Bolivia and Peru will be working together through a 10-year plan with a joint investment of around $500 million to restore and preserve Lake Titicaca, South America's largest freshwater lake. 

The deal is the result of political negotiations that were held through June 2015 and was signed by each country's environment minister in Bolivia's capital city of La Paz late last week, according to TeleSUR. The agreement is designed to improve biodiversity in the lake, with an emphasis on waste and environmental management through to 2025, reported the Digital Journal.

"On June 23 we had a historic meeting in an expanded cabinet between Peru and Bolivia," Bolivian Environment Minister Alexandra Moreira said during the announcement of the deal, "[And] we are proud that the environmental sector is the first to give concrete, direct results and with the signing of this agreement that sets the guidelines of action for the recovery of Lake Titicaca."

"For the short term we have a limit of $117 million and for the long term $400 million (USD)," Moreira's advisor, Sergio Arispe, explained, according to GlobalPost.

The initial stages of the plan will address solid waste management issues and sewage systems in the communities around the lake. Nearby mining and industrial operations have also contributed to major contamination problems, the Peruvian news agency Andina explains.  

Lake Titicaca is located at an altitude of 12,470 feet above sea level, making it the highest lake in the world. Around 3 million people in Bolivia and Peru rely on the lake's resources, and the surrounding area is also an important tourist destination.