Trash Talking The Gowanus Canal, One Of America’s Most Polluted Waterways

Environment, Personal, Science

Every morning before I unlock the door to the office, I walk a few extra steps onto the Union Street Bridge just to stop and smell the coal tar. Okay, so maybe it’s to take in the view, but water coming from the Gowanus Canal — one of the most polluted waterways in America — offers a stench most couldn’t imagine. People often find the canal to be nothing short of repugnant, but I disagree. There’s something so marvelous and mysterious about those murky waters and I’m eager to tell you more about them. 

I started at the Gowanus Canal Conservancy in early September of last year and began working with a group of seven fierce females, all of whom are strong and unapologetic environmental advocates. These women continuously guide me, teaching me everything I need to know to effectively lead our educational programming, which consists of walking tours, Citizen Science water quality testing field trips, clean and green stewardship events, and a whole lot more. This crash course gave me an intense and comprehensive understanding of the Gowanus Canal and why it’s so important to teach others about it. It’s not only a waterbody, but a place that has allowed me to refine my skills as an environmental educator and advocate, and harness a passion that lights a fire within my soul. So let’s dive right in. 


Service In Schools Leadership Institute

The Early Days

The Gowanus Canal is known as one of the most polluted bodies of water in America, but it wasn’t always this way. In fact, this canal began its life as a salt marsh — a wild, natural ecosystem that harbored an abundance of plant and animal life. Native American people, like the Lenape, depended heavily on the Gowanus salt marsh lands, respectfully utilizing its natural resources. These resources consisted of long and wild grasses, a plethora of fish and oysters, and brackish water, a mix of both salt and freshwater. (The water is brackish because the canal is linked to the Atlantic Ocean, the East River, and Hudson River.) 

Aside from harboring plant and animal life, salt marshes also provide protection. Being on an island, residents are subject to heavy coastal storms. In years past, salt marshes had the potential to reduce the speed and impact of these storms by absorbing the waves as they came through. Unfortunately, this particular salt marsh was later transformed into a canal, where much of the aforementioned natural greenery was paved over. This was not abnormal for the growing city. In fact, more than 75% of New York City’s salt marshes and wetlands have been paved over for development. This puts residents in a great deal of danger when considering the impacts of climate change and the inevitable future of storms increasing in both frequency and intensity. But before I get ahead of myself, I need to explain how the canal ever came to be. 

During the period of urbanization in the early 1600s, European settlers invaded the Gowanus area. (You know, the original immigrants, our ancestors.) They forced the Native people out and began building homes of their own. But it wasn’t until the late 1700s/early 1800s, when the industrial period kicked off, that environmental change really starting taking shape. To start, the European settlers decided to transform the salt marsh into an industrial canal to ensure a more effective transportation route. Obviously, there were no cars, highways, or Amazon Prime orders at this time and people wanted things faster and easier. (Such is the American way.) The salt marsh was dredged and channelized and bulkheads were installed to make room for boats. The Gowanus Canal quickly became one of the busiest working canals in America, which as you can imagine, did contribute a bit to its pollution problem. However, boat pollution was and is the least of this canal’s problems. 


Brownstoner – Historic Gowanus Canal

 Great Big Polluters 

During the same time the salt marsh to canal transformation was taking place, factories were being built up along the degrading shoreline. These factories came in all shapes and sizes — some were for box manufacturing, others for paints and inks, and then there were the three manufactured gas plants (MGPs). Nearly all industry played a role in polluting the Gowanus waters, but the MGPs were by far the biggest contamination culprits. These plants converted coal into electric energy, but in doing so, created a toxic, carcinogen-rich byproduct called coal tar. 

Coal tar can be described in two ways: on the bottom of the canal, it appears as slimy, black, and somewhat chunky. Coal tar has been lovingly nicknamed Black Mayonnaise for those reasons. However, coal tar is a gas and has the ability to seep both below the sediment and above the water and into the air. This form of coal tar appears as a colorful, oily sheen, similar to a soapy bubble blown from a toy wand. Coal tar, of course, is far more dangerous than a soapy bubble. It smells a lot worse too. 


