How to Design a Successful Water Main Replacement Project
Water main replacement projects can be daunting but don’t have to be. Whether you’re a public works director, engineer, or water system operator, you can have a smooth and successful project. With careful planning and the correct information, it is possible to design a water main replacement project that is efficient, cost-effective, and has minimal disruption to your water system, its users, and the traveling public. From understanding the project’s scope to choosing the right materials and methods, we’ll provide valuable tips and insights to help your project succeed.
Note to Readers
How do you determine which water mains should be replaced first? In his previous article of this three-part series, we provide things municipalities should consider when planning their next water main replacement project.
Read the First Article in this seriesStart With Good Communication
Kick-Off Meetings
Holding a kick-off meeting with your client should be your first step to ensure everyone understands the project’s goals. These meetings are beneficial because they can quickly address your client’s concerns, discuss known issues in the project area, and anticipate possible obstacles. Prepare a list of questions beforehand and keep the agenda focused on your client’s needs based on what you already know about them and the project area.
Communication and Public Relations Plan
Creating a communication and public relations plan is another way to address potential obstacles with your project. Communicating with the public earlier than you think you need to is imperative during the design stage to minimize complaints during construction. An excellent way to do this is to write a letter or design a door hanger for homeowners explaining the upcoming project and providing the engineer’s contact information for any questions.
Don’t forget the importance of communicating with neighboring businesses. Developing a questionnaire for them to complete can be helpful to understand delivery schedules, access needs, and special water usage requirements that may impact the design.
Communicating with utility companies during your project is also critical to understanding and avoiding utility conflicts. There may be opportunities for a private utility company to relocate old lines that are in conflict with the water main and share in the paving cost, creating a win-win situation. Building these discussions into your project early can benefit your clients and result in various cost-saving measures.
Data Collection
Data collection is one of the most critical steps in water main replacement design. This includes field surveys, reviewing existing record drawings, water service records, private utility maps, and in-field utility locates, and collecting geotechnical data. If the existing water main is aging and made of cast iron, the replacement project should determine whether lead services are present and consider appropriate methodologies and materials for replacement. Any soil conditions, such as corrosive or contaminated soils, should also be noted to ensure the proper materials are selected for the replacement.
Using drones for surveys is an efficient way to get high-quality imagery and data for a project. They can capture detailed information about terrain, topography, obstructions, and existing surface improvements to help plan and create precise surfaces and drawings for design. Engineers can gain valuable insights into the project area more quickly from drone imagery before construction begins.
With careful planning and the correct information, it is possible to design a water main replacement project that is efficient, cost-effective, and has minimal disruption to your water system, its users, and the traveling public.
Considerations When Replacing Your Water Main
When planning a water main replacement project, consider possible construction methods, such as open-cut versus trenchless technology, that could be used for the project. Factors like the depth of the existing water main, surface features, and the number of water services that need reconnected will help determine the most effective technology for your situation.
Additionally, you should review the new water main alignment. Offsetting it from the existing alignment could save money by keeping the current water main live during construction, which may help avoid utility conflicts and improve traffic control. For example, offsetting the new water main from the middle of the street to one side or the other may allow you to keep one or two lanes of traffic open on the other side. All lead service replacements must also be considered under EPA’s most recent Lead and Copper Rule Revisions.
You should review existing records and verify critical utility locations (horizontal and vertical) with potholing to avoid utility conflicts and costly change orders during construction. You can consult your local Department of Environmental Quality (DEQ) database for nearby Superfund or leaking underground storage tank sites to determine if contaminated soils could exist. Include appropriate specifications for removing and disposing contaminated soils and using nitrile gaskets (if PVC pipe or Ductile Iron is used). If the existing water main is asbestos cement (AC) pipe, ensure your specifications address DEQ’s AC pipe removal and disposal requirements and any required asbestos inspections.
The specifications should also consider appropriate traffic control and a planned construction sequence. We recommend keeping work zones as short as possible to reduce the impact on the public and businesses. One way to accomplish this is by working at night at tie-ins, which can save on temporary water and traffic impacts.
By considering these factors when planning your water main replacement project, you can ensure a successful outcome and minimize disruption caused by the construction.
Key Takeaways
When it comes to water main replacement projects, having a good communication plan and properly collecting data are the first steps. Then, you need to consider the construction methods, sequence of installation, new water main alignment, and verify utility conflicts. Different types of water mains require other considerations, such as mitigating corrosive soils or lead service replacements. By following these steps and best practices, you can ensure your water main rehabilitation project succeeds.
Missed the first part of this series? Read it here