Water Cycle and Waste Management · The water cycle is broken down into its various components and...

WATER CYCLE AND WASTE MANAGEMENT

LONGWARRY SALEYARDS

PREPARED FOR:

LONGWARRY SALEYARDS PTY LTD

JULY 2020

PAGE i 220035_WCWM_REO_003F.DOCX

Report Title: Water Cycle and Waste Management

Project: Longwarry Saleyards

Client: Longwarry Saleyards Pty Ltd

Report Ref.: 220035_WCWM_REO_003F.docx

Status: Final

Issued: 7 July 2020

Premise Australia Pty Ltd (Premise) and the authors responsible for the preparation and compilation of

this report declare that we do not have, nor expect to have a beneficial interest in the study area of this

project and will not benefit from any of the recommendations outlined in this report.

The preparation of this report has been in accordance with the project brief provided by the client and

has relied upon the information, data and results provided or collected from the sources and under the

conditions outlined in the report.

All maps, plans, and cadastral information contained within this report are prepared for the exclusive

use of Longwarry Saleyards Pty Ltd to accompany this report for the land described herein and are not

to be used for any other purpose or by any other person or entity. No reliance should be placed on the

information contained in this report for any purposes apart from those stated therein.

Premise accepts no responsibility for any loss, damage suffered or inconveniences arising from, any

person or entity using the plans or information in this study for purposes other than those stated above.

Version Revision

Date Details

Authorised

Name/Position Signature

003A 11/11/19 Draft for client review M Haege/Premise

003B 18/11/19 Final for Planning report M Haege/Premise

003C 19/12/19 Final for Approval M Haege/Premise

003D 05/05/20 Final for Approval M Haege/Premise

003E 29/06/20 SBR system, final M Haege/Premise

003F 07/07/20 Final – minor updates M Haege/Premise

PAGE ii 220035_WCWM_REO_003F.DOCX

TABLE OF CONTENTS

1. INTRODUCTION ..................................................................................................... 1

1.1 BACKGROUND ..................................................................................................................................................... 1 1.2 SCOPE OF THIS REPORT ................................................................................................................................... 2

2. WATER CYCLE ...................................................................................................... 2

2.1 FACILITY DESCRIPTION ..................................................................................................................................... 2

2.1.1 LOCATION .......................................................................................................................................... 2 2.1.2 OPERATIONS ..................................................................................................................................... 2 2.1.3 INFRASTRUCTURE ........................................................................................................................... 3

2.2 WATER DEMAND ASSUMPTIONS ................................................................................................................ 5

2.2.1 DOMESTIC WATER .......................................................................................................................... 5 2.2.2 LIVESTOCK .......................................................................................................................................... 5 2.2.3 TRUCK WASH .................................................................................................................................... 5 2.2.4 DUST SUPPRESSION ....................................................................................................................... 6 2.2.5 WASH DOWN ................................................................................................................................... 6 2.2.6 TROUGH WASH................................................................................................................................ 6

2.3 WATER SUPPLY .................................................................................................................................................... 7 2.4 WASTEWATER GENERATION .......................................................................................................................... 7

2.4.1 SOURCES ............................................................................................................................................. 7 2.4.2 DOMESTIC .......................................................................................................................................... 7 2.4.3 TRUCK WASH .................................................................................................................................... 7 2.4.4 TROUGH WASH................................................................................................................................ 8 2.4.5 WASH DOWN ................................................................................................................................... 8

2.5 WATER CYCLE ASSESSMENT .......................................................................................................................... 8

2.5.1 WATER CYCLE MODEL ................................................................................................................... 8 2.5.2 CLIMATE DATA ................................................................................................................................. 8 2.5.3 MODEL BREAKDOWN.................................................................................................................... 9 2.5.4 WATER CYCLE RESULTS ................................................................................................................ 9

3. SURFACE WATER MANAGEMENT .................................................................... 13

3.1 MANAGEMENT PHILOSOPHY ...................................................................................................................... 13

3.1.1 SETTING AND CATCHMENT DEFINITION ............................................................................ 13 3.1.2 SURFACE WATER MOVEMENT PATHWAYS ........................................................................ 16 3.1.3 EXISTING SURFACE WATER QUALITY .................................................................................... 17

3.2 ASSESSMENT METHODOLOGY ................................................................................................................... 17

3.2.1 STORMWATER QUANTITY ......................................................................................................... 17 3.2.2 STORMWATER QUALITY ............................................................................................................. 17

3.3 CONSTRUCTED WETLAND/DETENTION BASIN .................................................................................... 19 3.4 SURFACE WATER MODELLING RESULTS ................................................................................................. 19

3.4.1 PEAK FLOW ...................................................................................................................................... 19 3.4.2 QUALITY ............................................................................................................................................ 22 3.4.3 SITE YIELD ......................................................................................................................................... 22

3.5 SURFACE WATER MANAGEMENT CONCLUSIONS .............................................................................. 22

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4. LIQUID WASTE MANAGEMENT ......................................................................... 23

4.1 EFFLUENT SOURCES ......................................................................................................................................... 23 4.2 EFFLUENT MANAGEMENT SYSTEM ........................................................................................................... 23

4.2.1 EFFLUENT QUANTITY ................................................................................................................... 23 4.2.2 DESCRIPTION .................................................................................................................................. 23 4.2.3 SBR ...................................................................................................................................................... 24 4.2.4 EFFLUENT QUALITY ...................................................................................................................... 25 4.2.5 COMMISSIONING ......................................................................................................................... 25

5. DOMESTIC EFFLUENT MANAGEMENT ............................................................. 26

5.1 INTRODUCTION ................................................................................................................................................. 26 5.2 PRIMARY TREATMENT .................................................................................................................................... 26 5.3 SECONDARY TREATMENT ............................................................................................................................. 26

6. SOLID WASTE MANAGEMENT .......................................................................... 26

6.1 INTRODUCTION ................................................................................................................................................. 26 6.2 SOURCES AND ESTIMATED QUANTITIES ................................................................................................ 27

6.2.1 TRUCK WASH .................................................................................................................................. 27 6.2.2 GENERAL REFUSE .......................................................................................................................... 27 6.2.3 STOCK MORTALITIES ................................................................................................................... 27 6.2.4 SPENT SOFT FLOOR...................................................................................................................... 27 6.2.5 SBR SLUDGE .................................................................................................................................... 27

6.3 SOLID WASTE STOCKPILES ........................................................................................................................... 28 6.4 SOLID WASTE MANAGEMENT ..................................................................................................................... 28

7. SYSTEM MANAGEMENT ..................................................................................... 29

7.1 EFFLUENT TREATMENT SYSTEM ................................................................................................................. 29

7.1.1 EFFLUENT QUALITY TARGETS ................................................................................................... 29 7.1.2 COMMISSIONING PERIOD ........................................................................................................ 29 7.1.3 COMMISSIONING PLAN ............................................................................................................. 30 7.1.4 ONGOING MONITORING........................................................................................................... 31 7.1.5 EFFLUENT SYSTEM INSPECTION ............................................................................................. 32

7.2 SURFACE WATER SYSTEM ............................................................................................................................. 32

7.2.1 COMMISSIONING PERIOD ........................................................................................................ 32 7.2.2 SURFACE WATER QUALITY MONITORING .......................................................................... 32

8. CONCLUSION ...................................................................................................... 33

9. REFERENCES ...................................................................................................... 34

APPENDICES

APPENDIX A Flood Assessment

TABLES

Table 2.1 – Livestock sales ......................................................................................................................................................... 2 Table 2.2 - Water demand and supply ................................................................................................................................ 7 Table 2.3 – Annual rainfall statistics ....................................................................................................................................... 9

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Table 2.4 – Annual rainfall statistics ..................................................................................................................................... 11 Table 3.1 – Surface water catchments ................................................................................................................................. 16 Table 3.2 - Pollutant concentrations used in MUSIC modelling ............................................................................. 18 Table 3.3 – MUSIC catchment areas .................................................................................................................................... 18 Table 3.4 – TUFLOW modelling results ............................................................................................................................... 20 Table 3.5 – MUSIC Modelling Results ................................................................................................................................. 22 Table 7.1 – Summary of commissioning plan and actions ......................................................................................... 30

