Long-term variation in concentrations and mass loads in a semi-arid watershed influenced by historic mercury mining and urban pollutant sources

Guadalupe River is contaminated with mercury mining wastes from runoff associated with the historic New Almaden Mining District in the upper watershed that produced 40 million kilograms during its working life (1850-1975) and with PCB and other urban pollutants from a long history of urbanization and industrial land uses.

SFEI has been monitoring pollutant concentrations in the Guadalupe River during winter storms since October 2002. The result is one of the world’s most extensive data sets on mercury, PCBs, and other pollutant concentrations and loads in an urban river.  In a recent manuscript, SFEI staff used the dataset to answer three major questions.