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TW Ref – 17/4575

13 January 2017 Mr Malcolm Budd Section Head (Assessments) Delegate for the Board of the Environment Protection Authority GPO Box 1550 Hobart TAS 7001 BLACKMANS BAY WASTEWATER TREATMENT PLANT UPGRADE

DPEMP REQUEST FOR ADDITIONAL INFORMATION

Dear Mr Budd

I refer to your letter dated 15 December 2016 regarding the request for further information before assessment of permit application DA 2016-423 can be completed by the EPA Board. The information provided in the attached document is in response to this request.

I trust that the attached information responds to the queries raised. However, if you or your staff require additional clarification on any of these matters, please do not hesitate to contact Peter Philp, Senior Project Manager (E: [email protected], P: (03) 6237 8530).

Yours sincerely,

Peter Philp Senior Project Manager

Enc. Blackmans Bay DPEMP – Table 1: Additional Information Required by the EPA Board

Enc. Blackmans Bay DPEMP – Table 2: Other Matters Raised During the Public Consultation Period

Enc. Blackmans Bay DPEMP – Response to Request for Further Information (DPEMP Supplement)

Cc. Danielle McPhail, EPA

mailto:[email protected]

Tasmanian Water & Sewerage Corporation Pty Ltd HPRM record number: 17/4575 GPO Box 1393 Hobart, TAS 7001 Uncontrolled when printed

ABN: 47 162 220 653

Table 1: Additional Information Required by the EPA Board (from EPA letter dated 15 December 2016) – with reference numbers added

Ref Rep No./ Agency DPEMP Section no.

DPEMP Page no.

Comments and issues Additional information required

R1 EPA Tasmania 2.2 4 & 6 The location of current and proposed stormwater collection systems is not identified on the site plans in the DPEMP.

Provide a plan showing current and proposed stormwater collection systems.

R2 EPA Tasmania 2.5 16 Table 2-6 does not include design effluent performance expectations for enterococci. In order to assess potential impacts on recreational water quality in the receiving environment, enterococci levels in treated effluent need to be specified.

Add expected enterococci concentrations (median, 90th%ile & maximum limits) to Table 2-6.

R3 EPA Tasmania 2.8 32-34 Incident management during commissioning has not been fully addressed.

Details of proposed incident response measures during commissioning are to be provided.

R4 EPA Tasmania 2.8 32-34 It is unclear what criteria will be used to determine whether commissioning has been completed.

Provide criteria against which it will be determined that commissioning has been completed and the plant is operational.

R5 EPA Tasmania 2.8 32-34 There are limited details of how non-compliant effluent will be managed during commissioning.

Provide details of proposed disposal mechanisms for non-complying effluent produced during commissioning.

R6 Rep 1 & 6 6.4 73-81 Raise concerns that rock breaking equipment will be used during the construction period to break through hard rock causing noise and vibration impacts to nearby residents.

Provide details of the sound pressure output levels for items of equipment that may be used for the purposes of rock breaking, as well as details of any potential impacts and mitigation measures.

R7 PCAB 6.7 & Appendix B

90-97 Appendix B of the DPEMP states that Austrostipa bigeniculata was not observed on site but that suitable

Clarification is required in relation to the level of confidence that the species have not been overlooked as for the other listed species discussed. If there is a high level

habitat is present. of uncertainty (e.g. if Austrostipa grasses were present

but not identified to species level) it is recommended that a targeted survey be undertaken at the appropriate time of year (late November through March).

R8 EPA Tasmania 6.8 102-103 The DPEMP does not identify the types of trade waste generators discharging to the three STPs to be amalgamated to Blackmans Bay or the key contaminants expected within such discharges.

Provide a desktop analysis on influent data and the likely presence of any contaminants of concern reporting to the current STPs that are proposed to be amalgamated to the upgraded STP.

R9 EPA Tasmania 6.8.3 & Attachment D

105-106 Mixing zone modelling does not appear to have been correlated with “real life” outfall monitoring undertaken since 2009 under conditions of the existing STP. The results of these surveys, undertaken by CEE consultants and reviewed by EPA, should be used for verification of modelling outputs provided by GHD. For example, GHD scenario 10 predicts the dilution at 15 m from the outfall (= edge of the current mixing zone) to be 130:1. Field surveys indicate that actual dilution at this point was at least 200:1 during all surveys.

Revise the mixing zone modelling to verify the outputs through calibration against measured dilution rates.


105-106 The proposed mixing zone is based solely on toxicant levels.

Note that under the State Policy on Water Quality Management, the definition of “water quality indicators” includes biological organism or community. Biological impacts are therefore to be considered in the context of mixing zone determination.

Biological monitoring undertaken around the outfall since 2009 indicates that the area of impact exceeds

Review the proposed mixing zone in consideration of ambient monitoring (water quality, sediment and biology) undertaken around the current outfall over the last 6 years and revise the dimensions, if required, on this basis.

the size of the current mixing zone. The proposed mixing zone should be redefined with consideration of these findings.


105-106 The mixing has not been described as a three dimensional body within the receiving environment.

Describe any revised mixing zone as a three-dimensional body within the receiving environment and provide a figure to illustrate its location.

R12 EPA Tasmania 6.8 107-109 Table 6.8 of the DPEMP indicates an increase in Oil and Grease in the annual load to the outfall but this is not further discussed or justified.

Justify and discuss the increase in annual load to the outfall of Oil and Grease. Refer to influent characterisation of the three sewerage catchments for contextual information.

R13 EPA Tasmania 6.8 & Attachment D

112-113 Enterococci concentration has not been considered for recreational use in relation to ‘Fishos’, a popular surfing spot in the vicinity of the outfall.

In addition, the relevant trigger value for recreational water uses adopted by EPA Tasmania is 40 enterococci / 100 mL.

Consider the expected concentration of enterococci in effluent in relation to all relevant recreational water uses and undertake relevant mixing zone modelling / dilution calculations to demonstrate that there will be no unacceptable impact on human health.

Only modelling scenarios under which the plume is expected to rise to the surface (i.e. non-stratified conditions) need to be considered in this context. Within the scenarios covered in the modelling report (Attachment D), model run 2 in Table 6 would appear the most relevant to this scenario and should be updated to reflect the points above.

Tasmanian Water & Sewerage Corporation Pty Ltd HPRM record number: 17/4575 GPO Box 1393 Hobart, TAS 7001 Uncontrolled when printed

ABN: 47 162 220 653

Table 2: Other Matters Raised During the Public Consultation Period (from EPA letter dated 15 December 2016) – with reference numbers added

Rep No./ Agency DPEMP

section no.

DPEMP Page no.

Comments and issues Further Info requested [yes/no]

EPA Comments

O1 EPA Tasmania General Commitments should not be a statutory requirement but a statement by the proponent on how they will mitigate or manage to allow compliance with statutory requirements.

Yes Consider review and amendment of commitments.

O2 Rep 1 2.2 4-7 Concerned with the location of proposed infrastructure.

No The Board’s assessment is based on the application as submitted to Council. The Board will consider the location of infrastructure in relation to the potential environmental impacts on sensitive receptors.

O 3 Rep 2 2.2 4-7 Consider that the fencing of the proposed STP could be smaller.

No Matter outside the Board’s responsibilities for assessment of the application.

O4 Rep 3 2.10 35 Concerned that the public footpath linking the existing Blackmans Bay-Tinderbox Cliffs Walk with the developed Bushland Trail Loop will not be retained.

No Matters outside the Board’s responsibilities for assessment of the application.

O5 Rep 4 3 37-38 That other sites were considered and were more suitable due to the more isolated locations.

No The DPEMP sufficiently addresses consideration of alternatives.

O6 Rep 5 3 37-38 Considers a plant at Margate without discharge to waterways as more suitable.

No The DPEMP sufficiently addresses consideration of alternatives.

O7 Rep 2 & 6 4 43-44 TasWater has provided insufficient information in

relation to potential visual impacts and have not consulted one on one with landowners.

No Section 4 of the DPEMP provides details of public consultation undertaken by the proponent as required by the guidelines issued by the Board.

The public consultation period administered under LUPAA provides the opportunity for statutory representations to be made in relation to a proposal and the issues considered in the subsequent environmental and planning assessments.

O8 Rep 2 5.1 45-50 Concerned rezoning will affect management of open space.


O9 Rep 2 5.1 & 6.1 45-50 & 56-66

Consider the large rezoning to utilities reflects expected odour issues.

No The Board’s assessment will consider odour impacts and the potential for environmental nuisance or harm.

O10 EPA Tasmania 6.1.4 66 The DPEMP dictates that air emission management and incident reporting will be included in an Annual Environmental Report but there is no clear commitment in the DPEMP to the preparation and submission of this document.

Yes Consider revision of commitments to include Annual Environmental Report.

O11 Rep 1 6.1 & 6.4 56-66 & 73-81

Expects the environmental approval process to ensure that noise and odour from the upgraded STP will be significantly reduced once fully operational.

No The Board’s assessment will consider noise and odour impacts and the potential for environmental nuisance or harm.

O12 Rep 2 & 4 6.1 & 6.4 56-66 & 73-81

Concerned that plant will have negative impacts (visual, odour, noise, financial) on the surrounding properties.

No The Board’s assessment will consider noise and odour impacts and the potential for environmental nuisance or harm.

Visual and devaluation matters are outside the Board’s responsibilities for assessment of the application.

O13 Rep 6 6.4 73-81 Expect a detailed construction management plan to minimise noise and vibration impacts on nearby sensitive receptors. Including noise and vibration monitoring.

No The Board’s assessment will consider noise impacts and the potential for environmental nuisance or harm and mitigation and management.

O14 EPA Tasmania 6.6.4 87 The CMM is dictated as a key mitigation measure but does not form a commitment of the DPEMP

Yes Consider revision of commitments accordingly.

O15 PCAB 6.7 & Appendix B

90-97 Appendix B of the DPEMP has appropriately considered impacts to swift parrot (Lathamus discolour). Any clearance of swift parrot habitat be avoided during the species’ breeding season (September to January) if the species is present in the area. Information on breeding locations is made available each year on the Threatened Species Link (www.threatenedspecieslink.tas.gov.au)

No No further information required.

O16 PCAB 6.7 90-97 A threat to swift parrots is colliding with man-made objects such as chain –link fences. It is recommended that infrastructure (particularly fencing) is designed to minimise collision risk to Swift parrots where practicable. 17Additional information on this topic can be found at http://awsassets.wwf.org.au/downloads/sp027_minimising_swift_parrot_collision_threat_1apr08.pdf

Yes Provide details of how infrastructure will be designed to minimise collision risk to Swift parrots.

http://www.threatenedspecieslink.tas.gov.au/

http://awsassets.wwf.org.au/downloads/sp027_minimising_swift_parrot_collision_threat_1apr08.pdf


O17 EPA Tasmania 6.8.1 102 The presence of a popular surfing spot, “Fishos” in

the vicinity of the outfall is a relevant sensitive recreational water use not acknowledged in this section.

Yes This needs to be taken into account in the mixing zone determination. The information request in Table 1 already covers this point.

O18 EPA Tasmania 6.8.3 112 This section refers to thermotolerant coliforms trigger values specified in the ANZECC (2000) guidelines as the relevant standard for protection of recreational water uses.

