Mississippi water profile
Mississippi reports almost nothing above natural background
1,004 of Mississippi's 1,012 active community water systems have a current nitrate result — 99.2% of the state, among the most complete coverage on this site. 1 of them is at or above 3.00 mg/L as N.
Coverage this complete is what makes the result worth stating. Elsewhere on this site a quiet map can mean quiet water or thin reporting, and the two are hard to tell apart. Here they are not: Mississippi's utilities reported, and what they reported is low.
The exception is Okatoma Water Association #1, which reported 6.72 mg/L as N in Oct 2025, serving 3,981 people. It sits in the health-study range: below the federal limit of 10.00, inside the span where health studies report associations.
All 1,004 reporting Mississippi systems →
Two cautions, because a low public-system reading is a narrower claim than it looks. Nitrate is a one-way signal — elevated nitrate shows human nitrogen reached the water, but low nitrate does not show the reverse. In reducing aquifers, and much of the Mississippi Embayment is reducing, nitrate is stripped out entirely; the same conditions often carry elevated arsenic and manganese instead. And these are public systems. Private wells in Mississippi are not tracked as a complete system and are not in this inventory.
Because a single elevated system is not a pattern, Mississippi has no county map on this site. One point does not make a geography.
Coverage is uneven between states and is shown as it is rather than smoothed over. Where it is incomplete, and why.
Meanwhile
What the rest of the country reports
The national map covers 38,762 community water systems across 47 states. See where human impact is clear, or read what the breaks at 1, 3, 5 and 10 can and cannot tell you. The general science — how nitrate moves, why some ground is vulnerable, and why the legacy lingers — is on Where nitrate comes from.