El Salvador could become the first country to ban mining for precious metals in order to protect freshwater supplies
Around 90% of surface water in the country is already contaminated, largely due to agricultural runoff and lack of sewage treatment.
El Salvador is the most densely populated country in Central America and a fifth of its rural population lacks access to safe drinking water, according to the World Bank.
In July 2012 government tests on the San Sebastián river – where the US-based Commerce Group ran a gold-mining operation until 1999 – showed nine times the accepted levels of cyanide and 1,000 times the accepted levels of iron.
There are currently no active metal-mining operations in El Salvador, five years after then-president Antonio Saca, following strong public pressure, said he would not issue new permits.
Community organisations, church groups and environmentalists have come together to campaign against a cyanide leach gold mine proposed by Canada-based Pacific Rim in the northern department of Cabañas.
Some 62% of Salvadorans back a bill to ban the industry altogether, something that also received early support from current president Mauricio Funes’ leftist FMLN party.
A new water bill that would establish clean water for human consumption and food production as priorities is also being debated at the national assembly.
But Commerce Group and Pacific Rim are suing the government for more than $400m (£258m) through a World Bank trade tribunal called the International Centre for Settlement of Investment Disputes (ICSID).
With the opposition party taking a pro-mining stance, the issue could be key to the presidential election due in March 2014.