Are you actually running ranking reports?
here's what I see for 3 keywords in stamford:
Lawn Service Stamford: 9
Stamford lawn service: 12
lawn service in stamford: 11
Your site looks fine, and it's ranking well for a city with 123k population. You just need to crank up some backlinking to climb up to the top of page 1 - and if you hit a wall in climbing up the rankings, then look at your on page stuff.
Keyword density is almost irrelevant at this point. You need the particular keyword in your page content, but if you put it in too much, then google will penalize you. So, be careful.