US Groundwater Usage for Drinking Water: 51% of Population

According to the US Geological Survey (USGS), approximately 51% of the US population relies on groundwater as their primary drinking water source.

Breakdown

• Public supply systems: ~38% of population (125M people) — wells tapping aquifers
• Private wells: ~13% (43M people) — mostly rural, unregulated
• Surface water: ~49% (160M) — rivers, lakes, reservoirs (major cities: NYC, LA, Chicago, Boston, SF)

Regional Variation

• High groundwater dependence: Florida (90%+), Mississippi, Nebraska, Idaho, Hawaii, rural Midwest/Great Plains
• Low dependence: Northeast corridor, West Coast metros, Great Lakes cities

Aquifer Systems

• Ogallala (High Plains) — 8 states, irrigation + drinking
• Central Valley (CA) — agriculture dominant
• Floridan — Southeast
• Basin and Range — Southwest
• Glacial sand/gravel — Northeast/Midwest

Challenges

• Depletion (Ogallala, Central Valley)
• Contamination: nitrate (ag), arsenic (geogenic), PFAS, VOCs, saltwater intrusion
• Private wells: no mandatory testing; owner responsibility
• Climate change: recharge reduction, demand increase

Groundwater is invisible but critical infrastructure — half the nation drinks it daily.