STOCKTON — Under supervision of state regulators, workers at Deseret Chemical Depot have begun processing HT mustard agent-filled cartridges, or mortars, as part of ongoing disposal operations.

There are two types of mustard agent filled 4.2 inch mortars at Deseret Chemical Depot; HT mustard, which has a lower freezing point and makes up the majority of these munitions and HD, or distilled mustard. All munitions were reconfigured to remove their explosive propellant charges several years ago at the Chemical Agent Munitions Disposal System.

A Deseret Chemical press release said state regulatory authorities are observing the sampling and analysis of the HT mortars prior to disposal to ensure compliance with mercury emission standards. HT mortar destruction is expected to be completed this year.

Because HD mortars are likely to contain higher concentrations of mercury, they will not be processed until a new mercury filtration and capture system is installed this fall.

— Amy Joi O'Donoghue