Master’s Thesis: Geographies of Urban Filth

year: fall 2018

type: academic

location: Toronto

supervisor: Rick Andrighetti | committee member: Dereck Revington | Internal Reader: Anne Bordeleau

The thesis studies how our cultural understanding of dirt and cleanliness are bound to issues of class and race and how they are manifested within urban and spatial design. Boundaries are formed between clean and dirty, familiar and foreign, us and them, through the rejection of matter that is disturbing or threatening to us. The city carries with it multitudes of identities, consequently forming divided groups and communities within spaces of belonging and exclusion. Thus, the thesis proposes a theoretical approach which questions our current conventions and practice of categorizing spaces, unearthing and bringing us in touch with the rejected β€˜other’ within the city and within ourselves. This thesis grounds itself on existing ideas of identity and otherness by Julia Kristeva, R.D Laing, Krzysztof Wodiczko and Mary Douglas. In Julia Kristeva’s essays on abjection, she describes abjection as the discomfort caused when impurities and contamination become a threat to one’s own identity and order. It is when borders that are meant to protect us from the other, become ambiguous. The inherent fear of the abject breeds an obsession for purity which erases opportunities to engage with and understand those other to ourselves.

These ideas of the self and the other, cleanliness and dirt, are explored through the intervention of the North Toronto Wastewater treatment plant central to three physically and socially disconnected neighborhoods of different income levels and ethnic groups. The treatment plant sits hidden and disguised below city level within the Don Valley ravine, collecting and filtering wastewater from these neighboring communities and releasing it back into the Don Valley River. Mary Douglas examines our cultural understanding of dirt asserting that dirt only exists through our categorization of space. Materializing these ideas into spatial design, the design proposal seeks to challenge the tension that the pure vision of the city has with its dirtier and wilder counterpart which is the wastewater treatment plant, the ravines, and the sewers. The design proposes the breaking down of boundaries between perceived β€œclean” and β€œdirty” spatial and social constructs with the insertion of a public space and bath within the wastewater treatment facility. The departure from the safety of the familiar city, and entrance into ambiguous marginal territories, allows one to experience moments of vulnerability where the questioning of one’s own identity and reflection of one’s own strangeness allows for a deeper understanding of the other. With the appropriation of the wastewater treatment plant, the strangeness of oneself within the foreign environment allows the stripping of borders to confront the strangeness of another.

Public swimming pool in the North Toronto Wastewater Treatment Plant

Existing site plan: North Toronto Wastewater Treatment Plant

Existing site plan: North Toronto Wastewater Treatment Plant

Existing site: North Toronto Wastewater Treatment Plant

Existing site: North Toronto Wastewater Treatment Plant

dirt model as design tool

dirt model as design tool

dirt 6.JPG
building plan

building plan

section a

section a

section b

section b

section c

section c

section d

section d




New paths and walkways are introduced to connect the neighborhoods to the wastewater treatment plant. The light metal grill walkways merge with or are extensions of existing trails lifting them off the ground and through the canopy of the trees. Some walkways are passive, watching the processes of the site at a distance hidden within the trees, occasionally extending out to offer a view onto the site.


Others are more daring, meandering within the trees until it reaches the clearing of the wastewater treatment plant and thrusting itself over the pools of rushing wastewater. The path thickens above the water tanks and the railings tilt outwards offering an invitation to watch and stay a while vulnerable to the odors and sounds of the water.

The floating walkways play with the boundaries of the site, between the safety of the pure city and the filth of the wastewater treatment plant.


The walkways converge at the mound, the tallest point within the site. The existing mound which covers the digesters is extended and connected back into the landscape concealing the addition of a tertiary treatment space below it. The mound forms an informal separation between the existing operations of the wastewater treatment plant and the public space preserving visual connections while allowing critical operations on site to proceed undisturbed.

An existing cluster of sheds sitting above the mound is the main point of entry. They are encased within a glass enclosure on display as operating artifacts of the site. Within the glass enclosure, the interior of the sheds are cut away and revealed, housing the machines that churns the wastewater sludge within the digester tanks below them.

