E.coli testing sampled 

from the Woodlane wastewater treatment plant are over the acceptable limit for 

Class B effluent. With the results of 920/100mL and 870/100mL for “E.coli” and 

“E.coli Presumptive”, they are greater than the allowable 100/100mL for Class 

B effluent. This is a concern as the sample date range is only recent, dated 11 

October 2007 to 24 October 2007. 



2.2.2 Irrigation 

Class B treated effluent from the wastewater treatment plant is pumped to 

irrigate a woodlot through an inline dripper system with sight glass and 

manifolds. The land for the woodlot is currently owned by Council, including the 

adjacent open field between the woodlot and the treatment plant, approximately 

1.6km from the river and at an AHD of approximately 50m. 

Initial design documentation implied that a supplementary water supply would 

be required during the early growth period of the woodlot, by utilising the 

sewerage system to pump river water to the site. This is also shown on 

Drawing 91632/P01 (for tender only) with a temporary line connected into the 

flushing manifolds on the western side of the woodlot. No other details such as 

the temporary period required, the supply route and type, and location of 

provision point are available on any drawings. 

Site investigation reveals the presence of a few PE pipes near the woodlot, with 

a 60mm dia. pipe entering the woodlot from the south-western corner, similar to 

what is shown on Drawing 91632/P01 (see Appendix P Photos 22 and 24), 

possibly suggesting that this could be the temporary water supply line. The two 

flushing valves on the downstream of the supply line have also been located on 

site, however they were found to be disconnected at the time of investigation 

(see Appendix P Photos 20 and 21). 

What isn’t shown on the drawing is the presence of another 40mm dia. pipe 

which tees off from the 60mm dia. pipe at the south-western corner of the 

woodlot, and it appears that it eventually also enters the woodlot at 

approximately mid-way along the western perimeter (see Appendix P Photo 

22). A water meter was also found at the upstream of the tee-junction along the 

60mm dia. pipe with reading 003909 m 3 at the time of inspection, dated 13 

December 2007 (see Appendix P Photo 23). An isolation valve for each pipe is 

also present downstream after the junction. The exact origins of these two 

pipes are unclear as they are buried further upstream. 

Interestingly a second 40mm dia. pipe was found to run parallel with the first 

one, also buried upstream but was seen to continue to run along the western 

and northern perimeters of the woodlot, before going onto the western side of 



Woodlane Drive towards the north (see Appendix P Photos 25, 26 and 27). The 

exact destination, origin and direction of flow for this second pipe are unknown. 

Notwithstanding the above, as the scheme was commissioned and thereafter 

handed over to Council in 2001, and judging from the full-grown woodlot trees it 

is highly likely that the “early growth period” would have been exceeded and 

the temporary water supply no longer in use, as evident from the disconnection 

of the flushing valves. This can be further verified with the reading of the water 

meter at some later stage and compare with the reading recorded earlier to 

check if there has been any water flow through the 60mm and the first 40mm 

dia. pipes into the woodlot. 

Based on the final draft agreement between Council and the developer 

prepared by Norman Waterhouse ref: 227041/SDK0029, dated 24 December 

1999, as put forth by Council there was an extension of the developer’s 

obligation to maintain the woodlot beyond expiry maintenance period up to a 

point in time when the trees are established, or five years from the 

maintenance period expiry date, whichever shall be the last to occur. The 

maintenance period of the entire scheme undertaken by the developer was a 

minimum of 12 months from date of handover to Council, and until the 

Mypolonga Shack development has been connected to the new scheme. 

As per the treatment plant, the irrigation pumps were maintained by Aquatec, 

with automatic initiation of the pumps from a high level switch within the storage 

tank and turned off at low level response. The pumps are single phase 

centrifugal Grundfos NM 50.32.200.SKW, with 2.5L/s duty flow at 10m head. 

Similarly there have not been any records of any past maintenance of the 

irrigation system made available. 

Given the sludge age in the IAT it is likely that the drip lines contain 

considerable sludge. These lines should be checked for effective capacity. A 

site inspection also noted that one of the drip lines has been broken at the 

south-western end of the woodlot (see Appendix P Photos 18 and 19). No 

effluent was detected at this point. There is a high probability that the drip lines 

are blocked. These lines should be flushed and tested. 



