Long Island American Water (LIAW) was concerned about the condition of two of its water mains; crossing the Reynolds Channel, both mains serve as transmission mains to supply water to the Village of Atlantic Beach, a barrier beach community located on the south shore of Long Island.
After conducting visual inspections and leak detection surveys of the two transmission mains, LIAW determined that the west crossing was partially undermined and exposed at the bottom of the channel. A considerable leak was also discovered in this same main. The east crossing was found to be in satisfactory condition. LIAW elected to plan for the replacement of both crossings, with priority given to the west crossing because of its poor condition. Ultimately, the west crossing was completed in September 2011, while the east crossing is slated for replacement within three to 10 years.
H2M prepared design documents for the replacement of approximately 1,400 LF of existing 16” water main at the west crossing and approximately 2,200 LF of existing water main at the east crossing. The replacement consists of new 20” diameter, corrosion-resistant High Density Polyethylene (HDPE) pipe, installed via horizontal directional drilling (HDD). This trenchless excavation method eliminates the need to dig elaborate trenches in order to replace piping, reducing construction costs and minimizing the project’s impact on the surrounding area.