UK-based manufacturer of water management and plastic piping systems Polypipe has installed an effective solution for subsoil drainage at the tailings management faci- lity of Canadian gold miner Banro’s Namoya mining project, in the Democratic Republic of Congo (DRC).

The mine is situated at the south-western end of the Twangiza-Namoya gold belt, covers an area of 174 km2 and is expected to double the company’s projected gold production to more than 225 000 oz a year.

The Namoya site houses a substantial tailings management facility to process the leftover materials and wastewater from gold extraction. It also ensures that harmful particles do not enter the soil or groundwater.

Following a competitive tender, Polypipe’s ridgidrain twin-wall drainage system was selected to provide effective subsoil drainage.

Ridgidrain is ideal for nonpressurised subsurface drainage applications, with perforations at regular intervals along its length to allow safe and gradual drainage.

Manufactured in high-density polyethylene (HDPE), ridgidrain boasts abrasion resistance both internally and externally – protecting against sediment within the wastewater and the rugged mine environment. It also offers a high compression strength to withstand imposed loadings, yet is lightweight for ease of installation and transport.

Tailings management facilities are essential in ensuring that the mine operates in an environment-conscious manner, and the ridgidrain system allows for the controlled seepage of treated water.

The system can also deal with unpredictable fluctuations, such as stormwater, and is a crucial element of an effective water management system.

Polypipe supplied 1 386 m of its 500-mm-diameter and 190 m of its 600-mm-diameter ridgidrain twin-wall pipe, shipped using eight 40 ft sea containers, which required close coordination between Polypipe’s UK manufacturing operation and the shipping agent to meet deadlines and ensure the full order was despatched as one shipment.

“Plastic piping systems, such as ridgidrain, are up to 94% lighter than concrete alternatives. They are, therefore, safer to install and move around site, and also offer considerable environmental benefits,” says Polypipe export sales manager Philip Wood.

He adds that production and transportation are simplified and use less carbon, with the product often being reused elsewhere when the project ends.

“These factors are key considerations for mine operators and also make the product more cost effective. For these reasons, ridgidrain is growing in popularity in the African mining market,” Wood states.