Coal Tar (Black Mayo)















So back to the MGPs. Once this byproduct was created, it was immediately dumped into the canal, along with a host of heavy metals, including mercury and lead. The industry workers wanted nothing to do with the heinous materials and there were obviously no laws at the time forbidding this action. 

In 1972, The Environmental Protection Agency (EPA) passed the Clean Water Act, a law which made the dumping of toxic material illegal. While the Clean Water Act has made a significant difference, it arrived far too late to reverse the damage. The waterway is still very heavily saturated with the material, which is bad for humans, animals, and plants alike.

Coal tar, despite how toxic it may be, has its fair share of competition in contaminating the Gowanus Canal. 

More than 60% of New York City utilizes a combined sewer system, which means all wastewater and stormwater flow through the same pipe. In theory, this material should be transported to a wastewater treatment facility to be scrubbed of all contaminants, then released into nearby waterways. Unfortunately, too much rainfall can overwhelm the sewer system, rendering it impossible for all material to be treated. And where do you think all of that excess, untreated material goes? Our waterways! This process is referred to as Combined Sewer Overflow (CSO) and it’s a huge issue not only for the Gowanus Canal, but also for all other waterways in New York City, and many other waterways in older cities around the world. 

Back when these sewer systems were initially built, CSO wasn’t a concern to anyone, as was and still is the case for most environmental issues. But back then, the populations were smaller and when CSO events did occur, the damage was far less frequent and impactful. Today, in New York City, it takes less than 1 inch of rainfall to trigger a CSO event, which means they happen all the dang time. And it’s disgusting

But let’s consider what combined sewage overflow really consists of because it’s easy to chalk it all up to “stormwater” and “wastewater”, but there’s a lot more going down our drains and into our sewers than we often realize. A more comprehensive list of household CSOs include shampoo, conditioner, soap, face wash, toothpaste, urine, feces, toilet paper, detergent, bleaches and other toxic cleaning supplies, foods, liquids, cooking oils, and all the other weird stuff that somehow makes it down your drain. A more comprehensive list of outdoor CSOs include animal waste, car oil and other chemicals, litter, cigarette butts, and anything else rainwater can pick up as it flows down the street. And don’t forget, big industries also put a lot of nasty stuff down the drain — chemicals and toxic materials we probably know nothing about. Now imagine swimming in a big pool filled with all of this stuff? I don’t think so. 

How to successfully eliminate combined sewage overflow is a big question with no easy answer, and with the constant increase in population and climate change-related storms, change needs to happen quickly. Every year, the Gowanus Canal receives 377 million gallons of CSO. During Superstorm Sandy, it received 11 million gallons, just within the span of a few days. That’s a lot of material for our 1.8 mile canal. 


CSO Warning Sign

Luckily, there is hope. There are solutions to both of these complex issues and work is being done on a daily basis to ensure a cleaner and greener future. When I get to this portion of the tour, the children I’m teaching are skeptical, as would any reasonable, earth-loving humans be. But I’m also seeing the fire in their eyes. These kids are pissed and they want to do something about it. I once asked a group of sixth graders why they think people felt the need to transform a salt marsh into a canal. The answer was transportation of course, but instead I was met with “Because human beings are selfish. They have no respect for the environment and only care about themselves. They don’t care if the world burns down.” 

Imagine having that in your head at the ripe age of 12? These kids are going to make a difference. They must. 

It’s Complicated 

Back in 2008, the city put forth a request to rezone the Gowanus neighborhood. However, it was quickly shut down, as the Environmental Protection Agency (EPA) was working its case for a Superfund cleanup for the Gowanus Canal. In 2010, the EPA officially declared the Gowanus Canal a Superfund site, squashing any final hopes for a rezoning at that time. Now, nearly a decade later, plans for rezoning have returned.

