1
25-016
Assessment of Long-Term Physical Stability of Remediated
Mining Structures in Hualgayoc, Cajamarca, Peru: A Success
Story of the Center for Mining Environmental Research and
Studies (CIEMAN)
M. Portal
Cajamarca, PE
H. Lozano
Cajamarca, PE
F. Segobia
Cajamarca, PE
L. Goicochea,
Cajamarca, PE
F. Ysla
Cajamarca, PE
ABSTRACT
This case study evaluates the long- term physical stability
of various historical mining structures remediated by the
Center for Mining Environmental Research and Studies
(CIEMAN) in Hualgayoc, Cajamarca, Peru. The region
has a long history of mining activity, with remnants dating
back to pre-Inca times. CIEMAN has assumed responsibil-
ity for remediating 286 environmental liabilities in the area,
including adits, shafts, pits, tailings, and waste rock dumps.
The study analyzes the methods employed to stabilize these
structures, including geotechnical engineering techniques
and revegetation. Long-term monitoring results are pre-
sented, assessing the effectiveness of remediation measures
and predicting the future stability of the structures.
This study highlights the importance of responsible
remediation of mining environmental liabilities to ensure
the safety and sustainability of communities and ecosys-
tems affected by historical mining.
Keywords: Physical stability, tailings, waste rock dumps
and revegetation.
INTRODUCTION
Mine closure represents the final stage in the life cycle of
a mining operation. It is carried out by the organization
responsible for the extraction of minerals, ensuring the res-
toration of the environment and compliance with current
environmental and social regulations.
Mine closure and post-closure are crucial stages when a
mining operation comes to an end. These phases not only
guarantee the rehabilitation of the environment, but also
ensure that techniques are applied that promote sustain-
able production and minimize long-term environmental
impacts (Samadi et al., 2023).
Mwanza et al. (2014) to manage the millions of tons
of sludge and tailings material generated each year, mines
use tailings and waste dumps, designed to safely store these
wastes. During closure, constant monitoring is required to
ensure their long- term stability and prevent environmental
or safety risks.
The Hualgayoc region in Cajamarca, Peru, is known
for its long history of mining activity, dating back to pre-
Inca times. According to the Regional Environmental
Information System of Cajamarca (SIAR), in 2016 more
than 1,000 environmental liabilities abandoned for more
than 20 years were registered in this area. These environmen-
tal liabilities, which include wells, pits, tailings and waste
rock dumps, represent a continuous risk to the environment
and local communities, contaminating, among others, the
water consumed and used by people in neighboring areas.
Of these liabilities, only 500 have a closure plan, which
demonstrates the urgent need for remediation actions.
In this context, the Centro de Investigación y Estudios
Ambientales Mineros (CIEMAN) has taken an active
role in the remediation of environmental liabilities in
Hualgayoc. During the Mining 2024 Meeting of the
Institute of Mining Engineers of Peru (IIMP), Homar
25-016
Assessment of Long-Term Physical Stability of Remediated
Mining Structures in Hualgayoc, Cajamarca, Peru: A Success
Story of the Center for Mining Environmental Research and
Studies (CIEMAN)
M. Portal
Cajamarca, PE
H. Lozano
Cajamarca, PE
F. Segobia
Cajamarca, PE
L. Goicochea,
Cajamarca, PE
F. Ysla
Cajamarca, PE
ABSTRACT
This case study evaluates the long- term physical stability
of various historical mining structures remediated by the
Center for Mining Environmental Research and Studies
(CIEMAN) in Hualgayoc, Cajamarca, Peru. The region
has a long history of mining activity, with remnants dating
back to pre-Inca times. CIEMAN has assumed responsibil-
ity for remediating 286 environmental liabilities in the area,
including adits, shafts, pits, tailings, and waste rock dumps.
The study analyzes the methods employed to stabilize these
structures, including geotechnical engineering techniques
and revegetation. Long-term monitoring results are pre-
sented, assessing the effectiveness of remediation measures
and predicting the future stability of the structures.
This study highlights the importance of responsible
remediation of mining environmental liabilities to ensure
the safety and sustainability of communities and ecosys-
tems affected by historical mining.
Keywords: Physical stability, tailings, waste rock dumps
and revegetation.
INTRODUCTION
Mine closure represents the final stage in the life cycle of
a mining operation. It is carried out by the organization
responsible for the extraction of minerals, ensuring the res-
toration of the environment and compliance with current
environmental and social regulations.
Mine closure and post-closure are crucial stages when a
mining operation comes to an end. These phases not only
guarantee the rehabilitation of the environment, but also
ensure that techniques are applied that promote sustain-
able production and minimize long-term environmental
impacts (Samadi et al., 2023).
Mwanza et al. (2014) to manage the millions of tons
of sludge and tailings material generated each year, mines
use tailings and waste dumps, designed to safely store these
wastes. During closure, constant monitoring is required to
ensure their long- term stability and prevent environmental
or safety risks.
The Hualgayoc region in Cajamarca, Peru, is known
for its long history of mining activity, dating back to pre-
Inca times. According to the Regional Environmental
Information System of Cajamarca (SIAR), in 2016 more
than 1,000 environmental liabilities abandoned for more
than 20 years were registered in this area. These environmen-
tal liabilities, which include wells, pits, tailings and waste
rock dumps, represent a continuous risk to the environment
and local communities, contaminating, among others, the
water consumed and used by people in neighboring areas.
Of these liabilities, only 500 have a closure plan, which
demonstrates the urgent need for remediation actions.
In this context, the Centro de Investigación y Estudios
Ambientales Mineros (CIEMAN) has taken an active
role in the remediation of environmental liabilities in
Hualgayoc. During the Mining 2024 Meeting of the
Institute of Mining Engineers of Peru (IIMP), Homar