Standard Operating Procedure - ntepa.nt.gov.au · The ECM is accountable for planning and conducting regular internal audits, reporting to the Project Management Team on outcomes

ES-SOP-52 Active Discharge Management – Howley Creek

Revision 5 Revision Date:20/01/2018 Printed on: 8‐Dec‐17 Page 1 of 30

Once Printed, this is an ‘Uncontrolled’ Document

Standard Operating Procedure

ES‐SOP‐52

Active Discharge Management

Howley Creek

Environment Department

Revision Prepared Reviewed Approved Date Description Next Revision:

0 S.Barber 29/10/2015 Draft

1 S.Barber 22/11/2015 Draft

2 S.Barber 03/12/2015 Final

3 S.Barber P.McHugh P.McHugh 19/01/2016 Final

4 S.Barber 18/08/2016 Final

5 S.Barber L. Kerr/

S.Pearson P.McHugh 01/12/2016 Final

6 S. Barber L. Kerr 06/01/2016 Draft

7 S. Barber L. Kerr P.McHugh 20/01/2017 Final

8 S. Barber L. Kerr 20/03/2017 Added new

formula

9 S. Barber Y. Lim P McHugh 23/08/2017

Updated Creek 6

Rating Table and Curve

10 S Yang P McHugh P McHugh 07/12/17

Incorporated Pulse

Discharge Management

Plan




Context: The key documents relating to water management at the NTMO Cosmo Howley Project Area, active

discharge to the Howley Creek System, include the final but currently un-approved; and current:

Mine Management Plan and associated the Water Management Plan; and

WDL180-04 – Cosmo Howley and Brocks Creek Project Area (Commencing 6 January 2017 and expiring 30 September 2017);

“The licensee must as soon as practicable and in any case within 24 hours notify the NT EPA in writing by emailing [email protected] when an exceedance of three times the SSTVs at monitoring point CHCK06. Records for each sample required to be collected by this licence must be retained”. (NT EPA, WDL 180-03, pg 9)

WDL 180-03 provides the following qualitative discharge limits:

“Waste water(s) discharged from the authorised discharge points must not:

Contain any visible matter, floating oil and grease or petroleum hydrocarbon sheen, or litter or other objectionable floating matter;

Cause or generate odours which would adversely affect the use of the surrounding waters;

Cause algal blooms;

Cause visible change in the behaviour of fish or other aquatic organisms;

Cause mortality of fish or other aquatic organisms;

Cause adverse impacts on plants; or

Cause adverse impacts on drinking water supplies.

WDL180-03 also specifies that the operator adheres to the legislative requirements of the BUD (section 73 of the Act) and Environmental Protection Objectives (Part 4 of the WMPCA).

An Environment Protection Objective (EPO) is a statutory instrument to establish principles on which:

a) environmental quality is to be maintained, enhanced, managed or protected;

b) pollution, or environmental harm resulting from pollution, is to be assessed, prevented, reduced, controlled, rectified or cleaned up; and

c.) effective water management is to be implemented or evaluated.

Applicable legislation includes:

• Mining Management Act;

• Environmental Offences and Penalties Act;

• National Environment Protection Council (Northern Territory) Act 1994;

• Soil Conservation and Land Utilisation Act 1985 (NT);

• Waste Management and Pollution Control Act; and

• Water Act 1982 (NT).




Purpose: To ensure active discharge is managed at the Cosmo Howley Project Area to prevent

environmental harm and ensure appropriate actions are taken to manage significant rainfall events; maintain compliance; and incidents are identified and reported as soon as practicable.

Scope: This procedure covers active discharge management at the CHPA for the receiving Howley Creek.




Glossary:

Analyte

A substance or chemical constituent that is determined in an analytical procedure.

