Lessons Learned from Horizontal Directional Drilling Installation of HDPE Sewer Forcemains in Anne Arundel County, Maryland

摘要

Anne Arundel County is currently in the process of replacing approximately 25,000 linear feet (LF) of sewer forcemains (FM) using horizpntal directional drilling (HDD) for trenchless installation. The County has initiated a small diameter sewer FM replacement project to rehabilitate and/or replace small diameter sewer FMs that have reached the end of their useful life and/or have a history of breaks/failures. The County decided to use HDD to protect existing infrastructure and minimizing environmental disturbance and to streamline regulatory reviews and approvals. This paper focuses on six individual contracts in Anne Arundel County, Maryland that have utilized HDD. The challenges encountered on each of the contracts are highlighted and then summarized as lessons learned for general HDD installation. The conclusions from the lessons learned are summarized below: 1. The more information that is gathered in the design phase the smoother the construction phase will be. 2. The clearer the contract documents are the less room for change orders during construction. 3. A good public outreach program is essential.