FIGURES

Figure 1: Proposed Longwarry Saleyards site layout ............................................................................................... 4 Figure 2: Longwarry Saleyards water cycle schematic – average annual volume in ML/year ............... 10 Figure 3: Catchment Setting ............................................................................................................................................ 14 Figure 4: Existing surface water movement ............................................................................................................... 15 Figure 5: Culvert locations ................................................................................................................................................ 20 Figure 6: 1% AEP Surface Level Impacts ..................................................................................................................... 21 Figure 7: 10% AEP Surface Level Impacts ................................................................................................................... 21

PAGE v 220035_WCWM_REO_003F.DOCX

ABBREVIATIONS

BOD Biochemical oxygen demand

kL Kilolitre (1,000 L)

L Litre

m2 Square metre

m3 Cubic metre (1 kL)

ML Megalitre (1 million litres)

NH3 Ammonia

TN Total nitrogen

TP Total phosphorus

TSS Total suspended solids

220035_WCWM_REO_003F.DOCX

1. INTRODUCTION

1.1 BACKGROUND

Longwarry Saleyards Pty Ltd proposes to construct a new saleyard in Longwarry. The site, which would

be accessed from Sand Road between Thornell Road and the Princes Highway, comprises approximately

22.8 hectares of existing farmland.

The saleyard, known as the Longwarry Saleyards, would accommodate an annual throughput of up to

132,000 cattle (including 12,000 bobby calves). The facility would host an average of 146 sales per annum

including one fat cattle sale per week (total of 50 per annum), one cows & calves sale per week (total of

50 per annum), one store cattle sale per fortnight (24 per annum) and one dairy cattle sale per fortnight

(total of 22 per annum plus special sales as required by market conditions). The cattle sales would be

highly seasonal with larger sales occurring over the summer months, particularly in January.

The Longwarry Saleyards would comprise:

• A fully roofed saleyard with holding pens, sale pens, drafting and loading/unloading facilities;

• A central office building with offices, amenities and a café;

• Parking for trucks and cars;

• A three-bay truck wash and associated water storage tank;

• A maintenance shed and feed store;

• A surface water wetland/detention basin;

• Two rainwater tanks;

• A sequencing batch reactor (SBR) system to treat wastewater;

• Landscaping; and

• A sign.

Water for the facility would be provided through a combination of roof water harvesting, recycling and

connection to reticulated water supply. All liquid waste would be discharged offsite to sewer and an

integrated surface water management system would be used to effectively manage surface water. Solid

wastes would be temporarily stockpiled before being removed offsite.

This report presents an overview and assessment of the water cycle and waste management systems for

the proposed facility.


1.2 SCOPE OF THIS REPORT

This report presents:

• An assessment of the total water cycle at the facility including analysis of demand and supply;

• Details and assessment of the surface water management system; and

• Details and assessment of the liquid and solid waste management system.

2. WATER CYCLE

2.1 FACILITY DESCRIPTION

2.1.1 LOCATION

The site is located at 85 Thornell Road Longwarry, Victoria and can be accessed from Sand Road between

Thornell Road and Princes Highway. The site comprises approximately 22.8 hectares of existing farmland.

2.1.2 OPERATIONS

Annual throughput is expected to be up to 132,000 cattle. The facility would host an average of 146

sales per annum including one fat cattle sale per week (total of 50 per annum), one cows & calves sale

per week (total of 50 per annum), one store cattle sale per fortnight (24 per annum) and two dairy cattle

sales per fortnight (total of 22 per annum plus special sales as required by market conditions). The cattle

sales would be highly seasonal with larger sales occurring over the summer months.

The anticipated monthly sale breakdown and average sale numbers used for the water cycle modelling

are defined in Table 2.1.

Table 2.1 – Livestock sales

Month Proportion Head Average Sale Size

January 13.40% 17,688 1769

February 11.50% 15,180 1265

March 8.30% 10,956 913

April 6.10% 8,052 671

May 5.20% 6,864 490

June 4.30% 5,676 437

July 3.70% 4,884 407

August 4.10% 5,412 361

September 9.00% 11,880 990

October 11.50% 15,180 1084

November 11.20% 14,784 1232

December 11.70% 15,444 1931

Total 100% 132,000 904


2.1.3 INFRASTRUCTURE

Layout of the facility is shown on Figure 1. Details of infrastructure relevant to the water cycle are as

follows:

• Cattle pavilion roof area of 17,853 m2.

• The proposed central amenities building and landscaping occupies an area of 2,814 m2 with a roof area of 1,300 m2.

• The transport operator’s amenities, workshop and hay shed occupies an area of 364 m2.

• The paved area consisting of the trafficable areas and car park is approximately 33,343 m2 (sealed paved area of 30,693 m2 and unsealed paved area of 2,650 m2).

• The truck wash and solids stockpile pad cover areas of 1,540 m2 (roof area of 582 m2) and 1,035 m2 respectively;

• The effluent management system covers an area of 459 m2.

• The surface water wetland/detention basin occupies approximately 6,000 m2.

• The catchment area of the surface water wetland/detention basin is approximately 32,538 m2.


Figure 1: Proposed Longwarry Saleyards site layout


2.2 WATER DEMAND ASSUMPTIONS

The facility requires water to function. Assumptions relating to use and demand are outlined below.

2.2.1 DOMESTIC WATER

2.2.1.1 Staff, Agents and Patrons

• 4 full time staff present 6 days a week; each allocated 50 L/p/d.

• On sale days staff would increase by 18 (inclusive of 4 café); each allocated 25 L/p/d.

• On sale day and day before, 30 agent representatives would be present; each allocated 25 L/p/d.

• 150 patrons per store sale, each allocated 10 L/p/sale (being 6 L flush, 1 L hand wash and 3 L at the café).

• 30 patrons per cattle and calves sale, each allocated 10 L/p/sale (being 6 L flush, 1 L hand wash and 3 L at the café).

2.2.1.2 Transport Operator’s Amenities

• 20 transport operators would use the amenities block each sale day (have a shower etc and visit the café); each use is allocated 150 L/p.

2.2.1.3 Domestic Demand

The average annual domestic water demand derived using the above assumptions is 1.1 ML/year.

This demand would be split between the central amenities building and the transport operator’s

amenities.

2.2.2 LIVESTOCK

• Cattle drinking water allowance of 25 L/head/day.

• 50% stock numbers on day prior to sale, 100% stock numbers on day of sale and 5% stock numbers on day following sale.

2.2.3 TRUCK WASH

The anticipated average monthly sales distribution is shown in Table 2.1. These average sale numbers

were used to define the number of trucks coming in and leaving the facility using the following

assumptions:

• The breakdown of truck types bringing cattle into the facility is 28% B-double, 20% semi-trailers and 52% rigid trucks (same vehicle breakdown as the traffic assessment);

• The breakdown of truck types taking cattle from the facility is 28% B-double, 17% semi-trailers and 55% rigid trucks (same vehicle breakdown as the traffic assessment);

• The capacity of each truck type is:

– B-double 95 head

– Semi-trailer 65 head

– Rigid 15 head


• Every B-double, 80% of semi-trailers and 50% of rigid trucks delivering stock would use the truck wash;

• Washing time would be 70 minutes for B-doubles, 60 minutes for semi-trailers and 40 minutes for rigid trucks;

• The proposed truck wash at the facility would use hoses with a flow rate of approximately 1.6 L/s; and

• Two B-doubles and one semi-trailer would use the truck wash on non-sale days.

The above data therefore results in the following water consumption per truck wash:

• B-doubles 6.72 kL per wash

• Semi-trailers 5.76 kL per wash

• Rigid trucks 3.84 kL per wash

The average annual truck wash water consumption from this analysis is approximately 17.47 ML/year.