It should be noted that, consistent with the requirements of the NHMRC guidelines which have superseded the ANZECC guidelines, EPA have adopted a recreational water uses trigger value of 40 enterococci /100 mL for recreational water areas with sewage-derived discharges.


O19 EPA Tasmania Attachment D

Table 1 of the Mixing Zone report refers to ‘1000 cfu/100 mL thermotolerant coliforms’ as the relevant trigger value based on the ANZECC (2000) guidelines. Comment as for p. 112 above.


O20 Rep 6 6.11 122-142 Considers the proposal is not consistent with the relevant zoning.


O21 Rep 6 6.11 122-142 Considers that the proposal does not meet the planning scheme requirements in relation to design and visual impact.


O22 Rep 1, 4, 5 6.12 143-144 The proposed location of infrastructure will affect No Matter outside the Board’s responsibilities for

visual amenity. assessment of the application.

O23 Rep 1 6.12 143-144 Potential impacts on coastal landscape of Blackmans Bay.


O24 Rep 1 6.12 134-144 Concerned that hard rock will result in a change in design and increase elevation of infrastructure.


O25 Rep 5 6.12 143-144 Raises concerns of multiple persons in relation to visual impacts and property devaluation.


O26 Rep 6 6.12 143-144 Consider there is insufficient information provided to consider visual impacts and natural landscape qualities of the area.


O27 EPA Tasmania 8.1.1 165-166 The DPEMP proposes grab sampling of effluent, however composite sampling is considered more appropriate for this STP.

Yes Confirm use of composite sampling in the proposed monitoring program.

O28 Rep 1, 2, 4, 5 - - Concerned upgrade will affect value of surrounding properties.


O29 Rep 1 - - Makes reference to the proposed location of the ‘Margate Pipeline’.

No The pipeline does not form part of the application to which the Board’s assessment relates.

O30 Rep 2 - - Want to know who is responsible for resealing of Treatment Plant Road.


O31 Rep 2 - - Want Council and TasWater to consider a playground adjoining the plant.


Tasmanian Water & Sewerage Corporation Pty Ltd HPRM record number: 17/4575 GPO Box 1393 Hobart, TAS 7001 Uncontrolled when printed ABN: 47 162 220 653 Page 1

Blackmans Bay DPEMP – Response to Request for Further Information

The additional information required to assist the EPA board in their assessment is provided below and represents a supplement to the original DPEMP. The original ‘Comments and Issues’ and ‘Additional Information Required’ sections of Table 1 from the EPA letter dated 15 December 2016 are also provided for reference (in italics).

1. Stormwater Collection System (R1)

The location of current and proposed stormwater collection systems is not identified on the site plans in the DPEMP.

Provide a plan showing current and proposed stormwater collection systems.

Drawings 2828-020-12 and 2828-026-04 (refer Appendix A) indicate the current stormwater collection system for the Blackmans Bay STP site. Stormwater from the western side of the site is conveyed through a bluestone drain and collected via kerb and gutter on the western road and conveyed to a concrete discharge endwall in the south-western corner of the site. The eastern side of the site is collected and discharged at a point to the east of the existing aeration tank structure.

The preliminary design for the stormwater collection system associated with the proposed site augmentation is provided in drawing J15950-STP-G-101-IFT (refer Appendix A). Bunded areas will be installed at the bioreactor/inlet, sludge bins and digestor (highlighted in blue), with stormwater captured in these areas directed to the General Purpose Pump Station (GPPS) to be pumped to the inlet for treatment within the treatment plant. For stormwater collected from the west of the IDEA tanks, swale drains (red line) will be constructed to divert flow to rock check dams (red areas) for slow release. The design will also aim to minimise concentrated flows, for example, by not providing kerbs on roads. The design of the stormwater collection system will be further developed during the detailed design phase of the project.

2. Enterococci Performance (R2)

Table 2-6 does not include design effluent performance expectations for enterococci. In order to assess potential impacts on recreational water quality in the receiving environment, enterococci levels in treated effluent need to be specified.

Add expected enterococci concentrations (median, 90th%ile & maximum limits) to Table 2-6.

Based on the plant process and UV disinfection system power proposed by the Contractor, the estimated effluent concentrations for enterococci have been calculated and an updated Table 2-6 from the original DPEMP submission has been provided below.


Updated DPEMP Table 2-6: Design Effluent Performance of Upgraded STP

Parameter Unit Median 90th Percentile Maximum

Normal Winter Normal Winter Normal Winter

Ammonia (as N) mg/L 1 3 2 5 5 10

Total Nitrogen (as N) mg/L 7 15 10 25 15 35

Total Phosphorus mg/L 10 12 15

BOD5 mg/L 10 15 20

TSS mg/L 10 20 30

Oil & Grease mg/L 2 5 10

Thermotolerant Coliforms cfu/100mL 200 500 750

pH mg/L 6.5 to 8.5

Enterococci cfu/100mL 40 200 1000

3. Incident Management (R3)

Incident management during commissioning has not been fully addressed.

Details of proposed incident response measures during commissioning are to be provided.

The Commissioning Management Plan prepared by the Contractor will describe the aims and objectives of the commissioning process, along with the procedures, overall methodology, incident management, communication protocols, accountability and responsibilities for the construction verification, pre-commissioning, wet commissioning, reliability testing, and process commissioning of the proposed STP.

Prior to commencing Pre-Commissioning, the Contractor’s Commissioning Lead will run one or more workshops to assess the risks associated with the commissioning phase. Planning meetings will involve TasWater representatives including operations and maintenance staff. These meetings will review the specific risks associated with the major commissioning activities and outline mitigation measures wherever possible to reduce the risks that have been identified.

The outcome from these meetings will be documented in a commissioning risk register.

Prior to every significant commissioning activity (or major cut-over) a specific planning meeting will be held to review and update the mitigation measures previously included in the risk register and to update the task specific Commissioning Work Method Statements (CWMS) which describe the activity.


4. Commissioning Completion Criteria (R4)

It is unclear what criteria will be used to determine whether commissioning has been completed.

Provide criteria against which it will be determined that commissioning has been completed and the plant is operational.

Commissioning will be deemed to have been completed when all design, construction, pre-commissioning, wet-commissioning and process commissioning activities of the STP have been completed and Proof of Performance Test 1 (POPT1) has been carried out and passed in accordance with the Principal’s project requirements to the satisfaction of the Superintendent. POPT1 involves a 30 day system integrity test following the completion of physical works. The system integrity testing shall test the system over the current pollutant and hydraulic loading rates and shall include automated operation and simulated power failure.

5. Non-Compliant Effluent during Commissioning (R5)

There are limited details of how non-compliant effluent will be managed during commissioning.

Provide details of proposed disposal mechanisms for non-complying effluent produced during commissioning.

The proposed STP is designed with multiple process barriers in place to ensure effective treatment and full compliance with the EPA licence. Each process barrier has to achieve specified target values which guarantee the water quality standards.

Every commissioning risk will be assessed, eliminated or mitigated in accordance with the Commissioning Management and Water Safety Plans.

The Water Safety Plan which defines the Critical Control points, online instrumentation, external and plant sampling, alarming and reporting will be in place prior to commencement of commissioning. This Water Safety Plan will be developed integrating the Commissioning Risks Register Actions. Both the Commissioning Management Plan and Water Safety Plan will be developed in parallel during the detail design stage, incorporating commissioning inputs into the design, this includes:

• Delaying decommissioning of the existing treatment plant until process commissioning of the new process stream is successful and reliable.

• Online Monitoring connected with SCADA alarms with interlocks installed to prevent effluent non-compliances

• Temporary pumping from CCT to inlet works • Composite sampling ensuring capture of data throughout the day

An additional safety buffer is available at commissioning as the plant has been designed to a 2040 horizon. With the expected flows during commissioning, the new plant will have approximately 50% spare capacity. As an example of how this spare capacity can provide flexibility to manage non-compliant effluent, if one batch of the IDEA/SBR doesn’t meet the


COD, TSS or TN removal requirements, the aeration cycle can continue in the same tank until the required criteria is met before continuation of the treatment process. Both tanks not performing at the same time is very unlikely, however in the event that this occurs, the instrumentation will advise accordingly, providing enough time (24 hours) to initiate an emergency procedure such as temporary pumping to divert any non-compliant effluent to the head of the plant preventing discharge of effluent that would otherwise result in a licence breach.

6. Rock Breaking (R6)

Raise concerns that rock breaking equipment will be used during the construction period to break through hard rock causing noise and vibration impacts to nearby residents.

Provide details of the sound pressure output levels for items of equipment that may be used for the purposes of rock breaking, as well as details of any potential impacts and mitigation measures.

It is not anticipated that a rock breaker will be required for the works. The construction method regarding removal of rock will be ripping. The expected SPL associated with ripping is 75dBA at 1m.

7. Presence of Austrostipa (R7)

Appendix B of the DPEMP states that Austrostipa bigeniculata was not observed on site but that suitable habitat is present.

Clarification is required in relation to the level of confidence that the species have not been overlooked as for the other listed species discussed. If there is a high level of uncertainty (e.g. if Austrostipa grasses were present but not identified to species level) it is recommended that a targeted survey be undertaken at the appropriate time of year (late November through March).

An additional targeted botanical survey for Austrostipa bigeniculata was undertaken by GHD in December in 2016 (refer Appendix B). The survey was undertaken during the appropriate time of year for optimal identification of the species. The species was identified flowering at a reference site approximately 800 m from the project site. The species was not identified within the project site during the survey. From the results of the survey it can be concluded that it is highly unlikely that the species occurs within the project site.

8. Trade Waste Generators (R8)

The DPEMP does not identify the types of trade waste generators discharging to the three STPs to be amalgamated to Blackmans Bay or the key contaminants expected within such discharges.


Provide a desktop analysis on influent data and the likely presence of any contaminants of concern reporting to the current STPs that are proposed to be amalgamated to the upgraded STP.

A desktop influent screening report has been completed: Kingborough LGA Sewage Treatment Plants – Desktop Influent Risk Review. This document has been included in Appendix C of this supplement.

9. Mixing Zone Calibration (R9)

Mixing zone modelling does not appear to have been correlated with “real life” outfall monitoring undertaken since 2009 under conditions of the existing STP. The results of these surveys, undertaken by CEE consultants and reviewed by EPA, should be used for verification of modelling outputs provided by GHD. For example, GHD scenario 10 predicts the dilution at 15 m from the outfall (= edge of the current mixing zone) to be 130:1. Field surveys indicate that actual dilution at this point was at least 200:1 during all surveys.

Revise the mixing zone modelling to verify the outputs through calibration against measured dilution rates.

The mixing zone modelling has incorporated significant amounts of relevant local environmental data including current flows, salinity profiles and temperatures to model potential plume behaviour. Incorporating 1-2 measured real-time plume verification results from one-off studies is not considered to be an adequate method for calibrating a developed model.

Regardless of this, the results from the plume verification studies undertaken to date fit within the predicted dilution range between Run 9 and 10 of the GHD mixing zone report, which replicates two extreme stratification conditions at the current STP flows, which at the edge of the defined mixing zone vary in predicted dilution from ~300:1 (well mixed) to ~130:1 (strongly stratified).

