See the Greenwich Noise Ordinance at this link
Construction is regulated by time frame, not noise produced. Construction is allowed from 7 am to 6 pm Monday through Friday and from 9 am to 5 pm on Saturday (Sec 6B-6(a))
Gas-powered Leaf Blowers are regulated by time frame, not noise produced. Gas-powered leaf blowers are allowed from 8 am to 6 pm Monday through Friday and from 9 am to 3 pm on Saturday, Sunday and holidays. (Sec 6B-6(e)(3))