Mosheim, Tenn.—U.S. Nitrogen Co. LLC (USN) reports that malfunctions occurred in the midst of multiple startup attempts at its nitric acid plant here that led the company to exceed federal reporting requirements for the release of oxides of nitrogen within a 24-hour period. Federal, state, and local authorities were notified, and USN is assisting in their investigation. USN said it would ensure that all issues are resolved and equipment is tested before resuming operation of the nitric acid plant. Local residents reported and photographed an orange plume coming from the facility on Aug. 23. In two other recent matters, USN told authorities that it did not use selective catalytic restrictive equipment (SCR) when starting up an anhydrous ammonia plant and that storm water runoff levels exceeded the national cutoff limitations for magnesium, even though the company does not use magnesium in its production process. USN told Green Markets Aug. 29 that it continues to anticipate being fully operational within the next few weeks