Soil cheats polluting the ground

Tan Hui Yee, Straits Times 29 Jan 11;

The stink in Sengkang earlier this year could have been just the tip of the iceberg, according to two compost producers. Soil quality is a major issue in Singapore, where a rising number of developments shrinks the amount of topsoil. This creates incentives for contractors to cheat by stuffing cheap material like discarded wood chips into the ground, resulting in pollutive soil. One landscape architect goes as far as to say that seven out of 10 contractors will throw clay or waste material into planting pits the minute their backs are turned.

LAST September, the air smelled of rot in Sengkang.

After a flood of complaints, the authorities traced the stink to a 200-tonne pile of sludge and wood chips deposited as 'compost' on the site of a half-constructed waterfront district in the north-east of Singapore. Its builder Koh Brothers was fined $3,000 and made to remove the putrid mound from the site.

Like most matters in the Republic, it was swiftly dealt with and just as quickly disappeared from public consciousness.

But some in the landscape industry murmured that this had been a transgression long waiting to happen.

Depleting sources of topsoil, stagnant landscaping prices and fierce undercutting here have ripened conditions for waste and potentially pollutive wood chips to be buried underground, warn landscapers. And the Sengkang incident could just be a manifestation of how little Singaporeans know - and care - about what lies beneath.

Soil quality has been a growing concern, say experts. The import of soil is tightly regulated here because of the potential parasites and other destructive micro-organisms in the material, but the sources of local topsoil are shrinking. Rapid development has doubled the proportion of built-up area in Singapore from 27.9 per cent in 1960 to about 50 per cent now.

And even if soil can be found here, it may not be suitable. The island's predominantly clay soil needs to be either replaced or improved with compost to support urban planting.

Mr Simon Longman, the National Parks Board's (NParks) director of streetscape, says: 'We don't have good soil any more. We have very lousy soil. The cost of transforming lousy soil into good planting material has jacked up the costs.'

As a result, the cost of soil mixture can make up as much as 30 per cent of a landscaping project's value. This big-ticket item is a tempting target for contractors trying to cut corners.

Landscape architect Sherman Stave from Sitetectonix, who has been based in Singapore for the past 20 years, estimates that seven out of 10 landscape contractors regularly try to add inferior or waste material to their soil mixture to lower their costs. Building contractors are guilty too - some dump construction debris in planting areas to reduce their own waste disposal bill.

He says: 'They bury it in the site and then put about a foot of topsoil over it to cover it up.'

The Straits Times understands from landscapers that such infractions are highly lucrative.

Horticulture waste that has properly composted and pasteurised to get rid of pathogens and pests costs about $30 to $50 a tonne. In contrast, raw wood chips comprising ground pieces of pruned branches cost only $5 to $10 per tonne. Since a typical condominium landscaping project requires several thousand tonnes of soil mixture, a landscaper can save thousands of dollars by cheating on the soil mix and adding assorted fillers.

But that's not all. If the circumstances are right, a contractor can even be paid to use these wood chips. This was the case three years ago with ANA Contractor, which was tasked by wildlife group Animal Concerns Research and Education Society (Acres) to level its 2ha plot in Sungei Tengah for development. ANA filled the site with wood chips instead.

In the court case that followed when Acres sued ANA Contractor for damages, the contractor revealed that it was paid $20 'compensation' for each lorryload of wood chips it accepted from its sub-contractor. This amounted to about $40,000 for the whole project.

The resulting mixture rotted and stank, reportedly discharging brackish water that eventually polluted the groundwater and nearby Kranji Reservoir.

The National Environment Agency (NEA), when contacted by The Straits Times, said that it has encountered no other cases of contractors using pollutive soil mixtures in the past five years. While it conducts 'regular checks' on recycling companies to ensure they comply with environmental and public health concerns, it does not check on compost usage.

In a similar fashion, both the Urban Redevelopment Authority and the Building and Construction Authority say they do not regulate the environmental standards of material used for earthfill at construction sites.

But six major firms approached for this article privately admitted that these soil cheats were a problem in their industry.

The chairman of the Landscape Industry Association (Singapore), Mr Michael Teh, while stressing that this was the work of a minority, added: 'It's not something that we are proud of, but it's something that can happen when prices are depressed.'

