On Dec. 30, Mount Pleasant Waterworks released a traffic control plan notice to the public for the Ben Sawyer Intracoastal Waterway Water Main Connection project.
The notice described the upcoming traffic impacts, including a temporary access road for residents in the project area and the temporary closure of the multiuse path on Ben Sawyer Boulevard, from Center Street to Toler’s Cove.
Since releasing that notice, community members have reached out to us asking predominantly the same questions:
- Is this water main connection project necessary?
- Why do you need to stage the pipe on the west side of the causeway, closing the path?
- What are you doing to ensure the safety of the citizens who depend on the multiuse path as their main mode of transportation?
The answer to the first question is a resounding yes. Water infrastructure projects often fly under the public radar, but for those of us who understand the calculations involved in being able to promise water customers that they will receive clean drinking water every time they turn on the tap, this project is not only big news — it is critical. Planning for growth and increasing water demand is at the center of every decision made at Mount Pleasant Waterworks. It is this singleness of purpose that has allowed us to repeatedly make this promise for more than 50 years.
Mount Pleasant Waterworks relies on two sources for its water supply: groundwater from the Charleston Aquifer used in our reverse osmosis plants and purchased surface water from Charleston Water System. With last year’s decision by the S.C. Department of Health and Environmental Control to cut Mount Pleasant Waterworks’ groundwater withdrawal permit, we turned to Charleston Water System to accelerate the Ben Sawyer ICW Water Main Connection project. The project is jointly owned as it allows for sustainable water supply to both our customers and Charleston Water System’s wholesale customers on the islands.
Why do we need to conduct the work on the west side of the causeway? The construction method used to connect water mains separated by a body of water is called horizontal directional drilling. It will be used on this project to allow for the construction and pull-through of a 5,000-linear foot pipe, 90 feet below the Intracoastal Waterway. The pipe construction phase of the project includes delivery and lay down, assembly, pressure testing and disinfection of the steel pipe.
The location of the staging area for the construction of the pipe is dictated by the narrow causeway connecting Toler’s Cove to Mount Pleasant. There is simply no room on that strip of land outside of the road and bike path to stage this pipe. The road is only two lanes and therefore could not drop a lane without eliminating bidirectional traffic flow, which would impact about 15,000 vehicles a day (the DOT 2019 count for Ben Sawyer Boulevard). This would also greatly hinder emergency vehicle response times. The project’s exit hole will also be on the west side of the causeway (Toler’s Cove), and the pipe could not be hoisted over the road safely without major impacts to the marsh.
Understanding the popularity of the multiuse path in the project area, the project design team considered three alternative designs for the pipeline staging area in hopes of minimizing impacts. The alternatives either faced permitting issues due to environmental impacts or were cost prohibitive. None of the alternatives allowed for the path to remain open safely during construction. The multiuse path is unequivocally the best staging location of all considered alternatives.
Since the release of the traffic control plan, there has been much discussion about the safety of bicyclists and pedestrians during construction. South Carolina Transportation Secretary Christy Hall visited the project site recently and met with Mount Pleasant Waterworks, Charleston Water System, project engineers and representatives from Charleston Moves and East Coast Greenway.
The project team presented the following safety measures in place for the project:
- Variable message boards will be placed prior to the work zone to alert drivers.
- The speed limit will be reduced to 30 mph through the work zone to slow traffic down.
- Radar devices and speed boards will be placed in the work zone.
- Advisory signs will be placed in the project area, including “Share the Road.”
The contractor also will work additional hours to expedite the schedule.
We can only ask for motorists, cyclists and pedestrians to be patient and aware of the confined roadway and to share the road safely. We are committed to the safe completion of the project so that our community can enjoy the benefit of a more sustainable and reliable water supply.
Clay Duffie is general manager of Mount Pleasant Waterworks.