Environment – Page 2 – Geeky Girl Engineer

Man Swims the Gowanus Canal

Posted on October 18, 2015 by geek

I was planning to come to New York for the weekend, and by pure chance this was the weekend Christopher Swain announced he was going to attempt to swim the Gowanus Canal again. He tried in April but the threat of rain and then actual lightning, which caused the New York Police Department (NYPD) to order him out of the canal, prevented him from swimming the entire length. This time he was successful. He said he did it to raise awareness of the pollution of the Gowanus Canal. When being interviewed by reporters, he said he was concerned this would be perceived as a stunt. He said they would actually be collecting data that would be given to school kids, so they could help solve the problems affecting the Gowanus.

As an environmentalist, I appreciate him bringing awareness to the plight of the Gowanus. I even appreciate him wanting to bring awareness to school kids. Honestly though, as an environmental engineer, who works in the field of cleaning up hazardous waste sites, I can’t see what he is doing as anything other than a stunt. I seriously can’t think of any information he could gather that couldn’t be gathered from a person in a boat, a person who would not be exposing herself or himself to the risk that Mr. Swain is. At one point, Mr. Swain stopped swimming to collect data and told anyone listening that the water had a temperature of 64ºF and had a pH of 7.5. He started by saying “for the scientists out there” and then said he wished he had studied science harder or something to that effect. First, both those two pieces of data could easily be collected from a boat. Second, neither of those pieces of data tell me anything about the state of the Gowanus. The temperature just reflects that it is fall, and a pH of 7.5 is close to neutral and what is expected for a body of water. [Yes, thermal pollution, where water that is too hot is released into a body of water, is a thing that can affect water bodies because hot water has less oxygen, and the reduced oxygen would affect any wildlife in the water, but it is not a concern for the Gownaus.]

Also, I fail to see what school kids are going to do to help solve the problem. I completely agree in bringing awareness of environmental issues to children, but it is environmental professionals and perhaps community organizers who are going to solve the pollution problem with the Gowanus. The Gowanus has two main issues. First, it has hazardous pollution from years past that needs to be cleaned up. This is where the US EPA and Superfund comes in. Hazardous waste includes PCBs, heavy metals, and whatever other fun chemicals might be polluting the canal. Second, it has wastewater pollution from the past and current that needs to be cleaned up. New York City, like many old cites, has a combined wastewater system. This means that wastewater, the stuff that flows from your toilet and sink drain, and stormwater, the stuff from street drains, flows to the same destination. When it is not raining, it is not an issue. The wastewater all flows to various wastewater treatment plants where it is treated before being released to a river or ocean. During rain events, there can be a problem because the wastewater treatment plant may not be able to handle all the water flowing to it. In this case, untreated wastewater is generally directed to some location (technical term is outfall) where it enters a body of water, like the Gowanus. This is actually the main immediate risk to Mr. Swain. Most of the hazardous pollution is in the sediment at the bottom of the canal, and drinking one mouthful of the Gowanus water probably will not kill you, in terms of the hazardous chemicals, or at least not immediately. [DO NOT TRY THIS. THIS IS AN EDUCATED GUESS.] However, because of the untreated wastewater that flows into the Gowanus, the canal has a lovely concoction of viruses, bacteria, and who knows what other pathogens having their own little party. This would be my more immediate concern for him or anyone else who might accidentally ingest Gowanus Canal water, getting an infection of who knows what pathogen. [According to news reports I’ve seen, after the swim, he stated that he swallowed three mouthfuls. My advice is to go see a medical doctor.] It is also not clear to me if there is other pollution concerns to Gowanus, like outfalls from nearby business or stormwater from the nearby area that may contain things they shouldn’t.

The Gowanus Canal absolutely needs to be cleaned up, and regulatory authorities and the community are already working on it. It may not be proceeding at the speed Mr. Swain and the community would like. I completely understand that. Cleanups, such as the Gowanus Canal, take time and money. It takes professionals, the regulatory authorities, the groups being regulated, and the community to determine the best path forward. Unfortunately, it generally takes patience also. My completely biased opinion is that not enough money is dedicated by politicians to cleaning up all the different pollution in this country. Hence even more patience is needed. One final note, in all the news reports, Mr. Swain and the reporters keep making reference to the Gowanus Canal being a Superfund site. It is, but the issue of untreated wastewater being released into the canal and causing, in my opinion, the more immediate risk to him or anyone else who wants to go for a dip, does not normally fall under Superfund regulation. Superfund (aka CERCLA) regulates hazardous waste, and pathogens are not hazardous waste. However, when the U.S. EPA finalized the Record of Decision for the Gowanus Canal Superfund site, they did require the City to build two very large tunnels to capture combined sewer overflow during rain events. [Edited to correct my statements regarding Superfund and the untreated wastewater contamination.]