The initial purpose for the rezoning was to convert an old, industrial neighborhood into one of mixed use — a space filled with residential developments, restaurants, the works. This is still very much the case, but that overall vision could become much more meaningful. This transformation has the potential to be a very good thing, but it can also be terribly bad. For instance, all developments will be required to provide at least 40 feet of public space surrounding the canal. This provides an opportunity to enjoy additional greenspace as the canal becomes a healthier waterbody. A con that often comes up with any form of new development though, is the potential for gentrification. By building modern, high end developments, the price of real estate will soar, pushing lower income residents out. This happens all over New York City and all over the world. And while the rezoning proposal promises a small portion of additional affordable housing, current low-income developments are not well maintained. Plus, when we see the term “affordable housing” we must ask ourselves, affordable for who? 

During Superstorm Sandy, lower income residents living in the Gowanus housing community suffered the most. Not only does the housing complex lie directly on a floodline, but it is also neglected in many ways with damages, outdated components, and a general weak infrastructure. Residents of the Gowanus Houses were without power for 11 straight days, which meant disabled residents were unable to utilize elevators to leave their homes. They, along with other Gowanus residents, dealt with a significant amount of flooding, which brought toxic material from the Gowanus Canal up into the streets. 

But on this topic of nasty storms and climate change, it’s important to mention that this rezoning provides an opportunity to create a stronger, more resilient waterfront, one that could possibly withstand a future filled with intense storms. The Gowanus Canal Conservancy is working hard to promote its Lowlands Master Plan. This plan provides an abundance of suggestions and ideas for landowners and community members in an effort to build a neighborhood with a significant environmental focus. The goal is to create a space that is both effective in its green infrastructure and enjoyable for visitors and residents. 


Gowanus Canal Conservancy – Lowlands Master Plan

“Gowanus was once a literal lowland – a productive tidal marshland with a deep floodplain, salt meadows and oysters the size of dinner plates. Leveraging the upcoming Superfund cleanup and DEP’s investment in green and grey infrastructure, the Lowlands includes watershed and site-scale strategies for a cleaner, more resilient urban ecosystem.”  

The Conservancy is frequently making updates to this master plan to reflect community opinions and suggestions. This is very much a shared process. The Lowlands Master Plan provides a great deal of promise for a less frightening future, but community support is essential. If landowners choose to turn the other cheek, this work will be all for nothing. 

Nearly every space along the canal has been purchased. These developments will bring in hundreds, if not thousands, of toilets further contributing to the issue of CSO. There are plenty of responsible ways for landowners to manage this waste, but the question is, will they? 

The Turning Tides — Superfund Status 

In 2015, Christopher Swain went for a swim in the Gowanus Canal, and no, he wasn’t running from the cops as many often do. He intentionally did this on Earth Day to raise awareness for our waterways and to display just how badly we’ve damaged them. His plea for better water quality standards was heard loud and clear that day. 

Swain is not alone in utilizing the waterway as a means for advocacy. The Gowanus Dredgers Canoe Club often holds free, public events, which include a self-guided canoe or kayaking adventure. Some cringe at the thought, but many take the opportunity to learn more about the canal and gain a better understanding for what needs to be done. You can’t care about something you know nothing about, and this organization gets you up close and personal with Gowanus water. Though, I would advise you to keep your hands and feet in the vehicle at all times. 

While most wouldn’t jump into toxic sludge to prove a point, many think quite similarly to Swain. It’s safe to say that the tides are turning and positive change is en route. 

As mentioned earlier, the EPA declared the Gowanus Canal a Superfund (or Superfun!) site in 2010. This began a very long and tedious process. Many assume that once a Superfund site is declared, cleanup efforts begin almost instantly, but the process involves a lot more than people realize. To date, the total cleanup is projected to cost around $600 million, with estimates increasing every day. When I ask my students who’s responsible for paying this cost, I usually hear responses like, “Taxpayers!”, “Residents!”, or my personal favorite, “Donald Trump!” (if only that were true). But none of them have ever gotten it right.  

Potentially Responsible Parties (PRPs) are funding the cleanup. Remember those manufactured gas plants? Those are now owned by National Grid, who is responsible for funding roughly $100 million. Other liable corporations include Con Edison, Viacom, Sears, and the City of New York.

