At Goldcorp, protecting precious resources is a priority. We’re working to minimize our water footprint by reducing our consumption, and ensuring that any water we do use is returned safely and cleanly back to the environment. In recognition of UN World Water Day, we conclude our two-part series with how Marlin Mine safety returns water to adjacent waterways with its award- winning spillway.
Award Winning Spillway at Marlin
Goldcorp’s Marlin Mine located in the San Marcos region of Guatemala is in an area prone to tinder dry seasons for half the year and seasonal flash floods during the wet season. The region is also highly seismic. When building infrastructure to last for generations, these extreme conditions must be taken into consideration during the design, engineering and construction phase, for the safety of the community and its people.
In 2011, Marlin started construction on the emergency spillway to help mitigate risk of flooding damage to tailings dam and the surrounding area. The purpose of a spillway is to protect the dam and to control emergency discharges from the tailings impoundment during extreme storm events.
At Marlin, tailings are only discharged into the tailings impoundment once stringent, internationally accepted quality standards are met. Water is released from the impoundment following similar restrictions.
The Marlin spillway was designed to withstand the heaviest rainfall and runoff that could conceivably occur in the San Marcos region – an event known as the Probable Maximum Flood – which would douse the region with 1,300 mm of rain within a single 24 hour time period. This is the amount of rain the area receives in an average year. The 270 meter long structure has a labyrinth weir, concrete control walls and energy dissipaters to slow down and control the emergency release of water back into the adjacent rivers naturally. The spillway would only overflow during heavy rainfall events that typically would also flood the surrounding region.
Built to last for decades, the spillway was also designed to withstand an earthquake of up to 9.0 magnitude on the Richter scale. To provide reference, a 9.0 magnitude earthquake would create total devastation and could change topography. The 2012 earthquake in Guatemala measured 7.4 and the 1989 San Francisco earthquake had a magnitude of 6.9.
The impressive spillway structure is also grand in size, with walls up to nine metres high and up to 1.5 metres thick. Juan Vasquez, Marlin’s Civil Works Manager explains, “The spillway is a result of teamwork from everyone working at Marlin and is a source of pride.” This hard working team has shown that when design, engineering and construction work together, permanent infrastructure is not only safe and innovative; it can be architecturally appealing.
Marlin invested USD$14 million and used over 8,000 cubic meters of concrete to build the spillway structure. Residents from neighboring communities filled most of the 140 additional jobs the project created during construction, from 2011 to 2013.
The Marlin team’s hard work and ingenuity has been recognized externally. In April 2014, the spillway received the Infrastructure Excellence Award from Cámara Guatemalteca de la Construcción and Cementos Progreso.
Another win during the construction of the spillway was zero accidents or LTIs (Lost Time Injuries). Guatemala does not have a strong safety culture, which was one of the biggest challenges in building the spillway. Under the leadership of Manuel Aparicio, Marlin’s Head of Civil Engineering insisted that all engineering and construction contractors adhere to Goldcorp’s stringent safety standards. “Having no accidents during the construction of the spillway was one of our biggest successes.”