Building rural potable water systems (APRs) in Chile's northern region II can be three times as expensive as similar systems further south, the public works ministry (MOP) waterworks division director for the region, Gabriel Valdivia, told BNamericas.
One issue is water quality, which from region IV towards the south is relatively good, meaning that treatment systems are less intensive and therefore not as expensive, Valdivia said.
"In terms of quantity, from region IV south, although they are currently experiencing a drought, those drought conditions aren't permanent, they're periodic. In contrast, we as a region live with a permanent drought. The lack of water increases the concentrations [of minerals]," the official added.
In other areas water may have 100% more arsenic than permitted in drinking water, whereas in the region II town of Quillagua the concentrations are 10,000% to 20,000% over the norms, Valdivia said.
The concentrations of potentially harmful minerals are much higher in region II, which require plants with enhanced treatment capacity and that in turn increases costs.
"Another issue is the proximity to the key points in cities, which allows you to have workers and materials at hand. The distances [in the central/south regions] are short and there are few fuel costs," Valdivia said.
Along with the rural communities in region II being more isolated, there is more competition for labor, especially from mines in the area, the official said, adding that labor is very expensive.
The distance of water sources from communities is also an issue in the northern region, where groundwater is much scarcer. APRs are often fed from sources many kilometers away, requiring long pipelines.
"We already have stretches of pipeline which cross wooded or rocky terrain - these are complex sectors to cross and many times they can't be accessed by vehicles," Valdivia said.
The many challenges to building APRs in the region all add to final project costs.
"Here the costs are tripled - it should cost three times less," the official said.