How do I go about filing a complaint on my job?

Hello so my husband works for a shitty company and I was wondering how I go about reporting them. He is a foreman on a landscaping truck. He can be in charge of 3-4 people. He has been in situations where they are smoking meth in the truck. He also has videos of it happening. Countless times the employees go off in the woods to do weird stuff. Or him being underpaid, with no eval in over a year. They hire illegals which hey go for it, but they hire the ones that are lazy as heck and he does most of the work, while they are sitting in the work truck most of the day. He has complained until blue in the face and they just do not care. At this point it's just like oh hey so and so is here with another complaint and then make it out to be like he's the problem. They are not taking peoples safety into account. They know that people come to the job hopped up on meth and still send them out driving!!!!!!! The business needs to be audited on top of a lot of other things. the illegal activity that goes on here is ridiculous. He has had money deducted from his check for things he has never even received, gotten or even heard of before. PLEASE HELP!!!