3. WATER SUPPLY SYSTEM 

3.1 GENERAL 

According to the Secon drawings the major components of the water 

reticulation system are as follows: 

472m of 80mm diameter uPVC reticulation mains (sub-division) 

 

 

 

 

 

 

 

130m of 40mm diameter uPVC reticulation mains (sub-division) 

226m of 80mm diameter uPVC reticulation mains (shacks area) 

28m of 25mm diameter uPVC pumping main (from river) 

41 connections, 25 mm diameter uPVC (sub-division) 

18 connections, 20 mm diameter uPVC (shacks area) 

1 water treatment plant 

2 booster water pumps, DAB Jet 100 MX, 0.4m 3 /hr–3.3 m 3 /hr, 1 Hp, 

51m head max (river) 

Lot 19 of the Mypolonga shack area is not connected to the water supply, and 

the toilet block is believed to connect to the supply system as may have been 

indicated on Drawing 91632/P02 (as-constructed) and suggested from the 

feedback received from SA Water. 

Two Council-owned DAB Jet 100 MX booster pumps situated in a shed by the 

River Murray draws the river water to the water treatment plant via a 25mm 

pumping main with 0.75L/s duty at 6m head (see Appendix P Photo 28). 

3.2 WATER TREATMENT PLANT 

A flocculation and filtration plant, the FFA 75 atmospheric type water treatment 

plant at Woodlane was manufactured and installed in October 1998 by Abtech 

Environmental Services Pty Ltd. 

Council holds a copy of the Abtech Operation and Maintenance Manual for the 

plant (dated 12 October 1998), including diagnosis charts, technical data and 

recommended chlorine dosage rates. A specification sheet of the plant is also 

available to Council (refer Appendix K) and based on the sheet and Secon as- 



constructed Drawing 91632/WT1, the plant comprises the following major 

components (see Appendix P Photos 29 and 30): 

2 x 22kL water storage tanks 

2 x Grundfos Hydromaxi CR4-60,1.1kW with Danfoss VF Drive water 

booster pumps 

1 x flocculation tank 2.6m height x 1.8m diameter 

1 x 2244-4 fibreglass filter tank and filter media 

1 x chlorine doser Flex-Flo Model A114-4 Pump feed at 4.8G/day 

3 x doser pumps 240V 50Hz Premia 75, for sodium hypochlorite, 

0.95L/hr 

2 x 25L Flocculant 9423 

1 x 5L Polyelectrolyte 

1 x 25L Caustic (NaOH) 20% 

1 x 25L Chlorine 

1 x air compressor Tornado 21025 

Nominal flowrate of the plant is set at 45L/min, the caustic and polyelectrolyte 

chemicals are added for pH correction and flocculation/coagulation of water, 

and sodium hypochlorite added for the disinfection of the filtered water. 

The current servicing of the water treatment plant equipment is supposedly 

undertaken by Abtech about every 3 months, although there haven’t been any 

records to justify that this was done. A typical maintenance schedule of the 

plant issued by Abtech is attached in Appendix L, and it can be seen from the 

schedule that a daily check is required for most items, although again it is not 

clear if this has been carried out due to the lack of any records. 

Nonetheless from Council’s collection of documents there have been some 

loose records of filled-in clarification plant log sheets, however they are 

inconsistent and random and do not appear to be validated. A typical template 

of the log sheet has been attached in Appendix M for reference. 

The topping up of sodium hypochlorite solution is undertaken separately by SA 

Water twice a week, although they have indicated that they would prefer to 

cease providing this service. A typical weekly chemical dosage sheet filled in by 

SA Water is attached in Appendix N, dated 2 July 2007. These records have 



een sourced from SA Water directly and it may be a concern that Council 

does not keep a record of these dosage sheets, being the owner of the water 

supply scheme. 

It appears that Council had once made an attempt to establish a formal 

contract with SA Water for the full maintenance of the water supply system, 

taking effect from 9 March 2001 for a period of 24 months. An Agreement No. 

544 was drafted by Council but was never formalised, putting into question the 

credibility of the current services provided by Abtech and SA Water without the 

presence of any contractual terms. 