Mm Millimetres

BCPA Brocks Creek Project Area NT EPA Northern Territory Environmental Protection Authority

BoM Bureau of Meteorology SSTV Site Specific Trigger Values

CHPA Cosmo Howley Project Area

Treatment Water Water treated with 50% Caustic Soda (C50)

DO Dissolved oxygen Yr Year

DPIR

Department of Primary Industry and Resources (Previously Department of Mines and Energy)

QA/QC Quality Assurance / Quality Control

EC Electrical conductivity CHCK01 Upstream Howley Creek (Creek 1)

Freeboard

The vertical distance between the top of the dam and the full supply level on the reservoir

CHCK06 Downstream Howley Creek (Creek 6)

pH Measurement of acidity of a liquid.

m3/s Cubic meters per second (Cumecs)




Role/Title Responsibilities

General Manager (GM) Accountable for any communications with Regulators.

Review of Incident Notifications and Incident Investigations to be sent to DPIR, NTEPA or any other external stakeholders.

Determining if the DPIR or any other stakeholders should be notified of a negative trend or anomaly, that doesn’t constitute a statutory breach.

Ensure sufficient resources are available to managers for adequate environmental protection measures.

Site (Mine) Manager (SM) Accountable for management of environmental hazards and incidents (including response, notification and monitoring) in their area.

Review of Incident Notifications and Incident Investigations to be sent to DPIR, NT EPA or any other external stakeholders.

Implementing actions to prevent incidents occurring in their respective areas.

Determining if the DPIR or any other stakeholders should be notified of a negative trend or anomaly, that doesn’t constitute a statutory breach.

Delegate authority to team members so that individual responsibilities regarding environmental protection and compliance are upheld throughout the organizational structure;

Delegate authority (when necessary) to stop work and/or order the implementation of control measures as advised by the Environmental representative or a relevant authority representative (e.g. NT EPA);

Ensure sufficient resources are available to staff for the implementation of environmental protection measures.

Environment and Community Manager (ECM)

The Environment and Community Manager (ECM) provides effective, practical advice to the Management Team and Project staff on Occupational Health and Safety and Environmental requirements including compliance with relevant legislation, standards and guidelines. The ECM is accountable for planning and conducting regular internal audits, reporting to the Project Management Team on outcomes and improvements required. The ECM also ensures the effective implementation and on-going review of the Environmental Management System (EMS) across all areas of the Project and is responsible for coordinating the effective maintenance of all Projects’ environmental management program. The ECM will:

Ensure that all personnel and visitors are inducted and trained in their roles and responsibilities and are competent to perform the duties allocated to them;

Identify the environmental risks associated with certain work practices,




assess risks and collaborate with the SM to develop work methods that will minimize, eliminate or control these risks;

Liaise with subcontractors to ensure their activities are compliant with performance indicators that they are aware of the BCPA and CHPA water management process.

Delegate instructions and supervision for control measures to relevant staff members;

Ensure Water Management Plans are developed and valid as per conditions of Environmental Approval;

Coordinate with SM and Maintenance Superintendent (MS) on corrective actions taken to protect creeks from pollution and provide updates on managing actions taken within disturbed areas;

Ensure that task-specific environmental training methods (toolbox talks) are developed and delivered prior to environmentally sensitive work;

Review of Incident Notifications and Incident Investigations to be sent to DPIR, NTEPA or any other external stakeholders.

Meeting the legislated commitments made in the License and Water Management Plan regarding downstream and discharge water quality.

Determining if the DPIR, EPA or any other stakeholders should be notified of a negative trend or anomaly, that doesn’t constitute a statutory breach.

Incident investigation leader for those involving statutory breaches.

Drafting and releasing (following approval from GM and review from MS and SM) Incident Notifications and Incident Investigations to DPIR and any other relevant external stakeholders.

Holding discussions with DPIR and NT EPA regarding any incidents.

Incident investigation leader for those involving statutory breaches.

Implementation and regular review of the Active Discharge Management Procedure.

Audit the water management action plan; and Evaluate and monitor effectiveness of water treatment measures as well as water quality trigger values throughout the work site.

