11 Apr

Rain Barrel to Inbox: I’m Full

The next generation of scientists and engineers at Philadelphia’s Penn Alexander School are developing the next generation of rain barrels. The rain barrel, of course, is a staple of the Philadelphia Water Department’s Rain Check program, aimed at enabling residents to manage stormwater and prevent pollution from entering our rivers and streams.

PAS Tesla Robotics, a group of middle-school students who convened last year to compete in the FIRST Lego League competition, decided to take on an issue that affects the approximately 3,500 Philadelphians who own rain barrels: How do you ensure that residents empty their rain barrels before a storm? And how can we know that the barrels are effectively capturing water? The students invented Tessa, a smart, sensor-enabled rain barrel that can send a text or email to let people know when the rain barrel is full. In order to accomplish this high-tech feat, the group researched sensor technology and microcontrollers, learned to code in C++, and set up a cloud data service to send rain barrel notifications straight to a cell phone.

This week, PAS Tesla Robotics demonstrated Tessa to PWD, the Pennsylvania Horticultural Society, Drexel University and engineering firm AECOM; they expertly explained Philadelphia’s combined sewer overflow problem and the need for effective rain barrel management. The students are honing their presentation for the FIRST world championship in Detroit later this month. (Did we mention the team already won local and state competitions?) The live demo included a successful email notification from the test barrel when the barrel sensed it was full. And, of course, the team has already identified several improvements to the device, such as a more accurate sensor and incorporation of weather forecast data—stay tuned. Best of luck to Tessa and PAS Tesla Robotics in Detroit!

17 Nov

Crossing The Delaware

This week, students from Philadelphia’s Mariana Bracetti Academy Charter School crossed the Delaware River to present their underwater rover project in Trenton, N.J. The students dropped some submersible science on the Delaware River Basin Commission (DRBC), an interstate agency that regulates the protection and conservation of the Delaware.

In front of an impressive group of hydrologists, biologists, engineers and other DRBC staff, the 11th and 12th graders detailed last year’s progression from working with Arduinos, sensors and motors to building the OpenROV kit and launching it in Frankford Creek to observe aquatic life. The audience had plenty of feedback, including suggestions for mounting dissolved oxygen and pressure sensors on the rover, as well as a possible (and long sought-after) nickname: Frankie, after its maiden voyage in Frankford Creek. Thanks to DRBC for recognizing all the time and effort put in by the Mariana Bracetti STEM club.

06 Jul

All About the Benthos, Man

This week, the underwater rover built by high school students at Mariana Bracetti Academy Charter School embarked on its second voyage (read about the maiden voyage here) in Naylors Run, a tributary of Cobbs Creek in West Philadelphia. This time, the rover pilots were high schoolers spending the summer training as Watershed Stewards, a new program coordinated by the Philadelphia Water Department and the LandHealth Institute. The Watershed Stewards will spend 11 weeks learning about ecological issues and ways to protect our waterways and environment, and then look to (re)engage peers and residents with the creek during outdoor programming.

Given the game controller that operates the submersible rover, the Stewards took immediately to learning the controls and executed some of the vehicle’s best maneuvers yet. As the rover dived into a pool, it captured streaming video footage of catfish, satinfin shiners and other fish species. It also revealed one of the creek’s biggest challenges: trash that has accumulated in the creek. By documenting the conditions of Cobbs Creek, the Watershed Stewards can plan the best way to address the issues facing the benthos (the aquatic organisms at the bottom of the creek).

Using technology and looking at ecosystems as a whole are two important ways that the rover stays connected to its initial mission from the Climate & Urban Systems Partnership (CUSP), which funded the rover’s construction. Warmer air temperatures, stormwater and combined sewer impacts, algae blooms and other contributors to poor water quality are related to climate change. With the rover’s unique underwater perspective, Philadelphia students are making observations today that could prove valuable to researchers and problem-solvers.

15 Jun

Submersible Science: Philly Students Launch Underwater Drone with PWD

Submersible Science: Philly Students Launch Underwater Drone with PWD

While most Philadelphia students were heading home early due a heat wave this past Tuesday, four 11th grade students from Mariana Bracetti Academy were busy suiting up in full-body chest waders, a necessary piece of gear for the mission at hand: launching a submersible, camera-equipped drone in Frankford Creek.