The stratification on the day of the 2010 CEE plume verification for example (33 psu surface – 34 psu bottom) was very slight in comparison to the strong stratification used in Run 10 of the GHD model (<25 psu surface and 32.5 psu bottom) and therefore under these conditions, observation of greater mixing than 130:1 would have been expected during the CEE study in 2010.

Revision of the GHD mixing zone model is not considered necessary.

10. Non-Toxicant Considerations Associated with the Mixing Zone (R10)

The proposed mixing zone is based solely on toxicant levels.

Note that under the State Policy on Water Quality Management, the definition of “water quality indicators” includes biological organism or community. Biological impacts are therefore to be considered in the context of mixing zone determination.


Biological monitoring undertaken around the outfall since 2009 indicates that the area of impact exceeds the size of the current mixing zone. The proposed mixing zone should be redefined with consideration of these findings.

Review the proposed mixing zone in consideration of ambient monitoring (water quality, sediment and biology) undertaken around the current outfall over the last 6 years and revise the dimensions, if required, on this basis.

The basis for sizing the mixing zone in the GHD mixing zone report for the Blackmans Bay STP DPEMP aligns with our interpretation of the mixing zone principles of the State Policy on Water Quality Management (SPWQM), Sections 20 and 21. This approach takes into account biological impacts through consideration of chronic or sub-lethal toxicity from toxicants as required under Section 20.4 (e.g. mortality of fish or other aquatic vertebrates).

The methodology to establish the mixing zone for this and previous TasWater projects has been based not only on the SPWQM, but also the guidance outlined in the Framework for Ambient Monitoring of Receiving Waters in Relation to Wastewater Treatment Plant Discharges (EPA Tasmania, 2013). Specifically, this framework indicates that the role of the mixing zone is to manage toxicants, and not any bio-stimulant impacts that may exist beyond the mixing zone. An excerpt from this document is provided below:

The modelling undertaken for the DPEMP was based on previous guidance from the EPA, the precedence set by EPA-approved modelling of previous STP discharges, and the information provided in the Project Specific Guidelines. On this basis, we suggest retaining the proposed mixing zone of 15m in line with previous application of the SPWQM, potentially redefining the mixing zone in the future based on performance of the new plant.

11. Mixing Zone 3-Dimensional Definition (R11)

The mixing has not been described as a three dimensional body within the receiving environment.

Describe any revised mixing zone as a three-dimensional body within the receiving environment and provide a figure to illustrate its location.

The mixing zone is considered to be all the marine area from the surface to the seafloor within the already defined mixing zone perimeter in Figure 6-13 of the DPEMP.

12. Oil and Grease (R12)

Table 6.8 of the DPEMP indicates an increase in Oil and Grease in the annual load to the outfall but this is not further discussed or justified.


Justify and discuss the increase in annual load to the outfall of Oil and Grease. Refer to influent characterisation of the three sewerage catchments for contextual information.

The mass load data provided in Table 6-8 of the DPEMP compares the existing performance of the Blackmans Bay STP (BBSTP) with the median proposed treated effluent quality outlined in Table 2-6 of the DPEMP. The Contractor has guaranteed the proposed treated effluent quality for Oil and Grease (O&G) as 2.0 mg/L (50%ile) – equivalent to AMT. This concentration does not necessarily reflect the predicted actual removal performance with regard to this parameter. It is expected that the existing performance of the BBSTP with regard to O&G (i.e. 1.4 mg/L) will be maintained or further improved with the proposed upgrade as long as there is no significant decline in influent quality with the rationalisation of the satellite plants to BBSTP. Based on the information contained in the Kingborough LGA Desktop Influent Risk Review (Appendix C), the influent from the satellite plants provide no additional O&G relative to that already received at the BBSTP, with expected influent O&G between 55 and 75 mg/L for all plants under consideration.

Based on comparison with a TasWater plant that uses similar technology to that proposed as part of the BBSTP upgrade (i.e. batch feed, long SRT activated sludge), the Rokeby STP has averaged an effluent O&G concentration of 0.67 mg/L over the past five years, with an influent feed O&G concentration of 62 mg/L. Based on these predictions, we would expect that the daily load of O&G discharged from the BBSTP after rationalisation would be reduced from the existing load.

It is worth noting that even with the conservative O&G targets that have been guaranteed by the Contractor, this represents a substantial decrease in the combined mass load of O&G discharged from all the plants under consideration as part of this project – mostly as a result of decommissioning the Electrona STP which shows poor removal of O&G.

13. Recreational Water Uses (R13)

Enterococci concentration has not been considered for recreational use in relation to ‘Fishos’, a popular surfing spot in the vicinity of the outfall.

In addition, the relevant trigger value for recreational water uses adopted by EPA Tasmania is 40 enterococci / 100 mL.

Consider the expected concentration of enterococci in effluent in relation to all relevant recreational water uses and undertake relevant mixing zone modelling / dilution calculations to demonstrate that there will be no unacceptable impact on human health.

Only modelling scenarios under which the plume is expected to rise to the surface (i.e. non-stratified conditions) need to be considered in this context. Within the scenarios covered in the modelling report (Attachment D), model run 2 in Table 6 would appear the most relevant to this scenario and should be updated to reflect the points above.

Using the methodology outlined in the GHD mixing zone report and assuming a median site specific value of 10 CFU/100ml (as used for thermotolerant coliforms in the mixing report provided as part of the DPEMP submission) and the target criteria adopted by the EPA of 40


enterococci / 100 mL as the trigger value, the required dilution for the 90th percentile concentration was calculated as follows:

The dilution needed at the ‘edge’ of the mixing zone (D) was estimated as:

Dilution=(CEFF–CTV)/(CTV–CBG) where: CEFF is taken to be the 90th percentile concentration of the treated effluent; CTV is trigger value at the edge of the mixing zone; and CBG is the median concentration from the reference monitoring sites.

The required dilution is calculated as 5.3-fold. Comparing this to the mixing achieved in Model Run 2 from the mixing zone report (refer figure below), full dilution would be expected to be readily achieved <5 m from the diffuser ports, well within the proposed mixing zone. Therefore the modelling suggests there will be no unacceptable impact on human health outside of the designated mixing zone on nearby sensitive receptors, including the ‘Fishos’ surfing location.


Our response to other matters raised during the public consultation period where additional information has been requested is provided below. The original ‘Comments and Issues’, and ‘EPA Comments’ sections of Table 2 from the EPA letter dated 15 December 2016 are also provided for reference (in italics).

14. Commitments (O1)

Commitments should not be a statutory requirement but a statement by the proponent on how they will mitigate or manage to allow compliance with statutory requirements.

Consider review and amendment of commitments.

These commitments have been revised and have been included in Appendix D of this supplement.

15. Air Emission Commitment (O10)

The DPEMP dictates that air emission management and incident reporting will be included in an Annual Environmental Report but there is no clear commitment in the DPEMP to the preparation and submission of this document.

Consider revision of commitments to include Annual Environmental Report.

This commitment has been included in the revised list of commitments (refer Appendix D of this supplement).

16. Contingency Management Manual (O14)

The CMM is dictated as a key mitigation measure but does not form a commitment of the DPEMP.

Consider revision of commitments accordingly.

This commitment has been included in the revised list of commitments (refer Appendix D of this supplement).

17. Swift Parrot (O16)

A threat to swift parrots is colliding with man-made objects such as chain –link fences. It is recommended that infrastructure (particularly fencing) is designed to minimise collision risk to Swift parrots where practicable. 17Additional information on this topic can be found at http://awsassets.wwf.org.au/downloads/sp027_minimising_swift_parrot_collision_threat_1apr08.pdf

Provide details of how infrastructure will be designed to minimise collision risk to Swift parrots.

There are a number of potential options to address this. TasWater can:




• Reduce the footprint of the fence, • Change the alignment of the fence • Look at options to make the temporary and permanent fencing more visible to the

Swift Parrot.

Some of these solutions may cause issue with local landowners in terms of visual amenity.

TasWater will work with PCAB and the local Landowners to produce a solution acceptable to both parties.

18. Fishos (O17)

The presence of a popular surfing spot, “Fishos” in the vicinity of the outfall is a relevant sensitive recreational water use not acknowledged in this section.

This needs to be taken into account in the mixing zone determination. The information request in Table 1 already covers this point.

The recreational water use is acknowledged and has been addressed under R13 above.

19. Sample Collection (O27)

The DPEMP proposes grab sampling of effluent, however composite sampling is considered more appropriate for this STP.

Confirm use of composite sampling in the proposed monitoring program.

Composite sampling, rather than grab sampling will be used for collection of the samples for analysis of the Water quality (Laboratory) parameters listed in Table 8-1 of the DPEMP. This commitment has been revised and included in Appendix D of this supplement.


Our response to other matters raised during the public consultation period where additional information was not requested is provided in Appendix E. We have responded to those issues where we feel that a response in addition to the EPA response on the matter is required.

Appendix A: Stormwater Collection System Drawings

525Ø

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1:500 at A1

References

Datum

C

disclosed to third parties, or copied or reproduced whollyremains the property of TasWater and must not beThis drawing and the information it contains is, and

Sheet NumberTASMANIAN WATER & SEWAGE CORPORATION PTY LTD

DRAWING ISSUE

or in part or in any format without the written consentof the owners. The information contained herein is also

Project No

PROJECT DETAILS

Scale

ABN: 47 162220 653

REVISION

Sheet Size

Vault Folder

HPRM File Ref.

Discipline

DESIGN

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DATE

Designed

Verified

This drawing is produced on an A3 size sheet,DO NOT SCALE a sheet plotted at any other size.

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correct and up-to-date, but all details should be verifiedon site by the user prior to construction.

Rev. ApprovedDate

Revision Notes KINGBOROUGH SEWERAGE PROJECTBBT1-BLACKMANS BAY SEWAGE TREATMENT PLANT

GENERAL ARRANGMENTSITE PLAN

J.15950

PROJECTS

FSW11/378

P

AM 03.11.15

DF 03.11.15

NS 15.12.15

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1:500AHD (Tas.)A3

15.12.15 NS J15950-STP-G-1012015-

FOR TENDER

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LEGEND

Appendix B: Austrostipa bigeniculata Survey Report

09 January 2017

To TasWater

Copy to

From James Hill Tel +61 3 6210 0674

Subject Targeted Survey - Threatened Flora Job no. 3218264

1 Purpose This botanical survey was undertaken to satisfy a request for further information from the EPA Board in the assessment of permit application DA 2016-423 for the Blackmans Bay Sewage Treatment Plant (STP) Upgrade. The ecological assessment undertaken for the project suggested that the threatened flora species Austrostipa bigeniculata (double jointed speargrass) may have been overlooked during the original survey, as it was conducted outside of the optimum flowering time for the species, and it was noted that appropriate habitat for the species existed within the study area (i.e. the Land).

2 Scope To undertake a targeted survey for the threatened flora species Austrostipa bigeniculata, identified as potentially occurring within the proposed Blackmans Bay STP Upgrade area. In addition, two other species were considered during the survey, Cynoglossum australe and Lepidium pseudotasmanicum which were also identified as potentially having been overlooked due to the original survey timing, however, these species were considered to have a lower probability of occurring then Austrostipa

bigeniculata due to the vegetation types and habitat present within the study bounds.

