Acidic Plume Remediation Monitoring
- Performance Monitoring
- Natural Attenuation
||Pinal Creek, AZ (near Globe, AZ)
- Pump and Treat
- Monitored Natural Attenuation
USGS scientists have conducted long-term monitoring and field experiments
at the site of an acidic plume of contaminated ground water that
discharges to Pinal Creek, AZ. The plume is the result of acidic-mine
drainage from copper mining activities in the Pinal Creek Basin.
Information from USGS studies has been used by the Pinal
Creek Group to help develop a cost-effective plan for remediation
of the aquifer, and the Arizona Department of Environmental Quality
(ADEQ) has used USGS aquifer data to help design a sampling plan
for the remedial investigation of the site.
USGS scientists are monitoring the performance of the remediation
at the site using a network of wells and surface-water sampling
sites that is also used to investigate the fate of acidic plume.
Initial monitoring results have had an impact on remediation plans
for the site. For example:
- Despite ongoing remedial pumping during the first phase of a
pump and treat ground-water remediation effort, USGS water-quality
monitoring data indicated the continued degradation of water quality
in Pinal Creek, as a result of the discharge of contaminated ground-water
to the part of Pinal Creek where there is perennial streamflow.
These results prompted State and Federal regulators (ADEQ and
the U.S. Environmental Protection Agency, respectively) to collaborate
with the Pinal Creek Group to speed up the construction and implementation
of a water-treatment plant that could clean up contaminated water
in Pinal Creek. (Arizona Water-Quality Revolving Fund Administrative
Order, Docket No. W-38-98.)
- USGS scientists have also identified unexpected interactions
between remediation activities and natural attenuation processes
at the site. For example, ground-water pumping to divert contaminated
ground water to a water-treatment plant had the unexpected effect
of changing the natural characteristics of the stream channel,
subsequently increasing the effectiveness of natural processes
that remove metal contaminants from streamflow in Pinal Creek.
This demonstrates the potential for the enhancement of engineered
remedial activities by natural processes. Following the startup
of the water-treatment plant, USGS scientists have continued the
monitoring program to assess the long-term effectiveness of the
- Arizona Water Science Center
- Jud Harvey, USGS, National Research Program, Reston, VA,
- Brown, J.G., Bassett, R.L., and Glynn, P.D., 1998,
- Analysis and simulation of reactive transport of metal contaminants
in ground water in Pinal Creek Basin, Arizona, in Steefel,
C.I., and Van Cappellen, P., eds., Special Issue--Reactive Transport
Modeling of Natural Systems: New York, Elsevier, Journal of Hydrology,
v. 209, p. 225-250.
- Fuller, C.C., and Harvey, J.W., 2000,
uptake of trace metals in the hyporheic zone of a mining-contaminated
stream, Pinal Creek, Arizona: Environmental Science and Technology,
v. 34, no. 7, p. 1150-1155.
- Glynn, P.D., and Brown, J.G., 1996,
- Reactive transport modeling of acidic metal-contaminated ground
water at a site with sparse spatial information, in Lichtner,
P.C., Steefel, C.I., and Oelkers, E.H., eds., Reactive Transport
in Porous Media: Washington, D.C., Mineralogical Society of America,
Reviews in Mineralogy, v. 34, p. 377-438.
- Harvey, J.W. and Fuller, C.C., 1998,
- Effect of enhanced manganese oxidation in the hyporheic zone
on basin-scale geochemical mass balance: Water Resources Research,
v. 34, no. 4, p. 623-636.
USGS Acid Mine Drainage Remediation Projects
Back to Toxics Program Remediation Activities Index