Private Well Water Risk by State
USGS models estimate arsenic and nitrate risk for private (domestic) wells across the conterminous United States. Pick your state to see the modeled exposure and how to treat it. These are area estimates — Alaska and Hawaii are outside the USGS model coverage.
Alabama
Nitrate: 0% of wells over limit~2,590 on high-arsenic wells
ArizonaNitrate: 1.3% of wells over limit~16,978 on high-arsenic wells
ArkansasNitrate: 0% of wells over limit~1,151 on high-arsenic wells
CaliforniaNitrate: 10.4% of wells over limit~115,817 on high-arsenic wells
ColoradoNitrate: 0.7% of wells over limit~14,342 on high-arsenic wells
ConnecticutNitrate: 0% of wells over limit~52,105 on high-arsenic wells
DelawareNitrate: 12.7% of wells over limit~9,924 on high-arsenic wells
District of ColumbiaNitrate: 0% of wells over limit
FloridaNitrate: 0% of wells over limit~50,923 on high-arsenic wells
GeorgiaNitrate: 0% of wells over limit~34,975 on high-arsenic wells
IdahoNitrate: 3.7% of wells over limit~47,041 on high-arsenic wells
IllinoisNitrate: 0% of wells over limit~67,710 on high-arsenic wells
IndianaNitrate: 0.1% of wells over limit~150,861 on high-arsenic wells
IowaNitrate: 0.4% of wells over limit~35,650 on high-arsenic wells
KansasNitrate: 5.2% of wells over limit~6,166 on high-arsenic wells
KentuckyNitrate: 0.2% of wells over limit~6,707 on high-arsenic wells
LouisianaNitrate: 0% of wells over limit~6,462 on high-arsenic wells
MaineNitrate: 0% of wells over limit~102,452 on high-arsenic wells
MarylandNitrate: 6% of wells over limit~41,277 on high-arsenic wells
MassachusettsNitrate: 0% of wells over limit~30,548 on high-arsenic wells
MichiganNitrate: 0% of wells over limit~192,748 on high-arsenic wells
MinnesotaNitrate: 0% of wells over limit~80,354 on high-arsenic wells
MississippiNitrate: 0% of wells over limit~2,805 on high-arsenic wells
MissouriNitrate: 0% of wells over limit~10,233 on high-arsenic wells
MontanaNitrate: 0.1% of wells over limit~23,270 on high-arsenic wells
NebraskaNitrate: 2.2% of wells over limit~17,399 on high-arsenic wells
NevadaNitrate: 0% of wells over limit~21,534 on high-arsenic wells
New HampshireNitrate: 0% of wells over limit~60,962 on high-arsenic wells
New JerseyNitrate: 1.1% of wells over limit~40,563 on high-arsenic wells
New MexicoNitrate: 1.3% of wells over limit~30,990 on high-arsenic wells
New YorkNitrate: 0% of wells over limit~66,265 on high-arsenic wells
North CarolinaNitrate: 0% of wells over limit~119,631 on high-arsenic wells
North DakotaNitrate: 0% of wells over limit~2,013 on high-arsenic wells
OhioNitrate: 0% of wells over limit~189,191 on high-arsenic wells
OklahomaNitrate: 6% of wells over limit~4,340 on high-arsenic wells
OregonNitrate: 0.1% of wells over limit~26,055 on high-arsenic wells
PennsylvaniaNitrate: 3.9% of wells over limit~80,730 on high-arsenic wells
Rhode IslandNitrate: 0% of wells over limit~1,509 on high-arsenic wells
South CarolinaNitrate: 0.1% of wells over limit~28,133 on high-arsenic wells
South DakotaNitrate: 0.1% of wells over limit~1,181 on high-arsenic wells
TennesseeNitrate: 0.1% of wells over limit~5,242 on high-arsenic wells
TexasNitrate: 2.5% of wells over limit~95,453 on high-arsenic wells
UtahNitrate: 0.2% of wells over limit~2,132 on high-arsenic wells
VermontNitrate: 0% of wells over limit~9,716 on high-arsenic wells
VirginiaNitrate: 0% of wells over limit~52,796 on high-arsenic wells
WashingtonNitrate: 2.2% of wells over limit~52,249 on high-arsenic wells
West VirginiaNitrate: 0.6% of wells over limit~11,589 on high-arsenic wells
WisconsinNitrate: 0.8% of wells over limit~72,668 on high-arsenic wells
WyomingNitrate: 1.3% of wells over limit~6,214 on high-arsenic wells