f caf wastewater treatment report

Goulburn Valley Creamery – Kyabram Milk Processing Facility WA & DL Application Vol.1 Page|4 © 2021 Out-Task Environmental Pty Ltd. All rights reserved.

F CAF Wastewater Treatment Report

F.1 CAF Wastewater Treatment Report

abn: 37 160 560 556

a: 38 Wyndham Street, Shepparton

p: P.O. Box 1948, Shepparton, VIC 3632

t: 03 5831 3347

f: 03 5831 3343

e: [email protected]

w: cafconsulting.com.au

C:\USERS\VANDERWERFA\DOCUMENTS\WORKINGFILES\CAFCONSULTING.DELTEKPIM.COM\GVC\3338 WWTP REPORT VC 21.04.06 FINAL.DOCX

3338: R001

Report on

Wastewater Treatment Report for Works Approval Application Dairy and Milk Processing Wastewaters For

Goulburn Valley Creamery Version: C

6/04/2021

Version: C – 12 April 2021 C:\USERS\VANDERWERFA\DOCUMENTS\WORKINGFILES\CAFCONSULTING.DELTEKPIM.COM\GVC\3338 WWTP REPORT VC 21.04.06 FINAL.DOCX

"© -2016 CAF Consulting Services Pty Ltd All Rights Reserved. Copyright in the whole and every part of this document belongs to CAF Consulting and may not be used, sold, transferred, copied or reproduced in whole or in part in any manner or form or in or on any media to any person without the prior written consent of CAF Consulting.” Disclaimer of Liability: This report is provided “as-is” and with no warranties, express or implied, whatsoever for the use or the accuracy of the information contained therein. Use of the report and the information found therein is at the sole risk of the recipient. CAF Consulting Services Pty Ltd shall not be liable in any way for the accuracy of any information contained in the report, including but not limited to, any errors or omissions in any information content; or for any loss or damage of any kind incurred as the result of the use of any of the information.

Document Control

Version Date Author Reviewer

Name Initials Name Initials A 15 March 2021 Allen Gale AJG

B 19 March 2021 Allen Gale AJG Paul Moore PM

C 5 April 2021 Allen Gale AJG Rohan Ash RA

Version: C – 12 April 2021 C:\USERS\VANDERWERFA\DOCUMENTS\WORKINGFILES\CAFCONSULTING.DELTEKPIM.COM\GVC\3338 WWTP REPORT VC 21.04.06 FINAL.DOCX

Table of Contents 1. Introduction 2

2. Scope 2

3. Site and Project Descriptions 2

3.1 Site Location 2

3.2 Project Description 3

4. WWT Data Basis 3

4.1 Process Wastewater Characteristics 3

4.2 Existing WWTP Assessment 4

4.3 Existing Pretreatment Facilities 5 4.4 Alternatives to Aerated Lagoons Treatment 9

5. Calculation and Design Basis 11

5.1 Aerated Lagoons 11

5.2 Irrigation 13

5.3 Wet Weather Storage 13

6. WWTP Concept Construction Arrangements 15

7. Proposed Operating Arrangements 17

7.1 Priority Risks and Proposed Management Arrangements 17

7.2 Operating Arrangements 20

8. Start Up Considerations 20

9. Water Quality Outcomes 21

Version: C – 12 April 2021 Page 2 C:\USERS\VANDERWERFA\DOCUMENTS\WORKINGFILES\CAFCONSULTING.DELTEKPIM.COM\GVC\3338 WWTP REPORT VC 21.04.06 FINAL.DOCX

1. Introduction A new milk products manufacturing facility has been constructed within an existing IXL jam processing factory at 87 McCormick Road Kyabram, which commenced operation in October 2020. CAF Consulting has prepared the Wastewater Treatment (WWT) component of the Works Approval Application (WAA) prepared by Out Task Environmental (OTE) for the combined dairy and jam processing wastewaters. This document serves to supplement the OTE WAA.

2. Scope The scope of this report comprises:

• Participate in client workshops to discuss and obtain data and information relevant to WWT

• Provide commentary with respect to functional capability assessment of the existing jam processing WWT infrastructure.

