1. 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

2. Site location

3. 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 ; this affects the chemistry
The independent study was funded by the Nature Conservancy

4. 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

5. Sampling methods TNC PLP Field data and lab analytical data
May 2009, June 2009, June 2010
Field data and lab analytical data
Monthly
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)

6. 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

7. Data Presentation

8. 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)
(7.2)
Specific conductance (uS/cm)
11-47
(34)
9-97
(51)
Range and median, TNC data only

9. 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

11. 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

12. 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

13. 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

14. 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

15. Questions?
Tsin’aen
Camai
Thank you
Kendra Zamzow
CSP2