3 Methods The survey was undertaken by a GHD Senior Ecologist (Botany) on 21 December 2016, which is considered to be within the optimum timeframe to survey for this species, as specified in the attached notesheet and also confirmed by Dr Wendy Potts, Senior Botanist Threatened Species Section, Natural and Cultural Heritage Division, Department of Primary Industries, Parks, Water and Environment.

The survey area is detailed in Figure 1. The survey was conducted on foot utilising the random meander technique. Areas that were observed as containing the most suitable habitat were surveyed in greater detail utilising a grid technique.

A previous record of the species nearby was identified from the Natural Values Atlas Tasmania at 526780E 5238259N (GDA94 MGA55). This site was assessed prior to conducting the survey at the target site to confirm the presence of reproductive material on the species in the area. This site will be referred to as CL (confirmed location). This was undertaken to improve the confidence level of the survey that the species would not be overlooked due to survey timing.

4 Results The location at CL confirmed the presence of Austrostipa bigeniculata with good quality reproductive material present (refer Plate 1), this location is approximately 800 m north of the study area. The individuals noted at this site were situated on a steep slope within Allocasuarina verticillata forest (NAV) with a very sparse ground layer on a north facing slope.

Plate 1 Austrostipa bigeniculata at site CL

In general, the study area vegetation differs from that at site CL in both aspect and vegetation type with the exception of a small area of similar vegetation (aspect east) along the coastal fringe in the study area.

There were no individuals of Austrostipa bigeniculata, Cynoglossum australe or Lepidium

pseudotasmanicum recorded during the field assessment in the targeted survey study area.

5 Conclusion As the study was conducted at the optimum time of year for Austrostipa bigeniculata and there were confirmed individuals with reproductive material at site CL it is considered highly unlikely that the species has been overlooked within the Blackmans Bay STP Upgrade study area, therefore, the risk that this species will be impacted during project works is negligible. Cynoglossum australe and Lepidium pseudotasmanicum were not recorded during the survey, which was conducted at an appropriate time for these species, therefore the probability that they occur within the study area is considered very low.

In conclusion, permits under the Tasmanian Threatened Species Protection Act 1995 will not be required for the project.

Regards

James Hill Senior Environmental Scientist

FAG

DGL

FUR

NAV

DAD

DAD

FUR

DGL

FAG

526,600

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5,237,

200

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0 40 8020

MetresMap Projection: Transverse Mercator

Horizontal Datum: GDA 1994Grid: GDA 1994 MGA Zone 55 o

© 2017. Whilst every care has been taken to prepare this map, GHD (and DATA CUSTODIAN) make no representations or warranties about its accuracy, reliability, completeness or suitability for any particular purpose and cannot accept liability and responsibility of any kind (whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs (including indirect or consequential damage) which are or may be incurred by any party as a result of the map being inaccurate, incomplete or unsuitable in any way and for any reason.

TasWaterBlackmans Bay STP DPEMP

Threatened Flora Targeted Survey Figure 1

Job NumberRevision B

32-18264

10 Jan 2017Date

Data source: DPIPWE (imagery, cadastre), TasWater (infrastructure design), GHD (vegetation communities, points). Created by: jhill

2 Salamanca Square Hobart TAS 7000 Australia T 61 3 6210 0600 F 61 3 6210 0601 E [email protected] W www.ghd.com.au

Paper Size A3

LEGENDTargeted Threatened Flora Survey BoundaryConstruction CompoundInfrastructure footprintCut / fill footprint

Vegetation Communities (GHD Survey, June 2016)Dry eucalypt forest and woodland

Eucalyptus amygdalina forest and woodland on dolerite (DAD)Eucalyptus globulus dry forest & woodland (DGL)

Non-eucalypt forest and woodlandAllocasuarina verticillata forest (NAV)

Agricultural, urban and exotic vegetationAgricultural land (FAG)Urban Areas (FUR)

Drainage lineWaterwayCadastre

Threatened Flora of Tasmania

DescriptionA tufted perennial grass up to 1 metre tall that arises out of a tuft of basal leaves ⅓ to

½ the overall height. Stem: The stem is circular, finely ribbed and smooth. The nodes

(stem joints) are silky to the touch. Leaves: The leaves are tightly inrolled with blades

up to 25 cm long. The lower stem leaves are covered with short dense hairs, with the

upper stem leaves being smooth. The sheaths surrounding the base of the leaves are

ribbed. The lower sheaths are hairy with the upper sheaths being smooth and hairless.

Seedheads (panicle): The panicle is up to 40 cm long and with few flowers. The

branches and flower stalks are covered with tiny rough hairs. Spikelets (units of the

seedhead): The spikelets are green or purplish in colour and the leaf-like structures

surrounding the spikelets (glumes) are broad and inflated around the floret. The lower

glume is longer than the upper glume. Flowering is from November to January

(Walsh & Entwisle 1994). Seed cover (lemma): The seed cover is reddish brown at

maturity and approximately 1 mm long with a grainy surface and whitish hairs. The

long hair-like structure protruding from the seed cover (awn) is around 40 mm long

(description from Curtis & Morris 1994). Herbarium specimens have been collected

from September to December. This species was previously known as Stipa

bigeniculata.

Distribution and HabitatOn the mainland Austrostipa bigeniculata is known from New South Wales and

Victoria. In Tasmania the species is found mainly in the southeast and midlands in

open woodlands and grasslands, where it is often associated with Austrostipa nodosa

(Curtis & Morris 1994).

Austrostipa bigeniculata

FAMILY: POACEAE

BOTANICAL NAME: Austrostipa bigeniculata(Hughes) S.W.L.Jacobs & J.Everett, Telopea 6(4): 584

(1996)

COMMON NAME: doublejointed speargrass

COMMONWEALTH STATUS: (EPBC Act) NotListed

TASMANIAN STATUS: (TSP Act) rare


Tasmanian Herbarium specimen.



Key Sites and PopulationsKey sites occur on the Forestier Peninsula, Maria Island, Midlands, Queens Domain,

Hobart and south of St Helens near Beaumaris (TPLUC 1996).

Known ReservesNot known from any formal reserve.

Ecology and ManagementThis species may benefit from disturbance in the form of grazing, mowing and

slashing, however forest clearing adversely impacts upon Austrostipa bigeniculata

(TPLUC 1996).

Wind is the most likely pollination vector for this species (A. Hingston pers. comm.).

Conservation Status AssessmentThere is not enough information available to enable a meaningful reassessment of

Austrostipa bigeniculata. This species is likely to be under-recorded due to

identification issues and it is likely that some unvouchered records have been

misidentified.

Further Information� Curtis, WM & Morris, DI 1994, The Student’s Flora of Tasmania, Part 4B,

Printing Authority of Tasmania, Hobart.

� Tasmanian Public Land Use Commission 1996, Environment & Heritage Report

Vol IV, Background Report, Part C, Tasmanian Commonwealth Regional Forest

Agreement, Hobart.

� Walsh, NG and Entwisle, TJ 1994, Flora of Victoria. Volume 2. Ferns and allied

plants, conifers and monocotyledons, Inkata Press, Melbourne.



Tasmanian Distribution(From Natural Values Atlas records August 2008)

1:25 000 Map SheetsAnderson, Broadmarsh, Cawood, Hobart, Huonville, Interlaken, Jacobs, Launceston,

Lisdillon, Murdunna, New Norfolk, Richmond, Ross.

Date last modified: 18/8/2008

View

http://www.dpiw.tas.gov.au/threatenedspecieslists

Contact details

Threatened Species Section, Department of Primary Industries and Water, GPO Box

44, Hobart, Tasmania, Australia, 7001. Phone (03) 6233 6556; fax (03) 6233 3477.

Permit

It is an offence to collect, disturb, damage or destroy this species unless under permit.

Appendix C: Desktop Influent Risk Review Report

TasWaterKingborough LGA Sewage Treatment Plants

Desktop Influent Risk Review

November 2016

GHD | Report for TasWater - Kingborough LGA Sewage Treatment Plants, 3218235 | i

Executive SummaryTasWater have recently lodged a Development Proposal and Environmental Management Plan(DPEMP) for the upgrade of the Blackmans Bay sewage treatment plant (STP). In consideringthe proposal, the EPA have requested further information on influent quality and the likelypresence of any contaminants of concern reporting to the current STPs that are proposed to beamalgamated as a result of the DPEMP.

In response to this, GHD were engaged to undertake a desktop review of all currently availableinfluent quality data. A range of data and information was used in the review, including tradewaste customer information, influent and effluent quality, as well as sludge quality data.

The assessment identified that several metals were elevated in the sludge collected at alltreatment plants (namely zinc and copper, which is common for STPs), but were not at levels inthe subsequent effluent to cause significant environmental impact in the receiving environments.

From the data available, the assessment found no significant contaminants of concern in theinfluent that had not already been historically identified.

Considering the trade waste customers in the catchments are all below a Category 3 level andare comprised of a commercial-type customer base (e.g. restaurants, take-away stores,laundromats etc.), the assessment considered that there would be a low risk of significantquantities of an unknown contaminant of concern occurring in the influent stream.

TasWater have proposed to undertake an effluent screening program following commissioningof the upgraded Blackmans Bay STP, as well as additional monitoring during the commissioningphase if required.

GHD | Report for TasWater - Kingborough LGA Sewage Treatment Plants, 3218235 | ii

Table of contents1. Introduction.....................................................................................................................................1

1.1 Purpose of this report...........................................................................................................1

1.2 Scope and limitations...........................................................................................................1

1.3 Assumptions ........................................................................................................................2

2. Assessment Methodology..............................................................................................................3

3. Existing Trade Waste Inputs ..........................................................................................................3

3.1 Trade waste Volumes by Category......................................................................................3

3.2 Blackmans Bay STP ............................................................................................................4

3.3 Margate STP........................................................................................................................5

3.4 Electrona STP......................................................................................................................5

4. STP Sludge Analysis......................................................................................................................7

4.1 Blackmans Bay STP ............................................................................................................7

4.2 Margate STP......................................................................................................................10

4.3 Electrona STP....................................................................................................................13

5. Effluent Quality.............................................................................................................................16

6. Conclusions..................................................................................................................................19

6.1 Trade waste customers......................................................................................................19

6.2 Sludge and effluent ............................................................................................................19

6.3 Summary............................................................................................................................20

Table indexTable 3-1 Trade waste customer numbers and waste volumes by STP during the 2014-15

reporting period (1-July 2014 – 30 June 2015)....................................................................4

Table 3-2 Blackmans Bay Trade waste Sources .................................................................................4

Table 3-3 Margate Trade waste Sources.............................................................................................5

Table 3-4 Electrona Trade waste Sources...........................................................................................6

Table 4-1 Blackmans Bay STP sludge sample analysis (2010 – 2016) ..............................................8

Table 4-2 Margate STP sludge sample analysis (2009 – 2014)........................................................11

Table 4-3 Electrona STP sludge sample analysis (2009 – 2012)......................................................14

Table 5-1 STP Effluent Quality (All Sites) - Metal concentrations..........................................................17

AppendicesAppendix A – Influent Quality Data

GHD | Report for TasWater - Kingborough LGA Sewage Treatment Plants, 3218235 | 1

1. IntroductionTasWater recently submitted a Development Proposal and Environmental Management Plan(DPEMP) to upgrade the existing Blackmans Bay Sewage Treatment Plant (STP) to an8.53 ML/day treatment facility. This proposal involves the amalgamation of influent from fourexisting STPs in the Kingborough Local Government Area (LGA). These existing STP’s are tobe decommissioned as a result of the proposal (Blackmans Bay infrastructure will be reused).As part of the consideration of the proposal, the EPA have requested that TasWater undertakescreening investigations into existing trade waste streams to identify any parameters of concernthat will be diverted to the proposed Blackman Bay STP.

