Startup Grind Global 2020, Redwood City

Four surveys of the same blocks

Each survey walked Broadway, Middlefield Road and Hamilton Street around the theatre. The number of surveyors and the time they spent changed from day to day, so the fair comparison is litter per 100 m of street walked.

956

pieces on day one, the most of the four surveys.

56 to 79

pieces per 100 m walked on day one, against 37 at the baseline: 1.5 to 2.1 times as much.

50%

of day one's litter was paper: fliers, menus and cards (56% without the one-location records).

24 to 46%

fewer per 100 m walked on day two (43) than on day one, with half the surveyors.

Pieces each survey, by typeThe dark mark is the count in our April 2020 post.

Sun, Feb 9Baseline

392post: 317

Mon, Feb 10Opening night

538post: 622

Tue, Feb 11Day one

956post: 886

Wed, Feb 12Day two

564post: 568

PaperCigarette buttsPlasticWrappers and otherFood and glassOur April 2020 post

Pieces per 100 m of street walkedThe fair comparison: litter found for the ground covered. On day one, 280 pieces came from a phone that stopped moving; the hatched bar leaves them out.

Sun, Feb 9Baseline

37

Mon, Feb 10Opening night

49

Tue, Feb 11Day one

79

Without the one-location records

56

Wed, Feb 12Day two

43

Who and how longThe main run of each survey. Pieces are the whole survey: day one's include 26 from 2:32 pm, before the main run; day two's include 9 from 4:04 pm, before the main run.

Sun, Feb 9main run 3:39 pm to 4:05 pm

3 surveyors26 min out392 pieces30% paper

Mon, Feb 10main run 8:23 pm to 9:32 pm

2 surveyors69 min out538 pieces29% paper

Tue, Feb 11main run 3:28 pm to 7:11 pm

4 surveyors3.7 hours out956 pieces50% paper

Wed, Feb 12main run 6:47 pm to 8:19 pm

2 surveyors92 min out564 pieces35% paper

What the posts said, checked

Our April 2020 recap, the 2021 clustering write-up and a 2022 post, against the open data. The day counts in the posts do not match the file or each other; the file and the 2021 write-up agree on the baseline and day two.