• Provide a Wastewater Treatment Plant (WWTP) description and process flow

• Provide commentary with respect to wastewater quality inputs and outputs, wastewater quality monitoring and, biosolids management and Wet Weather Storage (WWS)

• Include commentary with respect to contingencies or response procedures that may apply to wastewater related odour mitigation, variable wastewater source quality, future growth and risks such as power loss, factory spills or WWT process upsets.

3. Site and Project Descriptions

3.1 Site Location The dairy and jam processing factory is located at 87 McCormick Road Kyabram. The existing jam processing WWT facilities are located at 847 Graham Road, Kyabram north of the factory. Locality information is shown in Figure 1 below. The existing jam processing wastewater site comprises three earthen lagoons with a total area of approximately 10 Ha and an operating depth of 1.5m.


Figure 1 Locality Plan

3.2 Project Description The GVC Kyabram milk and jam processing facility site layouts and process descriptions, as provided by GVC and HJF, are included in the WAA report. Jam processing wastewater has been discharged for many years to the earthen lagoons for disposal by evaporation. Jam production, and the associated wastewater quantities, have declined over the last decade or two and very significantly since August 2020 when the aseptic processing line was decommissioned. The lagoons are very old and have deteriorated in form, although the permeability of the base complies with EPA’s requirement of less than 10-9 m/sec, whilst the permeability of the embankments range between total and marginal compliance (refer to Geotechnical report in the WAA report). The ultimate Stage 2 proposal is to combine the dairy and jam process wastewaters in redeveloped lagoon-based biological treatment followed by land-based reuse for agricultural purposes under long term agreements with adjacent farmers. In the short term (Stage 1 WAA) it is proposed to construct new lagoons for the dairy processing wastewater that will be expanded to accommodate ultimate flows and loadings. At this time jam wastewaters will continue to be discharged to the southern evaporation pond, which is already licensed for this by EPA.

4. WWT Data Basis

4.1 Process Wastewater Characteristics The wastewater characteristics for dairy and jam processing are based on metering of water and trade wastes flows and sampling of the existing wastewaters discharged from the factories to the WWTP. Dairy processing wastewater characteristics are based on weekly composite samples of the wastewater discharging to Goulburn Valley Water’s (GVW’s) Kyabram WMF since the factory commenced operation in October 2020. These characteristics will be further defined by the continuing weekly composite sampling while the Works Approval Application is under EPA consideration. Detailed WWTP process design will be based on the more extensive monitoring data at the time of detailed design.

GVW WMF Site

Jam & Milk Factory Site 85 McCormick Rd Kyabram

Wastewater Ponds Site 847 Graham Rd, Kyabram


Jam processing wastewater characteristics are based on two composite samples taken in March and April 2020 (prior to August 2020 process decommissioning) and two taken in December 2020 (after August 2020 process decommissioning). As would be expected, the concentrations of most characteristics, including BOD, TSS, EC have reduced since the August 2020 decommissioning. A summary of the wastewater flows and characteristics for initial and ultimate stages are presented in Table 1.

Table 1 Dairy and Jam Processing Wastewater Characteristics Parameter Average Values

Initial (2022-2026) Ultimate (2026+) Dairy Processing Wastes

Process Regime 5 days/week, Mo-Fri 7 days/week Flow (ML/d) 0.43 0.648 BOD (mg/L) 2400 2400 COD (mg/L) 2700 2700 TSS (mg/L) 400 400 TKN (mg/L) 120 145 TP (mg/L) 20 22 TDS (mg/L) 1600 1600

Jam Processing Wastes Process Regime 4days/week, Mo-Th 4days/week, Mo-Th Flow (ML/d) 0.08 0.08 BOD (mg/L) 4500 4500 COD (mg/L) 5800 5800 TSS (mg/L) 350 350 TKN (mg/L) 10 10 TP (mg/L) 2 2 TDS (mg/L) 1900 1900

Combined Dairy and Jam Wastes Process Regime As above As above Flow (ML/d) 0.51 0.728 BOD (mg/L) 2694 2605 COD (mg/L) 3134 3002 TSS (mg/L) 393 395 TKN (mg/L) 105 132 TP (mg/L) 17 20 TDS (mg/L) 1650 1630

The following sanitation and cleaning chemicals are typically used onsite:

• Sodium hydroxide • Sulphuric Acid • Sodium Hypochlorite • Nitric Acid • Phosphoric Acid

Optimal recovery of cleaning and sanitation chemicals will occur at the factory, and thus will have manageable impact on the WWTP.

