Peruvian social conflicts showed signs of reactivating at two of the country’s largest copper projects this week, after protests had appeared to ease across the country this year.

About 600 protesters clashed with police and blocked roads to Freeport McMoRan Copper & Gold’s Cerro Verde mine in Arequipa region to protest traffic jams caused by Freeport work on a water treatment plant, in broadcast footage by local TV channel Canal N.

Freeport is building the US$452mn Enlozada water treatment plant, which will treat 2.4m3/s from the Chili river. The facility is part of its US$4.6bn expansion project to boost concentrator capacity at Cerro Verde to 360,000t/d of ore from 120,000t/d, and provide additional annual production of some 600Mlb (272,155t) of copper and 15Mlb of molybdenum starting in 2016.

At the same time, the Tambo irrigation board in the Islay province, also in Arequipa, announced a 48-hour regional strike this week to protest against Southern Copper’s US$1.3bn Tía María copper project, which received government approval this month. Local farmers, whose protests over water issues led to the suspension of the project in 2011, plan to march to the South Pan American highway, Radioprogramas reported.

Peru’s energy and mines ministry approved a new environmental impact study for the project in early August, and the company is waiting for a construction permit before starting work on the mine, CEO Oscar González Rocha said this week.

The company set up a 100mn-sol (US$35.7mn) fund for social spending in the region, including drinking water and sewage projects, this week.

Southern aims to start construction at Tía María by end-2014 and will take 20-24 months to build the mine, depending on mine equipment delivery. Tía María, which has an estimated mine life of 18 years, is scheduled to reach full production by early 2017 and will produce 120,000t/y of copper cathodes.

Since 2011, environmental protests in Peru, the world’s third-largest copper, zinc and tin producer, have also forced the suspension of projects, such as Newmont Mining’s US$4.8bn Minas Conga copper-gold mine, Zijin Mining’s Río Blanco copper project and Bear Creek Mining’s US$70mn Santa Ana silver deposit.