A western Wisconsin city that annexed land from neighboring townships in an effort to entice a large frac-sand mine could see its gambit reversed by state officials in a case that has the potential to discourage the spread of similar mining projects across the state.

The so-called “balloon-on-a-string’’ annexation — in which the city of Independence claimed authority over a long, narrow strip of land to extend its boundary to a large mining site miles away — was too arbitrary and irregular to meet state legal tests, the Wisconsin Department of Administration concluded. The annexation, which was designed in connection with a project by Texas-based Superior Silica Sands, would have placed the mine under city jurisdiction and exempted it from environmental regulation by Trempealeau County.

Jack Speerstra, chairman of the board in Lincoln Township, said he hopes the Oct. 6 ruling has a chilling effect on other Wisconsin cities that are contemplating far-reaching annexations.

“I hope this sends a message to city councils that they can’t just do these annexations at will,’’ Speerstra said.

The case has drawn attention from regulators and environmentalists across Wisconsin, in part because several other “balloon-on-a-string’’ annexation plans are under consideration in Trempealeau County.

Located across the Mississippi River from Winona, Minn., the county already is one of the leading frac-sand jurisdictions in Wisconsin.

Jimmy Parra, a staff attorney for Madison-based Midwest Environmental Advocates, said the state’s review addresses a growing problem. Wisconsin cities have broad powers to annex land without the consent of bordering townships, and they are taking advantage of the process to reap money from sand mining, he said.

“Hopefully, the agency’s opinion will serve as a warning to other cities rushing to annex these mines for tax benefits at the expense of nearby residents’ quality of life, air and water protections,’’ Parra said.

Superior Silica did not comment Wednesday, and officials of Independence did not return phone calls this week.

Township meeting Thursday

Speerstra said Burnside and Lincoln townships asked for the state review in part because the annexation would wipe out chunks of their tax base and end any hope of future development on the parcels.

In addition, he said, the annexation would remove regulatory authority of a potentially large frac-sand mine from Trempealeau County, which is known for its thorough standards and reviews.

If the neighboring townships of Lincoln and Burnside use the opinion to challenge the annexation in Circuit Court, a judge could negate it. If that happens, the townships would retain their geography and tax base, while the city would be denied its plan to raise $50,000 or more a year in sand-mining royalties.

Speerstra said Superior Silica is scheduled Thursday night to ask residents of Lincoln and Burnside townships not to challenge the annexation by Independence. Speerstra, a farmer, said he expects the company to offer the townships a package of financial incentives. The two townships have until the latter part of November to file a challenge in Circuit Court.

“We’ll listen … but we are not necessarily willing to make a deal,’’ Speerstra said.

A Wisconsin township’s ability to request an annexation review from the state is an option created by the Legislature in 2012. Since the option became available, the Department of Administration has conducted only two reviews.

A popular maneuver

“It’s excellent news for us,’’ said Mike Koles, executive director of the Wisconsin Towns Association, a lobbying group that has opposed balloon-on-a-string attempts as unfair to rural residents.

“This decision gives a pause to these kinds of annexations,’’ said state Sen. Kathleen Vinehout of Alma.

Both officials, along with Trempealeau County Board Member Sally Miller, said the unnatural configuration has become a popular way for mining companies to escape well-defined county regulations. County limits on hours of operation, noise, lighting and other standards don’t apply if a mine is considered inside city boundaries, and mines can run around the clock.

“The mines have not been shy about saying they wanted to get out from under county control,’’ Vinehout said.

In exchange for the redrawing of city limits, mining companies are paying cities royalties. Independence, for instance, stands to collect 15 cents for each ton of finished frac sand from Superior Silica Sands, one of the country’s largest providers of frac sand to the oil-drilling industry.

Koles said the deals place industrial operations in the vicinity of rural homeowners without giving them any elective voice over how the sites should be regulated. The involuntary annexations also rob townships of tax base and development opportunities, while complicating boundaries for law enforcement, firefighting, school enrollment, elections and road maintenance, Koles, Vinehout and Miller said.

Stephanie Marquis, a spokeswoman for the Department of Administration, said annexation law applies to territory being added to a city or village regardless of the land use. Reviews are handled on a case-by-case basis, she added.