Thanks for the ray of hope britsimon. What would we need to do to improve his chances, contact a good immigration lawyer?
You don't need an immigration lawyer - they really do not know the DV process (because they get little, if any, exposure to it) and you could end up spending money on a fruitless effort.
The trick is this...
On the O*Net database each job has a rating as you are aware (the level needed being Job Zone 4, SVP Range, 7.0 to < 8.0). You need to find a role that matches what he does, not what his title is. You can be a bit creative with the titles because they don't match.
So - I did a search for Waste water and hey presto here is one that matches (AND QUALIFIES!). So, Your hubby is now a Water/Wastewater Engineer!!! The operator tag would kill it, so engineer is what he would have to be described as. There may be others that are better for him, so have a browse around O*Net.
http://www.onetonline.org/link/summary/17-2081.01
By the way that role says Bright Outlook meaning it there are good prospects for someone in that job...
If you look at the summary and details of the tasks perfomed by a wastewater engineer, you can almost go down the list and tick off how close his role is to that description. IF you get a good level of matching, then you should be able to build a case around that. You would need a detailed CV, affadavits from managers/workmates etc. You would need to build a picture of him doing an engineering role, rather than standing knee deep in crap. I'm sure you see what I mean. Have a think and a chat with hubby. I'll find the thread of the couple that were successful just a couple of months ago and I am sure they would be able to help you compile a file if you wanted to go ahead.
EDIT: Here is the other case I was thinking of...
http://forums.immigration.com/showthread.php?559396-Qualifying-for-DV-by-Work-Experience