Septic Services serving Bucks County. Rated 5/5 (13 reviews). From their website: DPD Contractors is an excavation company founded in 1994 by David P. Dobrowolski.   We can perform all of your residential or commercial excavation or septic system installation and repair needs.   All work is performed with the owner on the job, ensuring that the job is completed correctly and all the details addressed.   We are located in Lambertville NJ.