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Works Approval: W6133/2018/1

IR-T04 Decision Report Template v2.0 (July 2017) i

Application for Works Approval

Division 3, Part V Environmental Protection Act 1986

Works Approval Number W6133/2018/1

Works Approval Holder

Water Corporation

File Number DER2018/000315

Premises Shire of Kellerberrin Storage Dam 2

Part of Lot 417 on Plan 185603

Kelleberrin, WA

(Crown Reserve 34935) As defined by the coordinates in Schedule 1 of the Works Approval

Date of Report 14 November 2018

Status of Report Final

Decision Report


IR-T04 Decision Report Template v2.0 (July 2017) ii

Table of Contents

1. Definitions of terms and acronyms ................................................................... 5

2. Purpose and scope of assessment ................................................................... 7

2.1 Application details .................................................................................................. 7

3. Background ......................................................................................................... 7

4. Overview of Premises......................................................................................... 8

4.1 Operational aspects ............................................................................................... 8

Commissioning .............................................................................................. 11

4.2 Exclusions to the Premises .................................................................................. 12

5. Legislative context............................................................................................ 12

5.1 Other relevant approvals ...................................................................................... 12

Planning approvals ........................................................................................ 12

Department of Health .................................................................................... 13

5.2 Part V of the EP Act ............................................................................................. 13

Applicable regulations, standards and guidelines .......................................... 13

Works approval and licence history ............................................................... 13

Clearing ......................................................................................................... 13

6. Consultation ...................................................................................................... 14

7. Location and siting ........................................................................................... 14

7.1 Siting context ........................................................................................................ 14

7.2 Residential and sensitive Premises ...................................................................... 15

7.3 Specified ecosystems ........................................................................................... 16

7.4 Groundwater and water sources ........................................................................... 16

7.5 Soil type ............................................................................................................... 16

8. Risk assessment ............................................................................................... 16

8.1 Determination of emission, pathway and receptor ................................................ 16

8.2 Consequence and likelihood of risk events ........................................................... 24

8.3 Acceptability and treatment of Risk Event ............................................................. 25

8.4 Risk Assessment – Dust emissions from construction .......................................... 25

Description of Dust emissions ....................................................................... 25

Identification and general characterisation of emission .................................. 25

Criteria for assessment.................................................................................. 25

Applicant controls .......................................................................................... 26

Key findings ................................................................................................... 26

Consequence ................................................................................................ 26


IR-T04 Decision Report Template v2.0 (July 2017) iii

Likelihood of Risk Event ................................................................................ 26

Overall rating of Dust emissions .................................................................... 27

8.5 Risk Assessment – Reuse of treated wastewater ................................................. 27

Identification and general characterisation of emission .................................. 27

Description of potential adverse impact from the emission ............................ 27

Criteria for assessment.................................................................................. 28

Applicant/Licence Holder controls ................................................................. 28

Key findings ................................................................................................... 30

Consequence ................................................................................................ 30

Likelihood of Risk Event ................................................................................ 30

Overall rating ................................................................................................. 30

8.6 Summary of acceptability and treatment of Risk Events ....................................... 31

9. Regulatory controls .......................................................................................... 32

9.1 Works Approval controls ....................................................................................... 32

Infrastructure and equipment ......................................................................... 32

Commissioing ................................................................................................ 33

9.2 Operational controls ............................................................................................. 34

Reporting ...................................................................................................... 34

Monitoring requirements ................................................................................ 34

Works approval and Licence ...................................................................................... 34

10. Determination of Works Approval conditions ................................................ 35

11. Applicant’s comments ...................................................................................... 36

12. Conclusion ........................................................................................................ 36

Appendix 1: Key documents .................................................................................... 37

Appendix 2: Summary of applicant’s comments on risk assessment and draft conditions .................................................................................................................. 38

Attachment 1: Issued Works Approval W6131/2018/1 ........................................... 41

Table 1: Definitions .................................................................................................................. 5

Table 2: Documents and information submitted during the assessment process ...................... 7

Table 3: Prescribed Premises Categories for related Licence L6071/1991/10 – Kellerberrin Wastewater Treatment Plant (WWTP) ..................................................................................... 8

Table 4: Shire of Kellerberrin chlorinator facility Category 54 infrastructure ............................ 11

Table 5: Works approval history ............................................................................................. 13

Table 6: Receptors and distance from activity boundary ........................................................ 15

Table 7. Identification of emissions, pathway and receptors during construction .................... 18

Table 8: Identification of emissions, pathway and receptors during operation ........................ 21


IR-T04 Decision Report Template v2.0 (July 2017) iv

Table 9: Risk rating matrix ..................................................................................................... 24

Table 10: Risk criteria table .................................................................................................... 24

Table 11: Risk treatment table ............................................................................................... 25

Table 12: Applicant’s proposed controls for dust emissions ................................................... 26

Table 13: Applicants controls for seepage from reuse of treated wastewater ......................... 28

Table 14: Risk assessment summary ..................................................................................... 31

Table 15: Summary of regulatory controls to be applied ......................................................... 32

Table 16: Infrastructure Requirements ................................................................................... 32

Table 17: Specified Licence limits .......................................................................................... 33

Table 18: Operational controls ............................................................................................... 34

Table 19: Monitoring requirements ......................................................................................... 34

Table 20: Wastewater Commissioning Quality ....................................................................... 35

Table 21 Summary of conditions to be applied ....................................................................... 36

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IR-T04 Decision Report Template v2.0 (July 2017)

1. Definitions of terms and acronyms

In this Decision Report, the terms in Table 1 have the meanings defined.

Table 1: Definitions

Term Definition

ANZECC Australian and New Zealand Environment and Conservation Council (ANZECC) 1997 Australian Guidelines for Sewerage systems, Effluent Management, National Water Quality Management Strategy.

ARMCANZ means the Agriculture and Resources Management Council of Australia and New Zealand

Applicant Water Corporation

Category/ Categories/ Cat.

Categories of Prescribed Premises as set out in Schedule 1 of the EP Regulations

cfu Colony forming units

Decision Report refers to this document.

Delegated Officer an officer under section 20 of the EP Act.

Department means the department established under section 35 of the Public Sector Management Act 1994 and designated as responsible for the administration of Part V, Division 3 of the EP Act.

DWER Department of Water and Environmental Regulation

As of 1 July 2017, the Department of Environment Regulation (DER), the Office of the Environmental Protection Authority (OEPA) and the Department of Water (DoW) amalgamated to form the Department of Water and Environmental Regulation (DWER). DWER was established under section 35 of the Public Sector Management Act 1994 and is responsible for the administration of the Environmental Protection Act 1986 along with other legislation.

EP Act Environmental Protection Act 1986 (WA)

EP Regulations Environmental Protection Regulations 1987 (WA)

mg/L milligrams per litre

NEPM National Environmental Protection Measure

NIMP Nutrient and Irrigation Management Plan

Noise Regulations Environmental Protection (Noise) Regulations 1997 (WA)

Occupier has the same meaning given to that term under the EP Act.

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PM Particulate Matter

PM10 used to describe particulate matter that is smaller than 10 microns (µm) in diameter

Prescribed Premises

has the same meaning given to that term under the EP Act.

Premises refers to the premises to which this Decision Report applies, as specified at the front of this Decision Report

Risk Event As described in Guidance Statement: Risk Assessment

TWW Treated wastewater

UD Regulations Environmental Protection (Unauthorised Discharges) Regulations 2004

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2. Purpose and scope of assessment

The Water Corporation (the Applicant) has submitted a Works Approval application to construct and install a new filtration and gas chlorination system, new pump and two 25 kilolitre (kL) holding tanks at the Shire of Kellerberrin’s Storage Dam No.2 to provide for Public Open Space (POS) irrigation (Football Oval and Hockey Field). The Works Approval Application was submitted on 15 February 2018.

