Independent listing. Not run by the City of Columbus. The City’s PDF is the official list.

Search testers › A to Z

All approved testers, A to Z

195 companies from the City of Columbus lists (Oct 16 2026) and Del-Co Water’s list (Jun 26 2026). Alphabetical; nobody pays to be here. To filter by town, utility or device, use the search.

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

R

S

T

U

V

W