2.2.4 DUST SUPPRESSION

The water cycle modelling assumes that dust suppression watering of the entire soft floor area would

take place prior to each sale. This is conservative as it is likely that dust suppression watering would not

be required in the cooler months. Dust suppression would be distributed through sprinklers and/or hand

watering. The dust suppression system would allow coverage of the entire cattle yard soft floor area.

Assuming an application of 3 mm over the area under the cattle roof, the potential total water used each

time is 52.2 kL. The modelling assumed 50% of this volume would be used on dairy cow sale days.

It is unlikely dust suppression would be required at the solids stockpile area due to the moisture

contained in the solids. However, water connection points would be available at this location so that

stockpiles could be watered if required. No water allowance is made for this activity as it is unlikely to

be required.

2.2.5 WASH DOWN

The scales, drafting yards, calf yards and dairy would be cleaned weekly or after each sale. This activity

would be undertaken using hoses with a flow rate of 2.7 L/s and would take 1 hour per area

(approximately 10 kL per wash down area).

2.2.6 TROUGH WASH

Stock water troughs would be cleaned every fortnight to remove a build-up of dust. This would use

approximately 45 kL each time.


2.3 WATER SUPPLY

The principle of the water supply arrangement is to minimise demand on existing supplies through roof

and surface water harvesting. Table 2.2 summarises the various water demands, their main water source

and top-up supply.

Table 2.2 - Water demand and supply

Demand Main Supply Secondary Supply Top-up Supply

Stock water Roof water tank NA Reticulated potable

Domestic – toilets Roof water tank NA Reticulated potable

Domestic – potable Reticulated potable NA NA

Truck wash Truck Wash Roof Water Surface Water Wetland Reticulated potable

Dust suppression Roof water tank NA Reticulated potable

Scale wash down Roof water tank NA Reticulated potable

Water trough cleaning Roof water tank NA Reticulated potable

All water from the rainwater tanks would be filtered prior to reuse across the site and all water reused

from the surface water wetland would be filtered and disinfected prior to use at the truck wash.

2.4 WASTEWATER GENERATION

2.4.1 SOURCES

Liquid wastewater would be generated from domestic amenities, the truck wash, trough washing, wash

down and rainfall runoff from the solids stockpile area and uncovered sections of the truck wash area.

2.4.2 DOMESTIC

Domestic effluent generated from the central amenities building and transport operator’s amenities

would be managed using on-site effluent management systems for primary treatment (septic tanks) with

the treated effluent then further treated through the facility’s effluent treatment system before being

discharged offsite to sewer.

2.4.3 TRUCK WASH

Analysis of the expected truck wash number presented in Section 2.2.3 indicates an average annual

truck wash water demand of approximately 17.47 ML/year.

The main wash bays of the truck wash would have a roof which would collect runoff to be stored in and

reused from the truck wash tank. This roof collects approximately 0.42 ML/year of water, which would

contribute to the demand of the truck wash.

The runoff from the uncovered sections of the truck wash area would be collected at the base of the

sloped truck wash slab and discharge to the solids separation system. Outflow from the solids separation

system would be pumped to the SBR system.

Some water would be removed in the separated solids and some water used in the truck wash would be

removed as residual water on the truck. These losses are estimated as 2% of the water consumption

which equates to 0.35 ML/year.


Therefore, the truck wash wastewater volume used for the design and assessment of the wastewater

treatment system and reuse scheme is estimated to be approximately 17.12 ML/year.

2.4.4 TROUGH WASH

Stock water troughs would be cleaned fortnight to remove a build-up of dust. During warmer months,

the trough water would be discharged onto the soft floor system; it would therefore not add to the

liquid wastewater stream. In winter months, and if conditions required at other times, trough wash water

would be collected by a tanker and discharged at the solids separation system.

Cleaning the troughs has an annual water demand of 1.1 ML/year, which is conservatively assumed to

all flow to the wastewater treatment system.

2.4.5 WASH DOWN

Wash down water from scales, drafting yards, calf yards and dairy would be piped to the solids

separation system.

2.5 WATER CYCLE ASSESSMENT

2.5.1 WATER CYCLE MODEL

A daily water balance model was used to assess the overall water cycle for the proposed development

and site. The model is used to:

• estimate the average annual demand for each water system at the facility;

• optimise sizing of various storages;

• assess the ability of the proposed water supply sources to meet demand; and

• assess capacity and storage requirements for the effluent management system.

2.5.2 CLIMATE DATA

The model uses 130 years of daily SILO rainfall and evaporation data for the site (1 January 1889 to 31

December 2018). The SILO data interpolates rainfall and evaporation values from surrounding climate

stations to provide a long-term data set for the specific location.

Rainfall statistics derived from the SILO data are compared to available data for three stations

surrounding the site in Table 2.3.

The long-term average annual and median annual rainfall data from the SILO dataset is higher than the

Longwarry data but lower than the Drouin West data. The SILO data provides a reasonable

representation of climate for the area.


Table 2.3 – Annual rainfall statistics

Station BOM

Number Years of Data

Mean Rainfall

mm

Median Rainfall

mm

SILO Na 130

(1889-2018)

948.6 938.2

Longwarry 085209 62

(1907-1969)

907.9 873.2

Longwarry (Gooneparoo) 085208 47

(1969-2016)

896.5 887.6

Drouin West 085024 60

(1902-1962)

1000.4 975.5

2.5.3 MODEL BREAKDOWN

The water cycle is broken down into its various components and the inflows and outflows are modelled

as follows.

2.5.3.1 Storage Inflows

• Rainwater tanks – receive runoff from the roof of the livestock exchange facility and receive top up water from the reticulated potable supply;

• Truck wash tank – receives runoff from the roof of the truck wash and top up water from the surface water wetland and the reticulated potable supply;

• SBR – receives wastewater from the truck wash, trough wash and wash down. This system also collects runoff from solids stockpile area and the uncovered area of the truck wash;

• Constructed surface water wetland/detention basin – catches surface water runoff from the site (hardstand and trafficable areas; and balance of the open areas) and treats the water before

discharging off-site; and

• The open storages receive direct rainfall input.

2.5.3.2 Storage Outflows

• Rainwater tanks – water for dust suppression, the cleaning out of troughs, wash down and livestock drinking water and spill flows to the surface water wetland;

• Truck wash tank – water for the truck wash with spill flowing to the surface water wetland; • SBR – treated water is disposed into the South Easter Water sewerage; • Constructed surface water wetland/detention basin – excess water spills to existing drainage; and • Evaporation from open water storages.

2.5.4 WATER CYCLE RESULTS

The water cycle results are shown on Figure 2. The total modelled average annual water demand for the

facility is approximately 34.5 ML/year. Water would be supplied through a combination of harvested

roof, treated runoff from the constructed surface water wetland and reticulated potable supply. On-site

supply makes up about 27.8 ML/year which is approximately 81% of the annual demand. A summary of

the key water cycle components is provided in Table 2.4.


Figure 2: Longwarry Saleyards water cycle schematic – average annual volume in ML/year

6.68

Truck Wash Saleyards 0.38 0.55

Roof Runoff Potable Roof Runoff Potable

Area = 582 m2 Top-up Area = 1.79 ha Top-up

0.68 1.52 26.67 12.60 4.24 0.10 0.08

2.49 4.28

15.53 0.72

SpillCentral Amenities Building Driver Amentities

13.63

Spill 16.11

5 kL septic tank 5 kL septic tank

Truck Wash

StockWater

Dust Suppression

Wash Down

TroughWash

17.47 5.68 7.41 1.75 1.08

1.10

1.29

Truck wash and solids stockpile 17.94 Solids 19.02 20.1Area 2010 m2 Stockpile

System

Area = 3.25 ha

Reticulated Potable Supply

Catchment runoff

Sewer

2 ML Rainwater Tanks4 ML Wetland200 kL Truck Wash Tank

Packaged SBR Treatment System


Table 2.4 – Summary of Longwarry Saleyards water cycle components

Component Purpose Receives inflow

from Outflow goes to

Sizing and preliminary design details

Size

Lining Pond

surface

area

m2

Pond

freeboard

m

Rainwater tanks To provide capture and reuse of roof

water to reduce the potable water

demand.