Presently, the irrigation water does not meet the water quality criteria as specified in the Department of Health (DoH) Guidelines for the Non-potable Uses of Recycled Water in Western Australia, prior to re-use by the Shire.

The project construction activities are anticipated to commence in January 2019 and be completed by August 2019.

The operation and control of the chlorination unit will remain with the Water Corporation.

The scope of assessment for this Decision Report relates to:

Works associated with the installation/construction of a new filtration and gas chlorination system with a capacity of 292 cubic metres (m3) per day with an annual daily average irrigation rate of 124m3/day and a maximum dosage of 5.5 mg/L;

The risk of emissions to the environment and public health during construction and operation of the chlorinator; and

The risk of emissions to the environment and public health by irrigating the POS with treated wastewater.

2.1 Application details

Table 2 lists the documents submitted during the assessment process.

Table 2: Documents and information submitted during the assessment process

Document/information description Date received

Works Approval Application Final 2018_02_2018 15 February 2018

Additional information on prescribed premises boundary (Water Corporation, 22 March 2018) – submitted in response to DWER request for further information dated 13 March 2018.

26 March 2018

Email correspondence – further information submitted:

Kellerberrin Shire Chlorinator Installation Project Works Approval Application Supplementary Information

15 May 2018

3. Background

The Water Corporation owns and operates the Kellerberrin Wastewater Treatment Plant (WWTP) under Licence L6071/1991/10. The Kellerberrin WWTP is licensed to treat up to 210 m3 per day. The WWTP consists of one Imhoff Tank and two secondary treatment ponds in parallel. Secondary treated wastewater (TWW) is discharged to the Shire of Kellerberrin Storage Dam No. 1, which also receives stormwater from the surrounding area.

Secondary treated wastewater from Storage Dam No. 1 is then chlorinated and pumped by the Shire to Storage Dam No. 2 located 1.5 km off-site to the north-west of the WWTP (separate premises). Storage Dam No. 2 also receives stormwater which is pumped from a stormwater dam approximately 1.9 km to the north-west of the WWTP.

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At present TWW at Storage Dam No. 2 does not meet the current Department of Health (DoH) Guidelines for the Non-potable Uses of Recycled Water in Western Australia, prior to re-use by the Shire. The Water Corporation is seeking to construct a new filtration and gas chlorination system, new pump and two 25kL holding tanks immediately after Storage Dam No. 2 to ensure the irrigation water applied to the POS meets the DoH guidelines. Table 3 lists the prescribed premises categories that have been applied for.

The works proposed at Storage Dam No. 2 will cause the site to be considered a prescribed premises for the purposes of Part V of the EP Act and thus a works approval will be required for related installation and construction works. Subsequent to construction and commissioning a licence will be required to operate the Premises.

Table 3: Prescribed Premises Categories for related Licence L6071/1991/10 – Kellerberrin Wastewater Treatment Plant (WWTP)

Classification of Premises

Description Approved Premises production or design capacity or throughput

Category 54

Sewage facility: premises –

(a) on which sewage is treated (excluding septic tanks); or

(b) from which treated sewage is discharged onto land or into waters.

292 m3 or more per day

4. Overview of Premises

4.1 Operational aspects

The Treated Wastewater Management (TWWM) compound will house the chlorination module, contact tanks, flowmeter, single duty self-priming pump and self-cleaning screen. Security fencing will be constructed around the perimeter of the compound which will be 1950 mm high with individual circular disk razor wire fixed to the top. There will be one lockable entrance to the compound. Water Corporation will excise this portion of the land from the Shire and the TWWM Compound will become the prescribed premises boundary. The chlorination module will be installed on a concrete slab with dimensions of 11.8m (L) x 4.3m (W) x 300mm (H). The chlorination module is fitted with gas detection alarms and emergency shut-off buttons on the interior and exterior of the module. A Self-contained Breathing Apparatus (SCBA) will be located with the module. The contact tanks will be installed on a concrete slab (separate to the one for the chlorination module) with dimensions 18.7m (L) x 5.6m (W) x 300mm (H). In the event of a rupture of the contact tanks, a drain and soakwell system will be installed to prevent treated water from leaving the TWWM Compound. A drain (17.5m x 890mm x 300mm) will be constructed along the northern edge of the concrete slab the contact tanks sit on. The drain will be constructed to a depth of 300mm over 100 mm thick sand bedding, above the sand bedding will be a 3mm thick HDPE liner to prevent loss from the drain to the sand bedding beneath. Above the HDPE liner will be 20mm of aggregate and above that layer will be 40mm aggregate fill to the surface. The current irrigation pump owned and operated at the Shire’s Storage Dam No. 2 will be replaced with a new 4 pole 22kW water pump and gifted back to the Shire. WC will also construct a new switchboard inlet and outlet isolation valves for irrigation control and dispersal within the Pump Shed. The Pump Shed is partially within the project area but it will not form part of the TWWM compound or the Prescribed Premises Boundary.

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Water Corporation intend to commence construction activities from January 2019 until August 2019. Clearing of vegetation will occur first to provide space for construction activities and laydown space for equipment. Most of the infrastructure will be completely installed by the end of July 2019 and the commissioning phase of the project will be conducted in two phases over July and August 2019. Figure 1 depicts the project area and associated POS irrigation areas. The project area as defined in Figure 1 covers the area where project activities will be undertaken and encompasses vehicle movements, the upgrade of the new power line to the TWWM compound, site works for new pipe infrastructure and tie-in to the existing pipe infrastructure.

Figure 1: Chlorinator project area and POS irrigation areas

Figure 2 depicts the ultimate prescribed premises boundary for the facility and includes GPS coordinates.

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Figure 2: TWWM Compound – prescribed premises boundary (as depicted by the purple line)

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Commissioning

Phase 1 commissioning will involve the testing of the infrastructure within the Treated Wastewater Management (TWWM) compound. During this phase of the commissioning all water used for testing will be discharged back into Shire Dam No. 2 from where it was withdrawn, via lay flat hose which will be temporarily connected as part of this phase. Phase two commissioning will involve the testing of the Shires Public Open Space (POS) infrastructure (Town Oval and the Hockey). During this phase, discharges will occur via the POS infrastructure. As required by the Department of Health (DoH), a total of six validation monitoring events will occur in this phase. All samples will be collected from the monitoring location situated directly downstream from the chlorination dosing point.

The Shire of Kellerberrin Storage Dam No. 2 WWTP Chlorinator facility infrastructure, as it relates to Category 54 is detailed in Table 4.

Table 4: Shire of Kellerberrin chlorinator facility Category 54 infrastructure

Infrastructure Site Plan Reference

Prescribed Activity Category 54

Receipt and disinfection of wastewater from the Kellerberrin Wastewater Treatment Plant

1 Variable speed pump

Schedule 1 to the Works Approval

Figure 3 below also outlines the process map for the facility.

2 200 micron self-cleaning screen filter

3 2 x Flow meter units

A flow meter will measure the quantity of wastewater pumped from Storage dam No. 2 into ‘Contact tanks’ and then the quantity sent to the irrigation network.

4 Disinfection system

Chlorinator

installed on a concrete slab

Provides residual disinfection in distribution tank and throughout the distribution system (free chlorine). The chlorine will be dosed, monitored and controlled automatically.

5 Treated wastewater conduit

Treated wastewater will be piped from the treated wastewater storage tanks (2 x 25kL) located onsite to irrigate Public Open Space

6 Treated Wastewater Storage tanks 2 x 25kL

7 Flow meter

A flow meter will measure the quantity of wastewater treated and after sent to the irrigation network.