Only three of the four STPs to be amalgamated accept trade waste, namely the existingBlackmans Bay STP, the Margate STP and the Electrona STP. The smaller Howden STP onlytreats domestic sewage.

In response to the EPA request, TasWater commissioned GHD to initially undertake a desktopassessment of the trade waste influent characteristics. This assessment was completed ratherthan undertaking a physical sampling program, as it is believed that currently available data andinformation should be sufficient to characterise any potential environmental contaminants ofconcern in the accepted trade waste streams.

1.1 Purpose of this report

GHD have prepared this report to identify contaminants of concern in the trade waste streamsfrom the relevant STPs associated with the Blackmans Bay DPEMP.

1.2 Scope and limitations

The review is based on desktop assessment of information and data provided by TasWater onthe Blackmans Bay STP, Electrona STP and Margate STP. The following information wasreviewed

2012-2013, 2013-2014, 2014-2015 and 2015-2016 Annual Environment Reports(AERs)

Effluent quality data 2013-2016

Sludge analysis data 2010-2016

Kingborough Trade waste Customer Records

Influent quality data 2013-2016

This report: has been prepared by GHD for TasWater and may only be used and relied on by TasWater forthe purpose agreed between GHD and the TasWater as set out in Section 1 of this report.

GHD otherwise disclaims responsibility to any person other than TasWater arising in connection with thisreport. GHD also excludes implied warranties and conditions, to the extent legally permissible.

The services undertaken by GHD in connection with preparing this report were limited to those specificallydetailed in the report and are subject to the scope limitations set out in the report.

The opinions, conclusions and any recommendations in this report are based on conditions encounteredand information reviewed at the date of preparation of the report. GHD has no responsibility or obligationto update this report to account for events or changes occurring subsequent to the date that the report wasprepared.


The opinions, conclusions and any recommendations in this report are based on assumptions made byGHD described in this report. GHD disclaims liability arising from any of the assumptions being incorrect.

GHD has prepared this report on the basis of information provided by TasWater and others who providedinformation to GHD (including Government authorities)], which GHD has not independently verified orchecked beyond the agreed scope of work. GHD does not accept liability in connection with suchunverified information, including errors and omissions in the report which were caused by errors oromissions in that information.

1.3 Assumptions

The Howden STP does not accept any Trade waste and has been excluded from thisassessment.


2. Assessment MethodologyThe DPEMP document outlined the volumes and types of trade waste customers reporting tothe various STPs involved in the amalgamation proposal. This assessment aims to characterisethe quality of the waste streams, which was undertaken as part of the DPEMP.

In the absence of specific trade waste quality data, alternative methods for detection ofcontaminants of concern have been utilised here, including:

Assessment of trade waste customer type and resulting likely contaminants of concern, asreported in TasWater Annual Environment Reports (AERs).

Trade waste input volumes.

Analysis of STP sludge composition chemical analysis undertaken at each of the STPs,with sludge acting as a potential end point location for contaminants of concern and hencea good indicator of waste stream content. This is especially true for some metal parameterswhich are likely to bind to the organic content of the sludge.

Analysis of available STP effluent chemical (metal) characteristics, including annualchemical screening, which may highlight elevated contaminants of concerns.

As background information for this assessment, available influent data for Blackmans Bay,Margate and Electrona STPs are provided in Table A, Table B, and Table C respectively.

3. Existing Trade Waste Inputs3.1 Trade waste Volumes by Category

A summary of the volumes of trade waste (by category) for each STP is provided in Table 3-1.The majority of trade waste inputs by volume (82%) are to the Blackmans Bay STP, with 14%by volume to the Margate STP and 4% to the Electrona STP.

Trade waste categories received range from Category 1 to Category 2C. No trade wastes aboveCategory 2C are currently accepted at any of the STPs.

Trade waste categories according to TasWater are as follows (fromhttp://www.taswater.com.au/Customers/Liquid-Trade-Waste/Commercial):

Category 1 Low Impact Liquid Trade Waste

A liquid trade waste discharge which is deemed by TasWater to have a low impact on thesewerage network, requires nil or only minimal pre-treatment and can be managed throughcleaner production methods.

Category 2 Low to Medium Volume and Low Impact Liquid Trade Waste

A liquid trade waste discharge which is deemed by TasWater to have a greater impact on thesewerage network than Category 1 discharge and requires passive or active pre-treatment priorto discharge into the sewer. The pre-treatment equipment is located at the source and is of aform which requires servicing and/or maintenance.

Category 3 Trade Waste – Medium Risk

Trade waste which through volume, composition or quality, individually or combined, poses amedium risk to the operation of sewerage infrastructure.


Category 4 Trade Waste – High Risk

Trade waste which through volume, composition or quality, individually or combined, poses ahigh risk to the operation of TasWater’s sewerage infrastructure.

Table 3-1 Trade waste customer numbers and waste volumes by STP duringthe 2014-15 reporting period (1-July 2014 – 30 June 2015)

3.2 Blackmans Bay STP

The existing Blackmans Bay STP accepts sewage from a variety of residential and commercialpremises, with no trade waste over Category 2C, as shown in Table 3-2.

There were 35 Cat 1 customers, 57 Cat 2A customers, four Cat 2B customers and four Cat 2Ccustomers.

The key parameters of concern in the trade waste streams for the Blackmans Bay STP wereidentified in the 2015/16 AER as ammonia, nitrogen, biological oxygen demand (BOD), totalsuspended solids (TSS), total dissolved solids (TDS), sodium, and oil & grease.

Table 3-2 Blackmans Bay Trade waste Sources

Trade waste Sources Number offacilities

Category

1 2A 2B 2C

Animal Boarding 1 1Automotive Service/Repair 6 5 1Bakery 5 5Biological load > Domestic 2 2Car Wash (Wand/Drive Through) 1 1Catering 1 1Child Care 3 3Church/Place of Worship 1 1Community Centre/Hall 1 1Green Grocer 1 1Hairdresser/Beauty Salon 8 8



Category

1 2A 2B 2C

Laboratories 1 1Laundromat (Coin Operated) 1 1Medical (inc. Dentist, Vet) 7 7Nursing Home/Care Home (Kitchen) 1 1Plant/Machinery Hire 2 2Primary/Secondary School 8 7 1Pub/Bar/Hotel 1 1Restaurant/Cafe 30 2 25 1 2Smallgoods, Butcher 1 1Supermarket 4 4Swimming pool 1 1Take Away/Fast Food 13 12 1

3.3 Margate STP

The Margate STP accepts sewage from a small number of residential and commercialpremises, with no trade waste over Category 2B, as shown in Table 3-3.

There were six Cat 1 customers, six Cat 2A customers, and one Cat 2B customer.

No key parameters of concern in the waste streams are identified in the 2015/16 AER, howeverfrom the identified trade waste sources, similar parameters of concern to the Blackmans BaySTP would be likely.

Table 3-3 Margate Trade waste Sources


Category

1 2A 2B 2C

Automotive Service/Repair 1 1Hairdresser/Beauty Salon 3 3Primary/Secondary School 2 2Restaurant/Cafe 5 1 2 2Smallgoods, Butcher 1 1Supermarket 1 1Take Away/Fast Food 1 1

3.4 Electrona STP

The Electrona STP accepts sewage from a small number of residential and commercialpremises, with no trade waste over Category 2A, as shown in Table 3-4.

There was one Category 1 customer and four Category 2A customers.

No key parameters of concern in the waste streams are identified in the 2015/16 AER, howeverfrom the identified trade waste sources, similar parameters of concern to the Blackmans BaySTP would be likely.


Table 3-4 Electrona Trade waste Sources


Category

1 2A 2B 2C

Primary/Secondary School 1 1Restaurant/Cafe 2 2Smallgoods, Butcher 1 1SupermarketTake Away/Fast Food 1 1


4. STP Sludge AnalysisWith only a limited number of parameters analysed in the influent streams of the STP, sludgeresults that contain a larger parameter suite have been analysed as an indicator of potentialcontaminants of concern in the influent. Sludge tests do not cover every potential parameter ofconcern, but do concentrate on non-organic contaminates such as total metals, oftenassociated with toxicants.

Annual testing of sludge from each of the STPs has been conducted intermittently between2009 and 2016. Results were compared to ANZECC 2000 Interim Sediment Quality Guidelines(ISQGs) and EPA TAS Bulletin No 105 (classification and management of contaminated soil fordisposal) as a gauge of the relevance of the concentration only.

4.1 Blackmans Bay STPResults of analysis of Blackmans Bay STP sludge for the 2010-2016 period are presented inTable 4-1. The results indicate:

Metals

Metals with concentrations that exceeded ANZECC ISQG-Low values included Cd, Cr, Pb,Ni

Metals with concentrations that exceeded ANZECC ISQG-High values included Cu, Hg, Zn

With respect to EPA Bulletin:105 contamination classifications, Cr, Cu, Hg, Zn were atconcentrations considered as Level 2 Contaminated.

Whilst sources of metal contaminants are difficult to pinpoint in the catchment, potential sourcesmay include naturally occurring levels in the water supply, run-off from premises using weldingequipment, car exhaust and engine oil run-off (e.g. from car washing facilities, automotiverepairs). The water in the catchment is also known to be slightly corrosive and may be reactingwith water supply infrastructure (e.g. copper piping).

When interpreting the results, it should be noted that any high concentrations of metals thatappear in the sludge may be the result of intensive concentration in the sludge of many smallsources rather than the result of a single high concentration source.

Hydrocarbons

Total petroleum hydrocarbon (TPH) tests showed that although the levels of TPH were high, thesilica gel clean-up procedure used on the fractions C10 – C36 showed that the concentrationsof TPH were of a biological nature (e.g. vegetable/animal oils and greases) rather than of apetrogenic nature. This is consistent with the type of trade waste customers in the catchment(e.g. restraunts/take away stores).

TPH in the C6-C9 partition were not sampled using the silica gel technique and therefore theslightly elevated 90th percentile levels may not be fully indicative of petroleum hydrocarbons;with a median value of 2.5, these hydrocarbon types are not seen as a significant issue in thewaste stream.

Other

Other monitored contaminants not included in the table that were sampled included a,b,d,g-benzene hexachloride, aldrin, chlordane, DDD, DDE, DDT, dieldrin, heptachlor and PCB. Therewere between six and nine samples of these parameters over the 2010-2016 period, with allresults below limits of reporting.


