The German broadcaster Deutsche Welle produces a lot of material in English; recently it released a ten-minute clip with the above title. I plan to use it in my class on water resources next year, it is that good. You can catch it here (the full URL is given below if need be).
Host Carim Soliman narrates it while sitting, appropriately, on a toilet. (You may notice the towel drying rack on his right; very common in Europe, but rare here, alas.)
As expected, the historical recap mentions the role of John Snow (of Broad Street pump fame), of London’s Great Stink’s role in the development of sewers, with a nod to Kit Harington of Game of Thrones (you have to watch).
It also talks about what happens when sanitation is lacking: disease, increased violence towards women and girls, and poverty. In that context there are interesting interviews, including with Alexandra Knezovich of the organization Toilet Board, which aims to bundle data gathering, toilets, sewers, and wastewater treatment into a business opportunity (for India alone, this represents a market estimated at US$97 billion). Also featured are Rolf Knoche of Engineers Without Borders (a very cool organization, that; here’s a link to the Canadian branch), and Dominic O’Neill of the Sanitation and Hygiene Fund.
Lack of sanitation is a huge problem, and one that climate change is making worse (think bigger storms and flooded pit latrines). As Soliman says about toilets: many, many people around the world need one, and we all need new ones.
The link to the video is listed below (as well as the link to the German version, if you prefer).
Newly discovered ultrasmall parasitic bacteria attached to a larger troublesome colleague
Steve Petrovski and his team in La Trobe University in Melbourne have discovered a brand new type of micro-organism: a supertiny bacteria that acts as a parasite to larger (normal) bacteria.
As reported recently in WaterWorld, Petrovski was looking for a biological means of controlling Gordonia Amarae, a bacterium that causes foam problems in wastewater treatment. But instead of finding a bacteriophage, as expected, he stumbled onto a completely new type of bacterium.
Whoa! There is a lot to unpack from the previous paragraph.
First, foam. It can be a big issue in wastewater treatment plants: a thick, unappetizing brown froth that stubbornly refuses to collapse when sprayed with water, impedes aeration, and potentially carries pathogens. This occurs when filamentous bacteria such as Gordonia Amarae colonize the bacterial broth used to clean up sewage. These bacteria release a surfactant in order to solubilize and eat non-soluble substances like oils.
Once established, they are hard to control; I found a recent review that lists a variety of nasty chemical methods – not ideal when you want to release treated wastewater into the environment.
Foam in a secondary treatment plant
Bacteriophages? These are viruses that prey on bacteria, including human pathogens. They are the ones that look like moon-landing modules, and are being considered as a way to treat some bacterial diseases that have become resistant to antibiotics (review here).
Petrovski thought he would surely identify a phage to deal with the pesky foam bacteria, but no, bacteria like Gordonia have tricks to defend themselves against virus attacks. But he and his team found a parasitic bacteria, something never observed before. That is big enough news to warrant a coveted publication in the prestigious Nature magazine, where the new bug is named as mycosynbacter amalyticus.
Said Petrovski:
“One particular bacterium — Gordonia amarae — is notorious for causing persistent and stable foams in wastewater treatment plants. Through our work to isolate a phage that will target G. amarae, we accidentally stumbled across another potential solution—a previously unknown microscopic parasite attached to the bacterium.
Some organisms related to G. amarae can also cause disease in humans and animals such as nocardiosis and bacteremia, and this novel ultrasmall bacterium could potentially be the cure.”
It’s a big deal, and not just for wastewater folks. Other types of Gordonia like to live in rubber, which can produce nasty complications when using catheters and similar things (review here).
So once again: studying shit (aka sewage) produces scientific gems. It should never be ignored.
Toronto’s Don River is undergoing a large makeover, one that aims to return the river to a semblance of ecological health. It’s an ambitious initiative, but already the river is no longer the dead open sewer it once was.
Due to intense urbanization and the increase in paved surfaces throughout the Don River watershed, there are fewer opportunities for stormwater to seep into the soil or be taken up by vegetation. Therefore much of the stormwater runs off the surface into the Don River resulting in streambank erosion and increased flooding during storm events. Combined sewers (carrying both stormwater and sanitary sewage) still exist in Toronto. Excessive runoff from large storm events can cause these sewers to overflow into the river, affecting water quality.
Hmm yes, combined sewers and paved surfaces, the bane of modern cities. But the main Toronto river ravines, especially the Don and the Humber, were treated as convenient waste disposal spots. And they stank. Roy MacGregor notes that the Don ravine was doused in perfume for the visit of Princess Margaret in 1958 (her itinerary had her cross over the river).
The Humber flooded badly in 1954; it took the death of 81 people, many drowning when the hurricane-driven flood tore away their homes, for the authorities to prevent building in the floodplains of the ravine rivers. At the same time, a growing awareness of the dangers of raw sewage disposal led to the development of wastewater treatment plants and higher capacity sewers. So there has been marked improvements.
Ravine slopes are strewn with trash. And every few hundred metres the banks are interrupted by pipes and outfalls, which attest to the river’s unspoken but primary function: open sewer. Excrement floating by – that simply wouldn’t do. Nor would watching all of it get washed away by catastrophic floods. Toronto is bent on eliminating both hazards.
McClearn wrote this to introduce Toronto’s new initiative to restore the Don, as part of an excellent series of articles on the river in the Globe and mail recently. The articles describe the challenges and the initiatives, from making the ravine trails accessible and inviting to all members of the Toronto community, minorities included, removing invasive species and promoting native flora and fauna, among others, and returning the lower Don to a semblance of natural state. But the biggy remains the control of sewage overflow:
The municipality has installed storage tanks for wastewater, for example, and ordered homeowners to disconnect their eavestroughs from storm sewers. The city’s street sweeping program reduces particulate matter and other contaminants that would otherwise end up in stormwater drains. A philosophy underpins all this: Stormwater should be dealt with close to where it falls rather than evacuating it wholesale through sewers, creeks and rivers.
The three new tunnels will effectively replumb older neighbourhoods, directing their sanitary sewage to the Ashbridges Bay Treatment Plant. Since construction began in 2018, a tunnel boring machine has excavated roughly half the 10.4-kilometre Coxwell Bypass tunnel, roughly 50 metres underground. Four of five large storage shafts, which will store stormwater during extreme rainfall until it can be treated properly, have also been cut. When all three tunnels are completed around 2038, combined sewer overflows would cease forever.
“Rerouting the CSOs is a big deal,” [senior project manager for aquatic monitoring and management Angela Wallace] said. “Once they take all of those offline, there should be some sort of recovery” in the watershed.
Kudos for Toronto! I never thought I’d say that but Toronto has lessons for Vancouver. In the same series Frances Bula writes
The same [neglect] is true in Vancouver, which given its topography should have many great ravine parks – but does not. Residents and businesses used ravines as garbage dumps and sewers for decades, before filling in many of them to make more land for houses and an unvarying street grid. As a result, only about 4 per cent of the land in Vancouver consists of original pieces of the natural environment. In Burnaby, next door, it’s 24 per cent.
The state of Vancouver ravines began changing three decades ago, when people living near some of the last remaining sections started trying to clean them up. “We were filling dumpsters two times a year with everything: universal gyms, home renos,” recalled Carmen Rosen, the director of a group, Still Moon Arts Society, that works on improving the Renfrew Ravine and adding art to it.
The culture of what we flush 