8 HDPE lined drain and soakwell system

To prevent treated water from leaving the premises during an emergency

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Figure 3: WWTP Chlorinator Flow Diagram

4.2 Exclusions to the Premises

The Water Corporation will install a Grundfos CRN 64-3-2 water pump equipped with a 22kW motor to pump water from the holding tanks to the POS. A new switchboard equipped with inlet and isolation valves for the POS irrigation. This infrastructure will not be located within the TWWM compound and therefore not considered part of activities of the Premises. Water Corporation has indicated that this infrastructure will be handed over to the Shire to operate once constructed.

Key Finding: The Delegated Officer notes that the infrastructure listed above will be installed on Shire owned land for the purposes of POS irrigation. The Delegated Officer considers the construction and operation of the related infrastructure to be outside DWER’s regulatory scope as the infrastructure will not be within the boundary of the Premises, nor do these activities meet a description of a prescribed premises category as defined in Schedule 1 of the EP Regulations.

5. Legislative context

5.1 Other relevant approvals

Planning approvals

Water Corporation is exempt from the requirement (under the Planning and Development Act 2005) to obtain development approvals for Public Water Works under a Local Planning Scheme.

The Water Corporation however has been in consultation with the Shire of Kellerberrin on the development. This has resulted in the Shire agreeing to the Water Corporation taking control of a portion of Reserve 34935 which will house the chlorination module.

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Department of Health

The Department of Health (DoH) considers that the use of recycled water for surface irrigation of POS presents a low risk exposure level, based on the Guidelines for the Non-potable Uses of Recycled Water in Western Australia 2011 and has issued an approval in principle for the project with the following conditions relating to human exposure of pathogens:

installation of the storage tanks in accordance with the relevant standards (AS4766:2006; AS3735:2001; AS3500.1:2015; WSA 129:2011);

demonstration of total chlorine residue between 0.2mg/L to 2 mg/L after a minimum contact time of 30 minutes;

submission of six weekly sampling results in compliance with the “Low” Exposure Risk Level recycled water quality after commissioning of the works and at the storage tank sample point outlet;

submission of the Recycled Water Quality Management Plan within the corresponding Process Control Table to the satisfaction of the DoH; and

signed Recycled Water Supply Agreement between the Shire of Kellerberrin and the Water Corporation to reflect the updated delivery points, recycled water quality standards and roles and responsibilities of each party.

A Licence to operate the Shire of Kellerberrin Storage Dam No. 2 WWTP Chlorinator module will not be granted until a final permit from DoH has been issued after complying with all conditions of the approval in principal including commissioning and validation of the plant.

5.2 Part V of the EP Act

Applicable regulations, standards and guidelines

The overarching legislative framework of this assessment is the EP Act and EP Regulations.

The guidance statements which inform this assessment are:

Guidance Statement: Regulatory Principles (July 2015)

Guidance Statement: Setting Conditions (October 2015)

Guidance Statement: Land Use Planning (February 2017)

Guidance Statement: Decision Making (February 2017)

Guidance Statement: Risk Assessments (February 2017)

Guidance Statement: Environmental Siting (November 2016)

Works approval and licence history

Table 5 summarises the works approval and licence history for the Premises.

Table 5: Works approval history

Instrument Issued Nature and extent of works approval

W6133/2018/1 14/12/2018 Installation of a chlorination unit

Clearing

Water Corporation intend to clear 0.81 hectares (ha) of vegetation (10 tress maximum) to provide room for infrastructure, install new pipe network within site and to upgrade power

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supply to infrastructure. Water Corporation have outlined that due to the utilisation of already cleared areas and access tracks throughout the project area, the actual clearing required will be no more than 0.316 ha. Heavy machinery will be used to clear the vegetation from the premises. A clearing exemption has been applied by Water Corporation under Regulation 5 Item 1 of the Environmental Protection (Clearing of Native Vegetation) Regulations 2004. This items states that that clearing to construct a building or other structure is exempt as long as all clearing on the property does not exceed 5 ha in a financial year.

6. Consultation

The Application was advertised in the West Australian on 26 March 2018 for a comment period ending on 16 April 2018. A letter inviting comment was also sent to the Shire of Kellerberrin on 16 April 2018.

DoH considers the use of recycled water for surface irrigation of the POS presents a low risk exposure level based on the “Guidelines for the Non-potable Uses of Recycled Water in Western Australia 2011” and has issued an approval in principle for the project with conditions.

DWER referred the draft works approval and Decision Report on 12 July 2018 to the Applicant.

7. Location and siting

7.1 Siting context

The project is located across four Lots, being Lot 326 on Plan 158856, Lot 417 on Plan 185603, Lot 420 on Plan 91534, and Lot 431on Plan 219397. All four Lots are vested to the Shire of Kellerberrin. Figure 3 below shows the project area across all four Lot boundaries.

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Figure 2: Project area location

7.2 Residential and sensitive Premises

The distances to residential and sensitive receptors are detailed in Table 6.

Table 6: Receptors and distance from activity boundary

Sensitive Land Uses Distance from Prescribed Activity

Residential Premises 130m west

Residential Premises 144m north

Residential Premises 170m south

Residential Premises 450m east

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While the Delegated Officer has identified that separation distances between wastewater treatment plants and sensitive receptors are to be determined on a case by case basis, having several residences in the immediate vicinity may increase the exposure to emissions at these receptors, and may be subject to greater regulatory controls, if approved. Figure 2 identifies the proximity of the WWTP to the residential receptors.

7.3 Specified ecosystems

Specified ecosystems are areas of high conservation value and special significance that may be impacted as a result of activities at or Emissions and Discharges from the Premises.

The application states that Eucalypt Woodlands of the Western Australian Wheatbelt are likely to occur within the project area. The project area is predominantly cleared of vegetation due to historical activities however a small extent within the northern portion of the project area is showing signs of regeneration following previous construction activities.

7.4 Groundwater and water sources

The distances to groundwater and water sources are not available for the TWWM compound and no on-site groundwater monitoring wells exist to verify the depth of the underlying water table. The application also did not provide any information relating to groundwater sources.

An ephemeral creek occurs approximately 1.06 km to the west of the football oval. However direct or indirect connectivity with this creek does not occur, given the distance from discharge to receptor and the land uses in between.

Water Corporation also noted that numerous roads, residential properties and small patches of bush separate the creek from the compound and the irrigation (discharge) areas (football oval and hockey fields).

Further information provided by the applicant on 4 July 2017 confirms that both discharge locations mentioned above have been identified to occur within a proclaimed surface water irrigation area under the RIWI Act 1914. Under this Act it is illegal to extract water without permit. However a search of the water reporting website did not identify any licensed groundwater bore or abstraction licence in that area.

7.5 Soil type

The application details that soil conditions surrounding the Shire of Kellerberrin Storage Dam 2 WWTP Chlorinator and within the POS’s are categorised as red loamy duplex soils with calcareous loamy cracking clays over lying grey sandy duplexes.

8. Risk assessment

8.1 Determination of emission, pathway and receptor

In undertaking its risk assessment, DWER will identify all potential emissions pathways and potential receptors to establish whether there is a Risk Event which requires detailed risk assessment.

To establish a Risk Event there must be an emission, a receptor which may be exposed to that emission through an identified actual or likely pathway, and a potential adverse effect to the receptor from exposure to that emission. Where there is no actual or likely pathway and/or no receptor, the emission will be screened out and will not be considered as a Risk Event. In addition, where an emission has an actual or likely pathway and a receptor which may be adversely impacted, but that emission is regulated through other mechanisms such as Part IV of the EP Act, that emission will not be risk assessed further and will be screened out through

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Tables 7 and 8.

