## Facts

- Dairyland Power Cooperative operated a coal-burning electric generating plant in Alma, Wisconsin, built in 1947.
- Neighboring farmers on nearby bluffs alleged the plant’s increased burning of high-sulfur coal caused large sulfur-dioxide emissions that periodically settled over their farms.
- Plaintiffs presented lay and expert testimony that fumes visibly injured vegetation, including whitening of alfalfa leaves, reduced growth, and damage to other plants and trees; they also reported accelerated rust and difficulty raising flowers.
- Although other potential sources of sulfur were mentioned (e.g., transportation activity on the river), evidence supported the plant as the principal source affecting plaintiffs’ properties.
- Plaintiffs sought damages for past crop injury and for diminution in the market value of their farms attributed to the ongoing emissions.

## Issues

1. Whether plaintiffs’ claim was properly treated as private nuisance rather than negligence, and whether a formal election of theory was required.
2. Whether, after proof of substantial property harm, the defendant could avoid nuisance liability by showing due care or by offering evidence of the plant’s economic and social value.
3. Whether the circuit court properly changed the jury’s answer from “no” to “yes” on whether crop damage was “substantial.”
4. Whether the verdict on diminution in market value was supported by the evidence, including whether the interference should be treated as permanent for valuation damages.

## Decision

- The Wisconsin Supreme Court held the emissions constituted a private nuisance causing substantial damage to plaintiffs’ crops.
- The court held plaintiffs could recover in nuisance without proving negligence, and no late-stage “election” between negligence and nuisance was required where the operative facts supported nuisance.
- The court affirmed exclusion of evidence offered to show Dairyland’s due care and the plant’s social and economic utility on the question of liability.
- The court upheld the trial judge’s change of the jury’s “no” answer on substantial crop damage to “yes,” because the evidence required a finding of substantial harm.
- The court ordered a new trial limited to the issue of diminution in market value; the crop-damage awards were left intact.

## Legal Principles

- A private nuisance claim turns on substantial, unreasonable interference with use and enjoyment of land; liability does not depend on proof of negligence when substantial property harm is shown.
- A defendant’s due care in operating a lawful enterprise does not defeat liability for a private nuisance that causes substantial damage to neighboring property.
- Evidence of an activity’s public benefit or economic importance is not a defense to compensatory liability for substantial private property injury caused by the activity.
- A court may change a jury answer when the finding is contrary to the only reasonable view of undisputed evidence and adjustment is necessary to conform the verdict to the proof.
- Where interference is continuing and likely to persist, the factfinder must make a coherent determination whether damages include diminution in market value consistent with the character of the nuisance.

## Conclusion

The court treated industrial air emissions that caused recurring, significant crop injury as a compensable private nuisance, rejected due care and social utility as liability defenses once substantial harm was shown, upheld the amended finding of substantial crop damage, and required a new trial to reassess whether and to what extent the farms’ market values were reduced by the continuing interference.


Jost v. Dairyland Power Coop., 45 Wis. 2d 164, 172 N.W.2d 647 (Wis. 1969)