Descriptive display bins
Below 10 FNU10–50 FNUAbove 50–200 FNUAbove 200 FNU
These colors only separate reported values for viewing. They are not water-clarity, drinking-water, ecological, recreational, impairment, or regulatory thresholds.
How to read this
Fact: each marker is a recent USGS stream-site turbidity measurement in formazin nephelometric units. The popup preserves its time-series ID, measurement time, reported unit, and approval status. Limit: turbidity is an optical measurement affected by suspended material, particle properties, color, bubbles, sensor condition, flow, and local context. It is not a direct measurement of sediment mass, contaminants, pathogens, or safety. One point does not represent an entire water body. The map infers no cause, trend, visibility, ecosystem health, drinking-water safety, recreational safety, or compliance.
Source contract
USGS modern Water Data OGC API, latest-continuous, parameter 63680. Requests are anonymous, keyless, limited to stream sites in the visible bounding box and preceding 48 hours, capped at 500 features, and protected by a 60-second client cooldown. Missing, nonnumeric, negative, nonpoint, or older records are excluded. No credential, proxy, saved measurement snapshot, or proprietary GIS service is used. Source/license notes · USGS API documentation
