City Report · April 17, 2026
Microplastics in Los Angeles tap water.
LADWP's most recent Consumer Confidence Report says the water passes every federally and state-regulated contaminant test. That's true. It's also true that microplastics are not on that list. The EPA only added microplastics to the Contaminant Candidate List (CCL 6) on April 2, 2026. No utility in the US currently tests tap water for microplastics. That's the gap we're filling — neighborhood by neighborhood — with at-home testing, published on The Water Map.
Where LA tap water comes from
Los Angeles draws from three main sources: the Los Angeles Aqueduct (Owens Valley and Mono Basin, ~30–45% of supply depending on year), the State Water Project and Colorado River Aqueduct (Metropolitan Water District imports, ~40–60%), and local groundwater (~10–15%). The mix changes annually based on snowpack and drought conditions.
All three sources are surface or groundwater that originated in the environment — rivers, reservoirs, snowmelt, aquifers. All of them are exposed to the environmental plastic load that has been measured everywhere on earth, from Arctic snow to deep ocean sediments. Treatment plants remove bacteria, heavy metals, and regulated contaminants. They're not optimized to remove microplastics.
What shows up
We've been running at-home testing across LA neighborhoods since March 2026. The pattern is consistent: almost every tap water sample shows some microplastic particles on the filter. Counts vary widely — by neighborhood, by household, by whether the home has an in-line filter — but zero-particle samples are rare.
Every test we run gets published as a pin on thewatermap.com. Neighborhoods with published results so far include Echo Park, Silverlake, Highland Park, Mar Vista, Venice, Koreatown, West LA, Pacific Palisades, and parts of the South Bay. The map grows with every kit a customer runs.
A typical LA tap water result. Not the worst we've seen. Not zero either.
Why the variation between neighborhoods
- Age of the pipes feeding your home. Older plastic service lines shed more than newer ones.
- Indoor plumbing. Homes with PEX or CPVC supply lines can add plastic downstream of the municipal main.
- In-home filters. Pitcher, under-sink, or RO systems change what actually reaches the glass.
- Water pressure and flow dynamics. High flow can dislodge particles from pipe interiors.
- Age of the home. Newer construction often has all-plastic supply; older homes may still have copper or galvanized.
Translation: your specific tap is the only tap that matters. Your neighbor's result won't match yours.
Test your own LA address
The Water Test at-home kit ships free in LA. $50, two tests. When you upload your result, it goes on The Water Map as a pin at your neighborhood. Over time we'll have neighborhood-level medians and filter-vs-unfiltered comparisons that no utility and no lab currently publishes.
Looking for your neighborhood? Check thewatermap.com for results already published near you.
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