But what exactly is the Superfund accomplishing? The goal is to solve one of the canal’s two major problems — the complete removal of coal tar. To do this, the EPA has a two step process referred to as dredging and capping. Workers begin by dredging (removing) up to 10 feet of contaminated sediment. That sediment is then transported to a dewatering facility, where water is separated from the contaminants. The water is treated and brought back to the waterway, while the contamination is brought to a landfill in New Jersey. I wasn’t very pleased when I was first given this information, but as it turns out, the complete elimination of toxic waste is pretty challenging and would definitely cost a pretty penny. Coal tar is referred to as a legacy pollutant for this reason, it’s really tough to get rid of. 

The second step of this process, the capping, is exactly what it sounds like. A three-layer cap is placed at the bottom of the canal to ensure no additional coal tar rises to the top. Unfortunately, since coal tar is such a powerful gas, it has the ability to seep hundreds of feet down. It would be impossible to dredge that much material or to ever ensure all portions of the coal tar was removed. The cap will keep that material out (hopefully). 

While the cap will provide a top layer that promotes the rebuilding of habitat, the habitat that currently exists in the canal will be disrupted and threatened. And YES, the canal has plenty of plant and animal life! If you had a super safe scuba suit and dove into the canal, you would likely find Atlantic Silversides, mummichogs, minnows, blue crab, horseshoe crab, eels, and mussels, to name a few. Floating on top of the water, you would find Snowy Egrets (a type of herron) and ducks. Along the shoreline, you would find a cornucopia of both native and invasive plant species. 


Gowanus Canal Conservancy – Superfund Site

The canal formerly housed an abundance of large oysters, but they’ve unfortunately been gone for quite some time. Luckily, there are many organizations, including the Billion Oyster Project, working hard to bring them back. Oysters, being filter feeders, are of utmost importance, as they have the ability to purify contaminated waters and would prove to be extremely beneficial to our waterways.

As a member of the Community Advisory Group (CAG), I have the opportunity to hear from EPA and City representatives at our monthly meetings. We receive updates on cleanup progress and whatever else they wish to bring up. This ensures the Gowanus community is aware of relevant changes as they’re taking place. CAG meetings can be really effective spaces.

The cleanup process will likely take quite a few years. Projections change often, but as we come closer to the decade mark of when the Superfund was announced, I think it’s clear that we still have a ways to go.

Going Green

So now we have a whole other issue to deal with — combined sewage overflow. Now, with the assistance of both green and gray infrastructure, CSO can be successfully managed. But we need a lot of it. Green infrastructure deals specifically with green spaces that can mimic nature’s natural processes, mainly to absorb stormwater. Gray infrastructure deals specifically with our sewers and how we can store additional sewage material in separate storage tanks or tunnels. The City is currently working to increase green and gray infrastructure in the very near future, however, even after all of the planned projects are completed, the Gowanus Canal will still receive about 115 million gallons of CSO per year. Of course, a 262 million gallon reduction is a great start, but we still want more. We want a waterway that can host a more diverse, vibrant collection of habitat and we want a waterway that can be used for recreational purposes. 

While both types of infrastructure are essential, my focus is always on the green. Green infrastructure is crucial for urban landscapes because it offers something a city rarely has. The city is inundated with concrete, pavement, and other impermeable surfaces. And what happens to stormwater when it hits the pavement? It just rolls right down the street, until it ends up in a sewer or a waterway, further contributing to CSO. But in less urban environments (imagine the countryside), CSO isn’t an issue because stormwater is easily absorbed by trees, plants, grasses, and other greenery. Thus the importance for green infrastructure in New York City. 

I discuss this issue with my students and walk them over to a bioswale, which is also referred to as a rain garden. Bioswales are incredible because they’re aesthetically pleasing greenspaces, filled with strong native plants, that can hold way more stormwater than one would ever expect. Bioswales look incredibly similar to tree pits, but have an inlet and outlet for water to filter in and out. A standard, 20ft x 5ft bioswale can hold 2,250 gallons of stormwater during any single rain event. Lucky for us, the desire for bioswales is constantly increasing, which means there are bioswales popping up all over NYC, helping to mitigate CSO. Though these structures seem simple, they’re actually highly engineered. Each bioswale is roughly 5 feet deep and is filled with materials like geotextile, porous concrete, gabion, native soil, and gravel to ensure maximum absorption. 