4.2 Existing WWTP Assessment The existing jam processing WWTP comprises three earthen evaporation lagoons (see Figure 2). There has been ample area to provide the necessary evaporation, with the first two lagoons being sufficient for several years. The total annual volume since the August 2020 decommissioning is small enough to be evaporated in one lagoon.


Jam processing wastewater discharges by gravity to a holding pit/pumping station from which the wastewater is pumped to the evaporation lagoons. The approximate areas of each lagoon, which have a maximum liquid depth of 1.5m are:

• Lagoon 1: 3.2 Ha (southern lagoon)

• Lagoon 2: 3.5 Ha (middle lagoon)

• Lagoon 3: 2.5 Ha (northern lagoon)

• Total Area: 9.2 Ha Geotechnical investigations comprising several boreholes in the base of lagoon 3 and embankments for all lagoons were undertaken in January 2021 to assess the suitability of the lagoon soils for aerated lagoon-based treatment of future dairy and jam processing wastewaters. The key findings from the geotechnical test undertaken on the samples are:

• Based on the results of this investigation, the material in the walls (BHs 1 to 6 and 10 to 15) generally consisted of a low to medium plasticity Silty Clay material with the base of winter storage 2 (BHs 7 to 9) consisting of medium to high plasticity Silty Clay.

• Some of the embankment material in its current state is considered marginal due to low plasticity and permeability rates slightly higher than EPA’s maximum allowable permeability.

• The material in the lagoon bases is a suitable base material.

• Compaction to 98% Standard is required to achieve 10-9m/s permeability requirement in all areas of the reconstructed lagoons.

• Erosion protection is recommended for internal and external surfaces of all embankments.

4.3 Existing Pretreatment Facilities Dairy processing wastewater pretreatment facilities were installed as part of the 2020 factory development. Wastewater from the tanker bay, milk silo and CIP tank farm bunded areas (including rainwater falling within the tank farm) and the dairy processing area discharge by gravity to a Trade Wastes Pit (TWP) adjacent to the factory (see factory layout plans in the WAA). The combined wastewater is pumped across the existing jam processing factory to a gravity separator on the eastern boundary adjacent to the existing jam processing holding pit/pumping station. The wastewater pretreatment schematic is presented in Figure 3. The gravity separator has three functions:

• Balancing of the widely variable dairy processing wastewater, depending on the process dumps and cleaning stages,

• pH correction using sodium hydroxide and sulphuric acid to a range of 6-10, but generally 7-8,

• Fats Oil and Grease (FOG) and gross solids separation. The residue FOG and settled solids are removed from the gravity separator by industrial waste contractor, Closter’s Group. The FOG is managed in an industrial waste treatment plant in Moama.

Effluent from the gravity separator is pumped to GVW’s Kyabram WMF under a Trade Wastes Agreement (TWA) with GVW. This is a temporary arrangement for 12 months while GVC obtains Works Approval and designs, constructs and commissions the proposed aerated lagoon based WWTP. The TWA expires in late 2021. Under the TWA, GVC has supplied 2 x 11kW surface aerators to add to GVW’s existing surface aerator capacity to accommodate the


GVW dairy trade wastes. These aerators will be relocated to GVC’s upgraded WWTP lagoons upon expiration of the TWA. GVC takes weekly composite samples of the dairy processing effluent from the gravity separator, has them analysed for a range of characteristics and reports to GVW as required under the TWA.


Figure 2 Existing Jam Processing WWT Lagoons


Figure 3 Wastewater Process Schematic


4.4 Alternatives to Aerated Lagoons Treatment Alternatives to the proposed aerated lagoons (AL) include:

• Facultative lagoons

• Anaerobic lagoon followed by AL

• High-Rate Anaerobic Lagoons (HRAL) followed by AL

• Intensive biological treatment processes such as traditional activated sludge or sequencing batch reactor technology.

