Lab data

Microplastics in LA Tap Water

Distribution from 50+ tap-water samples we counted under a microscope across Los Angeles. There is no federal limit for microplastics in drinking water — these are raw counts, not violations.

Microplastics

1 µm – 5 mm

Big enough to trap on a filter and count under a microscope. The numbers on this page are microplastic counts.

Nanoplastics

< 1 µm

Below the resolution of any optical method. Small enough to cross cell membranes and the blood-brain barrier — and roughly 90% of the plastic particles found in bottled water. We can't count them, but they travel with the microplastics we can.

48
Samples tested
and counting
9
Median count
particles per 100mL
11
Average count
particles per 100mL
21
Neighborhoods
across LA

Bottled water, brand by brand

We tested 7 bottled water brands for microplastics

Dasani, Liquid Death, Fiji, Evian, Crystal Geyser, San Pellegrino, and Path — every one came back positive for PET particles, and the aluminum cans scored as high as the plastic bottles. See which is the worst bottled water for microplastics, which has the least, and whether Crystal Geyser or your brand made the list.

Read the brand ranking →

Particle count distribution

How many samples fall in each range

9
0–2
5
3–5
11
6–9
11
10–15
6
16–22
5
23–35
0
36–50
1
50+
particles per 100mL sample

Percentiles

Where different cutoffs fall in our dataset

5
P25
9
Median
16
P75
26
P90
0
Cleanest
5
25th %ile
9
Median
16
75th %ile
52
Highest

Results by tier

How samples distribute across our particle-count tiers

Low
14
29%
Moderate
22
46%
High
11
23%
Very High
1
2%
48 total samplesParticles per 100mL

By neighborhood

Average particle count where we have 2+ samples

3
2 samples
4
2 samples
5
2 samples
5
6 samples
7
2 samples
8
3 samples
10
6 samples
10
3 samples
12
2 samples
13
3 samples
14
2 samples
15
2 samples
17
2 samples
22
2 samples

Sample images

48 microscope captures — the bright dots are microplastic particles fluorescing under Nile Red staining.

Samples are public, non-baseline tap water processed using Nile Red fluorescence staining. Particle counts are per 100mL. No federal safety standard exists for microplastics in drinking water. Updates automatically as new results are added.