The mountains of garbage that often fill the streets in the Italian city of Naples and surrounding areas aren't just a modern-day problem, suggest ancient wall inscriptions.

Using infrared reflectography, a non-destructive technique commonly used to peek beneath the surface of paintings, Italian researchers have brought to light two inscriptions against garbage dumping in the ancient Roman town Herculaneum.

The modest town was destroyed, along with its more famous neighbor Pompeii, in the first-century eruption of Mount Vesuvius.

The finding shows that even before the eruption buried Herculaneum under 75 feet of ash, local authorities were already trying to reign in trash.

Luciano Rosario Maria Vicari, director of an applied optics laboratory at Naples University, and colleagues analyzed Herculaneum's notice board, which was found on the eastern side of the city's water tank.

The board for public notices consisted of a plastered rectangular area that housed the "tituli picti," — painted inscriptions used to communicate decrees and measures.

Painted in black, the inscriptions were carefully placed on straight parallel lines carved on the plaster.

"The plastered area worked as a blackboard — the previous inscriptions were wiped with a thin plaster layer to make space to a new inscription," Vicari told Discovery News.

The most recent inscription was found by inscriptions expert Matteo Della Corte in the mid-1900s. It contained a decree by the magistrate Alficius Paulus against the dumping of waste.

Della Corte realized there was a second inscription on the plaster layer underneath, and tried in vain to bring it to light. Painted inscriptions fade quicky in the sun and rain, once exposed.

"Indeed, the ink was almost gone and the plaster was seriously damaged. But infrared reflectography has succeed in recovering that lost inscription, showing that we can apply this technology to other sites in Herculaneum and Pompeii," Vicari said.

The inscription below was another decree against garbage dumping in the area around the water tank. It was issued by two joint magistrates, Rufellius Romanus and Tetteius Severus.

"The authorities were very strict" said Vicari. "Transgressors, if free citizens, would have had to pay a fine. Lashes were reserved for slaves who infringed the rule."

Overlooking the Bay of Naples, Herculaneum was home to a wealthy elite, a cluster of fabulous villas and gardens.

"The town's social makeup was rather different from Pompeii's. But the fact that 'no dumping' decrees were repeated over and over on the board, means that this was a serious problem in the town," Herculaneum scholar Mario Pagano told Discovery News.

Vicari also found a third inscription, which has yet to be decoded. Most likely, it was made by a passer-by, as the water tank was close to a market, Vicari said.

"This is important research," said Pagano. "Inscriptions in Pompeii abound, but they consist mainly of electoral notices. The finding in Herculaneum, on the contrary, is rather unique."