The Lerma River as it crosses the State of México. The Lerma River as it crosses the State of México. milenio

Lerma River: 15 km are ‘biologically dead’

Researcher says its clean-up should be a priority of state's new government

The Lerma River — one of Mexico’s longest — is so polluted that one expert has labeled it “biologically dead” and environmentalists have described it as “an enormous stinking sewer” that requires an unprecedented effort to clean up.

The river originates in Almoloya del Río near Toluca in the State of México and empties into Lake Chapala in Jalisco and has long been plagued by wastewater contamination.

Excess rainwater mixed with sewage often bypasses outdated drainage systems and flows directly into the river.

Adding to the problem is that the Lerma’s upper basin is one of Mexico’s most developed industrial zones with around 2,500 factories, which produce chemical-containing wastewater that further upsets the river’s biological balance.

Carcinogenic heavy metals and trash are also present in the water.

Both environmentalists and citizens have demanded that the river be cleaned up because of the negative environmental, social, economic and political consequences of the contamination.

Gerardo Ceballos, a biodiversity researcher at the National Autonomous University, says cleaning up the Lerma “must be one of the priorities of the new [State of México] government.”

All sectors of society and government must take urgent measures because without clean water, humans won’t be able to live there, the academic warned.

Oxygen levels in the first 15 kilometers from the source are at 0% meaning that life cannot be supported, leading Ceballos to declare the Lerma River as “biologically dead.”

According to Enrique Collado López, an environmentalist and consultant, more than 425 million cubic meters of domestic and industrial wastewater are dumped into that stretch of the river each year.

He says the 30 treatment plants that currently treat water flowing into the Lerma are not enough to stop the damage.

However, Collado does believe that the river’s health can be restored but to do so a comprehensive plan and an investment of 60 million pesos (US $3.3 million) is needed.

Earlier efforts to clean up the river by authorities in the states of Michoacán and Jalisco along with the federal government were discontinued.

The problems faced by the Lerma are indicative of a wider freshwater crisis that affects other parts of the country including Mexico City, where millions of people lack access to potable water.

Source: Milenio (sp)

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