| Abbreviation | Definition |
|---|---|
| NPDES | National Pollution Dilution and Elimination System |
| NPDES | National Pollution Discharge Elimination System |
| NPEO | North Pole Environmental Observatory |
| NPFD | National Plan for Forestry Development |
| NPFPD | National Plan on Forest Protection and Development |
| NPI | National Park Institute |
| NPI | Noise Pollution, Inc. |
| NPP | National Parks Project |
| NPPR | National Pollution Prevention Roundtable |
| NPPR | Ndtablesnational Pollution Prevention Roundtable |
| NPROVS | NOAA Products Validation System |
| NPS | National Park Service |
| NPTH | Nez Perce Tribal Hatchery |
| NRA | National Recovery Administration |
| NRA | National River Authority |
| NRAP | Near Roadway Air Pollution |
| NRC | Natural Resource Committee |
| NRC | Neighbourhood Recycling Centre |
| NRDWP | National Rural Drinking Water Programme (India) |
| NRE | Natural Resource Education |