Facultative lagoons were not considered viable because of the significant area required (more than 20 Ha), which is not readily available in the immediate vicinity of the processing factory, and the potential for odours in the event of process overload. A concept-level assessment was undertaken of viable options. The comparisons are presented in Table 2.


Table 2: Comparison of Treatment Options

Parameter Process Anaerobic Lagoon/AL HRAL/AL Activated Sludge/SBR

Footprint Smaller but similar footprint to AL, could be accommodated in the existing lagoons area

Smaller but similar to AL, could be accommodated in the existing lagoons area

Smallest by large margin, easily accommodated in the area available

Capital Investment

Similar to AL, due to increased depth for anaerobic lagoon

Higher than AL due to need for synthetic rubber cover to entrap odours and digester gas generated in the process. Cover needs replacing every 15 years

Significantly higher than lagoon-based alternatives

Energy Consumption

Lower than AL Lower than AL. Potential to generate power from the digester gas by provision of gas motor or turbine for a positive energy position

Significantly higher than other alternatives

Complexity Similar to AL More complex than AL, primarily from power generation facilities

Significantly higher than lagoon-based alternatives.

Sludge Management

Similar to AL, with infrequent (10-15 years) lagoon desludging frequency

Similar to AL, with infrequent (10-15 years) lagoon desludging frequency. More difficult sludge removal from covered lagoon

Requires additional sludge treatment and dewatering facilities

Odour Potential High for open anaerobic lagoon with high strength variable trade wastes

Similar to AL Higher potential due to complex high rate treatment with high strength variable trade wastes

The most competitive alternative to AL is combined HRAL/AL. The potential energy positive for the digester gas is a major consideration, somewhat offset by the additional complexity with power generation. Initial capital investment is an important consideration for GVC, which also counts against HRAL/AL.


5. Calculation and Design Basis

5.1 Aerated Lagoons AL are designed to provide an oxygenated upper liquid layer, normally with a Dissolved Oxygen (DO) concentration of 2 mg/L, and to oxidise the BOD and nitrogen entering the lagoon. while anaerobic digestion of the sludge produced in the process takes place in the lower layers. The mixing energy required for AL is significantly less than complete mix aerated lagoons. Another significant advantage with AL is the much lower sludge yield. Plug flow has been found to produce the best performance of AL’s and so a length to width ratio in the order of 3 to 4 is considered advantageous. The greater the number of lagoons the less the total surface area and volume required. Design of the AL’s is based on wastewater industry-standard mathematical models for aerated lagoons and then checked against commonly used values for dairy and jam processing wastewater. The flows, loading and operating times in Table 1 were used for sizing. Lagoon detention time was determined using the following formula (USEPA Design Manual Municipal Wastewater Stabilisation Ponds, October 1983): t=n/kpm [(C0-Cn)1/n -1] (1) BOD concentration in lagoon effluent was determined using the following formula (USEPA Design Manual) Cn = Cn-1/[ kpm*t/n+1]n (2)

where t = detention time (days) n = lagoon number (in series) kpm = reaction rate at lagoon winter wastewater water temperature, Tw (150C) C0 = Influent BOD concentration (mg/L) Cn = Effluent BOD from lagoon n Cn-1 = Effluent BOD from previous lagoon Nitrogen removal is achieved by three pathways, in order of significance:

• Biological removal by nitrification/denitrification

• Uptake in biomass

• Settlement in sludge Removal is impacted by the pH in the lagoon, with higher removals as the pH increases. A similar approach has been taken to design for biological nitrogen removal using a reaction rate for biological N removal using the following formula (Middlebrooks, Reed, Pano - Nitrogen Removal in Wastewater Stabilisation Ponds; 1999): Ne = N0*e-K

T*(t+60.6(pH-6.6)) (3)

where:


Ne = Effluent Total Nitrogen (mg/L) N0 = Influent Total Nitrogen (mg/L)

KT = Temperature Dependent Rate Constant at Temperature T = K20*θ(T-20)