Table 4-1 Blackmans Bay STP sludge sample analysis (2010 – 2016)

Parameter Unit n Median 90th

PercentileMax

AN

ZEC

C IS

QG

–low

trigg

er

AN

ZEC

C IS

QG

–Hig

h

trigg

er

EPA

Bul

letin

105

Lev

el

1: F

ill M

ater

ial (

Max

)

EPA

Bul

letin

105

Lev

el

2: C

onta

min

ated

Soi

l

EPA

Bul

letin

105

Lev

el

3: C

onta

min

ated

Soi

l EPA Bulletin 105 Classification on 90th

percentile

Aluminium mg/kg 42 11300 14260 17600

Arsenic mg/kg 74 4 4 6 20 70 20 3000 30000 Clean Fill

Cadmium mg/kg 74 1.5 2 2 1.5 10 3 40 400 Clean Fill

Chromium mg/kg 74 55 124.9 218 80 370 50 500 5000 Level 2 Contaminated

Copper mg/kg 74 608 715.1 852 65 270 100 2000 7500 Level 2 Contaminated

Iron mg/kg 42 7925 11390 14600

Lead mg/kg 74 36.5 48 62 50 220 300 1200 3000 Clean Fill

Mercury mg/kg 74 1.62 2.57 8.34 0.15 1 1 30 110 Level 2 Contaminated

Nickel mg/kg 74 20 24.7 33 21 52 60 600 3000 Clean Fill

Selenium mg/kg 74 4 5 7 10 50 200 Clean Fill

Zinc Mg/kg 1065 1230 1540 200 410 200 14000 50000 Level 2 Contaminated

Ammonia mg-N/kg

67 10000 19200 54000



PercentileMax

AN

ZEC

C IS

QG

–low

trigg

er

AN

ZEC

C IS

QG

–Hig

h

trigg

er

EPA

Bul

letin

105

Lev

el

1: F

ill M

ater

ial (

Max

)

EPA

Bul

letin

105

Lev

el

2: C

onta

min

ated

Soi

l

EPA

Bul

letin

105

Lev

el

3: C

onta

min

ated

Soi


percentile

Nitrate/Nitrite mg-N/kg

67 0.5 2.5 87

Nitrogen mg-N/kg

66 58000 73500 92000

Phosphorus mg-P/kg

66 15000 21000 23000

Oil & Grease mg/kg 41 33400 46800 84200

TPH mg/kg 41 19000 29300 44400

TPH C6-C9 mg/kg 41 2.5 68 210 65 650 1000 Level 2 Contaminated Soil

TPH C10-C14*

mg/kg41 29.5 72 85 1000 5000 10000

Clean Fill

TPH C15-C28*

mg/kg41 195 364 450 1000 5000 10000

Clean Fill

TPH C29-C36*

mg/kg22 115 215 320 1000 5000 10000

Clean Fill

*Sampled using silica gel clean-up procedure, this is used to identify petrogenic hydrocarbons from the remaining non-petrogenic hydrocarbons of a biologicalnature


4.2 Margate STPResults of analysis of Margate STP sludge for the 2009-2014 period are presented in Table 4-2.The results indicate:

Metals

Metals with concentrations that exceeded ANZECC ISQG-Low values included Cd, Pb, Hg,and Ni.

Metals with concentrations that exceeded ANZECC ISQG-High values included Cu and Zn.

With respect to EPA Bulletin:105 contamination classifications, Cu and Zn were atconcentrations considered as Level 2 Contaminated.

Hydrocarbons

No sludge sampling for hydrocarbons was undertaken.

Other

Other monitored contaminants not included in the table that were sampled included a,b,d,g-benzene hexachloride, aldrin, chlordane, DDD, DDE, DDT, dieldrin, heptachlor and PCB. Therewas one sampling event for these parameters in January 2010, with all results below limits ofreporting.


Table 4-2 Margate STP sludge sample analysis (2009 – 2014)


PercentileMax

AN

ZEC

C IS

QG

–low

trigg

er

AN

ZEC

C IS

QG

–Hig

h

trigg

er

EPA

Bul

letin

105

Lev

el

1: F

ill M

ater

ial (

Max

)

EPA

Bul

letin

105

Lev

el

2: C

onta

min

ated

Soi

l

EPA

Bul

letin

105

Lev

el

3: C

onta

min

ated

Soi


percentile

Arsenic mg/kg 24 3 5 6 20 70 20 3000 30000 Clean Fill

Cadmium mg/kg 25 1 1 2 1.5 10 3 40 400 Clean Fill

Chromium mg/kg 24 24 42.8 50 80 370 50 500 5000 Clean Fill

Copper mg/kg 24 226 430 467 65 270 100 2000 7500 Level 2 Contaminated

Lead mg/kg 24 33.5 53.5 76 50 220 300 1200 3000 Clean Fill

Mercury mg/kg 23 0.25 0.636 0.71 0.15 1 1 30 110 Clean Fill

Nickel mg/kg 20 15.5 21.2 31 21 52 60 600 3000 Clean Fill

Selenium mg/kg 24 1 2 5 10 50 200 Clean Fill

Zinc mg/kg 25 717 1280 1680 200 410 200 14000 50000 Level 2 Contaminated

Ammonia mg-N/kg

7 3100 4840 6100


42 0.0015 0.5 2.5

Nitrogen mg-N/kg

36 375 23000 32000



PercentileMax

AN

ZEC

C IS

QG

–low

trigg

er

AN

ZEC

C IS

QG

–Hig

h

trigg

er

EPA

Bul

letin

105

Lev

el

1: F

ill M

ater

ial (

Max

)

EPA

Bul

letin

105

Lev

el

2: C

onta

min

ated

Soi

l

EPA

Bul

letin

105

Lev

el

3: C

onta

min

ated

Soi


percentile

Phosphorus mg-P/kg

7 7100 7740 8100


4.3 Electrona STPResults of analysis of Blackmans Bay STP sludge for the 2010-2016 period are presented inTable 4-3. The results indicate:

Metals

Metals with concentrations that exceeded ANZECC ISQG-Low values included Cd, Pb, andNi.

Metals with concentrations that exceeded ANZECC ISQG-High values included Cu, Hg, Zn.

With respect to EPA Bulletin:105 contamination classifications, Cu and Zn were atconcentrations considered as Level 2 Contaminated.

Hydrocarbons

No sludge sampling for hydrocarbons was undertaken.

Other

Other monitored contaminants not included in the table that were sampled included a,b,d,g-benzene hexachloride, aldrin, chlordane, DDD, DDE, DDT, dieldrin, heptachlor and PCB. Therewas one sampling event for these parameters in January 2010, with all results below limits ofreporting.


Table 4-3 Electrona STP sludge sample analysis (2009 – 2012)


PercentileMax

AN

ZEC

C IS

QG

–low

trigg

er

AN

ZEC

C IS

QG

–Hig

h

trigg

er

EPA

Bul

letin

105

Lev

el

1: F

ill M

ater

ial (

Max

)

EPA

Bul

letin

105

Lev

el

2: C

onta

min

ated

Soi

l

EPA

Bul

letin

105

Lev

el

3: C

onta

min

ated

Soi


percentile

Arsenic mg/kg 4 10.5 13 20 70 20 3000 30000 Clean Fill

Cadmium mg/kg 21 1 1 3 1.5 10 3 40 400 Clean Fill

Chromium mg/kg 22 19 42 62 80 370 50 500 5000 Clean Fill

Copper mg/kg 22 232 417.7 942 65 270 100 2000 7500 Level 2 Contaminated

Lead mg/kg 22 27 40.7 66 50 220 300 1200 3000 Clean Fill

Mercury mg/kg 22 0.5 0.987 5.8 0.15 1 1 30 110 Clean Fill

Nickel mg/kg 19 12 16.4 26 21 52 60 600 3000 Clean Fill

Selenium mg/kg 18 2.25 3.15 4 10 50 200 Clean Fill

Zinc Mg/kg 22 723 1889 4390 200 410 200 14000 50000 Level 2 Contaminated

Ammonia mg-N/kg

7 5400 32200 61000


7 0.5 11.9 29

Nitrogen mg-N/kg

7 61000 72000 75000



PercentileMax

AN

ZEC

C IS

QG

–low

trigg

er

AN

ZEC

C IS

QG

–Hig

h

trigg

er

EPA

Bul

letin

105

Lev

el

1: F

ill M

ater

ial (

Max

)

EPA

Bul

letin

105

Lev

el

2: C

onta

min

ated

Soi

l

EPA

Bul

letin

105

Lev

el

3: C

onta

min

ated

Soi


percentile

Phosphorus mg-P/kg

7 18000 19400 20000


5. Effluent QualityEffluent metal concentrations have been tested intermittently between 2012 and 2016, with theresults presented in Table 5-1. No other parameters have been assessed in the effluent otherthan those required by EPNs (e.g. nutrients, BOD5, suspended solids, thermotolerant coliforms,oil & grease and chlorine).

The metal results are useful in determining the proportion of metals not trapped in the sludgephase in the treatment process, which then estimates the potential for environmental impactfrom the metals in the effluent stream. It also potentially highlights any metals that were notidentified in the sludge that made it through the treatment process undetected.

Results were compared to ANZECC (2000) Guideline 95% species protection trigger values fortoxicants, this was done for indicative purposes only. Where marine trigger values wereunavailable, 95% freshwater trigger values were adopted as indicators (as the dischargeenvironment is marine/estuarine in all present/future cases).

Results show:

Blackmans Bay effluent showed elevated aluminium, copper and zinc.

Electrona effluent showed elevated chromium, copper and zinc.

Margate effluent showed elevated copper and zinc.

For all STPs, copper was significantly elevated above the trigger values shown, zinc wasmoderately elevated, and aluminium and chromium were not largely elevated.

It should be noted that the metal concentrations are at levels that would be sufficiently diluted inthe mixing zone of the various outfalls and therefore would be unlikely to pose a risk to theenvironment.


Table 5-1 STP Effluent Quality (All Sites) - Metal concentrations

Total Metal (µg/L) ANZECC95% MarineTrigger

ANZECC95%FreshwaterTrigger

Blackmans BaySTP

Electrona STP Margate STP

2015/16 2015/16 2015/14 2013/14 2015/16 2014/15 2013/14

Aluminium 55 71

Antimony <20

Arsenic 13 <15 <15 <15 <15 <15 <15 <15

Barium 5 16 9 12 7

Cadmium 5.5 0.2 <2 <2 <2 <2 <2 <2 <2

Chromium 4.4 (Cr VI) 1 (Cr VI) <2 6 <2 <2 <2 <2 <2

Copper 1.3 1.4 19 59 40 40 15 20 19

Iron 98

Lead 4.4 3.4 <10 <10 <10 <10 <10 <10 <10

Manganese 1900 35 33 30 31 42 30 45

Mercury 0.1* 0.06* <0.05 <0.05 0.06 <0.05 <0.05 <0.05 <0.05

Nickel 7* 8* <10 <10 <10 <10 <10 <10 <10

Selenium 11 <30 <30 <30 <30 <30 <30

Tin <10 <10 <10


Total Metal (µg/L) ANZECC95% MarineTrigger

ANZECC95%FreshwaterTrigger

Blackmans BaySTP

Electrona STP Margate STP

2015/16 2015/16 2015/14 2013/14 2015/16 2014/15 2013/14

Zinc 15 8 39 95 80 91 20 20 48

*ANZECC 2000 99 % species protection values used for these values.