Undaunted by the steamy temps, the students’ maiden voyage was the culmination of five weekly afterschool sessions they had spent assembling the drone through a program called greenSTEM. An effort of the Philadelphia Water Department, the educational program shows local students how jobs in science, technology, engineering and math (STEM) fields support the department’s watershed protection work.

Built using a kit greenSTEM instructors Matthew Fritch and Maria Horowitz obtained with the Fairmount Water Works through a CUSP (Climate & Urban Systems Partnership) grant, the propeller-driven rover fits in a suitcase and resembles a mashup of the original R2-D2 and a tabletop video projector.

Clearly eager to give it a spin, students Manuela Duran, Angel Cruz, Luz Gonzalez-Mateo and Candy Lucero-Sanchez were joined along Juniata Golf Club section of the stream by their teacher, Lauren DeHart.

“This group of kids has been really great, very engaged and super interested,” said Fritch, a PWD environmental engineer who started greenSTEM several years ago. “Having a dedicated* teacher like Mrs. DeHart who’s really involved and supportive of the learning process really makes a difference too, so this year’s program was a big success.”

While they began by learning about various aspects of coding and how custom-built sensors can help engineers solve distinct challenges, they finished their studies by soldering together parts and circuit boards before assembling the drone’s water-proof casing and laser-assisted navigation system.

Fritch also says that, in addition to building the machine, the students discussed how it could help scientists study parts of our watersheds that are normally hard and even dangerous to reach, requiring a human in scuba diving gear.

“This is something that can help us explore the health of local benthic ecosystems—the plants, fish, insects and crustaceans that are living in along the bottom of our rivers and creeks,” Fritch explained. “We don’t often get down there to look at it, but this could provide a window into an important world.”

For Horowitz, also a PWD environmental engineer, the drone provides an opportunity to get a closer look at her personal nemesis—litter. As one of the PWD staff members working to address the issue of “floatables”— that’s buoyant trash from surrounding neighborhoods that gets washed into our waterways—she is constantly looking for ways to take on and quantify litter.

The drone, she says, could help scientists get a better idea of how much trash ends up on stream and river beds.

“We spend a lot of time skimming for trash and getting litter off the surface,” Horowitz says, “but how much of it lingers and accumulates on the bottom? Is it mostly getting washed downstream, or is it causing issues throughout these habitats? Having that camera and lights is a pretty cool tool for seeing what’s happening down there.”

Clad in waders, Horowitz was on hand to help drop the (so far nameless) drone into the water as DeHart and her students, split between the creek and a nearby laptop with equipped with camera display and controls, watched:

View from the banks:


Check out this video from the rover’s cameras during Tuesday’s test run, and skip to the 3:30 mark to see some of the benthos critters Fritch mentions:

After the drone’s first trip wrapped up, Cruz and Duran took a minute to break down the project:

Now its fifth year, greenSTEM has worked with several other schools on projects like a solar-powered phone charging station with a rain barrel and bench, a network of soil moisture sensors, and a system to detect when storm drains are clogged and need clearing.

But Fritch says this year’s project with Mariana Bracetti was a special one.

“You could tell the kids were into it, and they helped to create something that really can help us understand our waterways better,” Fritch says.

—Brian Rademaekers

*After taking an accidental dip in the creek, DeHart simply swapped into a fresh pair of waders, and went right back to teaching; it’s no exaggeration to say she’s dedicated.

19 May

Smart Green Roof Project: Chapter 3

The roof has grown—SLA Beeber students wrapped up version 1.0 of their Smart Green Roof model at the Fairmount Water Works this month, completing the project by creating the storage layer and planting sedum. The storage layer—made of brightly colored plastic pieces beneath the soil (constructed from Locktagon toys)—is designed to hold water as it seeps through the soil and through a filter fabric.

