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