Ensure regular site inspections of site activities have been carried out and audits results to recommend improvements and correct dewatering related non-compliances;




Maintenance Superintendent (MS)

The Maintenance Superintendent (MS) is accountable for the efficient and effective coordination of field de-watering operations and maintenance of equipment. The MS ensures that risk-reduction controls are in place and regularly reviewed for safety, environmental and quality aspects of the Project. With regards to water management:

Ensure personnel are fully briefed on the relevant environmental management requirements prior to work commencing;

Direct construction works in a planned and regulated manner that avoids or minimizes impacts related to dewatering;

Ensure mine site personnel conduct works in accordance with statutory and approval requirements;

Co-ordinate and ensure toolbox talks are delivered;

Undertake actions in response to complaints in consultation with the ECM and Company;

Ensure water management procedures are implemented as advised by the ECM or Environmental Advisors;

Ensure that all environmental (and other) incidents are reported to the ECM as soon as practical; and

Stop work and report to the SM immediately if situations arise that are outside the scope or not covered by Safe Work Method Statements (SWMS).

Maintenance / Dewatering Department

Responsible for conducting inspections of the water management system infrastructure (including contingencies) before and after significant rainfall events, during discharge and water transfer.

Providing early notification to the Environmental Department if any water management issues arise;

Informing the MS, ECM and Environmental Department if there have been any overflows, seepage or spills.

Oversee and ensure the timely progress of the field dewatering operations;

Ensure all personnel are adequately supervised and ensure the competence of each individual engaged in the operation;

Ensure that all activities associated with the operations are undertaken in accordance with the requirements of this plan and are undertaken with due regard to the approved Water Management Plan (WMP), Waste Discharge Licence (WDL) and general working practices;

Responsible for complying with requirements that minimize potential risks due to work activities, and the installation and maintenance of dewatering equipment.




Environmental Officer (EO) Undertake and adhere to discharge monitoring programs outlined in WDL and WMP.

Daily monitoring and recording of site rainfall data;

Daily monitor Creek Gauging Stations;

Development, implementation and regular review of the Active Discharge Procedure;

Advising the de-watering department of decision to release water into the environment, including flow rate, timing/duration;

Providing support to the ECM

Retain a copy of the Waste Discharge Licence on-site for reference by appropriate personnel and provide a copy to contractors and sub-contractors;

Ensure compliance with the approved WMP and WDL;

Ensure that the required monitoring programs are implemented;

Ensure that daily monitoring programme checklist is up to date and recorded;

Ensure that appropriate records are kept and maintained;

Incident reports, investigations and implement corrective actions;

Recommend additions or changes to the water management based on site experience gained from past and continuous improvement;

Verify that the requirements of the Environmental Systems Standard Operating Procedures (SOP’s), plans, and actions resulting from Environmental audits on the project are fully carried out in accordance with the project requirements;

Ensure, through liaison with SM, MS and Specialised subcontractor that the water management plan is reflective of procedures implemented;

Promoting environmental awareness and socialization related with waste management amongst the workforce;

Inspect on site dewatering infrastructure;

Regular assessment of Howley Creek gauging station flows in relation to required dilution for discharges.

Hydrology Officer Inclusive to the responsibilities of the EO, as well as:

Design the mine site hydrology network and hydraulic structures;




Monitor the dewatering activities;

Supervise the as-built survey of the installed dewatering infrastructures;

Perform hydrology analysis across NTMO sites;

Provide advice to the SM, MS, ECM on proper implementation of water management related measures.

Ensure that water management records are managed.

Regular monitoring and recording of sites flow meters and discharge/transfer volumes;

Water level measurements as per WMP and Surface water monitoring program and discharge plan;

Regularly update site water balance.

Hazards Controls:

Sprains and Strains Appropriate lifting techniques.

Appropriate footwear.

Steep bank edges Take 5, anchor points and ropes

Exposure to climate Ensure fluids are readily available.

Hat and sunscreen.

Animal bite/attack Wear gloves.

Ensure first aid kit is available in vehicle as per Vehicle prestart requirements.

Working alone Radio contact, Spot messenger, Satellite phone, notification of whereabouts.

Exposure to contaminants Disposable nitrile, powder free gloves should be worn during sampling activities to protect skin against potential contaminants and QA/QC.

