Tuesday June 11, 2013

Cleaner flows

By MENG YEW CHOONG

star2green@thestar.com.my

Grease traps are mandatory in most restaurants, but unless they are emptied and maintained regularly, they do little to prevent oil and grease from entering drains and streams.

 

The importance of keeping rivers clean is seldom highlighted.

Throughout the whole of last year, Malaysia has been talking about clean rivers, and more so after the multi-billion ringgit River of Life (RoL) project was launched two years ago.

RoL is a Federal initiative to improve the water quality of the Klang River from something untouchable (categorised as either a Class IV or V river) to something that is suitable for recreational use (or close to Class IIb).

A class IV or V river can either be polluted with excessive levels of sediment, heavy metals or microbial life, such as the Eschericia coli (E. coli) bacteria or worse, the Enterococcus sp. and Cryptosporidium.

Most people still associate cleaning up rivers with installing boom traps to collect floating rubbish or throwing mudballs infused with a bacterial mix that is touted as a miraculous solution that will turn even the most putrid waterway into something clean.

While harvesting rubbish does have a role, it is the capture of the invisible stuff like dissolved heavy metals, fine suspended solids and nutrients (anything containing nitrogen, phosphorus or potassium) that will finally elevate the river to a more desirable state.

Capturing rubbish, while needful, tantamounts to picking up after the people. This alone is not sustainable, and in fact, does little to clean up a highly polluted river, argues river expert Dr K. Kalithasan.

Harvesting physical rubbish is an ongoing process as it is both the logical and expedient thing to do, and most municipalities do it. For example, Kuala Lumpur City Hall nets in at least 20 tonnes of river trash daily.

“No doubt, rubbish is an eyesore, and floating rubbish is the easiest to take care of. But it is time we stop judging whether a river is clean or dirty just by the amount of rubbish or even the colour of the water,” said Kalithasan of non-governmental organisation Global Environment Centre (GEC).

Data from the Drainage and Irrigation Department show that improperly treated or untreated sewage and wastewater from businesses are a significant source of pollution in rivers. For the Klang River, urban domestic pollution is the highest pollution contributor.

Foul stuff: Wastewater from homes that is discharged directly into drains is a major source of river pollution.

 

“We cannot just rely on gross pollutant traps (GPTs) and rubbish traps as they do not solve the problem at the source. The fact is that other significant pollutants are the many harmful suspended or dissolved chemical compounds in the water,” said Kalithasan.

Man-made inputs like soil erosion, surface runoff, faecal matter, detergent, urban domestic waste, industrial effluent, fertiliser runoff and residential waste all affect river quality.

Sewage is a significant source of pollution that can impede river cleansing efforts. According to Datuk Ahmad Suhaili Idrus, a Pemandu director for National Key Economic Areas (Greater KL/Klang Valley), improperly treated wastewater has the potential to impede the success of the RoL project that covers a portion of the 120km-long Klang River.

Sewage, which encompasses grey water like those from bathrooms and kitchens, should not be discharged into open drains but into the sewerage system.

Eateries are also a culprit when they discharge wastewater from their cleaning operations, or worse, allow oil and grease into open drains. Other than this, there is also seepage from improperly constructed landfills or illegal dumpsites all over the Klang Valley.

Though oil and grease (O&G) is biodegradable, their presence in the river raises the demand of oxygen, other than choking aquatic life by forming an impermeable film on the water surface.

The problem can be contained by the mandatory requirement (at least in Kuala Lumpur) for grease traps but KL City Hall does not have a standardised design for it.

“All commercial premises dealing with food must have it. Unfortunately, when it comes to monitoring its efficiency, there is no emphasis on how to maintain it.

“Who is going to collect the waste oil from the trap when it is full? Right now, the user installs it merely because the law requires it, and that’s about it,” said Mohd Ridhuan Ismail, executive director at the sewerage regulatory department of the National Water Services Commission.

He feels that local authorities should compel eateries to connect their washing basins to the septic system, instead of discharging directly into the drain. A proper setup means the wash water will flow through a strainer, then the grease trap, and, finally empties into the sewerage system. Indah Water Konsortium (IWK) confirms that the biggest problem it faces is (solidified) O&G in sewerage pipes. Hardened O&G leads to blockages.

Part of the sewage pollution problem is inherited. The thousands of sewage treatment plants (STPs) built before 1999 follow a standard that is outmoded now.

“Discharge from these STPs can never meet current environmental standards, no matter how well they are operated,” said Ridhuan.

IWK was awarded the concession by the Government in 1994 to manage sewerage services nationwide.

Since then, it has taken over the sewerage services from local authorities in all areas except Kelantan, Sabah, Sarawak, parts of Terengganu that come under the Central Terengganu Development Board (Ketengah), and parts of Johor that come under Johor Baru, Pasir Gudang, and the South-East Johor Region Development Authority (Kejora).

IWK operates around 4,700, or about half the STPs in the country, and it still “discovers” forgotten or dilapidated small STPs on a regular basis.

“A lot of STPs are owned by private parties such as hotels and institutions. We believe that there are about 4,000 STPs that are privately managed or forgotten, and it is quite difficult for us to monitor them,” said Ridhuan.

“IWK also needs to improve as not all of the 4,700 STPs are operating well. STPs built after 1999 are designed to meet new requirements, but under actual operating conditions, some do not meet the requirements all the time. For those located in the Klang Valley, the ROL programme will upgrade these plants or rationalise them by closing off smaller plants and rerouting the sewage to larger plants.”

Having fewer but more efficiently managed larger plants will enable the Department of Environment to monitor them. IWK maintains 79 regional facilities which are linked electronically to its headquarters and state DOE offices. These larger plants are said to consistently comply with current environmental standards.

“DOE is actually after the smaller plants as they are often the ones that fail to comply,” said Ridhuan.

IWK maintains that the load of biochemical oxygen demand, suspended solids, oil and grease, and ammoniacal nitrogen from its treated discharge in 2011 was below permissible levels, indicating “that our plants are generally functioning well in treating the sewage effluent before discharging into the waterways,” according to its 2011 performance report.

In Selangor, the South Klang Valley sewerage catchment is identified as one of the critical sewerage service areas due to its large number of housing and commercial lots, and wedged between these developments are a host of STPs and individual septic tank systems.

A RM110mil contract has been given out by the Energy, Green Technology and Water Ministry for works associated with sewerage rationalisation in Klang, which falls within the South Klang sub-catchment.

Expected to be completed in January 2017, this rationalisation is part of the works proposed under the Greater Kuala Lumpur/Klang Valley National Key Economic Area.

Under this project, a number of old STPs will be closed down, new pumping stations built along with new trunk sewers to channel the existing flow to larger regional STPs. This rationalisation will increase the operating efficiency and lower the operational expenditure of the sewerage system at sub-catchments.

While the Government takes care of the big ticket items like river cleansing, there is much to be done to educate the public on their role in clean rivers, added Kalithasan.

“People want to flush and forget, and don’t want to know where it all ends up. We still have people who are not paying their sewerage bills or desludging their individual septic tanks regularly. People just don’t see the importance of that.”

The Star online

Tuesday  June 11 2013.