Match3 Close4 Differs7 Not in the data1

Source	What it said	The data
Our recap, April 2020	A baseline survey on the Saturday, 48 hours before the event: 317 pieces.	The baseline in the file is Sunday Feb 9, 3:39 pm to 4:05 pm: 392 pieces in 369 photos, by three surveyors. The post's own map is captioned Sunday, and the 2021 write-up says Sunday and 392.	Differs
Our recap, April 2020	After opening night (Mon Feb 10), a three-person team picked up 622 pieces.	538 pieces of litter, plus 2 records of human or pet waste and 1 of urine, by two surveyors, 8:23 pm to 9:32 pm. The 2021 write-up says 613.	Differs
Our recap, April 2020	Day one (Tue Feb 11): 886 pieces.	956 pieces in 816 photos, by four surveyors, main run 3:28 pm to 7:11 pm (26 pieces came earlier, from 2:32 pm). 140 came in 12 photos of stacked fliers, mostly paper (132); 280 sit at one location where a phone stopped moving. The 2021 write-up says 868.	Differs
Our recap, April 2020	Day two (Wed Feb 12): 568 pieces.	564 pieces, the same as the 2021 write-up.	Close
Our recap, April 2020	1,993 pieces during the two-day conference.	The two conference days have 1,520 pieces of litter; with opening night 2,058; all four surveys 2,450. The post's own four counts add to 2,393.	Differs
Our recap, April 2020	QR codes at 78 locations, on trash bins and in bathrooms.	On Friday Feb 7 two surveyors mapped 92 cans and restrooms at 77 distinct spots: 79 cans (64 trash, 13 recycling, 2 ash) at 68 spots, and 13 restrooms.	Close
Our recap, April 2020	25% of all litter was tobacco.	610 of 2,450 pieces of litter were cigarette butts: 24.9%.	Match
Our recap, April 2020	To-go containers, fliers and business cards were the most common litter; tobacco a close second.	Paper first (945, 39%), cigarette butts second (610, 25%).	Match
Our recap, April 2020	Litter rose during the conference and fell as it came to a close.	Per 100 m of street walked: 37 at the baseline, 49 after opening night, 56 to 79 on day one (56 without the 280 one-location records, 79 with them), 43 on day two. Day one is the highest either way.	Match
Our recap, April 2020	On the last day, more paper near the tents, from marketing materials left behind.	Paper fell on day two: 197 pieces (35%), against 475 (50%) on day one. The file does not mark the tents.	Differs
Our recap, April 2020	Over 50 exhibitors signed a pledge to leave no litter behind.	Not something the litter data can show.	Not in the data
Clustering write-up, 2021	2,437 pieces over the four days (392, 613, 868, 564).	2,450 pieces of litter over the four surveys (392, 538, 956, 564).	Close
Clustering write-up, 2021	42 collection objects; 6 of them had litter more than 20 m away on average.	41 of the 79 mapped cans were the nearest can to at least one piece; 3 of those had litter more than 20 m away on average, half the write-up's 6.	Differs
Clustering write-up, 2021	The team picked up after the event, as it came to a close.	Opening night and day two were evening surveys (8:23 pm and 6:47 pm on). Day one ran through the afternoon, from 2:32 pm.	Close
Tips post, January 2022	In 2019, Startup Grind and Rubbish held the world's first zero-litter event.	The surveys were in February 2020, and they recorded 2,450 pieces of litter.	Differs

Watch the four surveys

One map, north up. First the cans and restrooms are mapped (the squares). Then each survey plays in turn: its litter shows in colour, turns grey by the next survey and fades by the one after, so every survey reads fresh. In each survey the clock slows to about a minute a second and the camera closes in on one surveyor. A panel counts each survey by type, with our post's count as a white mark, and a live screen shows the photos, each stamped with the time it was taken. At the end the four surveys stand side by side, at one scale. On day one, one surveyor's phone kept a single location for two hours; those 280 pieces are counted in a blue ring, not drawn as litter.

Press play for February 7 to 12, 2020, 92 seconds. It ends with photos from the surveys.

Open the map full screen

Day one was paper

Half of day one's litter was paper (50%; 56% without the one-location records). At the end of the day, from 7:05 to 7:11 pm on Hamilton Street, Surveyor B recorded 140 pieces in 12 photos, 132 of them paper, up to 22 at a time. The photos show piles of printed fliers and cards on tables. Two of them, blurred so no print can be read, play on the replay's live screen; the sharp ones are not shown because they carry print.

Share of each survey, by typePercent of pieces

Sun, Feb 9

30322098

Mon, Feb 10

29292021

Tue, Feb 11

50191119

Wed, Feb 12

35262216

PaperCigarette buttsPlasticWrappers and otherFood and glass

The cans

On Friday Feb 7, two surveyors mapped 79 cans (64 trash, 13 recycling, 2 ash) and 13 restrooms, so anyone could report a full can. The 2021 write-up matched each piece to its nearest can. Doing the same with the file: half of all litter lay within about 14 m of a mapped can, and 80% within 20 m.

How far each piece lay from the nearest canShare of the 2,450 pieces of the four surveys

13%

0 to 5 m

20%

5 to 10 m

20%

10 to 15 m

26%

15 to 20 m

11%

20 to 30 m

9%

30 m or more

The busiest cansPieces whose nearest can it was, and how far they lay on average

367 pieces16 m away on average

200 pieces14 m away on average

197 pieces34 m away on average

179 pieces16 m away on average

158 pieces28 m away on average

Cans inside the theatre count too, as in the write-up. 41 of the 79 cans were the nearest can to at least one piece.