Stairs cut through the floor bringing people underground into the bowels of the city, between the large cylindrical concrete digesters. Windows into the digesters give glimpses into the churning sludge where organisms break down the filth of the city into methane gas to heat the wastewater buildings and the steam room.

base image by photographer- louis perreault- les affluents

base image by photographer- louis perreault- les affluents

The walkway leads to the underground tertiary treatment space containing water filtration machines where water from the end processes of the secondary treatment is diverted into for further treatment. The darkness of the underground is illuminated by the skylights and their reflections on the pools of rushing water. The movement of the water is projected on people’s faces distorting them.


Steps downwards bring people between the tanks at eye level with the surface of the water, watching as others float between tanks of water, making eye contact with strangers acknowledging the smell, and a shared discomfort.

Water is carried from tank to tank through pipes guiding people through a series of water filtration processes. First, the ultra-filtration process filters water using membranes with the pore size of 0.1 micron, removing high and low molecular weight substances such as sodium and calcium. Next the rows of UV tanks deactivate DNA remaining in any organisms. The Reverse osmosis process then filters out drugs and viruses. At the end of the hall, the water receives the end process of filtration through the ozone activated carbon filtration machines which removes odor and taste.


Passing through the archway of the wall, the sound of the flow of water continues through the wall falling below into tanks that sit below the walkway. The large tanks hold the newly filtered water that once ran through the city and the bodies of its inhabitants, spilling out from spouts, under which people are showering.

Bodies catch the water spilling out washing away their filth, yet their eyes and mouths are closed weary of the cleanliness of the water that washes them. The water falls through the wooden planks under their feet bringing the dirt washed away from their bodies towards the wetland, within which people swim.

The bays of change-rooms are intimately arranged within a semicircle, resembling the digester tanks. The sun penetrates the skylights, and its warm yellow glow heats the concrete and floors. The small frosted glass windows break the monumentality of the concrete, opening views towards the wetland and a blur of moving bodies.


From the outside- in, the foggy windows distort views of faces, feet, legs and ankles… their occupants allowing a comfortable vulnerability.


Following the flow of water beneath the floor, and slipping between the bays of concrete cylinders, the wetland is revealed cupped within the mound. A shallow pool which receives water from the plant sits above the wetland, within which people soak their feet, and cool down during hot days.

A concrete island within the pool is a stage for performance or play, and the edge of the pool acting as seating or sunbathing. The concrete border drops away at the edge of the pool, creating a waterfall converging the water into a deeper pool contained beneath the surface of the wetland.


A discrete path leads into a third pool embedded deeper within the wetland, concealed by tall cattails, reeds, and other wetland species. There is a loss of orientation with only sounds of water falling and the occasional train passing by. It is a found space shared between strangers.

As the water is bathed in, the wetland species continue to filter the water.


The last pool operates as a heated pool during the wintertime. It sits above the wetland receiving hot water through a water channel from the boiler and steam room within the converted digester.


The swimming pools and the wetland is held by the retaining wall which swells with water released from the tertiary treatment process. Water slowly trickle down its sloped face where people sunbathe and play watching as the water rejoins the restored wetland which filters the water a last time before it flows into Don River.

Existing entrances into the underground bunker space lead onto existing catwalks which float between the 15 m wide by 10 m tall digesters.


The once decommissioned bunker allows three digesters to retain its original function. One digester is converted into a boiler and steam room, while the others are left as empty vessels appropriated as spaces for art installations and performances. New walkways extend into and through the concrete cylinders leading visitors from one realm of space to another, witnessing something beautiful and spectacular taking the place of the sludge that once churned within it.

Stairs from the catwalks lead to the bottom of the digesters, where people experience the space and artwork in more active ways. The base of the digesters drape open encouraging the interconnectedness of activities and artworks. Visitors slip from one digester to the next, the experience is an exploration of space, light and darkness, sounds,of each other and the self.


Exiting the bunker space, people leave the site from the mound they arrived from, returning, or continuing along another path.

The choreography through the site is not meant to force interactions between others but rather to provide a shift in perspective in how we perceive dirt or cleanliness, strange or familiar, in order to provide opportunities for meaningful interaction as a negotiation of differences. The interconnectedness and ambiguity of dirty and clean spatial categorization enhance moments of vulnerability allowing each person to reflect on, question, and perhaps rethink the ways we perceive those we see other to ourselves.


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