| S1Shell 1416 - Talleyville | Wilmington | — | ◇ UNVERIFIED |
| SFSheridan Ford Sales | Wilmington | — | ◇ UNVERIFIED |
| SHSiemens Healthcare Diagnostics - Rt 896, Glasgow | Newark | — | ◇ UNVERIFIED |
| SPSpi Polyols INC. | New Castle | — | ◇ UNVERIFIED |
| SCStandard Chlorine of Delaware, INC. Superfund Site | New Castle | — | ◇ UNVERIFIED |
| VVersogen-1603 | Wilmington | — | ◇ UNVERIFIED |
| WLWilmington Leather Coatings | New Castle | — | ◇ UNVERIFIED |
| 2P212 Pharma LLC | Newark | — | ◐ LIKELY ACTIVE |
| ALAir Liquide Advanced Separations | Newport | 100–499 | ◐ LIKELY ACTIVE |
| ANAstraZeneca Newark Facility | Newark | 100–499 | ◐ LIKELY ACTIVE |
| CCChemours CO Fc LLC | Wilmington | — | ◐ LIKELY ACTIVE |
| DCDel City #118 | Delaware City | 20–99 | ◐ LIKELY ACTIVE |
| DEDupont Electronic Polymers L.p. | Wilmington | — | ◐ LIKELY ACTIVE |
| EAEkc Advanced Electronics USA 2, LLC | Wilmington | — | ◐ LIKELY ACTIVE |
| FWFilmtec Water Usa, LLC | Wilmington | — | ◐ LIKELY ACTIVE |
| FIFujifilm Imaging Colorants | New Castle | 20–99 | ◐ LIKELY ACTIVE |
| FIFujifilm Imaging Colorants Inc. | New Castle | 20–99 | ◐ LIKELY ACTIVE |
| INInternational N&H USA, Inc. | Newark | 100–499 | ◐ LIKELY ACTIVE |
| LLaMotte | Newark | 20–99 | ◐ LIKELY ACTIVE |
| NSNewark Site | Newark | 500+ | ◐ LIKELY ACTIVE |
| NHNexpera Headquarters | Newark | 20–99 | ◐ LIKELY ACTIVE |
| NRNexpera - Red Lion | New Castle | 20–99 | ◐ LIKELY ACTIVE |
| SASatys Aftermarket Delaware LLC | New Castle | — | ◐ LIKELY ACTIVE |
| SNSDIX - Newark | Newark | 20–99 | ◐ LIKELY ACTIVE |
| WAWilmington Aquarius plant | Wilmington | 20–99 | ◐ LIKELY ACTIVE |
| LGLumos Group, LLC | Middletown | — | ◐ LIKELY ACTIVE |
| ACAmspec Chemical Corporation | Bear | — | ◇ UNVERIFIED |
| DUDanisco USA INC. - Newark | Newark | — | ◇ UNVERIFIED |
| DEDelrin Experimental Station | Wilmington | — | ◇ UNVERIFIED |
| FPFormosa Plastics Corporation | Delaware City | — | ◇ UNVERIFIED |
| FSFrontier Scientifc Services, INC. | Newark | — | ◇ UNVERIFIED |
| IMInternational Market Suppliers, INC. | Bear | — | ◇ UNVERIFIED |
| KCKuehne Chemical Co., INC. - Delaware City | Delaware City | — | ◇ UNVERIFIED |
| LILinde INC. | Delaware City | — | ◇ UNVERIFIED |
| MHMarcus Hook Termnial | Claymont | — | ◇ UNVERIFIED |
| NLNuzelmeyer LLC | Bear | — | ◇ UNVERIFIED |
| PTPenske Truck Leasing CO LP | New Castle | — | ◇ UNVERIFIED |
| P6Phillips 66 Caustic Scrubber Material | New Castle | — | ◇ UNVERIFIED |
| PDPolyguard Division of Dyk Automotive, LLC | Wilmington | — | ◇ UNVERIFIED |
 Siemens Healthcare Diagnostics, INC. | Newark | — | ◇ UNVERIFIED |
| SCSyntec CORP | New Castle | — | ◇ UNVERIFIED |
| TPTechmer Pm | New Castle | — | ◇ UNVERIFIED |
| VIVeltec INC | Newark | — | ◇ UNVERIFIED |
| VFVersogen - Fmc - S115 | Newark | — | ◇ UNVERIFIED |
