| Tier I Existing Severed and Mapped Growth Areas |
| Tier II-A Primary Mapped Growth Areas, Planned for Sewerage |
| Tier II-B Secondary Mapped Growth Areas, Planned for Sewarage |
| Tier II-C Future Mapped Growth Areas, Planned for Sewerage |
| Tier III-A Rural Communities Not Planned for Sewerage |
| Tier III-B Water Quality Strategy Areas, With or Planned for Sewerage |
| Tier III- Areas of Limited Sewer Service |
| Tier IV Resource Protection Areas |
| Incoporated Towns |