• Cattle yard roof • Potable water top-

up (or a balance

tanks may be used)

• Stock drinking water • Dust suppression • Wash down • Trough wash • Amenities buildings • Evaporation

2 x 1 ML Na Na Na

Truck wash tank To provide a storage from which

water can be taken from for the truck

wash to increase reuse of water

onsite.

• Surface water wetland

• Truck wash roof • Top up from

potable water

supply

• Truck wash 200 kL Na Na Na

Surface water

wetland/Detention

Basin

To manage site runoff to achieve

zero adverse impact as measured by

site discharge (peak flow) and

surface water quality.

• Hardstand trafficable areas

• General site areas

• Truck wash tank • Off-site discharge • Evaporation

Total ~ 4 ML 0.3 m clay

with 200 mm

planting layer

in

macrophyte

areas

Total ~ 5,000 0.5 above

spillway

CFB tank Rainwater harvest for non-potable

use.

• CFB roof • Potable water top-

up

• CFB toilets 20 kL Na Na Na

Solids removal

system

Mechanical separation of solids from

the effluent stream. System typically

comprises a collection sump (in-

ground) with agitator and pump

which pumps effluent over a wedge

wire screen.

• Truck wash • Wash down of

receival areas and

scales

• Trough wash down • Surface runoff from

the truck wash pad

and solids stockpile

area

• SBR treatment system

Subject to

detailed design,

but nominally

around 30 kL

Collection

sump is

typically

concrete and

areas

surrounding

the screen are

typically

concrete

Na Na


Component Purpose Receives inflow

from Outflow goes to

Sizing and preliminary design details

Size

Lining Pond

surface

area

m2

Pond

freeboard

m

SBR treatment

system

Secondary treatment system to

reduce solids, nutrients and organic

load prior to discharge to sewer. A

system to treat an average daily flow

rate of 55 kL/day and maximum of

175 kL/day is proposed subject to

detailed design.

• Solids separation system

• Domestic septic tanks

• Sewerage 50kL inflow balance tank

13 m diameter

SBR tank

50kL treated

water balance

tank

PVC liners

would be

used in both

the selector

and SBR tanks

Na Na

Septic tanks Treatment of domestic effluent from

the central amenities building and

transport operator’s amenities.

• Amenities • SBR treatment system

2 x 5 kL Typically

concrete

Na Na

Potable supply Domestic demand and top-up

supply

• Reticulated supply Na Na Na Na Na


3. SURFACE WATER MANAGEMENT

3.1 MANAGEMENT PHILOSOPHY

The surface water management philosophy is to:

• Direct upslope runoff around the site or use existing topography to divide catchments.

• Define catchments and treat runoff according to the level of potential contamination present.

• Capture all general site runoff in a system of grass swales.

• Harvest roof water and minimise the interaction of surface water with stock wastes.

• Treat the balance of surface flows emanating from site runoff through a grass swale and constructed surface water wetland/detention basin system prior to discharge.

• Limit peak discharge from the developed areas of the site to pre-development levels using surcharge storage in the wetland/detention basin system.

• Limit post development runoff volume to around pre-development levels by reusing water from the wetland/detention basin system.

• Ensure that the surface water management system does not divert or harvest stormwater from beyond the site that would normally not pass through the site.

• Ensure that no stormwater leaves the site without appropriate treatment.

3.1.1 SETTING AND CATCHMENT DEFINITION

The catchment generally falls in a south-westerly direction and discharges via two constructed drainage

lines situated to the south and west of the site. The southern drainage line moves water through four

box culverts under Thornell Road. The site in its local catchment setting is shown on Figure 3.


Figure 3: Catchment Setting

Existing surface water movement occurs as overland flow and within constructed drains as illustrated on

Figure 4. The site is relatively flat and shallow channels have been cut to improve drainage.

There are two discharge points of the existing site – the eastern half of the site discharges to the south

through the box culverts (refer to Figure 4) where runoff currently discharges to the constructed

drainage channel. The western side of the site discharges to the west into a constructed drainage channel

which slopes to the south.

Overland flow from the north of the site is carried west by the drainage channel to the north of the site

and then flows south through the drainage channel to the west of the site.

Drainage channels

Site discharge point


Figure 4: Existing surface water movement

The proposed development would be located in four catchments that currently discharge to the south-

west. This would include all the built infrastructure (buildings and hardstand) for the facility.

The surface water management system would separate the development into two catchments types and

manage runoff according to the level of potential contamination present. The two catchment types are:

clean water and minor contaminants. Structures, drains, diversion banks/bunds and ground shaping

would be used to define and separate the catchments.

Existing drainage lines are located to the north, west and south of the site as shown on Figure 4. The

drainage line to the north would divert runoff from the northern catchments prior to reaching the site.

Table 3.1 provides a summary of the two catchment types, the pollutants likely to be present and the

fate of the surface water emanating from each catchment type.

All wastewater would be managed in a closed effluent management system (refer to Section 4). Transfer

of effluent would be managed with pumps, pipelines and storage tanks.

Drainage channels

Site discharge point


Table 3.1 – Surface water catchments

Catchment

type

Elements of the Proposed

Development Contained

with the Catchment

Likely Pollutants Fate of Catchment Runoff

Clean • Saleyard roof • Roof of central amenities

building

• Truck wash and workshop roofs

• Suspended solids • Metals • Minor microbial content

from birds and dust

Roof water from the saleyard

would be collected in the main

rainwater tank and used as the

principal supply of water for the

stock drinking, wash down,

trough wash and dust

suppression.

Roof water from the central

amenities building would be

diverted to the surface water

wetland.

Roof water from the truck wash

would be stored in the truck wash

tank and be used as a minor

source for the truck wash.

Minor

Contaminants

• Car/truck parking areas • Trafficable areas/roadways • Central amenities building • Grassed areas • Landscaped areas

• Suspended solids • Minor nutrients and salts

from stock wastes that may

discharge from heavy

vehicles

• Minor microbial content • Very minor oil and grease,

hydrocarbons and metals

from trafficable areas

• Minor nutrients from paddock runoff

All runoff from the central

catchment would be directed to

the surface water wetland system

for treatment prior to reuse or

discharge offsite.

A significant proportion of the water generated from the clean catchment (roofs) would be used in the

development. Any spill from the rainwater tanks would be collected and treated in the surface water

wetland system before discharging off-site.

Runoff from the balance of the development area that may contain minor contaminants would be similar

to urban/agricultural land runoff. The major pollutants identified for this catchment are suspended

solids, nutrients and microbial content. There is the potential for very minor oil and grease, hydrocarbon

and metal loads from trafficable areas. Therefore, an integrated surface water management system

comprising of grass swales and a constructed surface water wetland system is proposed to manage

pollutants from this catchment prior to discharge.

3.1.2 SURFACE WATER MOVEMENT PATHWAYS

Spill from the rainwater tanks would be collected and treated in the surface water wetland system before

discharging offsite.

Therefore, the only potential pathway for water to move from the central developed site is limited to the

outlet of the constructed surface water wetland. The location of the discharge point is shown by culvert

number 3 on Figure 4.

The undeveloped area to the west of the developed site would travel through grass swales to the

constructed drainage channel to the west of the site. The undeveloped area to the east of the developed


site would travel to the south through grass swales into the constructed drainage channel and through

to one of the culverts along the boundary.

3.1.3 EXISTING SURFACE WATER QUALITY

There is no data available on the quality of surface runoff currently leaving the site. Existing surface water

quality would be impacted by agricultural activities (predominately grazing) and to a lesser extent by

urban infrastructure (e.g. roads). Given these catchment influences, the site runoff is unlikely to comply

with the water quality objectives suggested for rivers and streams in SEPP (Waters of Victoria). Existing

surface water quality would be characterised during the surface water wetland commissioning phase to

provide background data. This is detailed in the draft Environment Improvement Plan.

Potential impacts on receiving waters would be managed by adopting a neutral or beneficial effect

design approach for the management of surface water runoff. This concept acknowledges that existing

land uses generate pollutants and when a land use changes, management measures should be put in

place to ensure that the post development pollutant loads are equivalent to, or less than, the existing

pollutant loads. This approach ensures that any existing beneficial uses of water will be protected and is

consistent with contemporary engineering practices.

