The United Nations will consider an innovative stormwater treatment device as the solution to water pollution problems caused by urbanisation in the rainy Malaysia and Southeast Asia regions.
The United Nations Southeast Asia (UNSEA) will consider Hydro International’s Downstream Defender — a hydrodynamic separator designed to remove sediment, floating debris and associated pollutants from stormwater — as a solution for the region’s pollution problems.
The National Hydraulic Research Institute of Malaysia (NAHRIM) commissioned trials of the product and concluded that the Downstream Defender was effective in the capture and storage of gross pollutants carried in storm drains — including hydrocarbons, floating rubbish, silts and sediments — when it was tested in an urban area near to Kuala Lumpur.
Flow modifying components in the device enable sediments to be captured and contained in an isolated storage area, while a built-in trap retains oil and floating debris. NAHRIM will share its findings with UNSEA.
Malaysia: climate challenges
Rainfall is a major factor in transporting pollution to storm drains in Malaysia. Kuala Lumpur, for example, has an annual rainfall of nearly 2.4m with peaks up to 280mm in April and November. Short duration showers can realise 100mm or more in an hour.
The onset of rapid urban development in parts of Malaysia has increased areas of impervious surfaces leading to high surface run-off under intense rain storms, and has also increased the amounts of discarded waste such as polystyrene packaging, food and cooking oil, and hydrocarbons. These factors combine to create pollution in storm drains.
Urban Malaysia’s typical storm drainage comprises deep road side drains which discharge into high volume monsoon drains, and eventually into rivers. After storm events, the heavy load of silt and trash is visually evident in the rivers.
Government design guidelines called the Manual Sahran Mesra Alam Malaysia (MSMA) have placed increased emphasis on the need for storm water control at or near source, and for improved run-off quality.