Who surveyed

Four surveyorsNamed by letter, most records first; the open data holds no names

Surveyor AMon, Tue, Wed · 1,032 pieces

Surveyor BSun, Mon, Tue, Wed · 836 pieces

Surveyor CSun, Tue · 459 pieces

Surveyor DSun, Tue · 123 pieces

Counted, not mapped

2 records of human or pet waste and 1 of urine, all on Monday, are counted apart: they are not in the 2,450 pieces of litter and not on the map. The 67 records from a first visit on January 29 are photos of cans, benches and bike racks filed under litter types, so they are left out; so are the 19 benches, 8 bike racks and 1 other record mapped on Feb 7.

From the surveys

A few of the photos. On Sunday the litter was photographed where it lay; on the other days, in the grabber, lit pink at night. Photos with people, feet, shadows, cars or print are not shown.

Trash can, Fri, around the Fox Theatre — Trash can · Fri

Food, Sun, around the Fox Theatre — Food · Sun

Paper, Sun, around the Fox Theatre — Paper · Sun

Plastic, Sun, around the Fox Theatre — Plastic · Sun

Cigarette butt, Sun, around the Fox Theatre — Cigarette butt · Sun

Cigarette butt, Mon, around the Fox Theatre — Cigarette butt · Mon

Plastic, Mon, around the Fox Theatre — Plastic · Mon

Paper, Tue, around the Fox Theatre — Paper · Tue

Plastic, Tue, around the Fox Theatre — Plastic · Tue

Cigarette butt, Tue, around the Fox Theatre — Cigarette butt · Tue

Cigarette butt, Wed, around the Fox Theatre — Cigarette butt · Wed

Paper, Wed, around the Fox Theatre — Paper · Wed

About these numbers

The open-data file holds 2,477 records for this event. The four surveys are 2,290 of them, with 2,450 pieces (a photo can hold more than one piece). The rest are the Feb 7 mapping (120 records) and the Jan 29 visit (67).
Pieces are litter: paper, cigarette butts, plastic, wrappers and other, food and glass. The 2 records of human or pet waste and 1 of urine, all on Monday, are counted apart: they are not in the 2,450 and not on the map.
Per 100 m of street walked: each survey's recorded GPS routes, kept only within 150 m of that survey's own photos, mark the 10 m squares of street they cross; pieces are divided by that length. (The map leaves out any stretch where two GPS fixes are more than 25 m apart, so a gap never draws a line across a block; the lengths here use the full routes.) Sunday 1,060 m, Monday 1,100 m, Tuesday 1,210 m, Wednesday 1,320 m.
On day one, 280 of Surveyor C's records, 4:42 to 6:38 pm, share one location on Broadway, 27 m from the Fox Theatre. That phone recorded no GPS track, so where those pieces really lay is unknown. Their pieces count in day one's total; the replay shows them as one ring with their count, not as litter at that spot. Without them day one has 676 pieces over 1,200 m of street: 56 per 100 m, against 79 with them. Day one is the highest of the four surveys either way.
Distances to the nearest can use the 79 cans mapped on Feb 7, inside the theatre and outside, as the 2021 write-up did.
The replay draws each record at the phone's own position; the public file rounds positions to about 11 m. Each survey is shortened to a few seconds; in each close-up the clock slows to between 42 and 117 real seconds a second.
The file marks only Surveyor C's records as picked up, so this page does not use that flag; the photos show the grabber on Monday, Tuesday and Wednesday.
The photos on this page and the 28 on the replay's live screen were checked one by one at full size (no people, feet, shadows of people, cars or print), cropped, and carry no location data. Two night photos of the stacks were lifted in exposure; they are blurred, so no print can be read. Only the 39 photos in use are published. The live screen stamps each photo with the time it was taken.

Day one of Startup Grind 2020 left 1.5 to 2.1 times the baseline's litter per 100 m of street.