What makes this a “smart” model are the sensors designed to monitor how this miniature green roof uses and stores water. Soil moisture sensors and a temperature sensor can inform us about plant health; and an ultrasonic distance sensor looks down an observation well to gauge the level of water in the storage portion of the model. The data can be seen on an LCD display, and all of it is powered by a solar panel. The empty compartment in the lower right part of the model will someday house a pump that can irrigate the plants on demand. (That’s version 2.0 of the model.)

In April, the Smart Green Roof team brought the model to the Philadelphia Science Festival, where we demonstrated how green roofs work and what they do: capture stormwater, reduce the urban heat island effect, and save energy by insulating buildings.

This week, we finished with a trip to Villanova University to check out the green roof on top of the college’s CEER building. Because Villanova researchers have also outfitted their green roof with a variety of sensors and irrigation devices, it is very much like a scaled-up version of the Smart Green Roof model.

22 Mar

Smart Green Roof Project: Chapter 2

This spring, greenSTEM is delighted to have guest bloggers! We’re working with the Fairmount Water Works and high school students from SLA Beeber to create a smart green roof model using microcontrollers and sensors.

After researching green roofs and getting some exposure to Arduino programming, we are beginning to build the model. Kevin Magerr, an engineer with the Environmental Protection Agency (EPA), delivered the skeleton of the model: an acrylic box with different compartments for the soil/plants, electronics, and a water pump. Also joining us was Cara Albright, a PhD candidate with the Villanova Urban Stormwater Partnership. These experts helped guide the model’s development.

  • “We got our green roof model and it looks amazing. Kevin, an EPA engineer, and Cara, a student at Villanova University, helped us make plans for our green roof model.”—Tyheim

One way to monitor the effectiveness of a green roof is to look at how much water it can hold. Above, we plan to install a tube that acts as a well in the system. It will fill up with water and we can use an ultrasonic distance sensor to capture the level of water in the well. We talked about how the sensor works—it uses sound signals that bounce off the surface of the water, operating much the same way a bat uses echolocation to detect its surroundings—and experimented with different sizes of tubes to determine the most accurate measurements.

Terrance and Tyheim also began to wire an LCD display that will create a readout of the water level in real time. All of our prototyping is done with breadboards and jumper wires; once all the elements are in place, we will solder these circuits together to be able to look at multiple sensors and displays: water level, temperature, and soil moisture, for example.
Helpful links:
Ultrasonic (ping) sensor tutorial and code
LCD display tutorial and code
13 Feb

Smart Green Roof Project: Chapter 1

This spring, greenSTEM is delighted to have guest bloggers! We’re working with the Fairmount Water Works and high school students from SLA Beeber to create a smart green roof model using microcontrollers and sensors.

Fairmount Water Works is excited to partner with Matt Fritch and the Philadelphia Water Department to host four high school interns from Science Leadership Academy at Beeber. Chelby, Ashton, Tyheim and Terrance come to FWW weekly to meet with Matt, FWW educator Rachel O., and volunteer Billy K. We began the internship back in October, but we are just getting blogging now. Here are some observations from the past few months.

We began with tours of the Water Works and set some goals:

  • “The Fairmount Water Works can help me with my goals in many ways. I have learned to be a better person thanks to this place, it helped to shape who I am. Also, when I go to college, I might study to be a doctor or scientist so this helps for that.” —Tyheim
  • “FWW can help me meet different people and build connections.”—Chelby

We learned a bit about the history of FWW, walked around and learned about this historic place:

  • “One cool thing I learned was that people used to drink water straight from the river….When people went in boats in the river they boated in canals so they wouldn’t crash into the dam.” —Chelby
  • “There used to be seals here! And there used to be a pool area.” —Tyheim

Now it’s time to get to work. Matt is teaching us about Arduinos and how they are used to monitor different sites. Rachel is still trying to understand this, but she likes when Matt said that the Arduino is a really dumb computer. It can basically tell its sensor to do one thing: light on/light off, temperature readings, moisture, etc. We’ll be using our Arduinos to connect to sensors to monitor soil moisture. To water or NOT to water? That is the question.

We started learning about Arduinos and how to set them up to do different things. We learned to solder the appropriate parts.