Christopher Swain being interviewed before his swim

Mr. Swain and his support crew paddled to the start of the Gowanus Canal before he entered the water.

Christopher Swain swimming with his support crew behind him

Christopher Swain swimming the Gowanus Canal in a dry suit.

He takes measurements of the water.

After he reached the 3rd Street bridge, the NYPD provided an escort (either the water wasn’t deep enough or the bridges prevented it before).

Mr. Swain and escorts nearly at the end of the Gowanus Canal, just after the Gowanus Expressway bridge.

Newtown Creek

Posted on September 7, 2015 by geek

Manhattan skyline behind Newtown Creek Wastewater Treatment Plant

Newtown Creek is a natural creek that now resembles more of an industrial waterway and serves as a divider between Brooklyn and Queens in New York. I recently got a boat tour of it through Open House NY with superb guides from Newtown Creek Alliance and was able to see all the industrial facilities that are on it as well as a few places where its natural state is peaking through. Newtown Creek is heavily polluted because of New York City’s combined sanitary wastewater and stormwater system, which has led to untreated wastewater flowing into the creek during heavy rain events, and also industrial pollution, which has led to it being a Superfund site. A trip down Newtown Creek is almost history lesson down NYC’s past with some historic sites still visible like an old Standard Oil building. More modern parts of NYC also lie on the creek, most famously the newly redesigned and rebuilt Newtown Creek Wastewater Treatment Plant and its eight stainless steel digester eggs.

Brooklyn Queens Expressway

cement plant

DEP boat

Newtown Creek Wastewater Treatment Plant and DEP offices

Fuel tanks and barge

LPG (or possibly methane) tanks

mud flats

Recycling facility

Sailboats at entrance to Newtown Creek

old Standard Oil facility

swing bridge

Tanks

Newtown Creek Wastewater Treatment Plant

Sewage outfall with birds on boom line

Marine Waste Transfer Station

Posted on August 21, 2015 by geek

I got the chance to tour New York City’s brand new Hamilton Avenue Marine Transfer Station. It is scheduled to open next year and is located on the Gowanus Canal in Brooklyn. It will be the transfer point for household waste from ten Brooklyn community boards. It is the first marine transfer station there. All other waste is moved on trucks and rail. It is very impressive. Once operational, it will operate 24 hours a day and six days a week (no Sundays). Currently waste from the area goes to waste to energy incinerators. There will be 12 sanitation workers per shift plus one supervisor.

Trucks enter the building and are first weighed on a scale.

Scale where trucks get weighed when entering station

Once inside the building, the trucks back up to the edge of the floor and lower their trash onto the mixing floor below.

Area where trucks enter and then deposit waste onto mixing floor (right side)

Front loaders and other equipment on the floor below are used to push the waste through openings in the floor into containers waiting below the mixing floor.

Waste mixing floor with equipment to push waste into containers, the elevated floor on the left is where the trucks will lower their loads

The openings in the mixing floor are only as big as the standard containers that will accept the waste. The station aims to put 20 tons of waste in each container.

Looking down from waste mixing floor into hole where waste will be pushed into a waiting container

Once the container is full, equipment is then used to place a top on the waste container.

Row of toppers, equipment used to place top on top of container

The containers are moved the loading area to the topping area to the storage area on rails.

Loading bay, in foreground are toppers and behind, with yellow frames, are where containers will sit to receive waste

Cranes that are also on rails are used to move the containers from the building to stacking areas to finally the barge.

Equipment that is attached to crane to move containers

There are two cranes, but for safety, only one is used at a time. The other one is a backup during maintenance.

