In the dairy farm context, "stray voltage" or "stray current" lawsuits occur with some regularity. A recent ruling by the Minnesota Supreme Court declined to adopt a legal defense known as the filed rate doctrine to bar claims of this nature. In Siewert v. Northern States Power Co., 793 N.W.2d 272 (Minn. 2011), Minnesota's highest court concluded that the filed rate doctrine does not prevent plaintiff dairy farmers from seeking damages from an electric company where plaintiffs alleged that "stray voltage" from power lines harmed their dairy cows and lowered milk production. Though the ruling may eliminate a potential defense to a stray voltage claim against a utility in Minnesota, lawsuits involving agricultural production, including those concerning livestock such as dairy cows, are extremely fact-specific, complex, and can call into question many aspects of animal husbandry.

Under the judicially-created filed rate doctrine, lawsuits seeking to change rates or expand services of a regulated utility are barred. The rationale behind the filed rate doctrine is that regulation of rates is a complicated, comprehensive issue delegated to the appropriate regulatory agency. Courts lack both the expertise and the tools to adjust utility rates or change services established by the agency.

The Minnesota Supreme Court, concluding that under the facts of Siewert the filed rate doctrine largely did not apply, allowed the plaintiffs' case to go forward both on grounds of injunctive relief and money damages. The Supreme Court affirmed the Minnesota Court of Appeals' conclusion that the filed rate doctrine does not preclude plaintiffs' claim for damages because the claimed "damages were [not] linked to the filed rate itself."

The Court of Appeals had held that the filed rate doctrine precluded the injunctive relief sought by the plaintiffs, finding that those claims "would result in the court directing the scope of the service to be provided." Siewert v. Northern States Power Co., 757 N.W.2d 909, 917 (Minn. Ct. App. 2008). The Supreme Court reversed that ruling in part, reasoning that "[o]rdering NSP to abate the nuisance created by stray current, without directing NSP as to the particular means by which it was to do so, would not have added terms to the tariff or direct the scope of service to be provided." The Supreme Court recognized, however, that the filed rate doctrine barred plaintiffs' request that NSP be directed to "reconstruct the distribution lines to reduce or eliminate stray current."

Two of the six justices deciding the case dissented, believing that the filed rate doctrine justified dismissal of all of the plaintiffs' claims. Chief Justice Gildea, joined by Justice Dietzen, explained:

Because the Legislature has specifically charged the MPUC [Minnesota Public Utilities Commission] with adopting standards regulating how NSP is to deliver electricity and setting the rate that NSP may charge for that delivery, I would hold that the Siewerts' claims directly trigger the separation-of-powers and comity considerations that underlie the filed rate doctrine. In their claims, the Siewerts request that the judiciary order NSP to deliver electricity differently than the method set forth in the agency-approved tariff. The Siewerts also request that the judiciary assess damages against NSP because NSP has not delivered electricity in a manner different from that provided in the tariff. . . . But the Legislature has assigned to the MPUC the function of defining the manner in which NSP is to deliver electricity. Separation-of-powers and comity considerations counsel that the judiciary defer to that assignment.  

(citations and footnote omitted).

The dissenting justices concluded that the same rationale applied to bar the plaintiffs' damages claims, reasoning that "[i]f the judiciary cannot, consistent with the filed rate doctrine, require the regulated utility to perform additional services beyond those defined in the tariff, it follows that the judiciary cannot assess damages against the entity for failing to perform those additional services."

The court majority rejected NSP's alternative argument that Minnesota's 10-year statue of repose, Minn. Stat. § 541.051, barred plaintiffs' claims because the electrical system was an "improvement to real property" as defined by the statute. The court concluded that the plaintiffs' claims challenged NSP's operation of the electrical system rather than the system itself. The dissenting justices did not reach this argument, because, as noted above, they would have held that the filed rate doctrine precluded the entire lawsuit.

Litigants asserting stray voltage claims still face the difficult task of eliminating environmental, genetic, managerial, and many other factors on their road to proving causation. That is only part of the challenge, as proving the level of damages in the context of complex natural and biological processes is usually quite difficult. The analysis is fact-specific, expert-intensive, and far from precise. These factors should prevent the Siewert decision from increasing the number of stray voltage lawsuits that are filed.