Pierre River Mine Project

WATER AENV SIRS 15 – 43
Reference
Question No. 32
Section 12.1
US EPA (United States Environmental Protection Agency). 2002. National
Recommended Water Quality Criteria: 2002. US EPA, Office of Water
4304T. EPA 822-R-02-047.
Wetzel, R. G. 2001. Limnology: Lake and River Ecosystems, 3rd Edition.
Academic Press. New York, NY. 1006 pp.
Original SIR 299b
How does the change in the annual DO frequency distribution affect other water
quality parameters, including but not limited to: pH, ion mobility, algae and
plankton production and elemental biogeochemical cycling?
Although some biogeochemical processes affect both pH and dissolved oxygen
(DO), there is no direct relationship between these variables. Therefore, a change
in the annual DO frequency distribution would not directly affect pH.
The three major mechanisms controlling major ion concentrations in surface
water are rock dominance, atmospheric precipitation and evaporationprecipitation
processes (Wetzel 2001). A connection between DO and major ion
mobility has not been identified, provided the water is not anoxic.
In relatively well-oxygenated water, DO is not expected to be a limiting factor
for algae plankton production. Therefore, small increases in DO would not be
expected to have effects on productivity.
Redox potential is relatively insensitive to changes in DO, and redox potential of
surface waters will remain positive and fairly high as long as water is not near
anoxia (Wetzel 2001). As discussed in EIA, Volume 4A, Section 6.5.6, DO
concentrations are not expected to decline in receiving streams downstream of
the project. Therefore, the annual DO frequency distribution is not expected to
affect elemental biogeochemical cycling.
Wetzel, R. G. 2001. Limnology: Lake and River Ecosystems, 3rd Edition.
Academic Press. New York, NY. 1006 pp.
Request Volume 2, SIR 301a-b, Page 21-55.
Global action on climate change issues fundamentally requires the active
cooperation of major industrial operators working at a regional or local level.
32a What efforts are being made by Shell (in addition to efforts undertaken by
CEMA) to integrate project information with other proposed projects?
April 2010 Shell Canada Limited 12-45
CR029