This is a two phase project that is currently under way. The Underground Detention System #1  consist of 250 LF of 48” Perforated Corrugated Metal Pipe. 180 LF of 60” Corrugated Metal Pipe, backfilling with #57 Stone. We will remove around 4300 CYDS of dirt to install the detention system. The underground detention system #2 contains 3,000 LF of 48" Perforated Corrugated Metal Pipe and 350 LF of 60" Corrugated Metal Pipe. We will remove around 4700 CYDS of dirt to install this system. Between both systems it will take around 7500 tons of #57 stone to backfill, and approximately 400 tons of C-33 sand for pipe bedding on both detention systems.