| Abstract |
Hot springs related to the Chacana Caldera in Ecuador are located in several areas within and outside of the caldera border. Physical and chemical characteristics indicate high salinity hot springs ( more than 7100 µS/cm) and alkali-chloride secondary geothermal fluids with surface temperatures from 59 to 73°C, indicating a possible subsurface geothermal reservoir in the south of the caldera. The other hot springs in Chacana contain carbonate fluids mixed with groundwater (high Mg), which is typical of peripheral areas in a geothermal system. Currently, some hot springs in Chacana are restricted to direct use for bathing resorts, balneology and swimming pools. However, this represents a small amount of energy in Chacana considering the total hot spring flow. The total flow rate of the thermal water is 113 [l/s], representing 18.5 MWt, which is the minimum heat discharge. On the other hand, the thermal water has an average As concentration of 4.024 [mg/l], which is pouring naturally every second into the Jamanco river basin. That means around 3 tons of As per year, and 757 tons of As accumulate in water and sediments of Papallacta lake located in the lowest part of the river basin. Jamanco and Cachiyacu are currently geothermal pre-feasibility prospects in the south of the Caldera, thus this information has to be considered as an urgent environmental and social problem by the main authorities and local communities. |