If you work in water transmission systems, it is almost inevitable that at some point you will be designing or planning a system shutdown. This can be to establish a new system interconnection, conduct condition assessment on a pipeline, or rehabilitate a portion of the system. These are the points in the project that we intentionally put customers out of service temporarily in order to maintain or improve the system. Shutdowns are, without a doubt, necessary for maintenance, operation, and growth, but they also are the times when planning and process are most important.
Any failed or prolonged shutdown can result in service interruption to customers, loss of revenue to the owner, additional construction costs, negative customer impacts, and public relations nightmares. Accordingly, what can we, as professionals, design engineers, contractors, and owners, do to mitigate some of these risks?
Prior to reviewing some best practices to improve shutdown planning, it is important to understand the two major approaches to shutdown design:
- a performance-driven, contractor-led construction solution; and,
- a technically driven, engineer-led design solution.
Both approaches require design and planning and both have their place in the industry.
Contractor-driven solutions — Small-diameter connections or non-critical utilities may successfully rely upon a performance-based design that gives the contractor freedom in both when and how work is executed. This approach minimizes design schedule and cost, with the engineer providing notes, callouts, and performance criteria while developing a clear line of accountability in construction. Little information is given to the contractor other than performance expectations, and he/she is expected to make ends meet in the field. As an example, a 6-inch interconnection in an undeveloped area of town is considered as a good example of a contractor-driven approach.
The drawback of such an approach is increased construction risk. This relies heavily on a contractor’s ability, as he/she is expected to coordinate connection requirements and design with pipe manufacturers and suppliers. This can result in increased construction cost or confusion in bidding, with each bidder potentially planning execution of work differently and each having different capabilities. Accordingly, as a project and requirements grow in complexity, the level of detail in design and direction grows as well, ultimately leading to a fully engineered solution.
Engineer-driven solutions — As one would expect, the cons of a contractor-driven solution appear as pros for the engineered alternative. As the engineer develops detailed design documents and provides specific directions, greater clarity is provided for potential bidders. Thus, with a proper and complete design, construction risk and cost can be reduced. This approach also provides the greatest level of owner control, assuming an active role is taken in the design process to evaluate the solution, sequencing, direction, and documentation.
Obvious cons for such an approach are increased design costs and prolonged design schedule; however, construction accountability can also prove difficult. Regardless of effort expended during design, there will always remain some unknowns when working on or connecting to existing underground utilities. The more detail provided in design documents, the more opportunity for finger-pointing and fault finding if anything is not as presented. This may not be pleasant to discuss, but it is an inevitable truth in utility work and must be kept in mind when approaching a shutdown plan from this angle.
Take the right steps
Because each of these solutions have their place in the industry and because each alternative presents notable and distinct challenges, it is important that a team work together throughout the life of a project to plan for the shutdown. The following outlines some best practices that are most appropriate for an engineered solution but will benefit any shutdown. While these practices don’t guarantee success, following them will certainly improve the likelihood of success.
The best practices include:
- conduct properly structured meetings,
- execute a shutdown checklist,
- staff the job with a properly trained inspector, and
- keep the design engineer on call during construction.
Meeting is a word that can instill dread in the most hopeful engineer, contractor, or owner. However, when planning a water transmission pipeline shutdown, several meetings are critical to success. A minimum of four meetings is recommended for any shutdown of a major system. These should not get lumped into progress meetings but should rather be stand-alone, specific meetings, with the purpose of each as follows:
• Conceptual shutdown criteria meeting — This is proposed for conceptual (roughly 30 percent) design phase and is usually several months before any actual shutdown will occur. The purpose is to get all stakeholders in a room together to review the system, identify design criteria, review system functionality, and so on. It is critical that the owner have engineering/design, operations, maintenance, and inspection personnel at this meeting, as it is vital that each stakeholder see and hear the same thing from the outset of this work.
• Detailed design review meeting — This generally occurs around 70 to 90 percent design. It should be completed only after the full shutdown approach is sufficiently documented in plans and specifications but should allow sufficient time for the engineer to make adjustments if needed before bidding. The purpose here is for all to see, understand, and accept the proposed shutdown design and sequencing.
• Pre-shutdown meeting — This is generally held about two to four weeks before the proposed shutdown. This will be the first meeting the contractor is incorporated into the discussion (assuming design-bid-build procurement), and he/she should actually lead this meeting. The purpose is for the engineer and owner (operations, maintenance, and inspection at minimum) to hear the contractor’s specific plan and to ensure it aligns with design criteria and intent. The contractor should bring detailed plans for the approach including a schedule and sequence, materials list, identification of responsibilities, and specialty personnel needed.
