Originally posted at Voice of San Diego.
By Joel Hoffmann.

The billowing smokestack is a common meme for stories about air pollution. But it can skew our sense of where such pollution comes from.

Far less obvious but more widespread are the auto repair shops, boiler rooms and backup power generators of San Diego. And much like their menacing brethren, they need a license to pollute the air.

That’s where the San Diego County Air Pollution Control District comes in. Issuing permits for stationary sources of pollution — translation: not mobile, like cars and trucks — is a big part of what the district does. But permits aren’t one-size-fits-all, and that’s by design.

The district has to balance the public health risks of commercial pollution against the cost of compliance. And that’s why the cost of the permit and time it takes to get one rises with the level of risk.

“Quite frankly we don’t get many complaints about the cost,” said Tom Weeks, the air pollution district’s head of engineering, but “the time frame for issuing permits is sometimes an issue.”

Some machines don’t need a health risk assessment at all, but the big, billowing ones need the most attention. Time is money for the district — as it is with any service provider — so the cost of the permit also rises with the amount of time it takes to make sure a pollution source complies with the law.

Permit costs can run from a few hundred dollars for a simple asphalt kettle that holds roofing tar to more than a hundred thousand for the complex machines that make power plants work. That pattern holds for the time frame. Simple permits can be issued the same day. But for complex ones, the 180-day limit sometimes has to be waived.

About half of all permits are issued in a month or so.

“We get about 900 or 1,000 applications a year,” Weeks said. “There’s a whole range for types of equipment that we permit. But numbers-wise, probably the most common are engines, boilers and lots of auto body shops.”

When Weeks says engine, he’s talking about backup power generators. Chances are there’s one in your building if you work in a place with lots of computers. When the power grid goes down, these engines kick in.

The problem is that generator engines tend to run on diesel fuel, which is more dangerous to breathe than secondhand smoke. But the health risk is minimal when the generators comply with the law.

“If there are people living near that engine that will be exposed to high concentrations, we wouldn’t issue it,” Weeks said.

These generators account for about 15 percent of the permit applications the district receives each year. When the application comes in complete, it takes about two months to get one. And it’ll cost you about $2,000.

Weeks recommends that businesses apply for a permit before they buy a generator — or anything else that requires a permit — because having the wrong equipment can delay the process and drive up the cost.

“We sometimes have to require additional controls and changes to work practices to ensure compliance,” Weeks said. “But in the end, the vast majority do comply.”