3.2 ASSESSMENT METHODOLOGY

3.2.1 STORMWATER QUANTITY

The performance of the proposed stormwater management system was assessed using TUFLOW. This

model was used to estimate existing base case flows for the current site as per the details of the site

survey and aerial imagery, and the proposed case flows where topography and roughness are updated

to represent the proposed works.

A detailed description of the process and results can be found in Appendix A.

3.2.2 STORMWATER QUALITY

3.2.2.1 Model Description

The proposed stormwater management system and wetland configuration was modelled using the

Model for Urban Stormwater Improvement Conceptualisation (MUSIC) developed by the Cooperative

Research Centre for Catchment Hydrology.

MUSIC was developed as an aid to decision making and predicts the performance of stormwater quality

management systems. It enables users to evaluate conceptual designs of stormwater management

systems to ensure they are appropriate for their catchments. By simulating the performance of

stormwater quality improvement measures, MUSIC determines if proposed systems can meet specified

water quality objectives.

3.2.2.2 Pollutant Generation

The MUSIC software determines the pollutant loads generated by different land uses. By modelling the

pre-development land use, and a proposed stormwater management strategy, a comparison can be

made about the relative amounts of pollutant retention, and their expected concentrations.

A variety of land uses are proposed on the site, each with distinctive pollution generation characteristics.

The pollution generation rates assumed for the various land uses are listed in Table 3.2. Pollutant loads


are calculated based on these concentrations, the amount of rainfall and runoff and the effectiveness of

the proposed treatment systems.

The preliminary design of the constructed surface water wetland was modelled in the developed case.

Pollutant generation rates for the developed case were developed from the available literature.

Therefore, is it highly unlikely that significant nutrient runoff would occur from these areas.

Runoff from the hardstand areas was modelled as urban runoff as this provided higher pollutant loads

compared to commercial or industrial land use.

A summary of the pollutant generation rates used in the MUSIC modelling is provided in Table 3.2.

Table 3.2 - Pollutant concentrations used in MUSIC modelling

Pollutant

Average Concentration (mg/L)

Existing Agriculture Proposed

Roof (1)

Proposed

Sealed (1)

Proposed

Paddocks

Base

Flow

Storm

Flow

Base

Flow

Storm

Flow

Base

Flow

Storm

Flow

Base

Flow

Storm

Flow

Suspended

Solids 25 50 13 20 16 270 25 300

Phosphorus 0.20 1.1 0.15 0.13 0.14 0.50 0.2 1.2

Nitrogen 1.20 2 2.1 2 1.3 2.2 1.2 6.9

Source: (1) Fletcher et al (2004)

3.2.2.3 Catchment Areas

Catchment areas for each case modelled are summarised in Table 3.3.

Table 3.3 – MUSIC catchment areas

Model Area (ha) % impervious

Existing 7.285 0

Developed – roof 1.785 100

Developed – sealed 3.62 90

Developed – paddocks 1.88 0

The following soil properties were adopted for pervious catchment areas:

• Soil storage capacity 120 mm.

• Field capacity 50 mm.

3.2.2.4 Climate Data

Six minute rainfall and evaporation data for the period 15 August 1961 to 31 December 2000 was used

in the model from the Ellinbank Dairy Research Institute BOM Station (Station No. 085240). This data

was obtained from eWater which generates synthetic rainfall data for a given location based on

measured rainfall in surrounding areas.


3.3 CONSTRUCTED WETLAND/DETENTION BASIN

A constructed surface water wetland/detention basin system would provide stormwater quantity and

quality control for the site. The wetland system would include a permanent pool area that would

incorporate sedimentation zones, macrophyte zones and open water zones for water quality control.

The constructed wetland/detention basin would form part of a treatment train approach that would

improve the water quality of runoff leaving the site. Other components would include grass swales to

filter site runoff before it reaches the wetland system. The hydraulic residence time provided by the

wetland system would significantly improve water quality through sedimentation and nutrient uptake,

as well as providing oxidation and ponding to treat pathogens.

The proposed constructed wetland/detention basin shown conceptually in Figure 1 has the following

key design parameters:

• Inlet pond volume 2,000 m3;

• Macrophyte area 3,000 m2;

• Macrophyte area depth 0.4 m;

• Extended detention depth 0.5 m

• Additional Detention depth 0.6 m

• Total volume ~4,000 m3 @ normal water level (NWL).

The wetland macrophyte zone would have 200 mm high internal bunds that would trap water within the

macrophyte area in the event that greater than 200 mm of water is drawn from the wetland system. This

would maintain water in the macrophyte area.

Water for reuse in the facility would be drawn from the outlet pond. Prior to reuse, the water would go

through a filter and disinfection process to manage potential pathogens.

3.4 SURFACE WATER MODELLING RESULTS

3.4.1 PEAK FLOW

Peak site discharge through the five culverts under current and future site conditions was assessed using

TUFLOW. The locations of these culverts are shown in Figure 5. Results are summarised in Table 3.4

and detailed further in Appendix A.


Table 3.4 – TUFLOW modelling results

Culvert/

Tabledrain

ID

1 % AEP 10 % AEP

Base Proposed Impact Base Proposed Impact

No. 1 0.001 0.001 0.000 0.000 0.000 0.000

No. 2 0.086 0.060 -0.026 0.047 0.006 -0.041

No. 3 0.580 0.534 -0.046 0.211 0.185 0.026

No. 4 0.002 0.002 0.000 0.000 0.000 0.000

No. 5 0.390 0.346 -0.044 0.198 0.187 -0.011

No. 6 0.232 0.209 -0.023 0.123 0.122 -0.002

No. 7 0.182 0.125 -0.057 0.069 0.058 -0.011

The TUFLOW modelling results in the table above supports the results in Appendix A which

demonstrate there are no adverse impacts on neighbouring properties due to the development. In both

the 1% and 10% AEP events there no increase in peak discharges or peak flood levels external to the

site, as shown by impacts maps in Figure 6 and Figure 7. Consequently, there is no actionable flooding

nuisance resulting from the development.

Figure 5: Culvert locations


Figure 6: 1% AEP Surface Level Impacts

Figure 7: 10% AEP Surface Level Impacts


3.4.2 QUALITY

The MUSIC modelling results are summarised in Table 3.5 and show that the average annual pollutant

loads from the developed site are less than the existing loads. The water quality modelling demonstrates

that the downstream receiving environment would receive water with improved quality.

Table 3.5 – MUSIC Modelling Results

Parameter Existing

Post

Development

Pre-Treatment

Post

Development

Post-

Treatment

Post

Development

% Reduction

from Pre-

Treatment

Post

Development

% Reduction

from Existing

Flow (ML/yr) 19.1 47.9 13.2 72.4 29.6

TSS (kg/yr) 515 9890 306 96.9 40.6

TP (kg/yr) 4.38 19.4 2.22 88.6 49.3

TN (kg/yr) 23.8 104 17.5 83.2 26.5

3.4.3 SITE YIELD

The MUSIC model estimates existing average site yield from the catchment to be about 19.1 ML/year.

The proposed facility is estimated to discharge an average of about 13.2 ML/year; this is a decrease of

around 30%.

3.5 SURFACE WATER MANAGEMENT CONCLUSIONS

Surface Water Discharge Quantity

Mapping of the predicted impact due to the development to flooding on the site is shown in Figure 6

and Figure 7 as well as in Appendix A. The results show that onsite flooding is changed due to the

proposed works. However, these changes are contained within the site boundary and no flood levels

outside the site are impacted.

Surface Water Discharge Quality

The water quality treatment train including grass swales and the constructed surface water wetland is

designed to treat surface water from the site so that it is suitable for discharge from the site. Main

pollutants targeted for treatment are suspended solids and nutrients. In summary:

• The average annual load of suspended solids is reduced by 41% from 515 kg/year to 306 kg/year. Modelling results show the average suspended solids concentration in the water discharged from

the site falls from 26.3 mg/L to 25.5 mg/L.