K20 = 0.0129 Θ = 1.039 T = Winter Liquid Temperature 150 C t = Detention Time (days) In addition to biological removal, another 15%-20% of influent concentration will be removed by uptake in biomass and settlement in sludge. Phosphorus removal in the order of 15%-20% of influent concentration is achieved by uptake in biomass and settlement in sludge, (US EPA Wastewater Technology Fact Sheet; Aerated Partial Mix Lagoons; 2002) Oxygen requirements to maintain a DO concentration of 2 mg/L in the upper liquid layer were based on:

• 1.5 kg O2/kg BOD removed

• 5 kg O2/kg N removed Total aerator power requirements to meet oxygen demands from BOD and N removed were based on 1.5 kg O2 /kWhr at field conditions and a lagoon summer wastewater temperature of 280C. Aerator power required for each lagoon was based on the BOD and N reduction in each lagoon. Based on the above calculations the AL requirements are set out in Table 3. Table 3: Aerated Lagoon Treatment Requirements

Aerated Lagoon Requirement Stage Years 1-5 Dairy Only

Year 6 Onwards

1. BOD in Influent (mg/L) 2400 2630

2. BOD in Final Effluent (mg/L) 60 60

3. Nitrogen in Influent (mg/L) 120 130

4. Nitrogen in Effluent (mg/L) 60 60

5. Number of Lagoons in Series 2 3

6. Total Lagoon Detention Time (days) 46 33

7. Detention Time /Lagoon (days) 23 11

8. Liquid Depth (m) 2.5 2.5

9. Side Slope (1 in …) 3 3

10. Length/Width Ratio 3 3

11. Width at Liquid Surface (m) 40 40


12. Length at Liquid Surface (m) 120 112

13. Liquid Surface Area/Lagoon (sqm) 5000 4200

14. Organic Surface Load/Lagoon (kg BOD/sqm) 1024 1540

15. Total Oxygen Required for Organics and Nitrogen reduction (kg O2/day)

1742 3265

16. Total Aerator Power (kW) 55 99

17. Aerator Power/Lagoon (kW):

• Lagoon 1 44 66

• Lagoon 2 11 22

• Lagoon 3 Not Applicable 11

The TDS of the effluent will be in the same order as the effluent, with some increase due to net evaporation through the process.

5.2 Irrigation GVC has entered into agreements with two farmers adjacent to the WWTP for irrigation of the effluent on agricultural land. The two farmers currently irrigate with effluent from Kyabram WMF under long term agreements with GVW. GVC is proposing similar agreements. GVC is working conjunctively with GVW in coordinating short- and long-term irrigation land requirements for both parties. There is enough suitable land for the projected effluent volume of ~250 ML/year from 2026. Concentration of salts is likely to require shandying of the effluent (refer to Ag-Challenge Land Capability Assessments (LCA) attached to the WAA). The farmers have successfully carried out this practice with GVW’s effluent for over 10 years and therefore have demonstrated compliance experience. The locations and details of the proposed land for effluent irrigation, LCAs and irrigation strategy (by Ag-Challenge), are included in the WAA report.

5.3 Wet Weather Storage Storage of effluent to accommodate periods of wet weather is an essential component of the WWT facilities. EPA water balance calculations by OTE indicate winter storage capacity of 52ML is required for Stage 1 (112 ML/yr) and 116ML is required for Stage 2 (250 ML/yr) to cater for the 90th percentile wet year (see WAA). At a maximum depth of 2.5m the surface area is some 2 Ha at Stage 1 and 4.4 Ha at Stage 2. A more accurate design for Stage 1 and Stage 2 taking account of 1-in-10 wet years, wet weather/low evaporation conditions will be undertaken at detailed design.


Figure 4 WWTP and Irrigation Pumping Station Arrangements


6. WWTP Concept Construction Arrangements

Concept design arrangements for aerated lagoons for Stages 1 & 2 are presented in Figure 5. In Stage 1 the existing southerly pond will remain as is to provide ample area for continuing evaporation of the small quantities of jam processing wastewater. New AL’s 1 and 2 will be constructed by pushing the existing embankments into the base of the most northerly lagoon and reconstructing the embankments, based on balanced cut to fill, to provide a liquid depth of 2.5m, with 0.5m freeboard. A new wet weather (winter) storage will be constructed in the existing centre lagoon using the same construction methodology as for the AL’s. All these lagoons will be total new construction to provide the areas and volumes required and will be constructed to ensure compliance with EPA permeability requirements. The proposed construction methodology, as recommended by the geotechnical consultants is: For bases:

• Strip the wet, low strength material and silt deposits.