The identification of the sources, pathways and receptors to determine Risk Events are set out in Tables 7 and 8 below.

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Table 7. Identification of emissions, pathway and receptors during construction

Risk Events Continue to detailed risk assessment

Reasoning

Sources/Activities Potential

emissions Potential receptors

Potential pathway

Potential adverse impacts

Construction, mobilisation

and positioning of infrastructure

Vehicle movements on unsealed access roads

Noise Residential premises located 130m west and 144m north of the Premises.

Air / wind dispersion

Impacts to amenity, health and wellbeing

No

The activities at the Premises will need to comply with the Environmental Protection (Noise) Regulations 1997 (Noise Regulations).

Regulation 13 of the Noise Regulations states that, subject to a number of requirements being met, the prescribed standard for noise emissions as outlined in Regulation 7 does not apply to noise emitted from a construction site as a result of construction work carried-out between 0700 hours and 1900 hours on any day which is not a Sunday or public holiday.

Any works on a Sunday or public holiday will need to comply with the prescribed standard for noise emissions as outlined in Regulation 7 unless prior consent is given in accordance with Regulation 13(3).

No additional regulatory controls will be included on the works approval.

Dust

Residential premises located 130m west and 144m north of the Premises.


Yes See section 8.4

TEC Eucalypt woodland Potential suppression of photosynthetic functions

Yes See section 8.4

Construction of new infrastructure

Noise Residential premises located 130m west and 144m north of the Premises.



No

The activities at the Premises will need to comply with the Environmental Protection (Noise) Regulations 1997 (Noise Regulations).

Regulation 13 of the Noise Regulations states that, subject to a number of

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Reasoning



Potential pathway


requirements being met, the prescribed standard for noise emissions as outlined in Regulation 7 does not apply to noise emitted from a construction site as a result of construction work carried-out between 0700 hours and 1900 hours on any day which is not a Sunday or public holiday.

Any works on a Sunday or public holiday will need to comply with the prescribed standard for noise emissions as outlined in Regulation 7 unless prior consent is given in accordance with Regulation 13(3).

No additional regulatory controls will be included on the works approval.

Dust

Residential premises located 130m west and 144m north of the Premises.


Yes See section 8.4

TEC Eucalypt woodland Potential suppression of photosynthetic functions

Yes See section 8.4

Spillages of hydrocarbons from equipment and vehicles

Soils of the site and underlying groundwater

Surface runoff and seepage to groundwater

Soil contamination inhibiting vegetation growth and survival and health impacts to fauna

Contamination of water or deterioration of local groundwater quality

No

These emissions are unlikely to occur and in the rare event that they do they would be localised and minor in nature.

Under the Environmental Protection (Unauthorised Discharges) Regulations 2004 (UD Regulations), it is an offence to cause or allow certain materials to enter the environment in connection with a commercial or business activity.

The UD Regulations are intended to ensure that all people engaged in a commercial activity take responsibility for preventing the escape of contaminants from their business into the environment.

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Reasoning



Potential pathway


The UD Regulations and general provisions of the EP Act1 will apply to operations at the TWWM compound - no additional regulatory controls will be included on the works approval for these potential emissions.

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Table 8: Identification of emissions, pathway and receptors during operation


Reasoning



Potential pathway


Waste Water Treatment

Chlorination Plant

Chlorination of treated water

Odour Residential premises located 130m west and 144m north of the Premises.


Amenity and Health and wellbeing

No Chlorine is dosed directly into wastewater. As a result the Delegated Officer considers that the risk of associated odours will be low and therefore no further assessment and controls will be required.

Conveyance pipes and holding tanks

Rupture of pipes and/or of holding tanks resulting in treated wastewater discharged to land

Vegetation adjacent to discharge area


Stormwater runoff to land and seepage to groundwater

Soil contamination inhibiting vegetation growth and survival, facilitated growth of weeds, increase in nutrient levels in soil

Contamination of water or deterioration of local groundwater quality

No Rupture of tanks and pipe conveyance infrastructure is unlikely to occur during normal operations.

Tanks have an overflow system in-place which redirects any overflow back into Storage dam No.2.

The two holding (contact) tanks will be installed on a concrete slab. A drain and soakwell system will be installed to prevent treated water from leaving the TWWM Compound in the unlikely event that a rupture occurs within one of the tanks. The drain is to be HDPE lined and leads to a concrete soakwell for onsite infiltration/containment.

Under the Environmental Protection (Unauthorised Discharges) Regulations 2004 (UD Regulations), it is an offence to cause or allow certain materials to enter the environment in connection with a commercial or business activity.

The UD Regulations are intended to ensure that all people engaged in a commercial activity take responsibility for preventing the escape of contaminants from their business into the environment.

The UD Regulations and general provisions of the EP Act1 will apply to operations at the TWWM compound.

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Reasoning



Potential pathway


Associated regulatory controls will also be placed on the works approval to specify the equipment and infrastructure to be installed on-site. Complementary regulatory controls may also be included on the licence for these potential emissions with regards to maintaining this infrastructure and equipment.

Storage of chemicals

Breach of containment causing chlorine gas discharge to air

Human receptors Inhalation, Ingestion and dermal contact

Health No Chlorine gas is considered to be a Dangerous Good which are regulated by Department of Mines, Industry Regulation and Safely (DMIRS) under the Dangerous Goods Safety (Storage and Handling of Non-Explosives) Regulations 2007.

Water Corporation has indicated that the chlorination module will be fitted with gas detection alarms and emergency shut-off buttons on the interior and exterior of the module. A Selfcontained Breathing Apparatus (SCBA) will also be located with the module; additionally, WC operational practice states employees entering the compound will be required to have a SCBA in their vehicle when they enter the compound.

Re-use Scheme

Irrigation of treated wastewater

Release of pathogens via airborne water droplets from irrigation and/or direct contact with irrigation mist (ingestion).

Human receptors Direct contact and ingestion of harmful pathogens

Pathogens in the wastewater may cause gastroenteritis, spread disease or create other public health impacts

No The Department of Health regulates public health impacts from the wastewater scheme. The Delegated Officer has reviewed the Department of Health approval for the reuse scheme and considers it appropriate for the regulation of public health impacts.

The Delegated Officer considers that the treatment standard and the quality of water expected prior to irrigation will allow appropriate use of treated wastewater with a low risk to public health with operational control.

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Reasoning



Potential pathway


Treated wastewater applied to POS containing Nitrogen and Phosphorous


Irrigation to land and seepage to groundwater

Mounding of groundwater below the application area;

Inundation of the root zone;

Change in soil chemistry; and

Impacts to surrounding vegetation.

Yes See section 8.5

Note 1: It is a legal requirement that discharges of waste to the environment that have caused or are likely to cause pollution, material environmental harm or serious environmental harm must be reported as soon as practicable to the Chief Executive Officer (CEO) of DWER. Section 72(1) of the EP Act provides that an occupier of the premises (which may include vehicles, vessels and other equipment) on or from which a discharge of waste has taken place, has a duty to notify the CEO of DER of the discharge of waste that has caused or is likely to cause pollution, material environmental harm, or serious environmental harm.

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8.2 Consequence and likelihood of risk events

A risk rating will be determined for risk events in accordance with the risk rating matrix set out in Table 9 below.

Table 9: Risk rating matrix

Likelihood Consequence

Slight Minor Moderate Major Severe

Almost certain Medium High High Extreme Extreme

Likely Medium Medium High High Extreme

Possible Low Medium Medium High Extreme

Unlikely Low Medium Medium Medium High

Rare Low Low Medium Medium High

DWER will undertake an assessment of the consequence and likelihood of the Risk Event in accordance with Table 10 below.