Container crane

Base of container crane, on rails

Container cranes with station building to the left

Waste to Energy Plant

Posted on March 27, 2015 by geek

Last week I got the chance to tour a waste to energy plant. The plant receives non-hazardous, household garbage from municipalities, consumer businesses, government agencies, and international ports. It burns the waste and converts the energy given off during the burning to electricity, which is then put into the power grid. Some of the waste that comes from government agencies need secure destruction, and at the plant, the waste is put directly into the feed stream and burned, so as to allow the needed secure destruction. The waste from international ports, such as nearby airports, must be burned to prevent any pathogens entering the country that may affect agriculture, and so it also is fed directly to the feed stream. Interestingly, the municipalities that send waste to the plant discourage their residents from putting yard waste into the trash. Besides being environmentally unfriendly because yard waste can be composted and nutrients returned to the earth, the yard waste is also not good for the waste to energy process because it produces nitrogen oxides (NOx), which forces the plant to put in more pollution control.

There are 88 waste to energy plants in the US, and 45-46 are Covanta’s, the owner and operator of this plant that I toured. The plant receives about 1000 tons garbage/day and after burning it, produces about 300 tons ash/day, which is 10-15% fly ash and the rest bottom ash. Thus, the plant achieves about a 70% weight reduction and also a 90% volume reduction. The fly ash is sent to monofill, which is like a landfill but only accepts fly ash. Fly ash can be used in making concrete, so evidently there is currently research being done by both the concrete industry and various waste to energy plants as to if this fly ash can be used for concrete and thus also be reused.

With the exception of the trash that has to go directly into the feed, when it first comes to the plant, the trash is placed on floor where humans look at trash to remove anything that should not be going into the boiler. For example, inert material shouldn’t go into the boiler because not only does it not burn, it is also a heat sink and reduces the efficiency of the process. The trash is then put into a storage pile to be eventually fed into the boiler feed. A large claw moves the trash to piles, mixes the piles, and then moves trash from the piles into the boiler feed.

Pile of trash waiting to be burned

Large claw picks up trash to put into feed

Trash slides into the entrance to the boiler

The trash is sent to one of three boilers, each of which has six cells. The boilers burn the trash at 1800-2000°F (1300K). The boilers are initially heated up with diesel fuel, but then the trash sustains the burn. However everyday diesel fuel is used to test the burn.

The boilers

View through a boiler’s window of the trash burning

Pipes and ducts everywhere

The heat from the boilers is used to heat water to turn it into steam. The water is in a closed loop system, but they use about 20-25,000 gallons of water per day due to loss. [They use another 200,000 gallons/day for the cooling tower and are exploring with the nearby wastewater treatment plant using treated wastewater for this.] The water goes through a reverse osmosis treatment for purity, so nothing damages the turbines and the rest of the system. The produced steam is superheated but drops to 700°F before entering the turbines. There are two turbines with 14 stages. The steam turns the turbines, and that motion is converted into electricity in the generator. They produce 14.5 MW per turbine. Because of the work the steam does on the turbine, the steam enters the turbine at 600 psi and leaves in vacuum in a 10 ft length.

The turbine (gray and blue) and the generator (red and white stripes)

All the gases that leave the boiler pass through a series of air pollution control units. Ammonia, lime slurry, and carbon are used for pollution control. There are probes in the system to sample flue gas for pollution control additives that are needed. The treated gas then goes to a baghouse where particulates are captured. The air is below 300°F before going into baghouse, so it has cooled quite a bit.

The ash from the boiler is sent through a unit to remove all metals. The ferrous metals (attracted to magnets) are separated from the rest of the metals, and all the metals are sold for scrap.

Bottom ash entering the separator

Metal that has been separated

The whole process is monitored in a control room by one or two people. I was amazed at how simple the process was. I, the environmental engineer, was of course geeking out at the whole thing, but it was a really cool process and efficiently run.

Control panel monitors

Finally here is a very short video of a few scenes from the plant. This includes waste being loaded into the feed, the fire in the boiler, and bottom ash entering the metals separator.