• Rip the base a minimum depth of 300mm, moisture condition to within 2% of optimum moisture content and compact to achieve a minimum density ratio of 98% standard (AS1289, 5.1.1, 5.4.1 or 5.7.1).

For embankments:

• Strip the embankments of unsuitable material which includes topsoil, root zone material and silt deposits.

• Rip the existing embankments and spread/stockpile the material.

• Have the material inspected by a Geotechnical Engineer to ensure it is satisfactory.

• Moisture condition to within 2% of Optimum Moisture Content.

• Place in layers not exceeding 300mm, but also to a suitable thickness for the compacting equipment available and compact to 98% Standard (AS1289 5.1.1, 5.4.1 /or 5.7.1).

• On completion, the exposed surface should stabilised/protected to prevent erosion. On the upstream side, this may include beaching rock to prevent against wave action. On the downstream side, this may include topsoiling and grassing of the surface. The crest may have a crushed rock base applied to assist in trafficking and protecting the clay material.

In Stage 2 the additional AL3 and winter storage will be constructed using the same methodology as for Stage


Figure 5 Concept Lagoon Arrangements


7. Proposed Operating Arrangements

7.1 Priority Risks and Proposed Management Arrangements The primary risks and proposed management arrangements are set out in Table 4. The operating arrangements to accommodate these risks are set out in the following section. Table 4 Priority Risks Risk Management 1. Spill from transfer pipeline from gravity

separator to lagoons Ensure construction standards and materials are of high standard. Operator attendance and documented procedures to conduct regular inspections of the WWTP system. Repair pipe leak as an emergency procedure

2. Leak/seepage from lagoons Construct and maintain lagoon liners in accordance with geotechnical consultant’s recommendations, including monitoring of construction. Operator attendance and documented procedures to conduct regular inspections of the WWTP system. Provide temporary emergency plugging of the leak while permanent repairs undertaken.

3. Wastewater from gravity separator off specification

Continuous SCADA monitoring of flow, pH and temperature of discharge from gravity separator. Address with milk processing operators under clearly defined procedures and responsibilities. Weekly composite sample over one operating day. Mass of AL storage provides buffering for short term off-specification wastewater

4. Recycled water quality objectives exceeded

Unlikely to be a sudden issue due to the inherent buffering capacity in the AL’s and the wet weather storage. Monitor key parameters, such as electrical conductivity (EC) and pH with field measurements and sample on a regular frequency (between weekly and monthly) for other key parameters such as BOD, SS, oil and grease, organics, TDS and nutrients. Work closely with farmers to reduce recycled water application rates to match


nutrient and salinity loads to prevent plant and soil damage until the effluent is within specification.

5. Power loss Short term power loss will not present a problem due to inherent buffering given the large water volumes in the AL’s. Experience has shown that AL’s can be without aeration for up to two days before odours are likely to develop. Restore power as quickly as possible if on site issue. Longer term power outage are infrequent based on history in the Kyabram area. In the event of such an occurrence GVC will consider hiring generators to enable the operations to continue. In an extreme event oxygenation chemical could be dosed into the lagoons, although the effectiveness of this is debatable for large lagoon volumes without adequate mixing energy. Operate aerators at maximum capacity after power loss to restore DO ASAP.

6. WWTP process upset Upset from off-specification gravity separator feed covered by risk 3 above. Process upset within the lagoons is of low probability. Would require wholesale loss of biological organisms which would only occur from lack of DO or extremely toxic wastewater from gravity separator.

7. Odours from lagoons Lagoons have potential to generate odours, particularly if there is a loss of DO. The value for odour control with AL’s is the mechanical injection of oxygen, and associated controls to maintain positive DO levels at the control setpoint. In the event of occasional odours, the aerators will be turned up to maximise DO.

8. Excessive effluent for reuse in “wet” years (beyond 1-in-10 years occurrence)

There are large existing spare lagoons on site (in the order of 40ML) that can be used for storage for conditions exceeding 1 in 10 years occurrence.

