Siltbuster, the water treatment specialist, says it has designed and installed a surface water treatment solution for Anglo American at its Woodsmith polyhalite mine on the North Yorkshire coast of England.

The polyhalite deposit can only be accessed from within the North York Moors National Park, so extensive steps have been taken to limit the environmental impact of the mine, using innovative design solutions and engineering ingenuity, Siltbuster says.

The mine infrastructure has been designed to be sympathetic to its location: the number and size of the buildings has been reduced to a minimum, which, together with extensive landscaping and planting, will ensure the site is screened and blends in with the surrounding area. At the same time, mined ore will only be transported underground, in recognition of the sensitivity of the area, in a 37 km tunnel to the materials handling facility on Teesside, eliminating the need for surface transportation.

“This careful stewardship and protection of the surrounding environment has also extended to water management on site,” Siltbuster said. “During construction, the collected surface rainwater via the on-site collection drainage system can contain an elevated level of suspended solid particles which require removal prior to discharge back into the natural water courses to ensure there is no environment impact. The collected surface water passes through a series of lagoons to remove the gross solids, but the water can still contain elevated level of suspended clay particles that do not settle under natural gravity.”

Anglo American has, therefore, invested in a treatment system, with a high degree of system automation, located within a structure that blends in with the surrounding scenery, in line with the overall project design, the company says.

With the new modular treatment system in place, including 2no. HB200R Lamella Clarifiers with Mix Tanks, over 5.7 million litres of water can be treated each day. Continuous online monitoring of flow, pH and suspended solids of the treated surface water ensure discharge criteria are being met consistently before releasing back into the natural water course, Siltbuster explained. If any of the monitoring parameters are above the trigger level, the system will shut down automatically with an instant text alert submitted to the site operators.

Rob Staniland, Manager for Environment and Permitting at the Woodsmith Project, said: “It is essential that we have robust, reliable systems and partners to help us meet our stringent planning conditions and environmental safety targets. Siltbuster have proven to be just that, providing us with a great solution to helps us deliver on the minimal impact ethos of the whole project.”

Louis Pang, Project Manager, at Siltbuster, added: “The new treatment plant has not only provided an effective and easy-to-operate system, with the system design being modular and built off-site, the on-site construction and installation time was kept to a minimum, thereby minimising the environmental impact, an important environmental criteria set by Anglo American.”