CONTRA COSTA COUNTY (CBS SF) — Fire authorities in Contra Costa County on Wednesday showed off some of the thousands of dollars worth of illegal fireworks confiscated during East Bay undercover operations in the past month.

In the last 30 days, fire officials said they have collected about 300 pounds of fireworks with a price tag of about $4,000.

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The seized fireworks have been confiscated by authorities during operations held in Pittsburg, San Pablo and all over Contra Costa County. Fire investigators have been conducting undercover purchases of illegal fireworks in an attempt to reduce the quantity of dangerous explosives available on the street.

Most of the charges so far have been in connection with the possession, selling or delivering of fireworks. Any use of fireworks of any type is illegal in Contra Costa County and downright dangerous during the extreme drought conditions gripping the Bay Area and California.

So far, they have arrested four people this month in connection with fireworks. One of the people taken into custody was the suspect accused of sparking the May 31st Antioch fire that destroyed eight apartment units.

That Memorial Day fire in Antioch displaced 40 residents. The suspect arrested, 44-year-old Antioch resident James Sossaman, faces charges of unlawfully causing a fire to inhabited structures and being a felon in possession of a firearm, authorities said.

Fire investigators said there was just one small M-100 explosive behind that fire.

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“With the fire that happened in Antioch where an apartment complex burned down displacing 40 residents from just a single firework going off behind the residence. He set it off on his patio and ended up burning the complex down,” said Contra Costa Fire Marshal Chris Bachman. “So we are encouraging people not to set off fireworks this year. This isn’t the year to do it. They are illegal and we are asking for the community’s help.”

Bachman said they will continue removing illegal fireworks from the streets ahead of the holiday. He also said the community can help by informing Contra Costa Fire of illegal activity. Anyone who knows of any illegal fireworks being offered for sale can call and report it to county’s the arson tip line at 1-866-50-ARSON.

All fireworks are illegal in Contra Costa County, but keeping them out is an uphill battle. The so-called “Safe and Sane” variety are legal just to the east in Sacramento County and in neighboring Alameda — and ever further away.

“The ones behind me here are more commercial grade or approaching commercial grade and those are probably coming from out of state, perhaps Nevada or elsewhere,” said ConFire PIO Steve Hill.

It is not just the fireworks dealers here who are facing penalties. Anyone caught shooting off fireworks in the county faces a fine of $100 per firework for a first offense.

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The fine for a second offense goes to $200 per firework set off. Every subsequent offense, the fine rises to $500 per firework. Earlier this year, authorities said they fined a Contra Costa resident a total of $26,000 for shooting off fireworks