Precautions:

Crocodile safety required at creek sites and all water storage infrastructure. No discharge during dry season Recessional flows are highly variable; apply caution during interpretation of flow rates.




Pre task requirements:

Review weather forecasts and telemetry data;

Sampling conducted in accordance with WMP prior discharge.

PPE and equipment required:

Long sleeved shirt and long pants

Gloves

Safety glasses

Lace up steel cap boots

Satellite Phone

First aid kit

Sun protection

Sample Bottles & Esky with ice block.

Two Way Radio

Permanent Maker

Pen

Sampling field sheets

Spot messenger

Method of Work – Active Discharge during Wet Season

No. Stage/Task Comments and photos

1 Check the rain gauge at Brocks Creek, CHCK01 and CHCK05. Enter the total amount for the hour (eg. 12:01 – 13:00 is entered in the 13:00 log) for each site (Column M to Column O) to the corresponding hour and date in SOP 52.

Combined rainfall data (Column P) is a formula and should automatically update. If it does not, copy and paste the previous formula.

The tipping bucket rainfall data (BCPA, CHCK01, CHCK05) can be checked by logging onto the telemetry gauging station for each gauge location (BCPA- office complex, CHCK01, CHCK05)

https://data.envirotechmonitoring.com.au/Login.aspx

Record 0900 daily rainfall into the rainfall section in InViron.

http://inviron.perseverance.com.au/Inviron.aspx#/Data/DataBrowser

2 Check the flow rate at CHCK06 through the telemetry data and enter average hour flow in column Q of the log to the corresponding date and time (Attachment 1).







3 Check the electrical conductivity at CHCK06 through the telemetry data and enter average hour electrical conductivity.

If there is no discharge, then enter the hourly average EC at CHCK06 to column R (Pump off EC) for the corresponding date and time.

If there is discharge occurring, then enter the hourly average EC at CHCK06 to column S (Pump on EC) for the corresponding date and time.


4 Check the daily EC field data reading for HWP from the daily checks and enter value (Column T) to the corresponding date and time

Note: There is only one reading taken daily at HWP and the EC value taken is assumed to be the EC at HWP for that day (From 00:00-24:00).

As per Howely West Pit Treatment and Discharge Monitoring Program revised MMP August 2016.

5 Repeat steps 1-4 for a whole shift (6 hours)

6 At the completion of data entry for the hour, the operator will need to determine if the pump needs to be turned on, increase/decrease pumping rate (if it is running), or turned off based on the outcome of

See step 7 for pump on procedure

See step 8 for increasing/decreasing pump rate procedure

See step 9 for pump off procedure.






the spreadsheet.

7 To determine if discharge is possible, check that the flow at CHCK06 is bigger than 0.1 cumecs (Column Q), the calculated dilution EC is less than 500 us/cm (Column G), the pump on EC is less than 650 us/cm (column S), and the maximum pump rate is greater than 50 L/sec (Column I).

If these conditions are met, then discharge at flow close to the value shown in Maximum Pump (Column I).

Update Log page including date/time, shift number, notes/decisions, rate of pumping

The pump rate value is a maximum pump rate. The pump rate must be maintained on or below the maximum pump rate.

8 If pumping has already occurred, check the updated maximum pump (Column I) and adjust accordingly.

Update Log page including date/time, shift number, notes/decisions, new rate of pumping of analysis.

SOP52 Log

Note: If discharge pumps has been on for 12 hours, add the following to column W to the 13th discharge hour row. This will provide an Estimated Pump Off EC.

=((Q(13th hour discharge row)*S(13th hour discharge row)-((V(8 hours prior row) /1000)*T(13th hour discharge row))/(Q(13th hour discharge row -(V(8 hours prior row)/1000))

Do this for every hour after 12 hours of pumping until the pump needs to be turned off.

9 The pumps will need to be turned off if any of the following conditions occur:

CHCK06 flow is less than 0.1 cumecs






(Column Q) Calc Dilution EC is

greater than 500 (Column G)

Maximum pump rate less than 50 L/Sec

Pump On EC is greater than 650 µs/cm.

