Indiana water quality
Indiana has 3,776 active public water systems (9,914 on file total), 712 of them graded by TapGraded.
Grade distribution
Biggest water systems
CITIZENS WATER - INDIANAPOLIS
INDIANAPOLIS, IN · 880,345 served
FORT WAYNE - 3 RIVERS FILTRATION PLANT
FORT WAYNE, IN · 269,994 served
INDIANA AMERICAN WATER - NORTHWEST
GREENWOOD, IN · 210,510 served
EVANSVILLE WATER UTILITY
EVANSVILLE, IN · 182,444 served
SOUTH BEND WATER WORKS
SOUTH BEND, IN · 115,000 served
INDIANA AMERICAN WATER - S. INDIANA
GREENWOOD, IN · 104,445 served
CARMEL WATER DEPARTMENT
CARMEL, IN · 99,927 served
INDIANA AMERICAN WATER - JOHNSON COUNTY
GREENWOOD, IN · 86,813 served
CITY OF BLOOMINGTON UTILITIES
BLOOMINGTON, IN · 83,000 served
HAMMOND WATER WORKS DEPARTMENT
HAMMOND, IN · 78,384 served
Lowest-graded systems
Active, graded systems serving at least 10,000 people, ordered by lowest Tap Grade first.
CITY OF LAWRENCE UTILITIES
INDIANAPOLIS, IN · 49,000 served
PIKE-GIBSON WATER, INC.
OAKLAND CITY, IN · 10,000 served
ANDERSON WATER DEPARTMENT
ANDERSON, IN · 55,212 served
HUNTINGTON WATER DEPARTMENT
HUNTINGTON, IN · 17,300 served
BORDEN TRI-COUNTY REGION
BORDEN, IN · 11,000 served
RAMSEY WATER COMPANY, INC.
RAMSEY, IN · 16,475 served
MADISON WATER DEPARTMENT
MADISON, IN · 15,323 served
MISHAWAKA UTILITIES
MISHAWAKA, IN · 49,675 served
GREENSBURG MUNICIPAL WATER WORKS
GREENSBURG, IN · 12,650 served
WASHINGTON WATER WORKS
WASHINGTON, IN · 13,690 served
Cities in Indiana
Source: EPA SDWIS/ECHO · Data as of 2026Q2