A man pleaded not guilty Monday to felony charges of illegally disposing hazardous materials as related hazmat investigations spanned throughout the county.

The Environmental Protection Agency told NBC 7 the man was trying to extract gold from ore and other metals using mercury and illegally disposed the material.

Michael Starr, 49, left a short-term rental house in Pacific Beach in disarray in early October, according to prosecutors.

When clean-up crews came in, they noticed awful smells coming from the oven and called the police.

While bomb and arson investigators found no threat, law enforcement found signs of mercury having been illegally disposed down drains and in trash chutes.

Prosecutors said Starr also contaminated a house on La Jolla Farms Road with mercury.

Starr cooperated and led law enforcement to Golden Triangle Self Storage in Sorrento Valley, where he was storing mercury and other chemicals.

The EPA, San Diego Fire Department, and San Diego County Environmental Health all responded to the storage facility, investigating and cleaning for the past four days.

While extracting gold in this way is not illegal, disposing the mercury improperly is against the law.

Mercury contamination is dangerous because when the familiar metallic liquid metal gets warm, it turns into a gas and can be inhaled, causing health problems, according to Robert Wise with the EPA Emergency Response Section.

Starr declined to talk to NBC 7 about his case, and pleaded not guilty to the felony charges.