10 If creek flows are acceptable for discharge (calculated height), conduct surface water monitoring required for discharge.

As per Howely West Pit Treatment and Discharge Monitoring Program revised MMP August 2016.

11 If creek flows are acceptable for discharge (calculated height), Notify the DPIR of commencement of discharge.

Email notification to be made of commencement of discharge to;

[email protected]

Pollution NTEPA ([email protected])

Advised on commencement and cessation of discharge. Notification to including the current creek height and calculated discharge ratio.

12 Issue environmental advice memo and follow up with a verbal notification that discharge has commenced.

G:\NTMO Environmental Management System\4. Communication and consultation\2. Environmental Advice

13 Turn on dosing rig Turn key on at the dosing rig. The dosing rig needs to be running whenever water is pumped in or out of HW Pit to record sensor data. When pumping out of HW Pit but not pumping in then the dose rig screen will be running but the dose pumps will not be required to operate.






Treatment Plant – Switches on RHS of rig.

14 Access CITEC to control pumps/ pumping rate.

HW Pit discharge pipeline manifold






HW Pit Discharge Pipeline Flow meter

15 Download Treatment Plant Data

Whilst treating and/or discharging treated water, download the treatment plant data. On the PLC screen, unscrew cover to USB port, insert USB stick, click download on PLC screen. Remove USB when it says complete. Download daily and update spreadsheet daily. View data to assess for any anomalies.

G:\NTMO Environmental Management System\5. Operational Control\1. Operational Sites\Cosmo Howley\19. Surface Water\1. Discharge Management






Dosing Rig PLC Screen – Download Data

16 HW Pit Water Levels During Treatment, monitor HW Pit water levels. Maximum Operating Level (MOL) of HW Pit is 1117.9m. Daily water levels during discharge.

17 Daily – update the weekly DPIR/NTEPA water quality notification report.


Weekly Reports to include all flow records, creek height and calculated discharge ratio.

Email to Environmental Manager or Senior Environmental Advisor for submission to ;

[email protected]

Pollution NTEPA ([email protected])

18 Daily record the discharge volume/pump flows (L/s flow and ML/day) and record discharge activities.



19 Check Envirolab results as soon as they come in. Update in InViron and weekly DPIR/NTEPA water quality notification report.

Particular attention at Creek 6 water quality. Compare dissolved metals and against SSTV’s as per WDL and approved DPIR WMP.

20 Maintenance/de-watering department carries out inspections of key water management system infrastructure focusing on (ranked in order of priority):

Areas to focus on during inspections:

Are the pumps operational; Is the pipe work in sound condition; Are there any leaks/spills observed; Are the pumps transferring at their design rate; Are the contingencies in place and ready to operate in case

of an emergency?






Identified maintenance issues will be entered into Pronto as a work request to be actioned.

Attachment 1 Creek 6 Rating Table

Attachment 2 Creek 6 Rating Curve

Attachment 3 SOP Log 52 Inputs

Attachment 4. Surface Water Quality Management Actions and Reporting Requirements




Method of Work – Pulse Discharge


1 Check the rain gauge at Brocks Creek, CHCK01 and CHCK05. Enter the previous 24 hours of rainfall in the Pulse Discharge Control (PDC) sheet.

Enter the forecast rain for the following 3 days in the PDC sheet.

2 Check the flow rate at CHCK06 through the telemetry data record in the PDC sheet

3 Complete daily inspections of water management infrastructure and record water level for Dams 3, 2, and 7 and Howley West pit in the PDC sheet.

4 Check the daily EC and pH field data reading for HWP and Dam 3 from the daily checks and enter value to the PDC sheet against starting value.

Note: There is only one set of field readings taken daily at HWP and Dam 3 and the values taken are assumed to be for that day (From 00:00-24:00).

Additional field data to be recorded from telemetered gauging station at CHCK05 every 6 hours.

Recorded values to be entered into the PDC sheet.

