We found 23 public water systems that could serve the same population as Keystone Postmaster Grid (ordered by population size).
| Name | Areas served | Population served | Contaminant count | Violation count |
|---|---|---|---|---|
| Postmasters Village | Keystone Heights | 658 | 0 | 0 |
| Mcrae Elementary School Wtp | Keystone Heights | 529 | 0 | 3 |
| Geneva Lake Estates | Keystone Heights | 511 | 0 | 15 |
| Trinity Baptist Church | Keystone Heights | 450 | 0 | 0 |
| Keystone Inn Family Restaurant | Keystone Heights | 100 | 0 | 0 |
| In Loving Hands Daycare | Keystone Heights | 92 | 0 | 0 |
| Redd Team Mfgr. | Keystone Heights | 90 | 0 | 0 |
| Gadara Baptist Church | Keystone Heights | 80 | 0 | 0 |
| Aat Omega | Keystone Heights | 75 | 0 | 0 |
| Lakeview Villa Mhp | Keystone Heights | 35 | 0 | 0 |
| Shifty's Hideaway | Keystone Heights | 25 | 0 | 0 |
| Advance Auto Parts # 9307 | Keystone Heights | 25 | 0 | 0 |
| White Elephant Bar | Keystone Heights | 25 | 0 | 0 |
| Goldhead Branch State Park | Keystone Heights | 25 | 0 | 0 |
| Keystone United Methodist Church | Keystone Heights | 25 | 0 | 0 |
| Camp Immokalee | Keystone Heights | 25 | 0 | 0 |
| Little Rain Park | Keystone Heights | 25 | 0 | 0 |
| Geneva Oil Bp, Inc. Wtp | Keystone Heights | 25 | 0 | 0 |
| Circle K #6508 | Keystone Heights | 25 | 0 | 0 |
| Circle K #6211 | Keystone Heights | 25 | 0 | 0 |
| Lake Hill Baptist Church | Keystone Heights | 25 | 0 | 0 |
| Twin Lakes Park | Keystone Heights | 25 | 0 | 0 |
| Snack ; Gas #8 | Keystone Heights | 25 | 0 | 0 |