R J Hill Laboratories Limited 28 Duke Street Frankton 3204 Private Bag 3205 Hamilton 3240 New Zealand 0508 HILL LAB (44 555 22) +64 7 858 2000 [email protected] www.hill-laboratories.com T T E W This Laboratory is accredited by International Accreditation New Zealand (IANZ), which represents New Zealand in the International Laboratory Accreditation Cooperation (ILAC). Through the ILAC Mutual Recognition Arrangement (ILAC-MRA) this accreditation is internationally recognised. The tests reported herein have been performed in accordance with the terms of accreditation, with the exception of tests marked * or any comments and interpretations, which are not accredited. Certificate of Analysis Page 1 of 2 Client: Contact: Mark Burroughs C/- Oceana Gold (New Zealand) Limited PO Box 190 Waihi 3610 Oceana Gold (New Zealand) Limited Lab No: Date Received: Date Reported: Quote No: Order No: Client Reference: Submitted By: 2867192 12-Feb-2022 21-Feb-2022 87181 70057893 Reduced suite Jake Horne SPv1 Sample Type: Aqueous Sample Name: Lab Number: 1839306 11-Feb-2022 10:00 am 1839307 11-Feb-2022 10:40 am 2867192.1 2867192.2 2867192.3 1839308 11-Feb-2022 11:15 am Individual Tests pH Units 1.8 2.0 2.4 - - pH g/m3 as CaCO3 3,800 6,900 2,700 - - Acidity (pH 3.7) g/m3 as CaCO3 < 1.0 < 1.0 < 1.0 - - Total Alkalinity mS/m 798 1,018 811 - - Electrical Conductivity (EC) g/m3 < 0.00015 < 0.00015 < 0.00015 - - Dissolved Mercury g/m3 4,200 11,500 8,500 - - Sulphate Heavy metals, dissolved, trace As,Cd,Cr,Cu,Ni,Pb,Zn g/m3 50 117 30 - - Dissolved Arsenic g/m3 0.0053 0.038 0.0150 - - Dissolved Cadmium g/m3 0.35 0.80 0.26 - - Dissolved Chromium g/m3 1.25 4.8 12.5 - - Dissolved Copper g/m3 0.0006 0.0013 < 0.0005 - - Dissolved Lead g/m3 0.081 0.61 1.62 - - Dissolved Nickel g/m3 7.2 39 7.9 - - Dissolved Zinc The following table(s) gives a brief description of the methods used to conduct the analyses for this job. The detection limits given below are those attainable in a relatively simple matrix. Detection limits may be higher for individual samples should insufficient sample be available, or if the matrix requires that dilutions be performed during analysis. A detection limit range indicates the lowest and highest detection limits in the associated suite of analytes. A full listing of compounds and detection limits are available from the laboratory upon request. Unless otherwise indicated, analyses were performed at Hill Laboratories, 28 Duke Street, Frankton, Hamilton 3204. Summary of Methods Sample Type: Aqueous Test Method Description Default Detection Limit Sample No 1-3 Heavy metals, dissolved, trace As,Cd,Cr,Cu,Ni,Pb,Zn 0.45µm Filtration, ICP-MS, trace level. APHA 3125 B 23rd ed. 2017. 0.00005 - 0.0010 g/m3 1-3 Filtration, Unpreserved Sample filtration through 0.45µm membrane filter. - 1-3 pH pH meter. APHA 4500-H+ B 23rd ed. 2017. Note: It is not possible to achieve the APHA Maximum Storage Recommendation for this test (15 min) when samples are analysed upon receipt at the laboratory, and not in the field. Samples and Standards are analysed at an equivalent laboratory temperature (typically 18 to 22 °C). Temperature compensation is used. 0.1 pH Units 1-3 Acidity (pH 3.7) Titration to pH 3.7 with standard sodium hydroxide solution, bromophenol blue indicator. APHA 2310 B 23rd ed. 2017. 1.0 g/m3 as CaCO3 1-3 Total Alkalinity Titration to pH 4.5 (M-alkalinity), autotitrator. APHA 2320 B (modified for Alkalinity <20) 23rd ed. 2017. 1.0 g/m3 as CaCO3 1-3 Electrical Conductivity (EC) Conductivity meter, 25°C. APHA 2510 B 23rd ed. 2017. 0.1 mS/m 1-3 Dissolved Mercury 0.45µm f iltration, bromine oxidation followed by atomic fluorescence. US EPA Method 245.7, Feb 2005. 0.00008 g/m3 1-3 Sulphate Filtered sample. Ion Chromatography. APHA 4110 B (modified) 23rd ed. 2017. 0.5 g/m3
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