Gowanus Canal

Posted on November 12, 2014 by geek

Last month while in New York, I spent some time walking around Gowanus Canal because I’m an environmental engineer, and I couldn’t resist an opportunity to visit a body of water, infamous for being incredibly polluted. The Gowanus Canal is a Superfund site due to contamination with polycyclic aromatic hydrocarbons (PAHs), volatile organic contaminants (VOCs), polychlorinated biphenyls (PCBs), pesticides, and metals. However, the Gowanus Canal is also polluted with more ordinary pollutants such as bacteria from untreated wastewater from combined sewer overflow outfalls and other urban pollutants from surface runoff (and possibly illegal outfalls). The area residents are understandably pushing to get the canal cleaned up quickly, and the cleanup is a joint effort between the city, state, and federal government. The area around the canal is an interesting mixture of industrial, art galleries, and up and coming residential. It is actually a nice area. There is a Whole Foods Market next to the canal that has a nice little canal walk on the property, which features signs that say “This is the greenest supermarket in New York State. No smoking, please.” I will take them at their word about being the greenest supermarket, as I did notice solar panels and wind turbines in the parking lot. However I still had to laugh at the irony of the sign. On the bright side, the Gowanus Canal is not so polluted that should someone smoke near it, it is not in danger of catching on fire, like the Cuyahoga River did in 1969. While I was walking along the canal, I spotted a small boat with two people who seemed to be monitoring the water and also two people in a canoe. I guess the canal is safe to canoe on, if you just make sure you don’t touch the water to your skin and most definitely don’t let any get into your mouth, nose, eyes, or any other orifices. The canal does not look that polluted. There are areas with floating trash, but there are very few places where I saw a sheen. When I was there it did not smell either, but evidently especially in summer, it can smell. However, it is a good example of how appearance is not a good way to tell if something is polluted. If you want to read more about the Gowanus Canal, this article in Popular Science is pretty interesting.

Northern end of the Gowanus Canal

Bridge on northern end

Carroll Street Bridge

Stormwater discharge warning sign

A wooden dolphin that had a book attached to the top as some sort of art or memorial

View from the Third Street Bridge

Survey boat

Third Street bridge

People actually canoe on the Gowanus Canal

Barge sitting on the canal

Fourth Street Basin, next to the Whole Foods Market, with some sort of art in the sculpture in the water

Gowanus Canal southern end

Gowanus Expressway

Liquid storage tanks

USBG Holiday Exhibit

Posted on December 7, 2013 by geek

The United States Botanical Garden has an annual holiday exhibit that consists of fantasy model trains running through, by, and over various bridges, tunnels, and model structures. They also have models of numerous DC structures and buildings. All the models except the trains are made of natural materials and are built with amazing detail. They are simply gorgeous and the use of natural material is just genius. The model train exhibit also smells wonderful due to all the cedar in the room. Definitely worth the visit.

: Three bridges at model train exhibit

: Railroad support

: Blimp at model train exhibit

: Train exhibit pavilion

: Seattle Space Needle

: Model train on truss bridge

: Ferris wheel at model train exhibit

: Model train tunnel

: Unisphere at model train exhibit

: Hot air balloon at model train exhibit

: Model train exhibit

: Jefferson Memorial

: Library of Congress

: Library of Congress

: Library of Congress

: Lincoln Memorial

: National Museum of the American Indian

: Smithsonian Institute The Castle

: US Botanical Garden

: US Botanical Garden

: US Capitol

: US Capitol

: US Capitol

: US Capitol

: US Capitol

: US Supreme Court

: US Supreme Court

: US Supreme Court

: Washington Monument

: White House

Collecting Acorns

Posted on October 5, 2013 by geek

This morning I joined several other members of Arlingtonians for a Clean Environment (ACE) to collect native acorns and other nuts in Lubber Run Park. The nuts are given to Growing Native which then donates them to state nurseries in the area to grow and plant to restore watersheds. That was the plan at least. Most likely due to the weather, there were not that many acorns, and those that had fallen had already been claimed by squirrels and other animals. Most of us ended up picking up a bunch of trash as we wandered through the park. In fact below is my haul. I make a much better trash collector than a squirrel. I found one viable acorn, a bunch of trash and recyclables, and one archeological find (sort of), a vintage Pepsi bottle.

My haul after an hour in the park

Luckily other participants did much better than me. Overall, we had a pretty nice haul.

Nut sorting

Then all the nuts had to be sorted though. It was a group effort to try to identify which type of oak tree produced the various acorns. Even consulting the books, we were still sort of guessing at some of them.