• The average annual load of phosphorus is reduced by 49% from 4.38 kg/year to 2.22 kg/year. Modelling results show the average phosphorus concentration in the water discharged from the

site changes from 0.213 mg/L to 0.206 mg/L, essentially remaining the same.

• The average annual load of nitrogen is reduced by 26.5% from 23.8 kg/year to 17.5 kg/year. Modelling results show the average nitrogen concentration in the water discharged from the site

changes from 1.24 mg/L to 1.23 mg/L, essentially remaining the same.

Constructed wetlands remove contaminants through sedimentation, filtration, oxidation and plant

uptake. When considering the type of development in the catchment, the major pollutant sources are


suspended solids, organic matter, microbiological and nutrients. Constructed wetlands are sized to

target these major pollutants and in removing these, are also effective in removing other pollutants,

particularly particulate bound pollutants.

Surface Water Summary

Site discharge will occur in the same location as it does currently. Modelling shows that peak discharge

from the site is slightly modified from the current conditions, however there is no adverse impact to

flood levels outside of the site due to the proposed development. The concentrations of suspended

solids and nutrients in the water would essentially be unchanged and annual loads are expected to

decrease due to the development.

The water quality assessment indicates that the proposed surface water management system has a

neutral or beneficial effect on water quality. This will protect downstream beneficial uses consistent with

the principles of SEPP (Waters of Victoria).

4. LIQUID WASTE MANAGEMENT

4.1 EFFLUENT SOURCES

Liquid wastewater would be generated from the domestic amenities, truck wash, trough washing, wash


Domestic effluent generated from the central amenities building and transport operators amenities

would be managed using on-site effluent management systems for primary treatment with the effluent

then further treated through the facility’s effluent treatment system.

4.2 EFFLUENT MANAGEMENT SYSTEM

4.2.1 EFFLUENT QUANTITY

The design flow for the effluent management system is based on the peak weekly flow derived from the

water cycle modelling.

The peak weekly flow is 1,143 kL which equates to a design flow of 163 kL/day.

It is noted that this design value is 3.0 times the average daily flow through the system (55 kL/day) and

would provide a substantial design buffer to manage peak loads.

4.2.2 DESCRIPTION

The effluent management system includes:

• Solids separation;

• SBR wastewater treatment plant; and

• Pump station to transfer treated effluent offsite to the sewerage system.


4.2.3 SBR

Design

A sequencing batch reactor (SBR) will be used to treat effluent from the truck wash and wash down to

quality suitable for discharge as trade waste.

The SBR design basis is:

• Maximum flow rate 175 kL/day

• Average flow rate 55 kL/day

• Influent BOD


Helminth Removal

EPA Publication 464.2: Guidelines for Environmental Management – Use of Reclaimed Water (EPA, 2003)

notes that helminth removal can be achieved by methods such as sand or membrane filtration. The

proposed BSR will include a multimedia filtration system.

4.2.4 EFFLUENT QUALITY

The SBR system would treat the liquid waste to a standard suitable for discharge into South East Water

sewerage via a trade waste agreement.

The total modelled average annual effluent to be discharged from the site is approximately 20.1 ML/year.

The average, minimum and maximum daily discharges through the system to the sewerage were

modelled as follows:

• Average daily discharge of 55 kL;

• Minimum daily discharge of 0 kL;

• Maximum daily discharge of 163 kL.

The effluent treatment system design is expected to treat the effluent to the quality targets below for

discharge into South East Water sewerage:

• BOD ~ 20 mg/L

• TSS ~ 30 mg/L

• TN ~ 50 mg/L

• TP ~ 8 mg/L

4.2.5 COMMISSIONING

The effluent treatment system is based on biological processes that need to be effectively commissioned

to ensure the system provides a treated effluent that is fit for purpose. It is expected that the

commissioning period would be 12 months and would include the following stages:

• Testing system construction – mechanical and electrical testing, system filling and water tightness testing.

• Establishment of treatment processes – following initial filling, build-up of the required bacteriological populations would then commence. This could be enhanced by seeding the tanks

if it is considered necessary.

• Monitoring of system performance – once the system starts to establish the necessary biological populations, regular monitoring would be undertaken to track effluent treatment performance

through the system. This monitoring would typically include dissolved oxygen, pH, BOD/COD,

suspended solids and microbiological indicators.


5. DOMESTIC EFFLUENT MANAGEMENT

5.1 INTRODUCTION

The water cycle modelling indicates that the domestic wastewater load from the central amenities

building averages 1,314 L/day and ranges from 200 L/day to 3,325 L/day on peak sale days.

The modelled domestic wastewater load from the transport operator’s amenities averages 1,710 L/day

and ranges from 0 L/day to 2,975 L/day on peak sale days

Both systems would be designed to ensure they can manage increased loads during sale days.

The onsite effluent management system would be sized and constructed in accordance with AS/NZS

1547:2012 On-site domestic wastewater management and EPA Publication 891.3 Code of practice onsite

wastewater management (EPA, 2013). This latter reference applies to systems which treat up to a

maximum peak daily flow of 5,000 L/day. The design daily flow is within this limit.

5.2 PRIMARY TREATMENT

The domestic wastewater would receive primary treatment in a septic tank system. At this stage, it is

proposed to install a 5,000 L septic tank at both the central amenities building and transport operator’s

amenities.

AS/NZS 1547:2012 On-site domestic wastewater management requires that septic tanks retain the

average daily flow for at least 24 hours to settle the solids and float the scum effectively, so there is a

clear zone at the level of the discharge outlet. The proposed septic tanks would provide an average

hydraulic residence time of 3 to 5 days and greater than 24 hours for the peak day after allowing for

1,000 L sludge build-up.

5.3 SECONDARY TREATMENT

Discharge from the septic tanks would be pumped to the SBR and combined with the main effluent

stream for treatment and discharge to sewer.

6. SOLID WASTE MANAGEMENT

6.1 INTRODUCTION

As part of normal operations, the Longwarry Saleyards would generate a range of solid wastes including:

• Solids removed from the effluent treatment system (manure and organic matter from the solids separation system);

• Sludge recovered from the SBR;

• General waste and refuse; and

• Stock mortalities.

Less frequently the Longwarry Saleyards would generate spent soft floor material (woodchip/sawdust or

similar) from the cattle pavilion when replaced, which is assumed as an annual occurrence.


6.2 SOURCES AND ESTIMATED QUANTITIES

6.2.1 TRUCK WASH

Based on the solids removal efficiency and solids content of the effluent, approximately 1.5-2 m3/day of

solids is expected from the solids separation system.

Solids removed in the solids separation system form a pile in a concrete bunker. These are removed as

required and stockpiled. It is expected that the truck wash solids would be removed from the site as

soon as practicable but could remain on the stockpile area for up to 6 to 8 weeks. Therefore, up to

112 m3 could be stored onsite prior to being taken offsite.

6.2.2 GENERAL REFUSE

General municipal refuse would be generated by staff, agents, drivers and patrons. It is estimated one

small skip bin a week would be disposed of to a licensed waste facility. Appropriate waste receptacles

would be provided around the facility.

6.2.3 STOCK MORTALITIES

The proposed saleyards would provide less mortality risk to livestock compared to existing saleyard

facilities. The soft floor would minimise cattle slipping, and the covered yards would provide shelter for

animals in both hot and cold conditions.

Carcass disposal will be undertaken at a licensed waste facility.

6.2.4 SPENT SOFT FLOOR

The soft floor in the cattle pavilion would be turned (essentially lightly scarified) after each sale to

incorporate manure through the soft floor material. This post sale treatment would maintain aerobic

conditions and moisture control within the soft floor. This is an odour control measure.

The soft floor is progressively replaced over time. This material would be a valuable source of organic

matter and nutrients.

Spent soft floor material would be typically removed in rows. One run of pens would be approximately

140 m3 of soft floor material.

Spent soft floor material would be collected and stored in the solids stockpile area and disposed as soon

as practicable to an off-site licensed waste facility or composting facility.