In October 2004 GHD Pty Limited submitted a review report to Council for the 

Woodlane Water Treatment Plant to provide an assessment of whether the 

existing system is suitable for the supply of treated water to the sub-division 

and shack area. In the report it was mentioned that there had been periods of 

poor water supply quality, stemming from a single incident when there was a 

low level in the sludge storage tanks at the treatment plant, causing settled 

sludge to enter the water supply network. This could well be caused by the 

lower level of the filter tank outlet than the sludge tank inlet (refer Drawing 

91632/WT1), although this may need further investigation to verify. 

A capacity assessment was also undertaken and included in the GHD report, 

and from its review it is verified that the river supply pump with 65kL/day 

capacity is able to adequately supply the 41 allotments in the sub-division 

(including the toilet block) and 18 shacks, although GHD calculations are based 

on 40 lots and 20 shacks instead and with a seemingly high yield of 

400L/person/day. 

W&G believes that an average daily flow of approximately 30KL/day would be 

more appropriate with a peak daily load of 45KL/d. This is based on 41 subdivision 

lots @ 2.3 persons/lot @ 220L/person + 18 shacks @ 2.3 

persons/shack @ 220L/person = 30kL/day, which represents approximately 

46% of the river pump capacity (65KL/day). At the average daily flow this 

would equate to an 11ML/a demand. Even if the peak flow was adopted this 

would relate to 16.5 ML/a. 



Council have limited water consumption data since 2006. This indicated an 

average annual yield of 8.5ML. This is in line with the estimates completed by 

W&G and justifies using a lower design demand than proposed by GHD. 

A copy of the GHD report is attached in Appendix J for reference. 

3.3 ALTERNATIVE FUTURE WATER SUPPLY 

It is understood that Council has been exploring the feasibility of obtaining their 

future water supply for Woodlane sub-division and Mypolonga shack area from 

SA Water, and in response SA Water has provided two options. 

Option 1 would be the extension of an existing SA Water 100AC supply main 

along North Bokara Road, approximately 147m away from the edge of the subdivision 

at “Lot 7” (refer Appendix O) and 170m away from the toilet block. 

Additional supporting infrastructure required for this option are a pressure 

sustaining valve (PSV) with 20m pressure setting and a 25mm “roadside” water 

meter at the extension point. In addition, a 100kL balancing tank and a booster 

pump station with 4L/s duty at 30m head are also required, all of which shall be 

provided by Council. 

The second option comprises the tapping off a proposed SA Water pipeline that 

will run between Mypolonga and Wall Flat on the western side of Woodlane, 

connecting from the intersection of Woodlane Drive and White Hut Road about 

2.5km away from “Lot 7” of the sub-division (refer Appendix O). Likewise as 

Option 1, a PSV with 26.5m pressure setting and a 25mm water meter are 

required at the connection point, plus a balancing tank of 100kL capacity all to 

be at Council’s expense. Due to the larger elevation difference between the 

proposed connection and the sub-division (approx 40m static head), a booster 

pump station is not essential in this case. 

Council has proposed a third option being the tapping off the same SA Water 

supply but from the nearby public toilet block instead. Council proposes the 

extension of a poly pipe over an approximate 170m to the existing water 

treatment plant, with a connection to a simple float valve at a level that 

replenishes the tank before the treated water. With the low level sensor 

lowered, if demand exceeds the supply from SA Water then the treatment plant 

shall provide the water. The run time of the treatment plant is to be monitored 



with a view to decommission the plant. Council believes that the existing 

combined 44kL storage capacity at the plant will be good for at least 24 hours 

in the event that SA Water supply fails. Council views that with less than $2,000 

implementation cost there is a potential saving of $20,000 p.a. with a once off 

income from the sale of the treatment plant, and in turn potentially fund the 

purchase and installation of water meters to ensure cost recovery under a user 

pays system. 

W&G would suggest a modified version of Option 1 be progressed with SA 

Water as the preferred option. We would suggest that after the water meter 

that a pipeline be extended to the existing water treatment plant and the two 

existing tanks used for buffer storage. These two tanks have a combined 

capacity of 44KL, SA Water have suggested a 100KL storage. Given that 44KL 

is approximately equivalent to 1 days peak use the existing tanks may be 

adequate. Council could initially implement this solution at a very minimal 

construction cost and with very little disturbance to the existing infrastructure. 

