Afternoon of September 16
A SALT student's cleanup record

Green Action Challenge × World Cleanup Day 2026, Midterm Update

Our Neighborhood Map,
Drawn by Students' Steps

🏫 This issue is about SALT students

September 10 – 25, 2026

Hello! We are happy to share news from Green Action, part of the World Cleanup Day award program.
I'm Kwonseon Yoo, the editor of this newsletter.

This issue is about SALT students. On September 10, SALT opened a group on ITACITY. Over the next two weeks or so, 26 students logged 32 cleanup records as they walked around their neighborhoods. Together, they picked up 2,182 pieces of trash. During the same period, about 1 in every 13 participants across Korea was a SALT student.

Behind the numbers are short notes the students wrote themselves. They show why the students went back out into the neighborhood, so we put them at the end of this issue.

🗺 NEIGHBORHOODS SALT CARED FOR TOGETHER

Separate walks came together into one map

Students walked around their own towns and near the school. One person's record is just a small dot on a map. But when we bring 26 records together, they connect 12 neighborhoods. Their steps reached all the way from Bundang, Suji, and Wirye to Gaepo-dong in Seoul.

Green areas = places where SALT students cleaned up and left records
Dark lines = paths walked
September 12–23

With the records put together, the map shows right away where litter gathers. It is the starting point for deciding which parts of the neighborhood to look at first.

🔎 SEPTEMBER CLOSE-UP

Dochon-dong: each street collects different litter

40% of the litter SALT students picked up came from Dochon-dong in Seongnam, where the school is. When we matched all 875 items of litter to the nearest street (within 30 meters), each street turned out quite different. The thicker and darker the line, the more litter was found per 100 meters.

Thicker, darker lines = more items found per 100m
Gray = streets with no records
September 13–23

Put side by side, the litter on each street looked quite different.

We compared streets that were at least 90 meters long with 25 or more items recorded

• The shop alley: Mostly cigarette butts
  Dochon-ro 7beon-gil alone gave us 430 items of trash. That is almost half of all the trash in Dochon-dong. For every 100 meters students walked, they found 72 items, and 83% of them were cigarette butts. It is a shop alley crowded with restaurants and bars, 100 meters from the school.
• Apartment paths: Mostly plastic wrap
  On paths inside apartment complexes and buildings, plastic was the most common item at 44%. This was the only area where plastic wrap was higher than cigarette butts.
• Dochon-ro 26beon-gil: Filled with paper
  On Dochon-ro 26beon-gil, paper was the main item at 48%, passing cigarette butts at 41%.

Dochon-ro 7beon-gil: The street corner where butts gather

We made a 3D map of the street corner where they found the most cigarette butts, about 80 meters on each side. We drew the buildings with their real heights and colored the ones with shops orange. (We did not include any shop names.)

Building height = real number of floors
Orange = buildings with shops
Building data © VWorld, Ministry of Land, Infrastructure and Transport

• Shops on floor 1, homes upstairs
  Out of 27 buildings in the picture, 9 had restaurants, bars, or convenience stores. Building records list most of them as homes, but on the street they have shops on the ground floor and homes upstairs.
• Right in the middle of a narrow alley
  In just one small 10-meter square, students found 67 cigarette butts, the highest spot. Out of 357 butts found on Dochon-ro 7beon-gil, 81% were gathered within less than 20 meters of a restaurant or bar.

Even in the same neighborhood, each street has different trash depending on how people use it. The differences the students found show where to start in the neighborhood. Walking the same streets again later will show what has changed.

Three zones in Dochon-dong

Three spots where litter gathered, each for a different reason

When we mapped the Dochon-dong litter data, litter was especially concentrated in three places. The taller the bar on the map, the more litter we found there.

Bar height = items picked up at that spot (25 m × 25 m square)
Shapes = three zones · Blue water = Docheoncheon Stream

Based on SALT student records from 13 to 28 September. The dates and counting method differ from the section above, so the numbers are slightly different.

What does each zone need?

🧩 CLUES LEFT BY TRASH

Who was here, and what did they do?

Leftover litter hints at what happened in that spot. We labeled the litter in the students' photos and left out brand names.

September 13
A bench in Jeongja-dong, Bundang, recorded by a SALT student

A cup noodle container, a water bottle, and wooden chopsticks were left on the bench, with the cup noodle lid and a small piece of packaging on the ground. Since most of these are items people often buy at a convenience store, someone likely sat down to enjoy a snack and left them behind. How many people were here? When did they visit?

Morning of September 18
A bag collected by SALT students in the alley beside the school

A bag filled by SALT students in the alley beside the school contained pieces of newspaper, a face mask, a plastic cup, a straw, and a piece of wire. Most of these are small and light, so they are easy to miss.

💬 IN THE STUDENTS' WORDS

“Doing it at school with my friends was so much fun”

After a cleanup, you can leave a one-line note in the app. We picked three notes written by SALT students.

Where this photo was taken: found using the location recorded at that moment. Due to a small location difference (about 10m), we cannot tell the exact gap between the buildings.

In the alley beside the school building with friends
Morning of September 18

We shared these notes anonymously, fixing only the spelling. The gray line under each note shows the original Korean words. Hearts cover faces in the photos.

It was fun with friends, rewarding for our neighborhood, and helpful to others. The real reason our students went back outside is captured in these words, which tell us more than numbers ever could.

🌱 ONE MORE MONTH

The challenge continues until October 31

Thank you to the SALT students and teachers who walked and looked after the neighborhood. To the 23 students who have no records yet, please join us from today. Each record that adds up makes the neighborhood stronger. 🌱

For questions about applying for or joining the World Cleanup Day International Award,
please message the ITASEOUL KakaoTalk channel.

ITASEOUL (non-profit)     itaseoul@itaseoul.org     kywa.ita.city

Period: September 10, 2026 (SALT joined) to September 25 (last activity September 23)
public activity records of 49 SALT members (0 staff). National figures: ITACITY public activity records, September 7–25 (343 people). Dochon-dong street analysis: 875 item records within 1km of central Dochon-dong, each matched to the nearest OSM street (within 30m)
Base map © OpenStreetMap contributors
ITACITY citizen cleanup records (CC BY-NC 4.0)