Table 10: Risk criteria table

Likelihood Consequence

The following criteria has been

used to determine the likelihood of

the Risk Event occurring.

The following criteria has been used to determine the consequences of a Risk Event occurring:

Environment Public health* and amenity (such as air

and water quality, noise, and odour)

Almost

Certain

The risk event is

expected to occur

in most

circumstances

Severe onsite impacts: catastrophic

offsite impacts local scale: high level

or above

offsite impacts wider scale: mid-level

or above

Mid to long-term or permanent impact to

an area of high conservation value or

special significance^

Specific Consequence Criteria (for

environment) are significantly exceeded

Loss of life

Adverse health effects: high level or

ongoing medical treatment


public health) are significantly

exceeded

Local scale impacts: permanent loss

of amenity

Likely The risk event will

probably occur in

most circumstances

Major onsite impacts: high level

offsite impacts local scale: mid-level

offsite impacts wider scale: low level

Short-term impact to an area of high

conservation value or special

significance^


environment) are exceeded

Adverse health effects: mid-level or

frequent medical treatment


public health) are exceeded

Local scale impacts: high level

impact to amenity

Possible The risk event

could occur at

some time

Moderate onsite impacts: mid-level

offsite impacts local scale: low level

offsite impacts wider scale: minimal


environment) are at risk of not being met

Adverse health effects: low level or

occasional medical treatment


public health) are at risk of not being

met

Local scale impacts: mid-level

impact to amenity

Unlikely The risk event will

probably not occur

in most

circumstances

Minor onsite impacts: low level

offsite impacts local scale: minimal

offsite impacts wider scale: not

detectable


environment) likely to be met


public health) are likely to be met

Local scale impacts: low level impact

to amenity

Rare The risk event may

only occur in

exceptional

circumstances

Slight onsite impact: minimal


environment) met

Local scale: minimal to amenity


public health) met

^ Determination of areas of high conservation value or special significance should be informed by the Guidance Statement: Environmental Siting.

25



* In applying public health criteria, DWER may have regard to the Department of Health’s Health Risk Assessment (Scoping) Guidelines. “onsite” means within the Prescribed Premises boundary.

8.3 Acceptability and treatment of Risk Event

DWER will determine the acceptability and treatment of Risk Events in accordance with the Risk treatment table 11 below:

Table 11: Risk treatment table

Rating of Risk Event

Acceptability Treatment

Extreme Unacceptable. Risk Event will not be tolerated. DWER may refuse application.

High May be acceptable.

Subject to multiple regulatory controls.

Risk Event may be tolerated and may be subject to multiple regulatory controls. This may include both outcome-based and management conditions.

Medium Acceptable, generally subject to regulatory controls.

Risk Event is tolerable and is likely to be subject to some regulatory controls. A preference for outcome-based conditions where practical and appropriate will be applied.

Low Acceptable, generally not controlled.

Risk Event is acceptable and will generally not be subject to regulatory controls.

8.4 Risk Assessment – Dust emissions from construction

Description of Dust emissions

Particulate Matter (PM) and coarse particles may be generated during construction and clearing activities. Dust may also be generated from vehicle and machinery movements on unsealed roads and surfaces.

Dust generation is influenced by wind levels.

Identification and general characterisation of emission

Potential impacts from dust and particulate emissions include increased degradation of local air quality. Nuisance impacts on the comfort and amenity of residential receptors located as close as 130m west and 144m north of the Premises.

It has the potential to impact public health and affects both the respiratory and cardiovascular systems following both long and short term exposures. Dust may also cause nuisance impacts on the amenity of properties.

Dust may also impact on the photosynthetic abilities of flora within the TEC Eucalypt woodland area; however this relationship has not been well researched.

Criteria for assessment

The relevant criteria for assessment of dust emissions as PM10 is 50µg/m³ over 24 hours as specified in the National Environment Protection (Ambient Air Quality) Measure (NEPM). The NEPM is the relevant criteria for assessment in relation to human health and wellbeing.

26



Amenity impacts can be also be assessed against the general provisions of the EP Act, specifically whether fugitive dust unreasonably interferes with the health, welfare, convenience, or comfort of any person.

Applicant controls

This assessment has reviewed the controls set out in Table 12 below.

Table 12: Applicant’s proposed controls for dust emissions

Controls for fugitive dust

Control Description

Treated Wastewater Management Compound

Site speed limit onsite will be 40 km per hour; and

Water carts routinely operated during construction to reduce the chances of wind driven dust being generated and escaping the boundary.

Key findings

The Delegated Officer has reviewed the information regarding and has found: Due to relatively minimal disturbance area, with small population of private residential receptors and limited duration of construction works, risks can be adequately managed by adhering to the National Environment Protection (Ambient Air Quality) Measure (NEPM) 2003 and DWER’s A guideline for managing the impacts of dust and associated contaminants from land development sites, contaminated sites remediation and other related activities (DEC, 2011).

Consequence

Residential

Based on sensitivity to the nearest residential receptor, the Delegated Officer has determined that residences may experience low-level impacts to health and moderate impacts to amenity. Therefore, the Delegated Officer considers the consequence of dust emission impacts on residences to be Slight.

Environmental

Based on sensitivity of the TEC Eucalypt woodland area, the Delegated Officer has determined that flora within the area may experience minimal off-site impacts. Therefore, the Delegated Officer considers the consequence of dust emission impacts on the environmental receptor to be Slight.

Likelihood of Risk Event

Residential

Based on the close proximity to residents and the Applicant’s proposed controls, the Delegated Officer has determined that the likelihood of impacts from dust emissions could occur in exceptional circumstances. Therefore, the Delegated Officer considers the likelihood of a risk event occurring to be Possible.

Environmental

Based on the close proximity to the TEC Eucalypt woodland area, which is the closest environmental receptor, and the Applicant’s proposed controls, the Delegated Officer has

27



determined that the likelihood of dust emissions would probably not occur in most circumstances. Therefore, the Delegated Officer considers the likelihood of a dust consequence on environmental receptors to be Unlikely.

Overall rating of Dust emissions

Residential

The Delegated Officer has compared the consequence and likelihood ratings described above with the risk rating matrix (Table 9) and determined that the overall rating for the risk of dust emissions on residential receptors is Low.

Environmental

The Delegated Officer has compared the consequence and likelihood ratings described above with the risk rating matrix (Table 9) and determined that the overall rating for the risk of dust emissions on environmental receptors is Low.

8.5 Risk Assessment – Reuse of treated wastewater

Identification and general characterisation of emission

Treated wastewater from the Shire’s Storage dam No. is 2 situated on of part of Lot 326 on Plan 158856 and part of Lot 417 on Plan 185603 will be transferred to storage tanks (2 x 25kL) located within Lot 417 on Plan 185603. Treated wastewater will be utilised to irrigate the town oval and the hockey oval (Shires POS) – refer to Figure 1. Total maximum treated wastewater available for irrigation is 124kL/day with a dosage rate of 5.5 mg/L.

The applicant is proposing an application rate of 30mg/L for Nitrogen and 7.5mg/L of Phosphorus based on calculations from the “Water Quality Protection Note 22, July 2008, Risk Category D”.

Quarterly water monitoring data for the previous five years have been averaged and summarized below:

pH is slightly alkali at 8.0;

BOD is high at 34.2 mg/L;

E. coli is high at 21149 cfu/100ml;

Electrical conductivity indicates the water is fresh at 138.0 mS/m (779 ppm TDS);

TN is 33.9 mg/L; and

TP is high at 10.7 mg/L

The above represents the quality of treated wastewater before it is discharged into Shire Dam 1, where it is diluted with stormwater collected from the catchment and then transferred into Shire Dam 2 where it is further diluted with additional stormwater from the catchment.