A clean soft floor material laydown area would be provided to facilitate soft floor replacement.

6.2.5 SBR SLUDGE

Waste sludge from the SBR would be transferred automatically to the solids separation system as

required. The sludge would pass through the separation system with the filtrate returning to the

treatment process. Solids would be stockpiled with solids from the truck wash/soft floor and removed

as soon as practicable from site.

It is noted that sludge from the SBR is highly digested and has little organic content remaining which

significantly lowers the potential for odour from these solids.


6.3 SOLID WASTE STOCKPILES

Truck wash solids recovered from the solids separation system would be stockpiled in triangular

windrows with the following approximate dimensions:

• Based width = 6 m;

• Height = 1.5 m

• Batters = 1:2

• Length = 25 m

• Plan area (including 3 m access) = 340 m2

• Windrow surface area (for odour modelling) = 200 m2

• Windrow volume = 113 m3

• Access areas around each windrow = 3.0 m

Soft floor material would be stockpiled in triangular windrows with the following approximate

dimensions:

• Based width = 8 m;

• Height = 2 m

• Batters = 1:2

• Length = 20 m

• Plan area (including access) = 330 m2

• Windrow surface area (for odour modelling) = 230 m2

• Windrow volume = 160 m3

• Access areas around each windrow = 3.0 m

The area required for stockpiles is therefore a minimum of 670 m2. The nominated solids stockpile site

has an area of ~1,000 m2 and adequate dimensions to accommodate these stockpiles.

For odour modelling purposes:

• the truck wash material would require one windrow which would have a surface area for odour emissions of approximately 200 m2; and

• the maximum soft floor stockpile volume would require one windrow which would have a surface area for odour emissions of approximately 230 m2.

6.4 SOLID WASTE MANAGEMENT

There is no intent to utilise solid organic wastes on-site. All organic solids wastes would be removed off-

site as soon as practicable to a licensed waste facility or composting facility.

Recovered solids from the solids separation system and soft floor material would be temporarily

stockpiled on a sealed pad adjacent to the solids separation system, within a controlled drainage area,

with runoff draining back to the separation system collection sump. The stockpiling area would not be

covered to allow the solids to dry. The material would be transported off site when it is dry enough to

do so.

The duration of stockpiling prior to removal off-site would be monitored and determined by site

conditions and the operational objective of minimising the potential for offensive odours from this


source. Stockpiled material would be turned periodically to promote drying and aeration. Operational

experience from other sites provides the following indicative stockpiling activities:

• Truck wash solids – removed on average once per week and remain on the stockpile area for up to 6 to 8 weeks;

• Solids from the SBR – automatically transferred to the solids separation system and treated the same as truck wash solids.

• Soft floor material – replacement rotated and confined only to areas where the material has deteriorated beyond its useful life. Removal occurs on rotation over a 12 month period with

material remaining on the stockpile area for up to 3 to 4 weeks.

These timings are indicative only and would be confirmed through the EIP. Anecdotal data from other

sites indicates that these sources do not generate significant odour when managed as described. The

primary operational objectives would be to manage these solids to minimise odour generation.

Solids would be removed to appropriately approved and licensed facilities which would be detailed in

the EIP.

Quantities would be monitored by recording the amount of material taken off-site (truck numbers and

weight estimate).

7. SYSTEM MANAGEMENT

7.1 EFFLUENT TREATMENT SYSTEM

7.1.1 EFFLUENT QUALITY TARGETS

The effluent treatment system incorporates an SBR to treat the liquid wastes to a standard suitable for

discharging to sewerage. The proposed system is designed to ultimately achieve effluent quality meeting

the following targets:

• BOD ~ 20 mg/L;

• TSS ~ 30 mg/L;

• TN ~ 50 mg/L; and

• TP ~ 8 mg/L.

7.1.2 COMMISSIONING PERIOD

The effluent treatment system uses an SBR system to treat the liquid wastes to the required standards.

A commissioning period is required to effectively establish the treatment system. At a minimum this

would include:

• Testing system construction;

• Establishment of treatment processes; and

• Monitoring of system performance.

A commissioning period of 12 months is proposed from the commencement of operations to fully

commission the effluent treatment system to ensure it can consistently deliver treated water which meets

the design targets.


An outline of the commissioning process, controls, monitoring and reporting requirements is provided

in the following sections. The preliminary commissioning plan would be refined once detailed design is

completed.

7.1.3 COMMISSIONING PLAN

The preliminary commissioning plan and actions are outlined in Table 7.1. Details are provided in the

following section. System designers would be involved throughout the commissioning period and

would:

• Conduct training of site staff;

• Prepared commissioning and monitoring schedules;

• Review data and operational information;

• Respond to questions or operational issues;

• Oversee any changes to operational protocols;

• Regularly inspect the system commissioning progress; and

• Prepare a commissioning report.

Operations during the commissioning period would be undertaken by appropriately trained on-site staff.

Table 7.1 – Summary of commissioning plan and actions

Component Expected period Actions

Pre-commencement of operations 1-2 weeks Equipment testing

SBR establishment 16-20 weeks Effluent quantity recording

Effluent quality recording

Weekly system inspection

Adjust dosing

SBR stabilising/optimisation 20-24 weeks Effluent quantity recording

Effluent quality monitoring

Weekly system inspection

Adjust dosing

Online monitoring

Reporting 4 weeks Prepare commissioning report

7.1.3.1 Monitoring

Timing

Monitoring of the system would start at the commencement of truck wash operations. The following

monitoring would be undertaken during the operational phases.

1. Effluent quantity recording

2. Effluent quality monitoring

3. Weekly system inspection

Effluent Quantity Recording

Daily effluent quantity would be recorded through truck wash use.

AVDATA records of truck wash use would be downloaded and analysed to determine the average daily

effluent flow entering the system.


This data would be stored in digital records.

Daily rainfall records would be maintained.

Effluent Quality Monitoring

Where: Effluent monitoring locations would include:

E1 raw effluent from truck wash solids separation system discharge point

E2 outflow from SBR (discharge to sewer)

When: Samples would be collected every month commencing at the commencement of truck wash

operations (if effluent is present).

What for: Samples would be analysed for the following parameters:

E1 and E2

- Biochemical oxygen demand (BOD), mg/L

- Total suspended solids (TSS), mg/L

- pH

- E. coli, cfu/100mL

- Nitrogen suite (TN, TKN, NH3, NOx)

- Total phosphorus

7.1.3.2 Weekly System Inspection

The effluent treatment system would be inspected weekly during the commissioning period. The

inspection would note and record the following for the system:

1. Checks for leaks around tanks, reactor and pumping station/pumps;

2. SBR system monitoring panel and controls;

3. Chemical volumes;

4. Any solids build up; and

5. Any relevant operational comments – e.g. significant rain, higher than usual truck wash activity.

7.1.3.3 Reporting

A commissioning report shall be prepared after the initial 12 months of operation. This report would:

• Present an overview of the commissioning process;

• Present and discuss monitoring data;

• Describe any remedial actions or system modifications undertaken during commissioning; and

• Outline any management actions required to ensure the system meets the required quality.

7.1.4 ONGOING MONITORING

Ongoing system and environmental monitoring would be developed at the end of the commissioning

period and would be included in the EIP. It would include a combination of on-line system monitoring

and routine sampling.


7.1.5 EFFLUENT SYSTEM INSPECTION

The proposed treatment system is a robust, stable biological system that requires very little intervention

once fully commissioned. Normal plant management processes would include weekly inspection that

would target the following areas:

• SBR operation

• Dissolved oxygen levels

• Transfer pipe condition

Mechanical items (i.e. transfer pumps) would be subject to routine maintenance in accordance with

manufacturer’s recommendations and/or repaired as required. Routine monitoring would be used

throughout the commissioning period, and on a reduced frequency on an ongoing basis, to ensure the

system is functioning as expected.

7.2 SURFACE WATER SYSTEM

7.2.1 COMMISSIONING PERIOD

A commissioning period of up to 24 months is proposed from the commencement of operations to fully

commission the wetland system to ensure it can manage surface water flows from the site. Details would

be included in the EIP.

