We can’t just flush away horrors like ‘fatberg’
The world is slowly waking up to the harm caused by what goes down the drain. Studies are documenting the impact of urine-borne antidepressants and birth control hormones on fish populations. Consumers are shying away from soaps with microbead exfoliants, which become plastic fish food. We’re just beginning to see innovations to capture microfibres released in laundry water, which also contaminate the food chain.
For all the invisible and inadvertent harm we flush into our waterways, there are plenty of times we clearly should know better. And every one of them is expressed in the visceral horror of the “fatberg.”
Last week, the world learned of the Whitechapel fatberg, a 130-ton mass lurking in the sewers under east London. Each year, a nation in love with its fish ‘n’ chips and bubble and squeak pours millions of litres of cooking grease down the drain.
The fat congeals around other debris — particularly disposable wipes, diapers, condoms and tampons — which glom together to form giant pipe-clogging stalactites.
It’s not the first mass to wreak havoc with London’s 19th-century infrastructure. In 2013, sewer workers at Thames Water christened a 15-ton fatberg lurking under the borough of Kingston. At the time, representatives called it the largest “single congealed lump of lard” they’d ever seen.
Well, that was then, this is now. The Kingston fatberg was the size of a bus. The Whitechapel obstruction, at 250 metres, is longer than two football fields. It will take a team of eight workers three weeks to break it up with high-powered hoses. Plans are afoot to put a chunk of it on display at the Museum of London, to shock people into thinking about what they flush down the toilet.
Londoners are not the only transgressors. The most famous Canadian fatberg surfaced in Halifax in 2014. Heavy rains caused a floating mass to ooze up above street level, lifting a manhole cover in the middle of the road.
Heavy rains can also trigger “sewer bypass events,” wherein storm water overwhelms treatment facilities and untreated or partially treated sewage is released directly into waterways.
For example, frequent overflows have plagued Toronto’s combined sewers — an outdated system where storm water and sewage flow through the same pipes.
The City of Toronto website details items that should never be flushed or poured down the drain. Disposable wipes top the list: “even those that say flushable can cause a problem.” Other common offenders include condoms, dental floss, cotton swabs, facial tissue, paper towel and, perhaps surprisingly, tampons. Household hazardous waste, pharmaceuticals and grease round out the list of refuse requiring drainless disposal.
Personal wipes and baby wipes are a huge problem, “even the ones they’re calling flushable,” affirms Krystyn Tully, vice-president of Lake Ontario Waterkeeper, a charity working for clean lakes. Wipes often flow directly into waterways, she notes. “The City of Toronto employs workers whose sole job it is to clean wipes and debris off the overflow pipes.”
“When fat builds up in the sewer, raw sewage can overflow into creeks and rivers and lakes,” Tully adds. “Then you get the double whammy of grease and sewage.”
If there’s a silver lining, it’s that fatbergs can be recycled into biodiesel fuel. After filtering out water and solid contaminants, the typical haul is between 25 and 40 per cent oil, according to a video by biodiesel producer Argent Energy.
Of course it would be more sensible to skip a step and convert used cooking oil to biodiesel without the expensive recovery project. McDonald’s proudly proclaims more than half its UK delivery fleet is composed of “veggie lorries.” It’s a good start.