Water quality characterization of the Pebble prospect area in Southwestern Alaska Comparison of PLP and independent science team scope, methods, and results Kendra Zamzow, PhD Center for Science in Public Participation, Chickaloon, AK WAISC, Dillingham, AK March 2012

Site location

Independent team: what, why Stream sampling field chemistry (oxygen, pH, temperature) Analytical chemistry Metals, ions, cyanide, radioactivity, etc discharge Why Potentially impacted region extends beyond the claims of the Pebble Limited Partnership (PLP) Some rivers had no baseline water quality data PLP data is in pdf table format, limiting review options * Note Jamie’s hydrographs showed 2009 had the biggest spring melt of any year 2004-2010; this affects the chemistry The independent study was funded by the Nature Conservancy

Scope: geographic area 44 stream sites Nondalton 31 stream sites Iliamna Nondalton PLP Iliamna PLP EBD section 9.1.4, 9.2.3, Figure 9.1-2, 9.2-1 TNC TNC report Table 1, Figure 2

Sampling methods TNC PLP Field data and lab analytical data May 2009, June 2009, June 2010 Field data and lab analytical data Monthly 2004-2008 Composite samples across the stream (DH-48, DH-81) Filter at the end of the day Peristaltic pump disposable tubing and filters Filter on the bank (accurate representation of dissolved and “total” metals)

Sampling methods TNC PLP Triplicates or quadruplicates QA/QC Triplicates or quadruplicates 100%-20% of the sites Trip blanks Equipment blanks Temperature blanks Duplicates and triplicates 14% of the sites No information on trip blanks equipment blanks temperature blanks

Data Presentation

Results - Field parameters (TNC) Analyte May 2009 June 2009 June 2010 Temperature (C) 0-15 (1.5) 1-16 (8) Dissolved oxygen (mg/L) na 8-15 (12) pH 5.4 – 7.2 (6.7) 5.5-7.7 (7.2) Specific conductance (uS/cm) 11-47 (34) 9-97 (51) Range and median, TNC data only

Results – metals (TNC) Waters in and around the proposed Pebble Mine site have very low concentrations of metals Copper is elevated near the ore body A few sites had elevated aluminum, manganese, iron, cadmium, lead. None of these were elevated in the main rivers Metal concentrations increased briefly during ice break-up

Copper – Seasonal differences Blue – 0 to 1.8 ug/L Red – 4-6 ug/L Orange – 1.9 to 3.9 ug/L No color – no analysis Copper standard – 1.8 ug/L at hardness 15 mg/L

sites sites Alkalinity (soft water) concentration Dissolved organic material (plant matter) sites Box plots based on PLP Environmental baseline document Appendix 9.1B concentration sites

Trace elements meet water quality standards gross alpha, gross beta Antimony Arsenic Cadmium Chromium Copper Cyanide Lead Mercury Molybdenum Nickel Selenium Uranium Zinc meet water quality standards Cadmium, Total Copper, Total and Dissolved Lead, Total gross alpha, gross beta Antimony Arsenic Cadmium Chromium Copper Cyanide Lead Mercury Molybdenum Nickel Selenium Uranium Zinc

Summary: Clean, cold water Low metals. Some higher near ore deposit. Independent data is in agreement with PLP data. Little ability to buffer acid or mitigate metal toxicity. A small increase in metals will be noticed

Questions? Tsin’aen Camai Thank you Kendra Zamzow CSP2 www.csp2.org