My job description, on the other hand, is "operator".

I'm working in a water treatment plant, which cleans up $BIGMININGCO's waste water and releases it to the environment. As a very neat side-effect of the process, the metals that are removed from the water settle out into a metal concentrate that's actually fairly valuable, instead of being a toxic sludge that has to be stored forever. $BIGMININGCO likes this for the obvious reasons.

I love it when an environmental process isn't a money sink.

When things go well...

For the past week, I've hardly had to do anything. I've done several full shifts where all I had to do was run tests (every 3 hours, takes about 40 minutes including cleanup), mix chemicals (once a shift, if needed, takes 15-40 minutes depending on which chemical and how much I mix), and wander around the plant watching the numbers on the sensors never change.

One of my co-workers said his goal this year was to not have to do anything.

But when something goes wrong... One day while wandering around the plant shortly after lunch, I noticed that one of the numbers (ORP - oxidation reduction potential, an electrochemistry-related measurement that tells us how much of our main reagent hasn't reacted) had changed. I checked the trendline on the controller display and it was changing fast. So I had to move - I started by checking the main reagent, since how much goes in is strongly related to the ORP. Sure enough, the flow rate was way down, so I cranked it up to where it should be. A little while later the trendline flattened out and started heading back to where it belonged. (There's a delay between changing the chemical flow and seeing the changes begin, about 15 minutes in this case.) I ran an extra metal assay, because there are strict limits on how much metal we're allowed to release to the environment. Then, a while later, I noticed the trendline getting steep again, in the opposite direction. And... the chemical flow rate was way up. So, turn it down, watch the trendline flatten again, do another assay.

Fortunately, while the metal assay went up, it didn't get anywhere near our limit before it started going back down to normal. (Normal is about 1/4 our maximum allowed concentration, so we have lots of room.)

Since my skills don't run to fixing pumps when they break, I asked my co-worker to look at it when he took over for night shift. Turned out a little chunk of some solid junk got stuck in the pump and was messing with the flow rate.

That was an interesting afternoon. Interesting like the chinese curse. It doesn't look like much when I write it out, but that took from 1PM right to 5PM when I had to take my daily samples into the lab. I hardly got to sit down that afternoon.

So why an engineer?

The team that runs the plant is made up of two engineers and two tradesmen.

Last year, the first year the plant was running, the operators were all tradesmen. The problem with that was that the tradesmen just didn't have the background in chemistry to really understand what it was doing. They could see the effects of turning a dial and got some really good practical knowledge, but a lot of troubleshooting was done over the phone between an engineer who wasn't there and a tradesman who didn't know chemistry.

This year, at any given time there's 2-3 people up north; minimum is one engineer and one tradesman, with the idea that our skills will complement each other. So far it seems to be working - the other engineer and I understand the chemistry end of things and the tradesmen understand (and can fix!) the mechanical parts.

If you're either in engineering or the trades, you may be familiar with the tensions between the two occupations. For those who aren't familiar with it, tradesmen often look down on engineers as being all theory and no practice, and engineers often look down on tradesmen as being uneducated, interchangeable grunts. Neither of these is correct.

Me, I grew up in the trades (mom is a carpenter, dad is a heating/air conditioning guy) and went to school to be an engineer. Both of the tradesmen seem to like me. (Although one of them threatened to throw me in the clarifier the day I forgot my hard hat and the only spare I could find was white - the engineering colour. I think he was only joking...)