  • “Today we learned a little about Arduino and what it does. We learned that the soil moisture sensor senses the amount of water in the ground. We will probably be using this for our green roof. We also learned about other things the arduino can do with sensors.” —Tyheim

*We met on January 18 at Cira Green to look at the green roof. Rachel learned that the roof is designed to hold 500 people DANCING! She is hoping to get invited to that party.

  • “It’s really cool, but not at all what I expected. It is like a big park floating over the city. The views are fantastic. It cost $12 million to build.” —Chelby
  • “During our trip to the green roof I learned that the soil is being held up by flattened milk crates. The rain water is held up in a tank that is used for such things as toilet water.” —Terrance

We now have to learn a bit more about how green roofs are constructed, so we spent a few days researching. We’ll be making a model that can sit on a tabletop. Sensors will be incorporated into this model so we can tell the water level in the model. We have been practicing coding to make this sensor work.

17 Nov

Sensors Working Overtime


Back in June, greenSTEM helped students install web-connected soil moisture sensors at the Penn Alexander school and the Franklin Institute. These Soil Cell units were placed in garden beds and operate the same way as PWD’s other devices (which monitor green stormwater infrastructure), but with a slight difference: They use solar panels to keep the batteries charged. Over the last six months, these sensors have been virtually maintenance-free, requiring no battery changes.

Of course, we’re always making improvements. Above, SLA Beeber student Brandon soldered permanent connections from a soil moisture sensor and a thermistor (temperature sensor) to the circuit board. He’s also designed and built a post structure to elevate and mount the solar panel in an optimal position to receive sunlight and keep the Soil Cell charged. Installation is planned for the spring, and we’ll be exploring ways to do more with these sensor units that are constantly being charged. (Hint: The sensors are currently “talking” to us; what if we started talking to them?)

Check out the live soil and temperature data from the Franklin Institute’s ozone garden here.

02 Jun

SIM Goes To State


Last week, students from Philadelphia’s Mariana Bracetti Academy Charter School brought SIM (Sewer Inlet Monitor) to a statewide STEM competition in Lancaster where students from all over Pennsylvania came to present their inventions and innovations. The event was the culmination of months of work for the students in the STEM Challenge Club. The 10th graders identified a problem in their community (littering), conducted research and analysis on littering behavior and pathways (lots of trash ends up in sewer inlets), and came up with a solution: a waterproof sensor that detects sewer inlet blockages and reports it to the web and social media.


Partnering with Philadelphia Water, the STEM students devised SIM (above), an Arduino-based distance sensor that communicates via the 2G cellular network (yes, SIM has its own SIM card). When SIM senses an inlet blocked with trash, it sends data to the cloud storage site ThingSpeak and then begins a conversation on the messaging app Slack. The intent is to draw attention to littering behavior via social media and organized citizens’ action. Imagine if individuals adopted an inlet from a network of SIM devices shown on the map below:


Now imagine how much that would be appreciated by Philadelphia Water’s inlet cleaning crews, who removed more than 21 million pounds of debris from the city’s 79,000 sewer inlets in 2014. Not to mention the fish and other aquatic life in our rivers and streams, where the trash from sewer inlets can end up.

Alas, SIM did not end up winning the state competition—congratulations to the winning teams and all who participated. Our Philly students created something valuable to their community, demonstrated thoughtful work, and showed up ready to be challenged—this is what stewardship is all about. Below, an early SIM prototype being tested in the snow:


Expect to see a DIY guide for building your own SIM soon!

22 Mar

Root Kit 2016


As seen on Twitter: Philadelphia Mayor Jim Kenney speaking before an image of our very own Root Kit. Mayor Kenney was on hand to kick off last weekend’s Democracy Hackathon, and greenSTEM is very proud to have worked with civic hackers at Code for Philly to develop the hardware and software that went behind the Root Kit, a web-connected soil moisture sensor for rain gardens and other green infrastructure. If you’re looking to get involved with technology projects that benefit your neighbors and the city, stop by one of Code for Philly’s weekly meetups—no coding experience required.

But the point of this post is not merely to tout our product placement. A next generation of the Root Kit is coming. It’s even more advanced than the Soil Cell. It’s more powerful, less expensive, and open source all the way. As always, we’ll document how to build one of your own once we figure out all the problems with it have some nice photos.