While the TN and TP levels are slightly above the WQPN 22 guideline for Risk Category D, it is anticipated that the treated wastewater will pose low risk since the treated water will be further diluted with additional stormwater from the catchment.

Description of potential adverse impact from the emission

Reuse of treated wastewater for irrigation can cause land degradation, waterlogging and adversely impact natural waters causing salinity, turbidity, nutrient enrichment, leached trace metals, pesticides and other harmful wastewater contaminants. The nearest watercourse occurs approximately 1.1 km to the south west of the town oval.

28



Criteria for assessment

The following criteria have been used to evaluate the risk associated to reuse of treated wastewater:

Reuse water quality:

Department of Water and Environment Regulation’s- Water Quality Protection Note 22, July 2008

Department of Health’s Guidelines for the non-potable uses of recycled water in Western Australia, low exposure risk for surface irrigation with some restricted access and application.

Heavy metals in wastewater should not exceed the quality criteria for irrigation use given in the- Australian and New Zealand guidelines for fresh and marine water quality. August 2016

Ambient soil and groundwater impacts:

DER Guideline: Assessment and Management of Contaminated Sites (2014) provides ecological and human health assessment levels for soil.

DoH Guideline: Contaminated sites ground and surface water chemical screening guidelines (Non-Potable Use Guidelines). December 2014

Applicant/Licence Holder controls

The Delegated Officer has determined that the Works Approval Holder must facilitate the controls for seepage from reuse of treated wastewater listed in Table 13.

Table 13: Applicants controls for seepage from reuse of treated wastewater

Control Description

Proposed Infrastructure

The POS will have simple non continuous barriers that direct the public towards signage or fencing with lockable gates. There will be some restricted access and application of treated wastewater in line with DoH guidelines for low exposure risk;

Control and Alarm system will be implemented to detect any failure relating to the equipment’s, chlorination and contact tanks;

The control system will typically initiate purging of the contact tanks and recommence the disinfection process every 48 hours to ensure minimum residual chlorine concentrations;

The parameters will be monitored onsite which also send data to Perth operation centre;

Chlorination will be carried out by a set dosing rate and monitored, in the event the required concentration is not achieved the delivery valve will shut and water will be looped back to the Polishing Tank for re-dosing until reaching the required disinfection; and

The chlorine system will also be fitted with interlocks and an auto shut off, and if the chlorine is not dosed into the water, the pumps will not operate, so it cannot be sent to the POS.

Monitoring The Works Approval holder will be required to carry out monthly sampling of the wastewater prior to disinfection and prior to irrigating the public open space during commissioning;

29



Control Description

The Applicant will be required to carry out quarterly monitoring of the wastewater prior to disinfection and prior to irrigating the public open space after a licence has been issued for the site

The following parameters will be monitored as required:

E. Coli

Biochemical Oxygen Demand

Free Available Chlorine

pH

Total Nitrogen

Total Phosphorus

The applicant will meet the following criteria which is consistent with the quality Standards of Recycled Water guidelines

Parameter Limit Value

pH 6.5 - 8.5

Biochemical Oxygen Demand <20 mg/L

Nitrogen 30mg/L

Phosphorus 7.5 mg/L

Total Chlorine 0.2 - 2.0 mg/L

E. coli <1000 cfu/100ml

Proposed operation management

Ongoing operation and maintenance management will maintain efficient operation of the WWTP

Irrigation water will be tested for nutrient load

Irrigation water will be monitored online(alarm in place)

No irrigation will be carried out during rainy periods

Public will not be allowed access within the proposed irrigation area during treated water irrigation and drying times

WWTP site will be fenced and only authorized personnel will be allowed access

Re-use An ephemeral creek situated within 1.06 km to the POS irrigation site (football oval) is unlikely to flow continuously given the low average rainfall of the area;

Flow event in the creek are most likely to coincide with high rainfall events, resulting in a flushing of the creek and the dilution of irrigation water;

Entitlement Shire of Kellerberrin has agreed to accept treated wastewater to irrigate the POS as long as it meets the quality deemed appropriate by the Department of Health

30



Key findings

The Delegated Officer has reviewed the information regarding the impacts from reuse and has found:

1. The distances to groundwater information was not provided by the applicant.

2. Untreated sewage will need to be appropriately stored.

3. The WWTP will need to have contingency storage capacity for up to two days of normal flow if discharge is suspended due to maintenance issues.

4. Wastewater discharge should be efficiently managed to allow effluent to infiltrate or evaporate and prevent surface ponding or runoff from the irrigation area.

Consequence

Based on the information detailed above and that the wastewater will undergo treatment prior to discharge, the Delegated Officer has determined that the consequence from reuse of treated wastewater at the proposed irrigation area will be Minor.

Likelihood of Risk Event

Based on the information detailed above the likelihood of the risk event occurring due to reuse of treated wastewater causing minor consequences is Unlikely as the event will not occur in most circumstances.

Overall rating

The Delegated Officer has compared the consequence and likelihood ratings described above for the Risk Criteria (Table 9) and determined that the overall rating for the risk of discharges to land from the spray field on sensitive receptors during operation is Medium.

31



8.6 Summary of acceptability and treatment of Risk Events

A summary of the risk assessment and the acceptability or unacceptability of the risk events set out above, with the appropriate treatment and control, are set out in Table 14 below. Controls are described further in section 9.

Table 14: Risk assessment summary

Description of Risk Event Applicant controls Risk rating

Acceptability with controls (conditions on instrument)

Emission Source Pathway/ Receptor

(Impact)

1. Dust

Construction activities, vehicle movement

Air, moving with direction of wind.

Vehicles will be restricted to a maximum speed limit of 8km/hr, signposted, use of water carts and appropriate dust management will be implemented during construction

Slight consequence

Unlikely likelihood

Low risk

Acceptable subject to Applicant controls and the Environmental Protection (Unauthorised Discharge) Regulations 2004.

2 Leaching of nutrients into the groundwater and contaminated runoff to surface water receptors

Key nutrients include phosphorus and nitrogen wastewater

Irrigation of the POS with treated wastewater

Contamination of groundwater and surface water receptors through leachate of nutrients and contaminated runoff to surface water receptors

Management and infrastructure controls

Implementation of monitoring program

Adhering to quality standards for recycled water

Ongoing operation and maintenance management

Minor consequence

Unlikely likelihood

Medium Risk

Acceptable subject to Regulatory and Applicant controls conditioned

32



9. Regulatory controls

A summary of regulatory controls determined to be appropriate for the Risk Event is set out in Table 15. The risks are set out in the assessment in section 8 and the controls are detailed in this section. DWER will determine controls having regard to the adequacy of controls proposed by the Applicant. The conditions of the Works Approval will be set to give effect to the determined regulatory controls.

Table 15: Summary of regulatory controls to be applied

Controls

(references are to sections below, setting out details of controls)

9.1

.1

Infr

astr

uctu

re a

nd

eq

uip

men

t

9.1

.2

Co

mm

issio

i

ng

valu

e

9.1

.3

Op

era

tio

nal

co

ntr

ols

9.1

.4

Mo

nit

ori

ng

10.1

.5

Op

era

tio

nal

co

ntr

ols

Ris

k Ite

ms

(see r

isk a

naly

sis

in

secti

on

8)

1. Dust from construction and vehicle movements

Low risk, regulatory controls not required. Note: Environmental Protection (Unauthorised Discharge) Regulations 2004 apply.

