|Reference Category||Conference contributions|
|DOI / URL||link|
|Title (Primary)||Riverine flow-through of mine pit lakes: improving both mine pit lake and river water quality values?|
|Title (Secondary)||Agreeing on solutions for more sustainable mine water management – Proceedings of the 10th ICARD & IMWA Annual Conference, Santiago, Chile 2015, April 21-24|
|Author||McCullough, C.; Schultze, M.;|
|POF III (all)||T31;|
|Keywords||pit lake; mine closure; flow-through; AMD; salinity|
|UFZ wide themes||RU2;|
|Abstract||Coal mine pit lakes may form at mine closure when voids formed through mining extractions have
extended below groundwater. Internationally, acid and metalliferous drainage (AMD) is a common
problem for coal pit lake water quality. Even if not acidic, pit lake water quality may become degraded gradually through dissolution of contaminants and evapoconcentration.
Contaminated coal pit lake waters can present significant risk to both surrounding and regional
communities and natural environments. Pit lake waters may discharge into surface and
groundwater; or directly present risks to wildlife, stock and human end users.
Riverine flow-through is increasingly being proposed to mitigate pit lake water contamination. This
paper presents the motivation for, and key processes and considerations regarding a flow-through
final lake hydrology. International case studies as precedent and lessons for future application are
also described from a review of literature describing pit lakes that use or propose surface water
inflows and discharge as key components of their closure and pit lake management designs.
Chemical and biological processes such as dilution, absorption and flocculation and sedimentation
reduce solute loads from river and lake. We conclude that riverine lake flow-through may often be
a valid mine closure strategy for pit lakes with poor water quality. Although, we caution that
maintenance of existing riverine system values must be maintained first and foremost, we further
suggest that decant river water quality may, in some circumstances, be improved; notably in
examples of meso-eutrophic river waters flowing through slightly acidic pit lakes.
Flow-through closure proposals for coal pit lakes must be scientifically justifiable and follow a risk
assessment approach. Due to the high-uncertainty, biotic and physico-chemical attributes of both
upper and lower river and lake should be well monitored. Monitoring should directly feed into an
adaptive management framework approved by key stakeholders.
|Persistent UFZ Identifier||http://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=16075|
|McCullough, C., Schultze, M. (2015):
Riverine flow-through of mine pit lakes: improving both mine pit lake and river water quality values?
Agreeing on solutions for more sustainable mine water management – Proceedings of the 10th ICARD & IMWA Annual Conference, Santiago, Chile 2015, April 21-24
GECAMIN, Santiago de Chile, p. 1 - 10