5 Check caustic levels in the Dam 3 polishing dose rig supply tank and verify that it is operating at the required dose rate.

Note: Operational status checks to be included in daily checks.

6 Complete water sampling for Howley West, Dams 2, 7, and 3, Creek 5 discharge outlet, Dam 3 siphon outlet, Creek 5 downstream (CHCK05), and Creek 6 (CHCK06).

Samples are to be dispatched for analysis with a fast turn around time.

7 Upon receipt of approval to commence from the E&C Manager commence the Pulse

Email notification of commencement of discharge to be sent to:

NT EPA






Discharge at 18:00. [email protected]

Department of Primary Industry and Resources

[email protected]

Advised on commencement and cessation of discharge. Notification to including the start time, current creek height, calculated discharge rate, and field parameters.

8 Activate pumps in Howley West pit in accordance with supplier’s operational manual.

Howley West Pumps to be set to discharge @ 1,200 L/s.

9 Ensure that caustic dosing rig is operating at maximum rate.

Verify caustic levels in tanks will sustain production at maximum rate. Contact supplier to provide forecast of consumption and establish order date.

10 Open Dam 3 siphon bank. All siphons to be open.

11 Open siphons at Dams 2 and 7. All siphons to be open.



Notification of commencement of discharge to be made



14 Daily check of the dam and pit water levels.

During discharge, monitor HW Pit and Dam 3 water levels. Daily water levels during discharge






15 Daily – update the weekly DPIR/NT EPA water quality notification report.


Weekly Reports to include all field water quality measurements, flow records, creek height and calculated total discharge rate.

Email to Environmental Manager or Senior Environmental Advisor for submission to :

NT EPA

[email protected]

Department of Primary Industry and Resources

[email protected]

16 Daily record the discharge volume/pump and siphon flows (L/s flow and ML/day) and record discharge activities.



17 Maintenance/de-watering department carries out inspections of key water management system infrastructure focusing on (ranked in order of priority):

Areas to focus on during inspections:

Are the pumps operational; Is the pipe work in sound condition; Are there any leaks/spills observed; Are the pumps transferring at their design rate; Are the contingencies in place and ready to operate in

case of an emergency?

Identified maintenance issues will be entered into Pronto as a work request to be actioned.

18 Pulse discharge from all outlets to cease at 06:00 on Day 4.






19 Shut down HW Pumps, and close dam 3 siphons.

Continue siphoning of water into Dam 3 from Dams 2 and 7. Transfer of treated water to Dam 2 from Chinese 2 pit and Mottrams pit to continue at maximum rate to replenish treated water inventory.

Water treatment from Howley to HW Pit to continue at maximum rate to replenish treated water inventory.

20 Complete water sampling for Howley West, Dams 2, 7, and 3, Creek 5 discharge outlet, Dam 3 siphon outlet, Creek 5 downstream (CHCK05), and Creek 6 (CHCK06).

Samples are to be dispatched for analysis with a fast turn around time.

21 Complete sediment sampling for CHCK05 and CHCK06.

References & Links to Associated Documents # Description

1 CHPA WMP August 2016

2 WDL 180-05

3 ES-SOP01 Surface water sampling

4 ES-SOP03 Water sampling packaging and delivery

5 Berry.K (2016). Management of Active Discharge of Treated Waste Water to Howley Creek

6 SOP52 Log

7 Pulse Discharge Control Log




Attachment 1 – Creek 6 Rating Table Note: This rating table has been adopted on 22nd August 2017. Table figures have been provided by EnviroTech Monitoring in

‘2017 Monitoring Station Stream Rating Review’. As a single flow value (average/upper/lower) does not clearly represent the

creek system. Through the use of multiple values based on the state of the creek – stable/increasing/decreasing – advantages

can be taken such as: maximising potential discharge, reducing exceedances and refining control of the system through

greater understanding.

The base rules to be applied are:

Falling Trend: Lower Q

o Due to lower flow speeds despite higher gauge heights compared to rising flows (see Rating Curve

(Attachment 2)).