Bioswales are also low maintenance and the minimal maintenance that is required is handled by the Department of Environmental Protection, or DEP. Maintenance typically consists of tasks like removing litter, weeding, and pruning. 

There are also a host of green infrastructure projects throughout the city making an even larger impact. Sponge Park, while similar to a bioswale, is much larger and far more advanced. Sponge Park utilizes two massive underground storage tanks and can hold up to 1-2 million gallons of stormwater during a single rain event. 


DLAND Studio – Sponge Park

Other GI projects include rainwater harvesting tents, green roofs, and blue roofs, all of which are utilized at the Gowanus Canal Conservancy site. 

Funny enough, the last place I take my students is Whole Foods. And no, not for the delicious, overpriced snacks. As it turns out, this one specific Whole Foods in Brooklyn was deemed the most sustainable in the entire state of New York. Solar panels, wind turbines, electric car charging stations, permeable pavers, and an abundance of greenspace are some of the items visible by the parking lot. On the roof, Gotham Greens maintains one of a few rooftop gardens, offering its produce downstairs in the store. The Whole Foods building was also built completely from reused and recycled materials. Not many supermarkets operate this way, so it’s a joy to see that some corporations are doing their part to work in a sustainable, environmentally friendly manner. 

A Glimmer of Hope

When I wrap up my walking tours with students, I like to see what they took away from the 1.5 hours we just spent together. We also talk about ways they can make a positive impact on the environment. 

If there’s any single message I can leave with you, it’s this: We can all do our part to reduce harm to this earth. A lot of folks have the “my one vote doesn’t count” or “the big corporations are the ones to blame” mentality when talking about the environment, but if one million people collectively give up their plastic straws, we’re all making a big impact and we’re also driving the demand down for plastics — encouraging companies all over the world to adopt alternative practices. (i.e. providing metal, compostable, or paper straws in restaurants.) Change can happen if we make it. 

So here are a few ways you can make an ever so slight change to your daily life: 

  • Reduce your personal water use, especially during a storm. This will reduce CSO if you live in or anywhere near a city.
  • Say no to plastic straws or bring your own reusable straw. 
  • Say no to single use plastics in general (plastic silverware, plastic bottles, plastic containers, etc.) All of these items are made in a reusable form, so run to Target and grab yourself a to-go silverware set and a trendy reusable bottle. 
  • Eat less meat (or eliminate it if you’re feeling brave.) Meat consumption provides the highest rates of carbon emissions worldwide. (Beef is the worst offender.) Simply reducing your meat intake even a slight amount can drastically reduce your carbon footprint. 
  • Reduce energy consumption or consider renewable energy options, like solar.
  • Reduce, reuse, recycle, and compost! Try to create less waste when possible, reuse and recycle when you can, and compost if possible! There are a variety of compost options out there and I’m happy to help you learn more about them. 
  • Shop local. This reduces transportation-related carbon emissions. 
  • Shop for environmentally-friendly products, like cleaning supplies, hygiene supplies, etc. 
  • Support environmental issues on local and national levels. 
  • Volunteer with local organizations (like the Gowanus Canal Conservancy)
  • Educate yourself on potential solutions and share them with others! 

You get the picture. There’s a lot we can do out there and the above are just a few examples. I know all of this can sound a little daunting, but just remember, there’s hope! We’ve got a whole new generation of kids gearing up to fight this climate crisis, and while they shouldn’t have to step up the plate, many of them seem eager to do so. Like Ethan, a sixth grade boy I met on one of my tours. He told me, 

“When I grow up I want to become a Marine Biologist. I’ve wanted that since the third grade. I love doing things like this and taking any opportunity I can to learn about this stuff. Everything going on in the world can be so frustrating. Like people who litter! I’ll never do that. I’ll carry my trash with me for miles. But yeah. I’m really excited to become a Marine Biologist.” 


Students Discussing CSO

Ethan gives me hope and I hope he gives you hope too. And as for the Gowanus Canal, there are undeniable hurdles ahead. But I am confident that I will see a day where these murky waters once again offer home to a variety of species.