Tracer Study and Acid Rock Drainage Treatment
Kayenta, Arizona
Two projects are being implemented to assess and treat mine groundwater drainage. Western Water & Land personnel designed and implemented a groundwater tracer test to evaluate source water contributions from two pond impoundments to a nearby spring. An analytical flow and transport model was used to design the tracer tests. Two different tracers were injected in the source areas and a monitoring program was implemented to assess tracer breakthrough. Source contribution will be estimated once tracer peak concentrations are realized at the spring. In a related project, Western Water & Land personnel designed two small acid rock drainage treatment systems for flows from two acidic springs located near the mine. Infiltration of mine process water in the area is reacting with underlying rock strata resulting in the production of low pH water. The systems consist of small, lined catchment basins filled with limestone aggregate. The system is designed to exceed 24-hour retention time to increase water pH and precipitate metals and salts. The limestone aggregate will be accessible by skid loader such that spent or scaled-over limestone can be readily removed and replaced without damage to the catchment liner. Catchment water will discharge by way of a v-notch spillway to a nearby natural drainage. The spillway will be monitored for water quality. These systems are to be installed in the coming months.
Kayenta, Arizona
Two projects are being implemented to assess and treat mine groundwater drainage. Western Water & Land personnel designed and implemented a groundwater tracer test to evaluate source water contributions from two pond impoundments to a nearby spring. An analytical flow and transport model was used to design the tracer tests. Two different tracers were injected in the source areas and a monitoring program was implemented to assess tracer breakthrough. Source contribution will be estimated once tracer peak concentrations are realized at the spring. In a related project, Western Water & Land personnel designed two small acid rock drainage treatment systems for flows from two acidic springs located near the mine. Infiltration of mine process water in the area is reacting with underlying rock strata resulting in the production of low pH water. The systems consist of small, lined catchment basins filled with limestone aggregate. The system is designed to exceed 24-hour retention time to increase water pH and precipitate metals and salts. The limestone aggregate will be accessible by skid loader such that spent or scaled-over limestone can be readily removed and replaced without damage to the catchment liner. Catchment water will discharge by way of a v-notch spillway to a nearby natural drainage. The spillway will be monitored for water quality. These systems are to be installed in the coming months.