Oklahoma water quality
Oklahoma has 1,263 active public water systems (5,012 on file total), 866 of them graded by TapGraded.
Grade distribution
Biggest water systems
OKLAHOMA CITY
OKLAHOMA CITY, OK · 644,000 served
TULSA
TULSA, OK · 413,000 served
BROKEN ARROW MUNICIPAL AUTHORITY
BROKEN ARROW, OK · 116,330 served
NORMAN UTILITIES AUTHORITY
NORMAN, OK · 104,868 served
LAWTON
LAWTON, OK · 92,757 served
EDMOND PWA
EDMOND, OK · 79,408 served
MIDWEST CITY
MIDWEST CITY, OK · 55,935 served
MOORE PUBLIC WORKS AUTHORITY
MOORE, OK · 55,083 served
STILLWATER UTILITIES AUTHORITY
STILLWATER, OK · 53,000 served
ENID
ENID, OK · 49,347 served
Lowest-graded systems
Active, graded systems serving at least 10,000 people, ordered by lowest Tap Grade first.
WAGONER CO. RWD #4
BROKEN ARROW, OK · 25,792 served
STILLWATER UTILITIES AUTHORITY
STILLWATER, OK · 53,000 served
ALTUS
ALTUS, OK · 18,717 served
MCALESTER PWA
MCALESTER, OK · 18,206 served
OKMULGEE PWA
OKMULGEE, OK · 13,495 served
ROGERS CO RWD # 3 LAKE PLANT
CLAREMORE, OK · 10,470 served
CHICKASHA MUNICIPAL AUTHORITY
CHICKASHA, OK · 16,036 served
MUSKOGEE MUNICIPAL AUTHORITY
MUSKOGEE, OK · 38,310 served
DUNCAN PUBLIC UTILITIES AUTHORITY
DUNCAN, OK · 23,000 served
CREEK CO RWD # 2
JENKS, OK · 12,788 served
Cities in Oklahoma
Source: EPA SDWIS/ECHO · Data as of 2026Q2