6. ConclusionsThe assessment identified the following key points regarding the trade waste inputs into thestudied catchments of Blackmans Bay, Margate and Electrona STPs.

6.1 Trade waste customers

The Blackmans Bay STP has the largest number of trade waste customers and alsoreceives a significantly higher volume of trade waste than the remaining STPs

Customer trade waste categories for Blackmans Bay STP include up to Category 2C, forMargate the highest category is Category 2B and for Electrona, Category 2A is the highest.

For Blackmans Bay, the higher rated Category 2C customers included a car wash, nursinghome, and two restaurants.

For Margate, the higher rated Category 2B customers included two restaurants/cafes

For Electrona, the higher rated Category 2A customers included two restaurants/cafes, abutcher and a take-away store

Key parameters of concern in the waste streams for the Blackmans Bay STP wereidentified in the 2015/16 AER as ammonia, nitrogen, biological oxygen demand (BOD), totalsuspended solids (TSS), total dissolved solids (TDS), sodium, and oil & grease.

It was identified that the trade wastes from the remaining plants would have similarparameters of concern to the Blackmans Bay STP, based on customer type.

No Category 3 trade waste customers were identified.

Overall, from the customer records, there does not appear to be a significant risk of highvolumes of environmentally hazardous materials reporting to the various STP catchments (e.g.landfill leachate, industrial process waste etc.)

6.2 Sludge and effluent

Blackmans Bay STP sludge and effluent samples showed the following:

Various metals were shown to accumulate in the sludge at Blackmans Bay, with significantlevels of copper, mercury and zinc. There were also elevated levels of cadmium, chromium,lead, and nickel detected, albeit not as significantly elevated as the copper, mercury andzinc.

Effluent analysis showed that copper and zinc were also elevated in the effluent, howeverthe mercury detected in the sludge was not detected in the effluent. Aluminium wasdetected at levels slightly above guidelines.

Other chemicals sampled for included a,b,d,g-benzene hexachloride, aldrin, chlordane,DDD, DDE, DDT, dieldrin, heptachlor and PCB. None of these chemicals were detected inthe laboratory tests undertaken.

The contaminants of concern for Blackmans Bay were identified as zinc and copper. The sourceof the zinc and copper in the catchment is not easily identifiable, but may be related to watersupply, automotive run-off or potentially the slightly corrosive nature of the water in thecatchment (e.g. reacting with copper piping in the upstream supply side).

Margate STP sludge and effluent samples showed the following:


Various metals were shown to accumulate in the sludge; again, significant levels of copperand zinc were identified. There were also elevated levels of cadmium, lead, mercury andnickel detected, albeit not as significantly elevated as the copper and zinc.

Effluent analysis showed that copper and zinc were also elevated in the effluent.


The contaminants of concern for Margate STP were identified as zinc and copper, with potentialsources consistent with Blackmans Bay STP.

Electrona STP sludge and effluent samples showed the following:

Copper and zinc were identified as elevated again, along with mercury (in the maximumsample only). There were also elevated levels of cadmium, lead and nickel detected, albeitnot as significantly elevated as copper and zinc.

Effluent analysis showed that copper and zinc were also elevated in the effluent. Chromiumwas detected at levels slightly above guidelines also.


The contaminants of concern for Electrona STP were identified as zinc and copper, withpotential sources consistent with Blackmans Bay STP.

6.3 Summary

Overall, from the data available, this assessment has not identified a significant trade wastecontaminant of concern that had not been historically identified already. It is considered that,given the trade waste customer base types, there is a low risk of an unknown contaminant ofconcern entering the influent streams of the treatment plants. If Category 3 trade wastecustomers were present within the catchment, then self-screening of their waste stream wouldbe recommended to identify any contaminants of concern.

In conclusion, TasWater does not consider it necessary to undertake an effluent screeningprogram of the three STPs prior to their decommissioning. TasWater has committed to a rangeof treated effluent sampling and monitoring as part of the Blackmans Bay DPEMP, whichincludes annual effluent sampling for certain metals.

Following this desktop assessment, TasWater now proposes to undertake an effluent screeningprogram following commissioning of the upgraded Blackmans Bay STP. Composite samples ofthe effluent will be collected weekly for four weeks and analysed for a range of parameters. Anyparameter identified above relevant trigger values will be monitored in the receiving environmentas part of the proposed monitoring program outlined in the DPEMP. Additionally, a significantamount of process sampling will be undertaken during the proof of performance testing (POPT)phase of the project, which includes monitoring of the influent, effluent and sludge streams ofthe upgraded Blackmans Bay STP. If it is required, additional parameters could be added to thistesting program to allow for more targeted investigations.

GHD | Report for TasWater - Kingborough LGA Sewage Treatment Plants, 3218235

Appendices


Appendix A – Influent Quality Data


Appendix A – Influent Data

Table A Blackmans Bay STP influent data (2013-2016)

Parametern

Influent concentration (mg/L) (except pH)

Median 90th Percentile Max

Ammonia 73 46 60.7 181.2

BOD5 50 375 500 750

Nitrate/Nitrite 49 0.05 0.1 2.1

Nitrogen 73 64.7 84.9 243.2

Oil & Grease 48 61.95 78.07 179

pH 57 7.63 7.92 12.7

Phosphorus 73 11.1 14.24 39.2

TSS 72 322.5 451.2 1539

Table B Margate STP influent data (2013-2016)

Parametern

Influent concentration (mg/L) (except pH)


Ammonia 37 37.5 50.8 58.3

BOD5 51 360 540 880


Nitrogen 52 55.55 71.15 93.3

Oil & Grease 36 72.4 232.5 6960

pH 47 7.88 8.36 8.85

Phosphorus 52 8.6 12.34 14

TSS 51 262 457 1049


Table C Electrona STP influent data (2013-2016)

Parameter nInfluent concentration (mg/L) (except pH)


Ammonia 36 34.5 54.3 73.8

BOD5 50 300 482 620


Nitrogen 51 55.8 87 99.2

Oil & Grease 35 58.3 83.2 225

pH 47 7.61 8.19 8.42

Phosphorus 51 9 13.9 16.8

TSS 50 241.5 426.2 556

GHD

23 Paterson StreetT: 61 3 6332 5500 F: 61 3 6332 5555 E: [email protected]

© GHD 2016

This document is and shall remain the property of GHD. The document may only be used for thepurpose for which it was commissioned and in accordance with the Terms of Engagement for thecommission. Unauthorised use of this document in any form whatsoever is prohibited.3218235-45012/https://projects.ghd.com/oc/Tasmania/kingboroughdepreview/Delivery/Documents/EffluentDesktop review report.docx

Document Status

RevNo.

Author Reviewer Approved for IssueName Signature Name Signature Date

0 D. Elson D. Elson S. Lukies 28/10/2016

1 D. Elson D. Elson S. Lukies 07/11/2016

www.ghd.com

Appendix D: Blackmans Bay DPEMP – Revised Commitments Table

No. Commitment Applicable Section of DPEMP

1 TasWater will undertake community and stakeholder engagement leading up to, and during, construction.

Applicable to multiple sections

2 A Construction and Environmental Management Plan (CEMP) will be developed prior to commencement of construction.

Applicable to multiple sections

3 Trucks with potentially windblown materials will be covered. Air

4 Daily visual monitoring of the site for dust will be untaken during construction and water sprays applied to roads and stockpiles if needed.

Air

5 A complaints register will be established for both the construction and operational phases. All complaints will be logged, actioned and all outcomes documented.

Air

6 A Soil and Water Management Plan (SWMP) will be incorporated into the Site CEMP.

Surface Water

7 Weekly monitoring of water and sediment control measures will be undertaken during the construction period, with additional monitoring within 24hrs of a storm event.

Surface Water

8 Prior to construction a detailed stormwater design will be prepared (including review of the existing stormwater capture) to achieve the stormwater management targets for new developments as set out in the State Stormwater Strategy 2010 (unless it is not feasible to do so).

Surface Water

9 Any spills of environmentally harmful liquids greater than 100 L will be reported to the EPA, with commitment to undertake a groundwater monitoring event if deemed necessary by the EPA.

Groundwater

10 Noise complaints will be tracked using the online complaints register. All complaints will be logged, actioned and all outcomes documented.

Noise

11 Detailed design will address the required noise limits on equipment and acoustic enclosures as stipulated in this DPEMP and the Vipac Noise Report (2016); namely 85dBA or less for the inlet works, 80dBA (at 1m) or less for the odour control fan, 89dBA or less for the odour control fan

Noise


inlet duct and 84dBA or less for the exhaust from the odour control fan.

12 Care will be taken in the development and selection of enclosures for the IDEA blowers such that tonal noise emission breakout doesn’t generate potentially intrusive noise emissions.

Noise

13 A targeted inspection of areas proposed for subsurface excavations will be undertaken by a Certified Practitioner (Site Contamination Practitioners Australia) prior to construction to identify any areas of high risk for land contamination for subsequent soil testing, classification and management.

Waste

14 A Sewage Sludge Management Plan (SSMP) will be developed for the Project.

Waste

15 Any spilt waste will be immediately reported to the site manager and clean-up will occur.

Dangerous Goods and Hazardous Materials

16 Inspections and audits of environmentally hazardous material use and storage will be undertaken monthly.


17 Dangerous goods and environmentally hazardous materials storage, handling and clean up procedures will be incorporated into the site CEMP for the construction phase and the Operations and Maintenance Manual during the operational phase.


18 TasWater’s existing Sewage Treatment Plant Contingency Management Manual (CMM) and applicable existing Site Response Procedures (outlined in Appendix C of the DPEMP) will be adopted for the Project.


19 All areas of DGL community outside of the immediate development footprint will be flagged with temporary high visibility fencing and protected during construction works.

Biodiversity

20 All eucalypts outside of the immediate development footprint will be flagged with temporary high visibility fencing to ensure protection during the construction phase.

Biodiversity

21 Replacement planting will be undertaken for all mature Biodiversity


Eucalypt trees removed, at a ratio of 3:1 as part of the Landscaping Plan.

22 Weed and hygiene management will be incorporated into the site CEMP following the principles outlined in this DPEMP.

Biodiversity

23 Annual monitoring for the first five years of the landscaped area to assess success of tree growth, weed invasion and replacement plantings.

Biodiversity

24 An initial pre construction weed treatment will be undertaken, followed by 6 monthly weed surveys during construction, and additional weed controls applied as required.

Biodiversity

25 A post construction weed, pathogen and revegetation success survey will be undertaken at the completion of construction, with follow up surveys completed annually thereafter for a period of 5 years.

Biodiversity

26 Marine monitoring including water quality, benthic infauna and kelp monitoring will be undertaken in accordance with Section 8.1.3 of the DPEMP.

Marine and Coastal

27 If the marine monitoring program reveals marine impacts as a result of phosphorus in the STP discharge, the EPA will be contacted and phosphorus removal will be retrofitted to the STP and new emission limits established in consultation with the EPA.

Marine and Coastal

28 An Unanticipated Discovery Plan will be included in the Site CEMP and followed in the event of discovery of previously undetected heritage features.

