Evapotranspirative Cover System Performance Evaluation
Location
Nevada, USA
Client
Barrick Goldstrike Mining, Inc
Project Description
GSA conducted a 11 year cover system performance monitoring study at the closed AA Heap Leach Pad. GSA characterized soil cover and heap leach ore properties and installed fourteen instrument clusters into the cover system under various site-specific conditions such as slope and aspect. Soil water content, pressure potential, water flux meter and draindown data were used to estimate and model the net percolation through the cover system. Rooting surveys and in-situ hydraulic testing studies were conducted near the end of the study to determine sub-surface vegetation conditions and the cover material hydraulic properties 11 years after facility closure. Monitoring data demonstrated that the closed facility cover system performance limited net percolation to less than 1% of average annual precipitation.
Project Highlights
- Field and laboratory characterization of hydraulic properties of leach ore and cover system materials
- Design and implementation of automated cover system monitoring systems consisting of soil water content, pressure potential, and water flux meter sensors
- Long-term cover system maintenance and monitoring
- Data analysis, interpretation and reporting
- Modeling and predictions of long-term net percolation through closure cover systems
- Rooting surveys and post-monitoring hydraulic property assessments
