Effluent choking up our lifelines
RIVERS have long been regarded as the pipes leading to earth's largest rubblish dump: the oceans. But as more and more rivers get polluted, a rethink of the way we use these waterways are called for
TAN CHENG LI reports:
RIVERS are the earth’s lifelines. They provide water, which life on earth depends on.
Yet there are gaps in our understanding of the importance of rivers and in the way we use them.
More and more rivers in the country have become polluted in the last five years, according to the Department of Environment (DOE).
Of the 87 rivers monitored, six are deemed very polluted, 44 slightly polluted and 37 clean.
In fact, at least two rivers in the country, the Juru and Sepang, are dying if not dead, as human and animal excrement robs the water of oxygen, and chemicals poison the fish.
"To protect the no less than 1,500 rivers in the country which stretch for 35,000km, the public must stop seeing rivers as one huge drain," said Drainage and Irrigation Department director-general Datuk Shahrizallia Abdullah.
Indeed, what the public often thinks of as "water pollution" —the discharges from factories and rubbish from squatters — is only a fraction of the problem.
DOE director-general Dr Abu Bakar Jaafar said rivers are polluted more by sewage and silt rather than factory wastes.
Silt contaminate 66 per cent of the 7,600km of river monitored, sewage 20 per cent, manufacturing 10 per cent and rubber and oil palm effluent, two per cent. (See graph)
"Of concern is pollution from non-point sources which are widespread such as city streets, agriculture land, mines and construction sites which are more difficult to control and monitor," he said.
Loose soil in barren forests, construction sites and steep slopes are flushed into streams when it rains.
Nitrate and phosphate from heavily fertilised farms and estates seep into soil and streams.
Since most of us do not live next to a river, it is easy to think that we have done nothing to harm these waterways.
On the contrary, we are just as guilty as the industries, if not more.
Waste water from our kitchens eventually trickle into streams. Sewage from housing estates, although left to disintegrate in oxidations ponds, almost always end up only semi-treated when it flows into drains which lead to rivers.
The poultry, beef, mutton and pork we consume also leave behind a trail of sewage and organic waste in rivers before they reach our tables.
Our garbage might be buried in deep landfills, but leaked toxic leachate into groundwater and rivers.
Sulphur dioxide and nitrogen dioxide emitted by our cars turn into acid rain which eventually enter rivers.
And cruising along highways, how often do we think about the the soil erosion that accompanies such massive construction?
The water quality of rivers here have deteriorated with increasing levels of pollutants.
The United Nations Environment Programme (UNEP) found pesticide levels in some local rivers to be higher than those found in Europe. Phosphate in the Sepang, Setiu, Ibai, Terengganu, Dungun and Paka rivers have exceeded DOE limits.
Nitrates and phosphates fuel the growth of algae which cuts off light to underwater plants and, when it decomposes, lowers oxygen levels in the water.
Penang rivers experience the worst mercury pollution while in Johor, all rivers contain more lead than the DOE deems safe.
These contaminants eventually flow into estuaries and mangroves, rich habitats that offer spawning and feeding areas for fish and fowl.
Most of the poison that enters rivers does not stay there but is carried to the oceans, killing marine life and contaminating our food.
The scenario by 2020 looks bleak if the current trend is not halted or reversed as domestic, industrial and agricultural demand for water is expected to double by then and probably, so will the emission of waste.
Land demands for housing, industries, agriculture and infrastructure will put pressure on the opening of protected areas such as hill slopes and reserved lands which have high erosion rates.
The cost of polluted rivers can be expensive. The Asian Wetlands Bureau reports that catches by fishermen in the upper Pahang River have dwindled.
A study on Tasik Bera revealed a drop in fish species from 95 in 1982 to 56 last year.
Silt changes the river’s hydrological regime, resulting in floods.
Flood mitigating measures such as desilting, widening and deepening rivers, building dams and bunds do not come cheap.
Of the RM162 million for cleaning up and beautifying the Klang River, desilting alone will cost RM22 million.
City Hall removes 100 tonnes or 10 lorry-full of rubbish from the Klang River daily, the figure easily rises to 300 tonnes when it rains.
And the dirtier the river, the more chemicals are needed to render the water fit for drinking.
In the case of water from the Linggi River in Negri Sembilan, chlorine could not be used as it would react with pollutants and form carcinogens. Instead, the water is treated with expensive ozonation technology and activated carbon.
Apart from the problem of public attitude towards rivers — that they are open sewers — the present system where water policies are considered separately from land management, have led to Malaysian rivers being what they are today.
"Different agencies place different importance on rivers, sometimes with conflicting interests," says Universiti Teknologi Malaysia’s environmental engineering division head Maketab Mohamed.
Agriculture-based agencies channel water from rivers for irrigation without due consideration on the effects of reduced flow downstream.
Even the Drainage and Irrigation Department, concerned only about alleviating flood, had in the past underestimated the impacts of river engineering works, admits an official.
"It is only in the past few years that we try to include environmental considerations in flood mitigation work," he says.
Damming of rivers for water extraction by the Waterworks Department proved a mixed blessing, as they force relocation of rural folk, disrupt downstream fisheries and reduce total flow because of increased evaporation from reservoirs.
Rivers continue to be silted and choked by rubbish because of lax enforcement by local-authorities.
Riverine squatters ought to be relocated or alternatively, sanitation services be improved.
The lack of environmental plan-fling has led to 100 palm oil-based, 89 rubber-based and 283 manufacturing factories being found within watersheds, some are even located above water intake points.
The siting and zoning of industries needs attention to prevent a repeat of the Durian Tunggal incident where effluents overflow into the reservoir.
But sometimes, even if factory discharges comply with DOE standards, the volume may be just too much for a river to absorb. The laws at present control only the concentration of discharges, not the amount.
The DOE has adopted a new approach to control water pollution by classifying rivers according to their use (for water supply, irrigation, fisheries or recreation) so that different pollution loads can be set for them.
Some advocates have proposed that a national water board be set up to take charge of water supply and river management, such as Britain’s National Water Authority.
The state governments are not buying the idea of course, water being one of the few revenue earners that they own.
Environmental Protection Society president Gurmit Singh stressed that rivers cannot be cleansed if government efforts remain concentrated on desilting and rubbish removal.
He stresses that regulations on river reserves, water catchments, soil erosion control and effluent regulations must be enforced.
The Worldwide Fund for Nature is pressing for integrated monitoring of not only water quality, but flora and fauna as well.
It says existing legislations which are oriented towards water withdrawals should be changed to provide for conservation of aquatic resources and ecosystems, which are given little recognition.
It is obvious that our rivers cannot be protected only with laws and regulations alone. Their preservation will ultimately depend upon us adapting our behaviour to the water cycle.
And we should start having our houses and buildings front rivers rather than the other way around. Only then perhaps, will we accord rivers the respect due to them.
Source : Sunday Star February 21 1993
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