From a remote site in the heart of Bavaria, in southern Germany, the modest Solnhofen cement plant is claimed as a model for reducing pollution. The technology’s success in Germany, using SCR technology, has placed the Solnhofen plant at the center of an increasingly contentious debate in Texas over whether cement kilns in Ellis County — long a target of local clean-air advocates — should follow their German counterparts’ lead.

The outcome could have serious implications for local residents, who face the possibility of severe driving restrictions if air pollution cannot be reduced in other ways. The decision will rest with state and federal environmental regulators. But a growing number of cement kiln experts and engineers say installing the new pollution control technology at the three Midlothian kilns should be part of any plan to bring Dallas-Fort Worth into compliance with federal ozone standards by a 2010 deadline.

“As far as I can see, there is not a technical reason that it will not work,” said Al Armendariz, a chemical engineer at Southern Methodist University who is advising local clean-air advocates on pollution control alternatives.

The technology could cost tens of millions of dollars to install. And industry officials say that it’s still unproven for use in cement kilns and that there are differences between the local and German kilns that may prevent the pollution controls from working.

“I think there is a basic disagreement about whether this will work in Texas,” said Al Axe, an Austin lawyer representing the Portland Cement Association, the national trade group of cement kiln operators.

Studies however show that installing the pollution controls in the cement kilns would improve air quality in Fort Worth and Arlington.

“We proved the applicability of this technology in the cement industry,” said Sebastian Plickert, a cement industry specialist with the German Federal Environmental Agency. It should work in Midlothian, too, according to a state study by a group of cement kiln experts that said the system could cut smog-forming pollutants at local kilns by as much as 85 percent. The technology, they reported, is available, affordable and “must be seriously considered.”

The three kilns — TXI Operations, Holcim and Ash Grove Cement — are the region’s largest industrial source of nitrogen oxides, the chief man-made component of ozone. The nine-county region needs to cut an estimated 166 tons a day of nitrogen oxide emissions. Installing the pollution controls could slash as much as 20 tons per day of the ozone-forming pollutant, according to studies.

In May, a group of cement industry representatives and their consultants traveled to Germany to check out the Solnhofen plant. But at the time of the visit, the plant was not using the system. It was testing a different technology that the plant operators are considering as a backup. The system remains off-line, though German officials say it will soon go back into use.

The industry representatives wrote an unflattering report and submitted it in June to the Texas Commission on Environmental Quality.

Among other things, they reported that the less expensive pollution control system being tested as a backup at the kiln was working just as well. German regulators disagree, saying that if regulations required it to, the selective catalytic reduction system could easily reduce pollution to a greater extent than it does.

The American cement industry officials also raised concerns about reliability. The system at Solnhofen was found to have worked only 72 percent of the time in 2004 and 92 percent of the time in 2005, said Bob Schreiber, a St. Louis-based chemical engineer and the lead consultant for the cement industry trade association.

German officials were not pleased. They said the US industry representatives misled the plant manager, Gerd Sauter, who does not speak English. “Mr. Sauter was really upset” with the report, said Plickert, the German cement kiln regulator. “He had simply told them the facts and showed them the plant, and they didn’t tell him what they really were about to do.”

The cement industry wants to install the cheaper pollution control system, which is similar to selective catalytic reduction in that it chemically alters emissions. But the EPA says the alternative system would curb ozone-forming pollution only about one-third as much as the costlier system. Holcim installed the cheaper system at its Midlothian kiln this year in settling a legal challenge from environmental groups that were fighting the company’s efforts to increase emissions. The system came on line in April and halved emissions of nitrogen oxides, said Nick Tzourtzouklis, the environmental manager at Holcim’s Midlothian kiln. “It’s been a definite success,” he said.

TXI and Ash Grove are making moves to test that same technology at their plants this year, according to the companies’ officials. If it works, “we will make it permanent,” Grove said in a statement.