2. Leachate and runoff of nutrients

• • • • •

9.1 Works Approval controls

Infrastructure and equipment

The following environmental controls, infrastructure and equipment should be maintained and operated onsite for spill management, release of untreated and partially treated wastewater to the environment: Table 16 lists controls for the Premises.

Table 16: Infrastructure Requirements

Infrastructure Requirement

WWTP chlorinator unit

The Works Approval Holder must ensure WWTP chlorinator unit is designed to tertiary treatment standard including. The system must be constructed to the specifications listed in Table 4

Wastewater contact tank covers

The Works Approval Holder must insure that:

All contact tanks on site are covered and well ventilated

Negative pressure is maintained under the covers during normal WWTP operation

Storage of treated wastewater

The Works Approval Holder must ensure that at least two 25kL storage tanks be installed at the chlorinator site to ensure sufficient storage capacity of wastewater during the wet season and when rainfall meets the water needs of the turf;

33



Infrastructure Requirement

The two holding (contact) tanks will be installed on a concrete slab;

A drain and soakwell system is installed to prevent treated water from leaving the TWWM Compound in the unlikely event that a rupture occurs within one of the tanks;

HDPE lined drain and leads to a concrete soakwell for onsite infiltration/containment.

Storage of chlorine gas

The Works Approval Holder must ensure that all chlorination module will be fitted with gas detection alarms and emergency shut-off buttons on the interior and exterior of the module;

A Self-contained Breathing Apparatus (SCBA) will also be located with the module

Area closed off to general public

Trained staff for chlorine manipulation

Emergency procedures and safety calls available in case of incident

Drainage The Chlorinator slab must be designed with suitable stormwater drainage to convey only uncontaminated stormwater away from the Premises

Overflow infrastructure

A designated collection point (storage dam) for wastewater overflow events. Overflow events will not lead to uncontrolled release of wastewater to the environment. The collection point for wastewater will be inaccessible to the general public. Wastewater overflow will be directed back to the treatment system or removed from the Premises by an authorised person and disposed to appropriate waste acceptance facility.

Tank Overflow Tanks have an overflow system in-place which redirects any overflow back into Storage dam

Commissioing

The parameters detailed in Table 17 should be met by the Works Approval Holder at the Premises at the point of transfer of treated wastewater from the Premises to the POS.

Table 17: Specified Licence limits

Parameter Specified limit

Waste Quantity Max of 292kL/day

pH 6.5 – 8.5

Biochemical Oxygen Demand ≤20 mg/L

Nitrogen ≤30 mg/L

Phosphorus ≤7.5 mg/L

Total Chlorine 0.2 – 2.0 mg/L

E. coli <1000 cfu/100ml

Heavy metals Should not exceed the quality criteria for irrigation use given in Australian and New Zealand guidelines for fresh and marine water quality guidelines

Treated Wastewater supply to POS

Up to 124kL/day

34



9.2 Operational controls

The Delegated Officer has determined that the Works Approval Holder must facilitate the operation controls listed in Table 18 during operation of the WWTP chlorinator unit.

Table 18: Operational controls

WWTP chlorinator unit and associated infrastructure

Undertake regular inspections and schedule maintenance of system processes as required to maintain efficient operation of the WWTP chlorinator unit

Odour Monitor critical control points

Implement procedure for system failure events

Implement an odour complaint recording and investigation procedure

Wastewater overflow event Remove wastewater and solids to the maximum practicable amount

Wash the spill area to dilute any remaining wastewater and conduct it to a collection point/sump on site

Disinfect hard surfaces in high public exposure areas to reduce the risk to human health

All WWTP operators will be trained to carry out preventive maintenance and use operating procedures to stop escaping substances from entering the environment

The Works Approval Holder must ensure the WWTP chlorinator unit operates within the provisions of The Environment Protection (Water Quality) Policy 2003 (Water Quality Policy) which prohibits the pollution of the stormwater system and natural waters

Biosolids and Sludge management

Biosolids and sludge collected from the Premises is taken to an appropriately licensed facility for disposal

Irrigation of POS with treated wastewater

Irrigation of the POS with treated wastewater must occur only within the area designated in Figure 1

Irrigation should not cause waterlogging.

Sufficient storage of wastewater is required when irrigation cannot occur or be tankered off-site.

Reporting

The applicant will be required to submit a commissioning report to confirm whether the works specified in the works approval has been constructed or installed with no material defects and how site has complied with all the conditions which also includes results of the monitoring data required under this instrument.

Monitoring requirements

Works approval and Licence

In order to validate that conditions are being complied with by the Works Approval Holder, the following monitoring conditions are required in the Works Approval during commissioning and will be required in the Licence.

Table 19: Monitoring requirements

Monitoring point reference

Parameter Units

Averaging period

Frequency

Final treated E.coli cfu/100ml

Spot sample Monthly (NATA

35



effluent recycled water sampling point S4

(Schedule 1

Figure 2)

Nitrogen mg/L accredited analysis)

Phosphorous

Ammonia as N

Nitrate + nitrite + nitrogen

Biochemical Oxygen Demand

Total suspended solids (as turbidity)

Monthly (in-field non-NATA accredited analysis permitted); and

Monthly NATA accredited testing for verification purposes.

Total Dissolved Solids1

pH1 pH units N/A Monthly (in-field non-NATA accredited analysis permitted)

Volumetric flow rate

m3/day 24 hours Continuous

Note 1: In-field non-NATA accredited analysis permitted.

Table 20: Wastewater Commissioning Quality

Note 1: Guidelines for Non-potable uses of recycled Water in Western Australia 2011, Department of Health Note 2: WQPN 22 Risk Category D

10. Determination of Works Approval conditions

The conditions in the issued Works Approval in Attachment 1 have been determined in accordance with the Guidance Statement: Setting Conditions.

The issued works approval expires in 5 years from date of issue.

Parameter Limit Value

pH 6.5 - 8.51

Biochemical Oxygen Demand ≤20 mg/L1

Nitrogen ≤30mg/L2

Phosphorus ≤7.5 mg/L2

Total Chlorine 0.2 - 2.0 mg/L1

E. coli <1000 cfu/100ml1

36



Table 21 provides a summary of the conditions to be applied to this Works Approval.

Table 21 Summary of conditions to be applied

Condition Ref Grounds

Infrastructure and Equipment 1 and 2

Environmental compliance is a valid, risk-based condition to ensure appropriate linkage between the works approval and the EP Act.

Reporting 3, 4, 5 and 6

These conditions are valid, risk-based and consistent with the EP Act.

Emissions 7

This condition is valid, risk-based and consistent with the EP Act.

Monitoring 8, 9 and 10

These conditions are valid, risk-based and consistent with the EP Act.

Information 11 and 12

These conditions are valid and are necessary administration and reporting requirements to ensure compliance.

DWER notes that it may review the appropriateness and adequacy of controls at any time and that, following a review, DWER may initiate amendments to the Works Approval under the EP Act.

11. Applicant’s comments

The Applicant was provided with the draft Decision Report and draft issued Works Approval on 25 July 2018.

12. Conclusion

This assessment of the risks of activities on the Premises has been undertaken with due consideration of a number of factors, including the documents and policies specified in this Decision Report (summarised in Appendix 1).

Based on this assessment, it has been determined that the Issued Works Approval will be granted subject to conditions commensurate with the determined controls and necessary for administration and reporting requirements.

Steve Checker

MANAGER WASTE INDUSTRIES

REGULATORY SERVICES

Delegated Officer under section 20 of the Environmental Protection Act 1986

37



Appendix 1: Key documents

Document title In text ref Availability

1. Application for Works Approval –

Kellerberrin Gas Chlorinator Project W6133/2018/1

DWER records (A1619118)

2. DER, July 2015. Guidance Statement:

Regulatory principles. Department of

Environment Regulation, Perth.

