If a tree falls in a forest and no one is around to hear it, does it make a sound? If a hazardous vapor spews out of an industrial plant, but no regulator reacts, was there ever a leak?

Well, on July 6, Evergreen Oil workers decided not to stick around to find out. Some 70 workers walked off the job the minute they heard there was a leak at the hazardous waste and used motor oil recycling plant. It was a “self-evacuation,” according to the Alameda County Fire Department. One worker did go to a medical facility, was evaluated for exposure, and later released. Everybody else came back sometime after the leak was contained in the mid-morning.

But no worries, said the Alameda Fire Department. The leak was harmless to people’s health. And Newark City officials patted Evergreen’s plant manager on the back for, get this, reporting the leak properly and quickly. Sadly, that could be a first.

Here’s what we know about Evergreen Oil up in Newark, California in the East Bay area:  It handles hazardous waste materials like anti-freeze and other toxic waste. And it’s the only oil refinery recycling used motor oil here in the West. It employs a couple of hundred workers, generates about $36 million in sales each year, and has been operating since the mid 1980s.

Now, recycling used motor oil is a great idea. We want to live sustainably. And we need to do something about the underbelly of toxic waste in California from chemicals used to make computers to the engine oil you left behind at your last oil change.

The problem is that Evergreen Oil’s operations aren’t safe. It’s a serial toxic polluter with a very long record. The point isn’t just this particular leak on July 6, which was quickly contained. The point is this leak is part of a much bigger problem involving Evergreen’s record of operations, and its ability to negotiate its way out any real accountability.

Since opening in 1986, nearly every agency with the ability to fine Evergreen has done so. Evergreen’s been cited for dangerous levels of cyanide, arsenic, and other harmful chemicals in its wastewater, for violating public health standards, for the toxic gases it has allowed to emanate from the site and that have, on occasion, reached the nostrils of school children, for poisonous fumes and odors at the site, for an explosion, and for illegally handling, treating and disposing of hazardous waste.

Yet, almost every single time, California’s Department of Toxic Substances Control has given Evergreen a pass to stay out of court with wrist-slap fines and promises the company will clean up its act. But somehow, Evergreen is never clean. Since it opened, Evergreen has had at least five major fires at its facility, at least three major oil spills, over 100 hazmat and odor incidents requiring the Newark Fire Department’s response, and thousands of complaints from the community to local authorities. If that wasn’t enough, in March 2011, a huge explosion at the Evergreen facility involving a hydrochloric acid tank and waste oil sent flames hundreds of feet into the air and nearly required an evacuation of the surrounding areas.

It’s understandable that local officials and the community want the jobs. But when it came to land use, local officials didn’t think much about the plant’s location. Evergreen operations are less than half a mile from a housing development. A former Newark City Manager, Alberto Huezo, put it like this to the Oakland Tribune: “This goes back to the fact that it’s an industry we desperately need. But it was put in the wrong place—and the neighbors were there first.”

An alphabet soup of state and local regulators has authority over Evergreen. It has permits for hazardous waste handling, storage, and disposal, air quality, waste water and more. But all these regulators seem to be leaving it to the next guy to figure out what went wrong and who’s responsible for enforcement. There are some boots on the ground investigating, but nothing is bubbling to the surface yet.

The Department of Toxic Substances Control should step in as the lead regulator. Evergreen is a hazardous waste plant, after all. But the department says its permit exempts from regulation the part of Evergreen’s plant involving certified recycled oil since it is no longer considered a “hazardous material.” That’s the part of the plant where the leak allegedly occurred. Never mind that recycled oil still contains toxins. And what leaked wasn’t the oil anyway, it was a hazardous heat transfer chemical used in the refining process.

As the DTSC investigates its own authority to regulate, its first instinct should always be proactive and protective. Because when an Evergreen falls, it definitely gives off smells and sometimes much worse.