A D.C. man got a break on his property taxes because he argued that his home stood on land where the U.S. Army once dumped mustard gas.

The head of D.C.’s tax office says that the $2.6 devaluation in commercial property tax assessments discovered by the Post is not as alarming as it seems.

The District stands to lose $48 million in property-tax revenue this year after more than 500 developments were overvalued by the city’s appraisers and had to be reassessed.