## Facts

- Plaintiffs were homeowners in Thomas Addition, a residential subdivision on the northwest side of Carroll, Iowa, platted in 1959 and subject to residential restrictions, with only limited commercial zoning on lots adjoining U.S. Highway 71.
- U.S. Highway 71 ran north–south between the subdivision (east side) and defendant Clark Ready Mix Company’s property (west side).
- Plaintiffs had lived in their homes for several years, and the neighborhood consisted of established residences rather than industrial uses.
- In 1970, Clark purchased land across the highway from Thomas Addition and later constructed and began operating a cement ready-mix plant.
- The plant included a cement silo, bins for sand/gravel/crushed limestone, truck driveways, and a diesel-powered front-end loader; ready-mix trucks and delivery vehicles used the site regularly.
- Portland cement was delivered by tank trucks and blown under air pressure through pipes into compartments in the silo; the system required venting to release pressure.
- Clark used a bag-filter system (vibrating canvas bags) intended to capture cement dust during venting, but in actual operation a noticeable amount of cement dust escaped into the air.
- When winds blew from the west, dust drifted across the highway onto plaintiffs’ properties, settling on lawns and plantings and on outdoor items such as furniture and clotheslines.
- Plaintiffs also complained of disturbance from plant activity (including equipment and truck operations), adding to interference with ordinary residential use.
- Plaintiffs filed an equity action seeking an injunction to stop operation of the plant at that location as a private nuisance.
- The trial court found the plant constituted a nuisance but declined to enjoin its operation; plaintiffs appealed.

## Issues

1. Whether Clark’s ready-mix cement plant operations (including recurring cement dust and related disturbances) substantially and unreasonably interfered with plaintiffs’ use and enjoyment of their residential property, constituting a private nuisance.
2. If a nuisance was shown, whether equitable relief should include an injunction closing the plant’s operation at that site rather than denying injunctive relief.

## Decision

- The Iowa Supreme Court reviewed the case de novo because plaintiffs sought equitable relief, giving weight to the trial court’s fact findings but not being bound by them.
- The court concluded plaintiffs proved a continuing private nuisance affecting nearby residences.
- The court reversed the trial court’s refusal to grant injunctive relief.
- The court remanded with directions to issue a writ of injunction closing the plant’s operation at that location.

## Legal Principles

- A lawful business may constitute a private nuisance if, in light of the locality and surrounding land uses, it causes a substantial and unreasonable interference with neighboring owners’ use and enjoyment of their property.
- Recurring airborne particulate emissions that deposit on neighboring residential property and interfere with ordinary household and outdoor use can support a finding of nuisance.
- In deciding whether to enjoin a nuisance, a court in equity considers the character of the neighborhood, the seriousness and frequency of the interference, and whether legal remedies (such as damages) are adequate for an ongoing invasion.
- When an established residential area is subjected to continuing dust and disturbance from a nearby industrial operation, equity may require abatement by injunction, even if the business operation has economic value.

## Conclusion

The Iowa Supreme Court held that Clark Ready Mix’s operations across U.S. Highway 71 from Thomas Addition created a continuing private nuisance through recurring cement dust (and related disturbances) that materially interfered with homeowners’ residential use, and it ordered the district court to issue an injunction closing the plant at that location.


Helmkamp v. Clark Ready Mix Company, 214 N.W.2d 126 (1974)