Should Council find that this storage is not adequate then an additional 50KL 

tank could be added at a later date. Council may choose to add this additional 

storage to provide a greater buffer storage at the site that can supply the area if 

the supply through the SA Water main is interrupted for an extended period of 

time. This 50KL storage could be provided with an off the shelf poly tank, 

provided it was fenced off, This would provide a cheap storage solution. If 

vandalism is of concern then a concrete tank could be used. 

This option has a low capital cost, removes the need to pump from the Murray 

River, reduces Council’s risk exposure, reduces Council’s maintenance and 

monitoring requirements and would result in minimal disruption to local 

residents. 

Finally the advantage of being able to embark on its provision almost 

straightaway makes Option 1 a more sound option for Council, as opposed to 

having to be tied down with the progress of the new proposed pipeline 

construction. 

SA Water has expressed to W&G that they shall provide a budgetary costing 

for the supply and installation of both the 20m and 26.5m pressure setting 

PSV’s and the “roadside” water meters. A comparison of implementation cost 

between all three options can thereafter be undertaken for further assessment. 



However at the time of preparation of this report this has yet to be received. 

Recent feedback from SA Water has indicated that the costing will be provided 

to W&G by the second week of February 2008. 



4. ISSUES AND RECOMENDATIONS 

4.1 SEWAGE SYSTEM 

The reticulation network is generally in a good condition and has sufficient 

capacity to cater for expected levels of residential expansion. 

The operation of the WWTP needs to be reviewed. The plant should be fully 

desludged once every 3 months, unless a sludge thickening tank is provided. 

The sludge age in this plant is outside the optimal working range. 

Removal of the water treatment plant will also benefit the WWTP as the 

coagulated sludge will not be released to the sewer. The water treatment plant 

is having pH adjustment and also coagulant. Both these chemicals will be 

impacting on its operation. 

A waste activated sludge path needs to be introduced to the plant. 

The irrigation system needs to be reviewed to determine its operational 

effectiveness. The broken lines need to be repaired and the irrigation system 

should be flushed. 

4.2 WATER SUPPLY 

The current system appears to be operating effectively. However Council 

should be monitoring water quality on a more regular basis if they continue to 

operate the plant. 

W&G recommends that Council pursue an SA Water supply from the existing 

100mm main. Initially this could be connected directly to the existing water 

treatment plant. Council can then monitor the system and determine if a larger 

buffer storage is warranted. 

Switching to the treated supply would improve water quality and consistency of 

water quality. It also minimises Council’s risk as a water supplier. 

Water licence for the shacks for domestic usage purposes should be obtained 

from the DWLBC. This is imperative as the water supply comes from the 



Murray River and a licence is necessary as part of EPA’s and DH’s compliance 

conditions. 

4.3 OPERATION AND MAINTENANCE 

W&G as bounded by the Contract with the Council shall proceed to compile an 

Operation and Maintenance manual hereafter the submission and acceptance 

of this report and Council issue a purchase order for the remaining works. This 

will allow Council to identify proper work method statements, safe working 

instructions and possess standard hygiene and manual handling procedures for 

their staff working on the systems. 

Desmond Chong 

for 

WALLBRIDGE & GILBERT 



APPENDIX A 

SECON Consulting Engineers Drawings List 



APPENDIX B 

Aeroflo WWTP Layout 



APPENDIX C 

Sewer Pump Curves 



APPENDIX D 

Sewer Assets Register 



APPENDIX E 

Sewage Capacity Assessment 



APPENDIX F 

DAC Approvals 



APPENDIX G 

DH Approval December 1998 



APPENDIX H 

DH Approval 21 Aug 1996 



APPENDIX I 

DH Approval 17 December 1996 



APPENDIX J 

GHD Water Treatment Plant Assessment 



APPENDIX K 

Abtech WTP Specifications 



APPENDIX L 

Abtech WTP Maintenance Schedule 



APPENDIX M 

Abtech Plant Log Sheet 



APPENDIX N 

SA Water Chemical Dosage Records 



APPENDIX O 

SA Water Main Layout 



APPENDIX P 

Photographs

wastewater disposal and water supply preliminary report woodlane

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