7.2.2 SURFACE WATER QUALITY MONITORING

The EIP would include the proposed monitoring program for surface water during and after

commissioning of the wetland. Samples would be collected four times per year and analysed for:

• Electrical conductivity;

• pH;

• Total suspended solids;

• Total nitrogen;

• Nitrate;

• Ammonia; and

• Total Phosphorus.


8. CONCLUSION

Assessment of the water cycle for the proposed Longwarry Saleyards demonstrates that adequate

supplies can be sourced through a combination of roof and surface water harvesting, and top up supplies

from the reticulated potable supply. The average annual water demand is 34.5 ML/year with

27.8 ML/year provided via water recycled or captured on site.

Surface water management would be based on separating catchments and managing runoff according

to the level of potential contamination present. Peak site discharge and quality would be managed

through a treatment train approach with grass swales and a constructed surface water

wetland/detention basin. The water quality assessment indicates that the proposed surface water

management system has a neutral or beneficial effect on water quality. This will protect downstream

beneficial uses consistent with the principles of SEPP (Waters of Victoria).

Liquid wastewater would be generated from the domestic amenities, truck wash, trough washing, wash


All liquid wastes would receive treatment in a SBR treatment system and would then be pumped offsite

to the sewerage system.

Solid wastes would include solids separated from the effluent management system, spent soft floor

material, stock mortalities and general waste and refuse. Recovered solids and soft floor material would

be stored in a designated solids stockpile area which has adequate area to manage the expected

maximum stockpiles. Stock mortalities would be removed from the site as required to a licensed waste

facility. General waste and refuse would be collected in receptacles and transferred to a small skip bin

for offsite disposal.


9. REFERENCES

EPA Victoria (Publication 891.3, 2013) Code of Practice, Onsite Wastewater Management

T. Fletcher, H. Duncan, P. Poelsma, S. Lloyd (2004) Stormwater Flow and Quality, and the Effectiveness of Non-Proprietary

Stormwater Treatment Measures – A Review and Gap Analysis

Marcos von Sperling and Carlos Augusto de Lemos Chernicharo (eds) (2005) Biological Wastewater Treatment in Warm Region

Climates.

Appendix A FLOOD ASSESSMENT

FLOOD ASSESSMENT

PROPOSED LONGWARRY SALEYARDS

PREPARED FOR:


JULY 2020

FLOOD ASSESSMENT LONGWARRY SALEYARDS


PAGE i GEO-0008 1903272 HIA_REV4.1.DOCX

Report Title: Flood Assessment

Project: Proposed Longwarry Saleyards

Client: Longwarry Saleyards Pty Ltd

Report Ref.: GEO-0008 1903272 HIA_Rev4.1.docx

Status: Final Rev4.1

Issued: 8 July 2020

Premise Australia Pty Ltd (Premise) and the authors responsible for the preparation and compilation of

this report declare that we do not have, nor expect to have a beneficial interest in the study area of this

project and will not benefit from any of the recommendations outlined in this report.

The preparation of this report has been in accordance with the project brief provided by the client and

has relied upon the information, data and results provided or collected from the sources and under the

conditions outlined in the report.

All data and information contained within this report are prepared for the exclusive use of Longwarry

Saleyards Pty Ltd to accompany this report for the land described herein and are not to be used for any

other purpose or by any other person or entity. No reliance should be placed on the information

contained in this report for any purposes apart from those stated therein.

Premise accepts no responsibility for any loss, damage suffered or inconveniences arising from, any

person or entity using the plans or information in this study for purposes other than those stated above.



PAGE ii GEO-0008 1903272 HIA_REV4.1.DOCX

TABLE OF CONTENTS

1. INTRODUCTION ........................................................................................................ 1

2. THE DEVELOPMENT ................................................................................................. 2

3. DATA .......................................................................................................................... 3

4. HYDROLOGIC ASSESSMENT .................................................................................... 4

4.1 METHODOLOGY .................................................................................................................................................. 4 4.2 DESIGN RAINFALL INTENSITY & TEMPORAL PATTERNS .................................................................... 4 4.3 RAINFALL LOSSES ............................................................................................................................................... 5 4.4 RESULTS .................................................................................................................................................................. 5

5. HYDRAULIC ASSESSMENT ....................................................................................... 6

5.1 METHODOLOGY .................................................................................................................................................. 6 5.2 MODEL EXTENT AND TOPOGRAPHY .......................................................................................................... 6 5.3 HYDRAULIC ROUGHNESS ................................................................................................................................ 7 5.4 HYDRAULIC STRUCTURES ............................................................................................................................... 9 5.5 BOUNDARY CONDITIONS ............................................................................................................................... 9 5.6 PROPOSED CASE MODEL CHANGES .......................................................................................................... 9 5.7 RESULTS ................................................................................................................................................................ 10

5.7.1 IMPACTS OF DEVELOPMENT .................................................................................................... 12 5.7.2 SENSITIVITY ANALYSIS ................................................................................................................ 12

6. CONCLUSION .......................................................................................................... 13

7. QUALIFICATIONS .................................................................................................... 14

8. REFERENCES ............................................................................................................ 15



PAGE iii GEO-0008 1903272 HIA_REV4.1.DOCX

TABLES

Table 5.1 – Adopted Manning’s n Values ............................................................................................................................ 7 Table 5.2 – Flow through the culverts under Thornell Road ...................................................................................... 11 Table 5.3 – Total Discharges from Site ............................................................................................................................... 12 Table 5.4 – Flow Comparison from Basin for Sensitivity Analysis ............................................................................ 12

FIGURES

Figure 1: Site Location .......................................................................................................................................................... 1 Figure 2: WBNM Sub-Catchment Assumptions ......................................................................................................... 4 Figure 3: TUFLOW Model Extent ...................................................................................................................................... 6 Figure 4: TUFLOW Proposed Case Topography Assumptions ............................................................................. 7 Figure 5: TUFLOW Base Case Manning’s Assumptions .......................................................................................... 8 Figure 6: TUFLOW Proposed Case Manning’s Assumptions ................................................................................ 8 Figure 7: TUFLOW Proposed Case Wall and Bunds ............................................................................................... 10 Figure 8: Location of Culverts under Thornell Road and Table Drain Reporting Points ......................... 11

APPENDICES

Appendix A – Proposed Site Drawings

Appendix B – Base Case Flood Maps

Appendix C – Proposal Case Flood Maps

Appendix D – Predicted Flood Impacts



PAGE iv GEO-0008 1903272 HIA_REV4.1.DOCX

EXECUTIVE SUMMARY

This Flood Assessment report details the impacts to flooding likely to arise from the proposed Longwarry

Saleyards Development located in Longwarry, Victoria. The report demonstrates how the development

meets the acceptable performance outcomes with respect to the Melbourne Water requirements.

The key aims of this Flood Assessment are to set adequate flood immunity levels for the proposed

livestock exchange and to demonstrate no adverse impacts to external properties within the catchment.

These aims have been met by developing an WBNM Hydrologic and TUFLOW Hydraulic flood model

(with Rainfall on Grid). These models included appropriate changes to the existing scenario model, to

reflect the proposed works. The proposed development and adopted stormwater infrastructure, which

were utilised within the modelling, demonstrated that the anticipated post-development flood regime

through and external to the site, demonstrates adequate mitigation which illustrates no adverse impacts

external to the site.

.



PAGE v GEO-0008 1903272 HIA_REV4.1.DOCX

ABBREVIATIONS

AEP Annual Exceedance Probability

AHD Australian Height Datum

ARR19 Australian Rainfall and Runoff 2019

DTM Digital Terrain Model

fi Fraction impervious

IFD Intensity Frequency Duration

LiDAR Light Detection And Ranging



PAGE 1 GEO-0008 1903272 HIA_REV4.1.DOCX

1. INTRODUCTION

Premise has been commissioned by Longwarry Saleyards Pty Ltd to prepare a Flood Assessment for the

proposed Longwarry Saleyards. The site is located on Thornell Road, on

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