Heritage

29 A vegetation screen will be planted along the western boundary of the new STP as outlined on the Figures in the DPEMP.

Visual

30 A Health and Safety Management Plan (HSMP) will be prepared for the construction phase and incorporated into the Site CEMP.

Health and Safety

31 Health and safety management will be included in the site specific Operations and Maintenance Manual.

Health and Safety

32 A site specific Operations and Maintenance Manual will be prepared and reviewed every 5 years once established.

EMS


33 The contractor will prepare a Traffic Management Plan (either stand alone or as part of the CEMP) prior to construction.

Traffic

34 An online complaints register will be maintained during the construction period and any traffic related complaints will be registered, addressed and reported back to the complainant.

Traffic

35 Continuous flow monitoring equipment used to measure outflows from the plant will be inspected on a weekly basis to ensure functionality.

Monitoring

36 Weekly and annual treated effluent composite samples will be collected and analysed for the parameters outlined in Table 8 1.

Monitoring

37 Monthly audits of biosolids monitoring procedures will be undertaken to ensure procedures are in accordance with the Tasmanian Biosolids Reuse Guidelines 1999, or as otherwise approved by the Director.

Monitoring

38 A supplement to the EPN licence Annual Environmental Report (AER) containing a summary of environmental performance of the Project and specifics from the environmental disciplines (where AER inputs are listed in the DPEMP) will be submitted annually to the EPA as an attachment to the AER. The supplement information will be based on the same reporting period as the EPN reporting period.

Monitoring

39 A Decommissioning and Rehabilitation Plan will be prepared for the site at such time as directed by the EPA.

Decommissioning

Appendix E: Partial Response to Other Matters where Additional Information was not Requested

Comments and issues EPA Comments

TasWater Response

O1 Commitments should not be a statutory requirement but a statement by the proponent on how they will mitigate or manage to allow compliance with statutory requirements.

Consider review and amendment of commitments.

Addressed in full in the DPEMP supplement

O2 Concerned with the location of proposed infrastructure.

The Board’s assessment is based on the application as submitted to Council. The Board will consider the location of infrastructure in relation to the potential environmental impacts on sensitive receptors.

O3 Consider that the fencing of the proposed STP could be smaller.

Matter outside the Board’s responsibilities for assessment of the application.

There is a possibility to reduce the footprint of the fence line; however this will require some joint discussions between PCAB and TasWater along with surrounding Landowners. The current fence line was designed to minimise any damage to “Swift Parrot” habitat. (ie Encircle the habitat, rather than go through and potentially remove some limbs.) TasWater will engage with PCAB and surrounding land owners.

O4 Concerned that the public footpath linking the existing Blackmans Bay-Tinderbox Cliffs Walk with the developed Bushland Trail Loop will not be retained.

Matters outside the Board’s responsibilities for assessment of the application.

The realignment of the Bushland Trail loop will retain the existing link.

O5 That other sites were considered and were more suitable due to the more isolated locations.

The DPEMP sufficiently addresses consideration of alternatives.

O6 Considers a plant at Margate without discharge to waterways as more suitable.

The DPEMP sufficiently addresses consideration of alternatives.

O7 TasWater has provided insufficient information in relation to potential visual impacts and have not consulted one on one with landowners.

Section 4 of the DPEMP provides details of public consultation undertaken by the proponent as required by the guidelines issued by the Board.

The public consultation period administered under LUPAA provides the opportunity for statutory representations to be made in relation to a proposal and the issues considered in the subsequent environmental and planning assessments.

TasWater is committed to working with Landowners. There have been two recent advertised public community information sessions (19/11/16 and 24/11/16). As a result of those sessions and queries to our Website, TasWater has produced a number of “Flyovers” showing likely visual impacts from individual properties and continues to meet “one on one” with landowners to demonstrate the “Flyovers” and to address concerns. There has been one meeting with a concerned Landowner in Suncoast Drive on 21/12/16 and there are 3 others scheduled in for Landowners along Tinderbox Road on 16/1/17 and 20/1/17.

O8 Concerned rezoning will affect management of open space.


The proposal is assessed to comply with the applicable use and development Zone standards under the Scheme (see DPEMP and further information response) and is therefore assessed to be consistent with the Zone Purpose. Specifically, the proposed operation, noise emissions of the use is such that it does not result in an unreasonable impact on the surrounding residential amenity, and the proposed setbacks, building height and design of the plant is such that it seeks to minimise the adverse impact on nature values of the Zone. The area outside the fence encircling the Treatment Plant will remain available for recreational use.

O9 Consider the large rezoning to utilities reflects expected odour issues.

The Board’s assessment will consider odour impacts and the potential for environmental

nuisance or harm.

O10 The DPEMP dictates that air emission management and incident reporting will be included in an Annual Environmental Report but there is no clear commitment in the DPEMP to the preparation and submission of this document.

Consider revision of commitments to include Annual Environmental Report.


O11 Expects the environmental approval process to ensure that noise and odour from the upgraded STP will be significantly reduced once fully operational.

The Board’s assessment will consider noise and odour impacts and the potential for environmental nuisance or harm.

O12 Concerned that plant will have negative impacts (visual, odour, noise, financial) on the surrounding properties.

The Board’s assessment will consider noise and odour impacts and the potential for environmental nuisance or harm.

Visual and devaluation matters are outside the Board’s responsibilities for assessment of the application.

O13 Expect a detailed construction management plan to minimise noise and vibration impacts on nearby sensitive receptors. Including noise and vibration monitoring.

The Board’s assessment will consider noise impacts and the potential for environmental nuisance or harm and mitigation and management.

O14 The CMM is dictated as a key mitigation measure but does not form a commitment of the DPEMP

Consider revision of commitments accordingly.


O15 Appendix B of the DPEMP has appropriately considered impacts to swift parrot (Lathamus discolour). Any clearance of swift parrot habitat be avoided during the species’ breeding season (September to January) if the species is present in the area. Information on breeding locations is made available each year on the Threatened Species Link (www.threatenedspecieslink.tas.gov.au)

No further information required. TasWater will work with PCAB and the contractor to minimise disturbance to the breeding season of the Swift Parrot.

O16 A threat to swift parrots is colliding with man-made objects such as chain –link fences. It is recommended that infrastructure (particularly fencing) is designed to minimise collision risk to Swift parrots where practicable. 17Additional information on this topic can be found at http://awsassets.wwf.org.au/downloads/sp027_minimising_swift_parrot_collision_threat_1apr08.pdf

Provide details of how infrastructure will be designed to minimise collision risk to Swift parrots.


O17 The presence of a popular surfing spot, “Fishos” in the vicinity of the outfall is a relevant sensitive recreational water use not acknowledged in this section.

This needs to be taken into account in the mixing zone determination. The information request in Table 1 already covers this point.


O18 This section refers to thermotolerant coliforms trigger values specified in the ANZECC (2000) guidelines as the relevant

No further information required.

http://www.threatenedspecieslink.tas.gov.au/




standard for protection of recreational water uses.

It should be noted that, consistent with the requirements of the NHMRC guidelines which have superseded the ANZECC guidelines, EPA have adopted a recreational water uses trigger value of 40 enterococci /100 mL for recreational water areas with sewage-derived discharges.

O19 Table 1 of the Mixing Zone report refers to ‘1000 cfu/100 mL thermotolerant coliforms’ as the relevant trigger value based on the ANZECC (2000) guidelines. Comment as for p. 112 above.

No further information required.

O20 Considers the proposal is not consistent with the relevant zoning.


Representation 6 states that "the proposed use does not further any of the purpose statements and therefore fails the relevant test under Clause 8.10.1c) of the Planning Scheme." There is no subclause 8.10.1c) under the Kingborough Interim Planning Scheme 2015, which sets out the matters the planning authority must take into consideration when determining an application. It is assumed the representation is referring to Clause 8.10.2 which sets out the additional matters the planning authority must have regard to for a discretionary use, including under subclause (a) "the purpose of the applicable zone".

As a discretionary use, Council must have regard to the Environmental Living Zone Purpose. The Zone Purpose describes the desired outcome or rationale to be achieved by the zone use and development objectives and standards. The Purpose should therefore be met if the Zone standards are met.

The upgrade will involve an extension of the existing plant footprint resulting in the plant being sited closer to the residents in the adjoining Environmental Living Zone and the clearance of a small number of listed native trees in this area. These impacts are minimised through the earthworks, which will minimise the appearance of the plant as it will be cut into the slope, and the proposed landscaping which will involve landscaping and replanting where tree clearance is unavoidable.

More broadly the proposed use is necessary to provide required essential services for the adjoining residential area and will improve the overall environmental outcomes for the provision of sewage infrastructure in the area. The plant has always existed on this site, and essentially a buffer area between the existing plant and adjoining residences including the former caretaker's cottage. The proposal will not be substantially altering the historic purpose of the site.

O21 Considers that the proposal does not meet the planning scheme requirements in relation to design and visual impact.


Representation 6 states that "... the proposal is not supported by sufficient information to allow a proper assessment under these criteria [Design standards under P1 and P4]. TasWater has provided further information to Council to further demonstrate the visual impact of the proposed works.

As outlined in the DPEMP, the existing plant is surrounded by native vegetation to the north, east and south. The proposed upgrade works will result in an expansion of the footprint to the west. This area is largely cleared and contains lesser environmental values as compared to other areas on the site. Although some vegetation clearance is unavoidable this will be mitigated in accordance with the EPA requirements, and is also consistent with Council's offset policy, through landscaping and replanting.

The information provided is assessed to be adequate to demonstrate compliance with the applicable scheme standards in terms of design and therefore the objective "To ensure that the location and appearance of

buildings and works minimises adverse impact on natural values and on the landscape" is met.

O22 The proposed location of infrastructure will affect visual amenity.


The design has been specifically cut into the slope to minimise visual amenity and landscaping has been designed to also reduce any visual impact.

O23 Potential impacts on coastal landscape of Blackmans Bay.


O24 Concerned that hard rock will result in a change in design and increase elevation of infrastructure.


The infrastructure will be constructed to the levels shown in the DPEMP.

O25 Raises concerns of multiple persons in relation to visual impacts and property devaluation.


The design has been specifically cut into the slope to minimise visual amenity and landscaping has been designed to also reduce any visual impact. The new plant has been designed to reduce odours and noise which are currently impacting potential value of properties.

O26 Consider there is insufficient information provided to consider visual impacts and natural landscape qualities of the area.


See responses above.

O27 The DPEMP proposes grab sampling of effluent, however composite sampling is considered more appropriate for this STP.

Confirm use of composite sampling in the proposed monitoring program.


O28 Concerned upgrade will affect value of surrounding properties.


The new plant has been designed to reduce odours and noise which are currently impacting potential value of properties. The design has been specifically cut into the slope to minimise visual amenity and landscaping has been designed to also reduce any visual impact.

O29 Makes reference to the proposed location of the ‘Margate Pipeline’.

The pipeline does not form part of the application to which the Board’s assessment relates.

O30 Want to know who is responsible for resealing of Treatment Plant Road.


TasWater is responsible for repairing any damage that may occur as a result of any construction work.

O31 Want Council and TasWater to consider a playground adjoining the plant.
