REGION FOUR - Monmouth
| Region 4 | County |
| Aberdeen Township | Monmouth |
| Allenhurst | Monmouth |
| Allentown Borough | Monmouth |
| Atlantic Highlands | Monmouth |
| Bayshore Regional Sewerage Authority | Monmouth |
| Belmar | Monmouth |
| Brielle | Monmouth |
| Deal Borough | Monmouth |
| Eatontown | Monmouth |
| Eatontown Sewerage Authority | Monmouth |
| Fair Haven | Monmouth |
| Farmingdale Borough | Monmouth |
| Freehold Borough | Monmouth |
| Freehold Township | Monmouth |
| Hazlet Township | Monmouth |
| Keyport Borough | Monmouth |
| Little Silver | Monmouth |
| Loch Arbour | Monmouth |
| Manalapan Twp | Monmouth |
| Manasquan Borough | Monmouth |
| Manasquan River Regional Sewarage Authority | Monmouth |
| Matawan Borough | Monmouth |
| Middletown Sewerage Authority, Township of | Monmouth |
| Middletown Township | Monmouth |
| MillStone Twp | Monmouth |
| Monmouth County Bayshore Outfall Authority | Monmouth |
| Ocean Township | Monmouth |
| Ocean Township Sewerage Authority | Monmouth |
| Oceanport Borough | Monmouth |
| Red Bank Borough | Monmouth |
| Rumson Borough | Monmouth |
| Sea Girt | Monmouth |
| Shrewsbury Towship | Monmouth |
| Two Rivers Water Reclamation Authority | Monmouth |
| Union Beach | Monmouth |
| Upper Freehold Township | Monmouth |
| Wall Township | Monmouth |