1. 6 3 4 5 2 1 Arapahoe Basin Ski Resort Keystone Snake River
Chihuahua Gulch 3
Keystone
Snake
River
Keystone Ski Resort
Peru
Creek
Pennsylvania
Mine 4 5
Cinnamon Gulch 2
ACID MINE
DRAINAGE
Montezuma
CURRENT STATE OF THE WATERSHED SLIDE
Dissolved concentrations of many metals of biological concern is pH dependent
Thus, pH of the stream is the dominant controlling factor of the distribution of metals in the dissolved or colloidal phase
In this figure, pH is plotted in 3 discrete intervals
Notice the 3 apparent main sources of pH related stress in the system, the Pennsylvania Mine, Cinnamon Gulch, and the Upper Snake River
Upper Snake River, iron oxide precipitation, natural sources, has it’s own flora and fauna that exist under these extreme conditons
The Pennsylvania Mine, large producer of Summit County silver into the mid-1940’s, continues to produce, now believed to be one of largest sources of aqueous metals and acidity in the watershed
AMD discharge into Peru Creek from the Pennsylvania Mine, not end of the pipe, oozes out of the bank over a stretch of river
Visible delineation between low pH / iron oxides, pristine Chihuahua Gulch, and higher pH, aluminum oxides
Nice riffle pool meandering stream. Might expect to see trout in here…
Town of Keystone, traditional environmental indicators of acid-rock drainage (i.e. bright-orange / white coated substrates, low pH) are muted, pH recovers to circum-neutral and stream substrates are less visibly coated with metal-oxides
Sts. John Creek
Sts.
John
Key: Instream pH
<4.3
>6 1
NATURAL IRON BOG
Deer
Creek
Upper
Snake
River
From: Fey, D. L., S. E. Church, et al. (2001)