Stable Trend: Average Q

Rising Trend: Upper Q

Values have been calculated from raw data collected from each respective Telemetry station over the 2016‐2017 wet season.




Gauge

Height Average Q (m3/s) Lower Q (m3/s) Upper Q (m3/s) Range (m3/s) % Variance from mean

(%)

0.14 0 0 0 0

0.2 0.014

Existing Rating

<20%

0.3 0.030

0.4 0.068

0.5 0.138

0.6 0.270 0.203 0.336 0.133 24.7

0.7 0.475 0.369 0.581 0.212 22.3

0.8 0.724 0.582 0.865 0.283 19.6

0.9 0.966 0.700 1.23 0.531 27.5

1 1.44 0.869 2.00 1.13 39.4

1.1 1.75 1.12 2.38 1.27 36.2

1.2 2.19 1.50 2.88 1.38 31.6

1.3 2.75 1.96 3.55 1.59 28.8

1.4 3.29 2.70 3.89 1.19 18.0

1.5 4.04 3.35 4.74 1.38 17.1

1.6 4.48 3.66 5.30 1.64 18.3

1.7 5.01 4.19 5.83 1.64 16.3

1.8 5.42 4.50 6.34 1.84 17.0

1.9 5.81 4.67 6.95 2.28 19.6

2 6.17 4.84 7.50 2.66 21.6

2.1 6.37 4.90 7.83 2.93 23.0

2.2 6.56 4.92 8.20 3.28 25.0

2.3 6.66 4.75 8.58 3.83 28.7

2.4 6.88 4.87 8.90 4.03 29.3

2.5 7.20 5.00 9.40 4.40 30.6

2.6 7.46 5.33 9.60 4.27 28.6




2.7 7.80 5.70 9.90 4.20 26.9

2.8 8.08 5.96 10.20 4.25 26.3

2.9 8.40 6.30 10.50 4.20 25.0

3 8.71 6.51 10.90 4.39 25.2

3.1 9.10 6.91 11.30 4.40 24.1

3.2 9.55 7.30 11.80 4.50 23.6

3.3 10.23 7.85 12.60 4.75 23.2

3.4 10.75 8.30 13.20 4.90 22.8

3.5 11.43 8.95 13.90 4.95 21.6

3.6 12.15 9.50 14.80 5.30 21.8

3.7 13.23 10.20 16.27 6.07 22.9

3.8 14.29 11.14 17.44 6.30 22.1

3.9 15.67 12.22 19.11 6.89 22.0

4 17.55 14.15 20.95 6.79 19.4

4.1 19.88 15.32 24.45 9.12 22.9

4.2 21.35 16.40 26.30 9.90 23.2

4.3 22.35 17.40 27.31 9.91 22.2

4.4 23.30 18.00 28.60 10.60 22.7

4.5 24.54 18.56 30.52 11.96 24.4

4.6 25.67 19.20 32.14 12.94 25.2

4.7 27.09 19.97 34.22 14.26 26.3

4.8 28.50 21.00 36.00 15.00 26.3




Table Usage Notes:

Annual onsite flow measurements must be conducted to maintain table accuracy and validity to current conditions. This will be achieved in consultation with EnviroTech Monitoring and field validated during the wet season annually;

New tables are released where onsite measurements define accuracy or relationship changes. Ensure at all time the correct table version and period of applicability when utilising the table. The most recent tables will be incorporated into the sites discharge SOP;

Table can be considered out of date if onsite flow measurements are not conducted for > 12 months.




Attachment 2. Creek 6 Rating Curve

Attachment 3 Newmarket Gold SOP52 Log inputs

Runoff

Coeffici

ent

Season

total

(mm)

Catchment

storage

(mm)

Wet

catchment

(1/0)

Calc CHCK06

flow

(cummces)

Rising

Level

(1/0)

Catch‐

ment

Sulphate

Dilution

Factor

Calc. Pump

(L/sec)

Shift

Rainfall

(mm)

Average

rainfall

(mm)

CHCK06

flow

(cumecs)

PUMP OFF

EC (us/cm)

PUMP ON

EC (us/cm)

