monitoring and evaluating reclamation outcomes: a case study of the roy pray mine by: ashley...
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Monitoring and Evaluating Reclamation Outcomes: A Case Study of the Roy Pray Mine
By: Ashley BembenekEnvironmental Consultant
Image retrieved from Google Earth
Roy Pray Mine Near Lake City, Colorado
Denver
Grand Junction
Lake City
Historic Mining near Lake CityHistoric Mining near Lake City - Gold and silver - From the 1870s to 1920s
From Kansas State Historical Society
Image retrieved from Google Earth
Palmetto Gulch - Heavily impacted area - 303(d) listed in 2002 for Cd, Cu and Zn - Led to additional data collection and TMDL
Roy Pray Mine Reclamation Project2003: Bulkhead sealed at Roy Pray Adit
2005: Adit waste pile relocated and re-graded
Roy Pray Mine Reclamation Project Objectives
Bulkhead sealed to reduce flow from the mine adit
Tailings pile removed from direct contact with stream and re-graded to reduce erosion potential
Post-Reclamation Water Quality Monitoring Objectives
Have reclamation activities at the Roy Pray Mine reduced metal concentrations in surface water samples?
How has flow from the adit and adjacent pre-existing seeps changed following reclamation activities?
Roy Pray WQ Monitoring Areas
Below: Palmetto Gulch
Above Roy PrayBelow Roy Pray
Roy Pray Mine
Roy Pray WQ Monitoring Areas
Below: Palmetto Gulch
Roy Pray Mine
Below Roy Pray
Above Roy Pray
Cadmium Concentrations: 1999-2010
Cd concentrations above the Roy Pray & in Palmetto Gulch have remained relatively stable through time
Initially, Cd concentrations declined at the Roy Pray Mine & immediately below the mine
Cadmium in µg/L
More recently, Cd concentrations have increased
Cu concentrations in Palmetto Gulch have remained stable
Elsewhere, Cu concentrations have increased over time
Increases above & at the mine adit do NOT account for all of increases measured below the mine
2010 data from below the Roy Pray has the highest Cu concentrations measured to date
Groundwater seeps interact with mine pool water or other lowquality water--- Cu concentrations are very high
Copper Concentrations: 1999-2010
0
5
10
15
20
25
30
35
40
45
1999 2000 2002 2004 2005 2006 2008 2010
Dissolved Copper (ug/L)
Above Roy Pray
Roy Pray Mine
Below Roy Pray
Below: Palmetto Gulch
Copper in µg/L
Zn concentrations above Roy Pray & in Palmetto Gulch have remained stable
Zn concentrations initially declined at the Roy Pray Mine
Since 2005, Zn concentrations have risen at the mine and immediately below it
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
1999 2000 2002 2004 2005 2006 2008 2010
Dissolved Zinc (ug/L)
Above Roy Pray
Roy Pray Mine
Below Roy Pray
Below: Palmetto Gulch
Zinc Concentrations: 1999-2010
Zinc in µg/L
Metal concentrations on the rise, what has flow done?
Flow from the mine adit issimilar to pre-reclamation levels
Flow from below Roy Pray Minehas likely increased over pre-reclamation levels
LocationYear 2000
Month July June September June JulyAbove Roy Pray 0.34 1.62 0.01 0.64 0.17Roy Pray 0.03 NM 0.04 0.01 NMBelow Roy Pray 0.51 2.24 0.09 1.95 0.37Below: Palmetto Gulch 1.87 9.94 0.38 NM NM
2005Flow (cfs)
2010
Currently, metal loads are lower than pre-reclamation metal loads
However, there is little evidence to suggest chemical or hydrologic stability at this location
Additional data is needed to better understand current conditions
Responsive Management
Project data translated into information to direct further management actions
Additional reclamation strategies will be developed, as needed
Project partners have agreed to collect more water quality samples and additional data
Conditions at the Roy Pray Mine highlight the need for post-reclamation monitoring and evaluation
Questions or Comments…
Additional questions:Ashley Bembenek
Image retrieved from Google Earth Image retrieved from Google Earth