NParks, whose maintenance contracts for public parks and streetside greenery accounted for 6 per cent of the landscape industry's estimated $1.4 billion revenue last year, is confident it has licked the soil problem for its own work. It imposes stringent tests and inspections and also published specific standards for soil mixtures in 2009, making it harder for landscapers to cheat.

No one, however, knows the extent of the problem in the rest of landscaping work in Singapore.

The manager of a medium-sized landscaping company, which counts a town council among its clients, told The Straits Times that it is a matter of just cheating a bit, but not too much, to remain under the radar. 'If you don't go too far, nobody will notice it.'

His company tries to make its own compost from the branches and leaves it collects from the landscaping work. Without special equipment, this process can take three months or more. In the brisk world of Singapore development, that is three months too long.

He admits: 'Sometimes we don't wait for that long before we mix the wood chips into the soil. We just don't have the time.'

He knows the ensuing rot that continues beneath the soil attracts millipedes and damages saplings over time.

In a way, such cheating is facilitated by the recycling business.

Every year, the Garden City produces more than 200,000 tonnes of leaves, branches and other types of horticulture waste from the regular maintenance work on its urban greenery. To incinerate it, landscape contractors have to pay $77 per tonne. Many, however, prefer the cheaper option of sending it to recycling companies, which mostly charge them $30 to $50 per tonne of waste.

These recycling companies then either process the horticulture waste into compost or mulch, or burn them to generate heat and power.

According to the NEA, there are nine horticulture waste recyclers in Singapore, of which three - Kiat Lee Landscape and Building, GreenBack and ecoWise group - are the major compost producers.

GreenBack and ecoWise, a listed company, allege that backyard operators are collecting horticulture waste for the quick cash, only to grind down the wood and pass the unprocessed waste back to contractors for mixing into soil.

To the untrained eye, the wood chip-laced soil looks 'fertile' because it looks dark.

Of course, random soil tests are conducted by consultants overseeing landscaping work, but these are easily rigged, says landscape architect Mason Tan.

'When you go for inspection, they'll show you the good soil. When your back is turned, they will dump in the bad soil and cover it up,' he says, adding that many projects are done at night because of tight construction schedules.

Similarly, ecoWise group chief executive Lee Thiam Seng suspects that rogue contractors could be buying small quantities of the real compost to evade detection.

'Every alternate week', he says, the company gets a complaint about the quality of its compost which is purportedly used extensively on a development. After ecoWise investigates, it usually discovers that it had sold the contractor in question just one or a few truckloads of its compost.

A typical planting project in a new development requires hundreds of truckloads of the material.

Both ecoWise and GreenBack, which take no more than a month to process compost and produce about 6,000 tonnes every month in total, say they are hurting from the foul play.

Mr Lee laments: 'We are losing a seven-figure sum annually on composting. This is a lousy business to go into, because there is no enforcement.'

His company, he says, survives on its other types of recycling businesses and treats its composting programme as a way to fulfil its corporate social responsibility.

The greater worry is whether the soil cheats are causing pollution.

GreenBack's business development director, Mr Allan Hui, for example, fears unscrupulous contractors are resorting to using wood chips derived from industrial waste wood and household furniture to save money.

The varnish and other wood preservatives inside will not just impede plant growth, but also potentially contaminate the soil and groundwater, he warns.

And such a cost will be borne by many generations to come.

The rot beneath
Straits Times 29 Jan 11;

How do you tell if the soil under your feet is suspect? Landscapers The Straits Times spoke to gave three tips.

# If the ground is waterlogged all the time and algae starts appearing on top: Some contractors cheat by filling most of the ground with clay and putting a thin layer of proper soil mixture on top. But clay cannot absorb water well, hence the frequent flooding.

# Many, many millipedes: Millipedes feed on decomposing vegetation and other organic matter, and exist naturally on soil. However, when a lot of unprocessed wood chips are mixed into the soil - and these wood chips start to decompose - millipedes multiply rapidly.

# Black so what?

Don't be fooled by the colour of the soil. Dark-coloured soil may look fertile but it can be easily created by mixing in fake compost or wood chips.