For example, for a 36-inch-diameter pipeline shutdown that had to be completed in less than 72 hours to replace existing bar-wrapped concrete cylinder pipe, a final shutdown meeting and field walkthrough was not conducted with the contractor. Despite several discussions about connection alternatives and general team buy-in of the approach, no one understood that part of the contractor’s proposal was to replace less pipe than designed to connect at an existing joint, once found in the field. The result was confusion during construction and a contractor installing 26 feet rather than 68 feet of new steel pipeline, changing thrust restraint mechanisms and requiring an emergency design response. This likely would have been avoided with a pre-shutdown walk through onsite.
• Final preparation meeting — A final meeting should be held a day or two (at most) before the shutdown is to take place. Ideally, this should be held on location and jointly led by the contractor and inspector, as these two stakeholders need to be working in harmony. This provides the owner and engineer an opportunity to put eyes on the site, identify conflicts, and walk through the sequence. Without a doubt, things will be seen here that have been overlooked or left undiscussed in previous meetings. Further, this gives all parties a final “go/no-go” approval, which should be documented as part of a final checklist.
To be clear, no checklist can cover every situation on any potential project. However, that is not really the intent of checklists. The purpose of such an exercise is to ensure that while focusing on the highly technical and unique project elements, you don’t overlook the small, standard, day-to-day stuff.
Ideally, every owner develops their own shutdown checklist so that it can be specifically developed around your operation. Only then can it truly match your nomenclature, operating procedure, and organization structure. However, the lack of a client-developed checklist is no excuse to skip the exercise.
In shutdown planning, a checklist should be required before final “go” approval but should be started at the first meeting (conceptual design) and updated at each subsequent meeting until completion just before work commences. The final document should be maintained in project files, kept onsite during work, and include sign-offs from all project stakeholders.
The first two practices identified above (meetings and checklists) are primarily planning activities — that is, work before the shutdown actually takes place. Having the proper inspection personnel onsite and ensuring the design engineer is on-call and readily available during the shutdown are, conversely, construction tasks.
It is vital that inspection personnel be involved during the design process for any large pipeline shutdown. It is also critical that the inspector hear directly from the engineer what the design intent is, what critical elements must be monitored, and what can negatively impact the system if not properly addressed. No amount of planning can compensate for poor or uninformed decisions in the field. Understanding existing pipe material, proposed pipe material, how the two are designed to interact, how connections are to be made, and how thrust is to be handled are some of the key elements that must be understood by the inspector.
Always have a senior inspector (someone with experience through several critical system shutdowns) onsite before a pipeline is cut. If the majority of a broader project is overseen by an inspector without this experience, ensure that a senior inspector can support him or her with oversight on the shutdown. This provides a valuable training opportunity while giving all parties greater peace of mind in the work planned.
Engineer on call
This is quite possibly the most important of all the best practices given here for any engineer-led solution. Our industry defines construction support from a design engineer in many ways. The effort required to support an owner through construction can vary from simply being available if/when called to providing a resident project engineer onsite full time. The spectrum is broad and changes with the owner and project complexity. Regardless of the general construction services philosophy of an owner, a system shutdown should be a time when the design engineer must be available.
Every engineered tie-in and shutdown is unique, and regardless of details provided and meetings held, no one knows the design intent like the engineer. No one is better equipped to understand how a surprise in the field will affect the original design like the engineer. A qualified contractor can and will develop solutions if needed to address unknowns. A qualified inspector can evaluate those solutions from past experience and give good feedback on their feasibility and compliance with owner standards. But the engineer bears the responsibility to provide a safe and functional design and, as such, must be aware of, evaluate, and ultimately sign off on any modification.
During the final shutdown meeting and as part of final “go” approval, it is recommended that the engineer remain available for any team member to contact him or her at any time (24/7) during the work. Once a pipeline is broken into and customers are without water, immediate response is required and availability should be guaranteed to address field issues.
What will your next water transmission system shutdown look like? Will it involve differing pipe materials, an urban construction environment, a limited construction window, or complex connection designs? The above best practices provide a few tools to add to your toolbox to help ensure success, regardless of the project elements.
Every shutdown is unique, every project site has a new challenge, and every project has a new surprise. With effective meetings, a thorough checklist, and a qualified team available during construction, the fear, anxiety, and nervousness that surrounds a system shutdown can be lessened.
Justin Reeves, P.E., is an associate and team leader at Lockwood, Andrews & Newnam, Inc. (LAN; www.lan-inc.com), a national planning, engineering, and program management firm. He has nearly 15 years of experience designing water and wastewater pipelines. He can be reached at email@example.com.