299 A.3d 372
Del.2023Background
- Monsanto was the sole U.S. manufacturer of PCBs from ~1930–1977; PCBs are persistent environmental contaminants linked to serious health and ecological harms.
- Delaware alleges Monsanto knew of PCB toxicity as early as the 1930s–1950s, concealed dangers, continued promoting and selling PCBs, and even counseled customers against returns.
- PCBs have been detected in Delaware’s rivers, bay, state-owned lands, former military property, and public-trust resources; the State incurred investigation and remediation costs.
- On Sept. 22, 2021 Delaware sued Monsanto entities for public nuisance, trespass, and unjust enrichment seeking cleanup costs.
- The Superior Court dismissed: held Delaware’s nuisance/trespass claims barred because Monsanto was a product manufacturer with no control at time of release; held state lacks exclusive possession over public-trust lands (no trespass there); dismissed unjust enrichment as jurisdictional/merits failure.
- The Delaware Supreme Court affirmed dismissal as to unjust enrichment and trespass to trust lands, but reversed as to public nuisance and trespass to lands the State owns outright, remanding for further proceedings.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether a product-based or post-sale control requirement bars environmental public nuisance | Monsanto’s manufacture/sale plus knowledge and active concealment substantially participated in creating the nuisance; no separate product/control element required | Product-based nuisance claims disfavored; defendant must control instrumentality at time of nuisance | No categorical product/control barrier; liability may attach where defendant substantially participated (e.g., knew, concealed, continued supply) |
| Whether State has standing to sue for trespass to public-trust (subaqueous) lands | State claims exclusive possession (right to exclude) of trust lands and may sue for trespass | Public-trust lands are held for the public; State possession is non‑exclusive so no trespass standing | State lacks exclusive possession of trust lands; trespass claims to those lands dismissed |
| Whether State may plead trespass for lands it owns directly (non‑trust) | State owns certain parcels outright and alleges PCB contamination from adjacent sources tied to Monsanto’s conduct | Monsanto argues it did not enter or control PCBs on those parcels so trespass fails | State plausibly alleged trespass for directly owned parcels (exclusive possession + substantial contribution to entry) |
| Whether unjust enrichment survives and can recover remediation/future cleanup costs | Unjust enrichment is available as standalone in Superior Court; Monsanto was enriched by avoiding cleanup costs | Unjust enrichment is equitable or fails because defendant was not relieved of an otherwise enforceable obligation; future obligations do not alone show enrichment | Superior Court had jurisdiction, but unjust enrichment claim fails on the merits: no showing Monsanto was relieved of an otherwise enforceable duty or that statutory/emergency exceptions apply |
Key Cases Cited
- Keeley v. Manor Park Apts., Sec. 1, Inc., 99 A.2d 248 (Del. Ch. 1953) (liability can extend to those who substantially participated in creating a nuisance even after transfer of property)
- Crosse v. BCBSD, Inc., 836 A.2d 492 (Del. 2003) (unjust enrichment characterized as a legal, not equitable, claim)
- Nemec v. Schrader, 991 A.2d 1120 (Del. 2010) (elements traditionally required for unjust enrichment)
- Fleer Corp. v. Topps Chewing Gum, Inc., 539 A.2d 1060 (Del. 1988) (definition and contours of unjust enrichment)
- Illinois Central R. Co. v. State of Illinois, 146 U.S. 387 (U.S. 1892) (foundational public-trust doctrine regarding state custody of subaqueous lands)
- City of San Jose v. Monsanto Co., 231 F. Supp. 3d 357 (N.D. Cal. 2017) (survived motion to dismiss public nuisance against Monsanto for PCBs)
- City of Seattle v. Monsanto Co., 237 F. Supp. 3d 1096 (W.D. Wash. 2017) (denying motion to dismiss public nuisance claim alleging Monsanto knew and concealed PCB hazards)
- Abbatiello v. Monsanto Co., 522 F. Supp. 2d 524 (S.D.N.Y. 2007) (public nuisance claim against Monsanto survived motion to dismiss)
- New Mexico v. Gen. Elec. Co., 467 F.3d 1223 (10th Cir. 2006) (state guardian of public trust lacks the possessory interest needed for trespass in certain natural-resource contexts)