I would agree with a lot of what Tony said. First of all the site looks nice, this is a good signal to people. A quality site from an atheathics point of view signals that your a "real company" I would also add the BBB logo up higher, I almost missed it. These kinds of logos help establish trust.
A "call to action" is important. What do you want people to do, call you, email you, fill out some form? Make it easy for them. put the number in the header of every page. I might even replace or reduce the tagline" your on-site wastewater professionals" to make room for your phone number.
The only other nit picky thing is I would change the Case study 1, 2, 3 to something more descriptive. Environmental friendly case study. new home, etc.
Testimonials are good though again convey some trust, along with the pictures. Nice to have a site with pictures of the steps of the process.