9. Third party reuse farmer fails to meet user site management plan commitments

Farmers will be bound by long term agreements to minimise the likelihood of default. GVC will continue to source other potential third party reusers as a fallback in the event of default.


10. Excessive sludge accumulation in lagoons

The sludge produced in the aerobic biological process will continue to stabilise under anaerobic conditions in the lower layer of the AL’s. The consequence is that desludging is only required about once every 10 years. More sludge will accumulate in the first lagoon where the greater biological reduction occurs. GVC will monitor and record sludge accumulation annually (by dipping) and desludge the lagoons before the sludge accumulation is excessive. Operation of the lagoons will continue during the desludging process. The resultant biosolids are a valuable fertiliser and GVC will ensure reuse of the biosolids is in accordance with EPA biosolids guidelines in place at the time of each 10 years desludging campaign.

11. Algal growth in wet weather storage Algal growth in wet weather storages is an operational matter. Third party reuse site management controls generally involve excluding livestock from irrigated areas for a few days after irrigation. This would only be required in the event of blue-green algal blooms in the GVC wet weather storage lagoon. However, all reuse operations are based on cut and carry (refer to Ag-Challenge LCAs in the WAA) so livestock will not be exposed to this risk.

12. Excessive noise from aerators and pumps

Undertake comprehensive noise analysis to assess likely potential. This has been undertaken as part of this WAA. Place limits on sound power levels when specifying aerators and pumps.


7.2 Operating Arrangements The nominal aerator arrangements, to be confirmed at detail design stage, and taking advantage of the two GVC aerators to be relocated from Kyabram WMF, are set out in Table 5: Table 5 Concept Aerator Arrangements Lagoon

No. Stage 1 Stage 2

Aerator Power Required (kW)

No./Size Aerators Aerator Power Required (kW)

No./Size Aerators

1 44 1 @ 22kW, 2 @ 11kW

66 3 @ 22kW

2 11 1 @11 kW 22 2 @ 11kW

3 Nil Nil 11 1 @ 11kW

The aerators will be fitted with variable speed drives to enable Dissolved Oxygen (DO) control between 1.0 and 2.0 mg/Lin the upper layer. This serves two purposes:

• Assurance of the minimum DO to maintain aerobic conditions in the upper layer.

• Avoidance of over-aeration during times of loads less than design to minimise the consumption of power.

Organics (BOD) will be reduced to less than 60 mg/L. Nitrogen will be reduced by at least 50% by nitrification and release to atmosphere, adsorption by the biomass in the biological process and settling in biological sludges (sufficient oxygen has been allowed for nitrogen oxidation). Phosphorous will be reduced by about 20% due to adsorption by the biomass in the biological process and settling in biological sludges and solids (see Section 5.1 for design basis and references). The inlets and outlets for each lagoon will be multi-offtake design with baffles around the offtakes to prevent carryover of any floatables to downstream lagoons. A pumping station will be constructed at the Graham Road end of the WWTP to transfer effluent for third party reuse. The station will be dual pump, duty/standby operation and will transfer to existing irrigation distribution systems within the reuse properties. The pumps will be housed in a building to minimise noise.

8. Start Up Considerations Stable operation is likely to take at least 6 months, depending on the growth rate of biomass. Seeding of the lagoons with active biomass from an operating AL facility in the Kyabram area will be provided to minimise the time for stable operation. The effluent quality is unlikely to meet the predictions in section 9 below during this start-up period, which emphasises the value of imported seed sludge to minimise start-up time. Operations during start-up will be closely monitored to minimise the risk of short term off specification conditions.


9. Water Quality Outcomes Predicted effluent quality from the wet weather storage after stabilisation of the AL treatment process is set out in Table 6. Table 6 Predicted Effluent Quality

Parameter Predicted Quality

BOD < 60 mg/L

TSS < 60 mg/L

FOG < 5 mg/L

TDS < 2000 mg/L

TKN < 60 mg/L

TP < 16 mg/L

SO4 < 100 mg/L

pH 7

These predictions have been used in assessment of irrigation requirements.

f caf wastewater treatment report

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