If you are going to dig up the street in the city of Boston, understand that there are people there to ensure you do it right.

"If you fail, you’re gonna have to fix it," said Mark Cardarelli, Supervisor of Utility Coordination and Compliance for the city of Boston's Public Works Department. "There’s nothing I can do. The city comes first."

Cardarelli said there are roughly 5,000 permits distributed every year for excavation of Boston streets. Companies like Verizon and Comcast dig to lay fiber-optic cable. National Grid tears up stretches to repair gas line. And well over a hundred different private contractors working for individual homeowners and commercial properties lay underground pipes that tap into city water mains.

"We have rules set up from A to Z," said Cardarelli.

Every company that works under the street is required to finish the job by repairing the surface of the street. The city has a three-year warranty on that patch in the asphalt.

Cardarelli said about 10 percent of those patches go bad — cracking at the edges, crumbling, sinking, etc. — and he remembers the days when determining who made what patch — and holding them to account — was a logistical nightmare.

"There was one particular one...a really bad patch," he recalled. "It was in downtown Boston where it could have been anybody: the water, the gas, private, steam. So, I brought them all out and I said, 'Who did this?' And they gave me this."

Cardarelli crossed his arms and pointed in opposite directions.

"They gave me a 'that-a-way. It wasn't me." he continued. "So I said, you know what? I’m tired of that."

Cardarelli began looking for a solution and learned from a counterpart in New York City about a unique system they had recently employed to combat the same problem, using small circular plastic discs called A-tags — short for asphalt tags — a product manufactured by Rhino Marking and Protection.

"Mark called me, oh, about 10 years ago now," said Tom Preston with Rhino Marking and Protection. "So, I worked with Mark on devising a system with these A-tags."

When embedded in the surface of the asphalt, the round plastic A-tag looked like a poker chip. Each Boston A-tag has the year in the center, making it easy to identify when the patch was laid and whether it’s still under warranty.

Cardarelli decided the big companies who do a lot of digging would get a custom color and their name at the bottom.

"I said National Grid, you’re yellow; Boston Water and Sewer, you’re blue. MWRA [Massachusetts Water Resource Authority] you’re light blue. Comcast and Version you’re orange; Eversource, you're red; the steam company, you're white," he explained.

But Rino only had so many color options and there were the hundred plus private contractors who might dig and be required to patch the roadway to deal with. Cardarelli and Preston decided that all private companies would get green A-tags came up with a numbering system.

"They all have on the outer ring, an identifying number," said Preston. "And that corresponds to a contractor's number on a big, gigantic list that the city holds on to."

"So when the inspector goes out, on the green he has a sheet," said Cartarelli. "And says, number 6 [for example] is this guys name."

Since 2011, anyone who patches the street after digging it up has been required to embed their custom A-tag. Companies can be fined if they do not, but Cardarelli said the compliance rate is about 98-99 percent.

The companies have to buy them, but they cost only a few hundred bucks per year at most. And Cardarelli says the program has saved Public Works a lot of headaches, and saved the city of Boston plenty of money.

"We now can identify the poor patches right away," he said. "We can get the repairs done in a timely manner and that’s a win-win for everybody."

Recently, Cambridge followed Boston’s lead and instituted the same program.

Preston said his company has introduced versions of the system to other cities like Pittsburgh, Louisville and Denver.

They are everywhere and they are hard to miss which, Cardarelli said, is the point.

"We have maybe 15 inspectors. Nobody can be everywhere," he said. "But that tag allows everybody in the city of the Boston to, basically, be an inspector. From the Mayor down to Mrs. Jones or Mrs. Smith."