HWP EC

(uS/cm)

Max

Shift EC

(uS/cm)

Catchme

nt EC

(uS/cm)

Status Pump

Rate

(L/sec)

RC PS S C Qcalc T CS D Acalc P6 P1 Q1 E1OFF E1ON HEC EMAX CEC (ON/OFF A

CALCULATIONS/HYDROLOGICAL CONTROLS DateTime

(Hour End )

Shift CONTROLSRAW SHIFT INPUTS




Attachment 4 – Surface Water Quality Management Actions and Reporting Requirements

ACTION LEVEL

Water Quality Trigger Values

CHCK06 - SSTVs as per current WDL Corrective Action

Internal Reporting Requirements

External Reporting Requirements

1 Exceedances of default or SSTV pH, EC and DO values at CHCK06 using the 7 day rolling median results based on 24 hour medians.

Record exceedance and assign severity classification as per Section 29*

Investigation following ANZECC (2000) procedures

Report to NTMO EC Manager

Formal notification to DPIR and EPA if required

2

Exceedances of default or SSTV values at CHCK06 for metals (and other analytes with SSTVs or default values) by 25% of the SSTV or default values, on three sampling occasions (noting that the second and third samples will be analysed and the results received within 4 days with a 24 hour lab turnaround time). Therefore, any exceedance time will be limited to approx.one week.

Record exceedance and assign severity classification as per Section 29*

Resample within 24 hours of receipt of laboratory report to confirm result.

Investigate source of toxicants

following ANZECC (2000) procedures

Internal response required to assess active discharges.

Manage through routine

Report to NTMO

EC Manager and Maintenance Superintendent.

Notify EPA and DPIR within 24 hours.

If NTMO do not consider this a reportable incident, provide justification to DPIR and EPA. Further consultation with DPIR & EPA may be required




ACTION LEVEL





procedures.

Exceedances of 3 times the default or SSTV value at CHCK06 on three or more sampling occasions & thereafter subsequent consecutive exceedances.

Cease active wastewater discharge. Internal response required to assess active discharges.

Complete risk assessment to determine severity classification as per Section 29*.

Investigation source of toxicants following ANZECC Guidelines

Manage through routine procedures

Report to NTMO

Environmental Superintendent, Maintenance Superintendent and General Manager.

Notify EPA and DPIR within 24 hours.

If NTMO do not consider this a reportable incident, provide justification to DPIR and EPA. Further consultation with DPIR & EPA may be required

3 - Outside ANZECC Stock Water Guidelines (SWG) at CHCK06.

- Unauthorised discharge, loss of previously

Immediately cease active wastewater discharge. Required to rectify within

Event/Hazard/Incident/Injury Report to be completed.

Report to NTMO

Notify and report within 24 hours as an incident to EPA and DPIR. Following WDL and DPIR Section 29




ACTION LEVEL





contained waste water. Poor management of discharge.

- Non-compliance with WDL.

- Potential or actual environmental harm or pollution.

compliance ASAP.

Complete risk assessment to determine severity classification as per Section 29*.

Follow up Investigation.

Management team. requirements

*DPIR Draft Guideline ‘Environmental incident reporting under Section 29 of the Mining Management Act’ ** Uncertainty of measurement can be up to 20% for some laboratory analytical protocols. A minor exceedance may not be an accurate recording of the concentration. Applying a factor of 25% to the SSTV or default value, takes into account laboratory or sampling errors and removes unnecessary reporting when risk to the environment is low.




OPERATING PROCEDURE ACKNOWLEDGEMENT

This is to certify that I have read the instruction in:

Northern Territory Mining Operation (NTMO) Standard Operating Procedure

ES-SOP-52

Active Discharge Management – Howley Creek

I have read, understood and agree to abide by all of the site rules, regulations and practices.

I understand that failure to comply with these rules, regulations and practices may result in serious disciplinary action.

I acknowledge that a copy of this procedure is available to me.

Employee Name: Signature:

Employee Company: Date

Once completed this form is to be forwarded to the Relevant Department Manager.