In declaring the emergency, Peru's Environment Ministry said the contamination included high levels of lead, barium and chromium as well as petroleum-related compounds.
Protesters say fracking could have "enormous implications" for the local environment particularly about the contamination of waste or flowback water once it has been used in the fracking process.
The fields have been operated for roughly 12 years by Pluspetrol, the country's biggest oil and natural gas producer, and it will be obliged to clean up the contamination, said Environment Minister Manuel Pulgar-Vidal.
In Africa, because of economic pressures and slower evolution of environmental awareness, local communities have been particularly exposed to the detrimental effects of mining contamination on public health, agriculture and the environment.
The United Nations Environment Programme's Post-Conflict Assessment Unit has published a report on DU contamination found in Bosnia-Herzegovina up to seven years after the conflict there.