Consulting reference material to identify the acorns

We sorted them as best we could, then bagged the various type acorns and other nuts separately to give to Growing Native.

Bagging the nuts

Hopefully at least some of the collected nuts will be viable and produce saplings. At the very least, it was a nice couple of hours spent in a nice park, and we removed a bunch of trash.

The nut and trash collecting volunteers from ACE

Household Hazardous Waste Disposal

Posted on October 3, 2013 by geek

Previously I wrote, or ranted, about stupid smoke detector design, and at the end of the post I mentioned that smoke detectors have a small amount of radioactive material in them, and thus they should be disposed of properly. I didn’t say specifically how because it really depends on where you live. I live in Virginia, and I have since learned that there is no place in Virginia to dispose of them. My county’s website says they have no way to dispose of them and to try to return them to the manufacturer, but if you can’t find any other way to dispose of them, they can be thrown away in the trash. I contacted Kidde, the manufacturer, and they said they will accept them, you just have to mail the smoke detectors to them. The customer service representative I spoke to said just put “for disposal” on the package, and they will take care of them. I actually had a total of three to return because I had the malfunctioning one plus two ones I had originally bought before I had the hardwired ones installed. So last month, I mailed three smoke detectors back to Kidde. It cost me $6.15, but I now have a clear conscience. This may seem a bit much to some people, but I am an environmental engineer. My career has mostly been dedicated to cleaning up and properly taking care of human and hazardous waste. It has also been about dealing with contamination when waste was not taken care of properly, so there is no way I am going to improperly dispose of waste unless it is completely impossible not to do so.

Here is a fun quirk of United States environmental law, my smoke detectors are non-hazardous because they were used in my house. Those same smoke detectors, if used in a commercial or other non-household setting, are hazardous. Hazardous waste in the US is regulated through the Resource Conservation and Recovery Act (RCRA, pronounced rick-ra). Under 40 CFR §261.4(b)(1), “household waste, including household waste that has been collected, transported, stored, treated, disposed, recovered (e.g., refuse-derived fuel) or reused” is considered to be non-hazardous and exempt from RCRA regulation. There are a bunch of reasons why this exemption is in RCRA, but how you treat your legally-not-hazardous, but technically-hazardous, household waste comes down to a bit of just because you can do something, doesn’t mean you should. However, disposal of household waste is also governed by state and local regulations. Just because federal laws allows you to dispose of household hazardous waste in the trash, does not mean your municipality will because they are the ones who actually have to deal with the waste.

Most people know that fluorescent bulbs contain a small amount of mercury, and thus if you ever break one indoors, you should open the windows and leave the room while the mercury volatilizes. It is because of this mercury that most (or possibly all) municipalities and/or waste disposal companies state that fluorescent bulbs should not be put in the trash. The vast majority of trash in the US is sent to landfills and the rest to incinerators, and mercury does not belong in either of these type of disposal facilities. Also, and just as importantly, the bulbs can easily be broken during transfer from your trash can to the truck, while in the truck (especially if it compacts), at the transfer station, at the disposal site, and all the places in between. If it breaks, the workers can be exposed to the mercury, and thus it is not just about protecting the environment but also the workers.

There is more household waste that is technically hazardous. Aerosol cans can become explosive if punctured. Various cleaning, home maintenance, and vehicle fluids routinely used in household are hazardous to the environment. Conversely, both prescription and over-the-counter (and for that matter illicit) unused drugs should be disposed of in a seal container and put in the trash. Putting unused drugs in the trash is far better for the environment than putting them down the drain where they will eventually get into the waterways. Wastewater plants are not designed to remove chemicals like drugs, but that is a post for another day. [I suppose if someone is trying to dispose of their illicit drugs it is most likely because the police are raiding their house, and they are really not thinking about the environment but about jail, but I still don’t want to drink water with trace amounts of cocaine because some druggie upstream of my water treatment plant was trying to evade arrest.]

The point of all this is, think before you toss something in the trash. Spend a little time on your municipalities website, as most now have them, educating yourself on what can and can’t be thrown in the trash and where things that can’t be thrown in the trash can be disposed. While you are at it, educate yourself on what things can and can’t be recycled in your area. There may be a recycling market in your area for something you didn’t even realize.