Philadelphia County, PA Water Table Trend
Philadelphia County, PA: what the water table is actually doing
Philadelphia County's representative monitoring well shows depth to water declining, slower than most declining counties, a fitted trend of 0.6 ft per decade over 79 years of readings.
One well stands in for Philadelphia County's whole aquifer here, the honest simplification every page on this site carries.
What the well actually measured
The most recent reading put water 32.2 ft below land surface. Readings span 1948-03-30 to 2026-09-23, 175 measurements from USGS well USGS-400217075142101 (Ph 540), part of the National Water Information System. The qualifying bar and the OLS fit behind this trend are documented in the methodology guide.
Where Philadelphia County ranks
Of the 1,449 US counties with a usable trend, Philadelphia County ranks 990th from fastest-rising to fastest-declining, 1 is the fastest-rising water table measured, 1449 the fastest-declining. About 1,573,916 people live in Philadelphia County, Pennsylvania. See the fastest-moving counties guide for how Philadelphia County stacks up against the most extreme cases nationally.
What a declining table means for a well pump
Because Philadelphia County's water table is actually declining, not just a general worry, a well owner here should consider comparing home-warranty plans that cover well-pump failure before one happens.
A dropping table says nothing about water quality
Whether Philadelphia County's water table is rising or falling is independent of what's actually in the water. Depletion can concentrate naturally-occurring minerals, so it's worth checking directly with a water test rather than assuming a depth trend says anything about quality.