The Committee wrestled with the issue of multiple piece of equipment numerous times over the past few years. We decided that it isn't practical to limit this. First, the amount of noise is not just a function of how many pieces of equipment there are; it also depends on their position, their direction, and the presence or absence of reflecting surfaces. Two units in one setting may be a more severe problem than 3 in another, for example.
Moreover, restricting the number of units would increase the length of time the crew operates, and it could also increase costs for landscapers.