DER 2015a

accessed at www.dwer.wa.gov.au

3. DER, October 2015. Guidance Statement: Setting conditions. Department of Environment Regulation, Perth.

DER 2015b

4. DER, August 2016. Guidance

Statement: Licence duration.

Department of Environment

Regulation, Perth.

DER 2016a

5. DER, November 2016. Guidance

Statement: Risk Assessments.

Department of Environment

Regulation, Perth.

DER 2016b

6. DER, November 2016. Guidance Statement: Decision Making. Department of Environment Regulation, Perth.

DER 2016c

http://www.dwer.wa.gov.au/

38



Appendix 2: Summary of applicant’s comments on risk assessment and draft conditions

Condition Summary of Licence Holder comment DWER response

Works Approval

Condition 1 (p7) The bold text of condition 1 appears to be incomplete and should be a separate condition (condition 2) that includes the text of condition 6 and Table 2.

Typographical error corrected.

Condition 2, 3, 4 & 5 (p7, p8) Conditions 2, 3, 4 & 5 should be re-titled conditions 3, 4, 5 & 6. All condition re-numbered, typographical errors corrected.

Condition 4 (p8) Should refer to condition 13 under the Monitoring section. Typographical error corrected.

Condition 4 (p8) Clarification of the term “environmental performance” is requested or remove the word environmental

Environmental word removed.

Condition 6 (p8) Typographical error, condition 6 appears to be part of a missing condition 2. Typographical error corrected.

Condition 7, 8, 9 & 10 (p8, p9) Reporting conditions 7, 8, 9 and 10 are a repeat of conditions 2, 3, 4 & 5. Typo error corrected, all conditions re-numbered again.

Table 2 (p8, p9) Table 2 appears to be part of a missing condition 2. Table 2 will remain part of condition 6.

Table 3 (p9) The Exclusions/Limitations/Requirements column of the Specified Emissions row should refer to condition 14 rather than condition 10.

All condition re-numbered, typographical errors corrected and therefore specified emissions row should refer to condition 10 relating to commissioning criteria rather than condition 14.

Condition 12 (p10) Clarification of the term “Books”. As defined in the Environmental Protection Act 1986.

Condition 13, Table 4 (p10) Title of table should be “Monitoring Effluent Requirements” rather than “Authorised Emissions Table”.

Changed to monitoring requirements

Condition 13, Table 4 (p10) Typographical error, The monitoring location should refer to Figure 2 Typographical error corrected.

Condition 13, Table 4 (p10) The monitoring point reference is “WQ1 - final effluent to recycled water storage tank 1 & 2’. Given this is not the final (post-chlorination) sample point please amend to “S4 – Treated outlet sample point”

Changed to S4

Condition 14, Table 5 (p11) The criteria for Total Nitrogen and Total Phosphorus references the Water Quality Protection Note 22 (WQPN 22) Risk Category D (DoW 2008). The criteria,

Changed to Maximum inorganic Nitrogen (as N) and Maximum reactive Phosphorus (as P) as stipulated in WQPN 22

39



however, within WQPN 22 relates to maximum inorganic nitrogen and maximum reactive phosphorus. It is requested that these criteria be amended to Total Inorganic Nitrogen (TIN) and Filterable Reactive Phosphorus (FRP).

Schedule 1, Figure 2 (p13 Please find attached an updated WWTP flow diagram (Kellerberrin WWTP Process Control Table).

Flow diagram replaced

Schedule 2, Table 6 (p15) Item 4 refers chlorine being dosed, monitored and controlled automatically. The Corporation is concerned that this implies that there is a relationship between dosing and monitoring which is not true; dosing is a set rate based upon flow rather than residual concentrations.

Changed to set dosing rate

Schedule 2, Table 6 (p15) Item 6 should refer to Treated Wastewater Contact tanks rather than Treated Wastewater Storage tanks.

Corrected

Schedule 2, Table 6 (p15) Item 6 specifies the dimension of the concrete slab; the Corporation queries the need to include the dimensions of the concrete slab as a control and requests the dimensions be removed.

Dimensions removed

Schedule 2 Table 7 (p15, p16) The Specification/Drawings column for the Works row refers to Table 7; should refer to Table 6.

Corrected

Schedule 2 Table 7 (p15, p16) The storage of treated wastewater requirements should provide reference to storage of treated wastewater to ensure the minimum contact time with chlorine, as required under the Guidelines for the Non-potable Uses of Recycled Water in Western Australia (DoH 2011). Remove reference to ensuring sufficient storage capacity of wastewater and replace with requirement to provide minimum contact time with chlorine prior to being sent to the irrigation network.

Removed and replaced

Schedule 2 Table 7 (p15, p16) The overflow infrastructure requirements refer to construction of designated collection point/sump for wastewater overflow. Due to capacity of the contact tanks and height differential between the tanks and storage dam it is impractical to: 1) construct a designated collection point/sump; and b) redirect overflows back to the storage dam. As per item 8 in Table 6 a HDPE lined drain and soakwell system will be constructed to prevent the uncontrolled release of treated wastewater in the event of an overflow.

Designated point/sump for wastewater overflow requirement removed. DO has noted that a HDPE lined drain and soakwell system will be constructed to prevent the uncontrolled release of treated wastewater in the event of an overflow instead.

Decision Report

Table 4 (p11) Item 4 should refer to total chlorine rather than free chlorine. Replace “free chlorine” with “total chlorine”.

Changed to total chlorine

Table 13 (p28, p29) Infrastructure description: the control and alarm system relates to equipment failure including chlorination failure and contact tank overflow. The control system

Changed to proposed infrastructure

40



will typically initiate purging of the contact tanks and recommence the disinfection process every 48 hours to ensure minimum residual chlorine concentrations. The instantaneous flow rate and total quantity of treated wastewater irrigated will be monitored on-line; however, no water quality parameters will be monitored by on-line analysis. Amend infrastructure description to reflect proposed design.

Table 13 (p28, p29) Monitoring description: monitoring should refer to total chlorine rather than free chlorine. Monitoring of E. coli upon issuing of the licence should be monthly; however, all other parameters should be quarterly. Replace “free chlorine” with “total chlorine” and amend the proposed licence monitoring frequency.

Replaced “free chlorine” to “total chlorine” and amend the proposed licence monitoring frequency to quarterly

Table 13 (p28, p29) Management description: monitoring of irrigation water will be limited to instantaneous flow rate and total quantity of treated wastewater irrigated. Public access will only be restricted during treated wastewater irrigation and drying times. Amend management description to reflect proposed operation.

Amended to reflect proposed operation management

Table 13 (p28, p29) Entitlement description: the stated chlorine dosage rate is indicative only. There may be times where dosing range may be exceeded to ensure the required residual chlorine concentrations. Amend entitlement description to reflect proposed operation.

The delegated Officer has decided that the entitlement description will remain

Table 14 (p30, p31) Multiple references to treatment and/or storage tanks rather than contact tanks. Replace “treatment” and “storage” tanks with “contact” tanks

Table 15 now. All references to treatment and/or storage tanks changed to contact tanks

Section 9.2.2 and Table 18 (p32, p33)

Section 9.2.2 states that the monitoring requirements in Table 18 will be required as conditions in the Licence; however, the frequency of these requirements are for commissioning activities (i.e. weekly monitoring of nutrients). Clarification that the frequency of the monitoring requirements of Table 18 will be reviewed in the Licence application.

Amended to reflect commissioning period and will be reviewed when processing an environmental licence for the site.

41



Attachment 1: Issued Works Approval W6131/2018/1