Before any water utility starts working on detailed plans and specifications―which I’ll refer to as “Design” in this blog―for water distribution and wastewater collection system projects, there is a phase that typically involves the word “Planning.” The one consistent aspect of planning is that different utilities use various terms for it, such as capital planning, master planning, preliminary design, comprehensive planning study, basis of design report, or project prioritization, to name a few. In this blog I will try to identify what I think is the best terminology. I generally based my terms on the planning horizon: Master Planning involves using long term population and flow forecasts to lay out major facilities over a fairly long-time horizon. Capital Planning looks at projects needed in the next few years. It includes developing pipe sizing, pump station locations and sizing, tank locations and sizing for the design phase, and cost estimates to evaluate project funding. Master Planning: The Big Picture Master planning (also referred to as comprehensive planning studies) uses 20- to 50-year forecasts to lay out major transmission or interceptor piping, locate pump stations and tanks, and determine implementations timelines. While the pipe and other facility sizing should be reasonable, they

Most of us are familiar with the concept of “triage” in medical emergencies. During large-scale crises, medical staff can only treat a certain number of patients. To prioritize which patients receive treatment first, they apply the principle of “the greatest good for the greatest number,” dividing patients into three groups. Those who will recover without immediate attention and can receive care later. Those who will not survive regardless of how much attention they receive. Those who will only survive with immediate attention. These categories are commonly applied on battlefields and other emergency situations. Fortunately, in the water, wastewater and stormwater industry, we aren’t faced with such life-and-death decisions. However, these principles also can be applied when responding to widespread pipe breaks or flooding. Widespread Pipe Breaks Let’s explore how using triage can help prioritize pipe break response. On most days, there are sufficient utility crews ongoing pipe breaks. But what about those days when there are too many pipes breaks to deal with all at once? The obvious example is earthquakes which can break many pipes simultaneously. During extreme weather events, such as hurricanes or extreme cold, like the Texas freeze a few years ago, can create such an emergency.

“Variable frequency drives (VFDs) are valuable technology, and they always save energy in water and wastewater system pumping.” The first part of that statement is true, and the second part is generally true but not always. There are exceptions that engineers and operators need to be aware of when they are buying and operating pumping systems. A question I frequently pose is: “What is the best speed to run a variable speed pump?” I receive a variety of responses, but the correct one is, “Off.” If you can select a pump that operates at an efficient operating point, allowing it to run near its best efficiency point (BEP), it will outperform a variable speed pump which tends to have fluctuating operating points along the pump efficiency curves (Walski et al., 2001). ApplicationTurning pumps on and off requires storage to meet demand when the pumps are Off. In water systems, pumped flow is often directed to elevated tanks, which allows the tanks to be filled and drained with constant speed pumps. This has the added benefit of turning over the water in the tank improving disinfectant residuals. In wastewater systems, the storage occurs on the suction side of the pump, with

Engineers and scientists love graphs. With one image, they can convey as much information as many pages of text and do it in a way that can be clearly visualized. Nowadays, with software, we can do so much more with graphing, but that’s not always the way it was done. Here is how simple graphs used to look like in the past, drawn on preprinted graph. Straight line y=mx+b Here is a graph you can get from Excel today: Sure, anybody can draw a graph on arithmetic graph paper. But what happens when you have data that cover several orders of magnitude and data aren’t very evenly spaced. You could take the logarithm of each point and plot it that way, but then you would need to continuously convert the data from the log scale to your original values. For example, “the graph says 3.52 but that’s the log of the real value that is 3311”. The key of course is to have graph paper with logarithmic scales. Your graph paper would look like this: The figure shows 3 cycle log-log paper. Straight line y = aXb In Excel the figure could look like this: Sometimes, however, only one axis

For academic researchers, “Impact Factors” is a familiar term – it is designed to measure the impact of your publications. If you are outside of the academic world, you have probably never encountered it, but how much do these metrics really tell us? Impact factors emerged as a way to compare research papers. Academia often measures a researcher’s success by the number of publications, which influences tenure and promotion decisions at universities. The problem was that not all journals and papers are of the same quality. Universities needed a way to determine the caliber of research without having to actually read every paper. The solution? If a paper was cited by other researcher within a few years of publication, it is assumed that the paper and the journal it appears in must have an impact. Over time, this has evolved into a formal system for calculating Impact Factors, with journals proudly listing their scores. To judge individual papers, metrics like “categorized-normalized citation impact” were developed using similar logic along with a “percentile group” score to compare a researcher’s work with papers in a similar field. But I question: “impact on whom”? I feel that the impact of a paper in

When precipitation falls on land, in the short term, there are two places it can go: runoff to streams or infiltration into the ground. In the long term, evaporation also matters, but during a precipitation event, it isn’t important. Runoff enables water to be used for a variety of purposes as it makes its way to the ocean. Along the way, however, it contributes to flooding, erosion, and is usually moving too fast to be captured. From an environmental and water efficiency standpoint, it is generally better to have most of the water infiltrate into the ground, reducing flooding, nurturing plant life, and later contributing to base flow in streams, flattening out runoff hydrographs. But first, a digression that always troubles me: “What is infiltration?” There are at least two answers: In hydrology and some hydraulics, infiltration is the precipitation that makes its way into the ground. However, if you’re talking about sewers, infiltration is a subsurface water that leaks into sewers when it shouldn’t (i.e., the I part of I&I). The first infiltration is generally a good thing; the second is a bad thing. The result is sentences like “Infiltration into the subsurface can result in additional infiltration into

Cities and towns often rely on local consultants to provide them with water, wastewater, and stormwater modeling. By bringing modeling efforts in house, municipalities can benefit from: Saving Money Often, even the smallest projects can come with a hefty price tag. By using in-house professionals, municipalities can save the money typically spent on consulting and use it toward capital improvements. Improved Reactions to Emergency Situations When a city handles its own model and has an in-house expert, they can more efficiently respond to emergency situations without having to wait for consultant analysis. This situation also holds true for leak detections, helping to reduce lost water. Model Consistency Many municipalities have a bunch of smaller, separated models. By combining these smaller models into one large model, the entire system can be analyzed. This combined model also creates a baseline for expectations of how modeling can be done in the municipality. System Efficiency As municipalities begin to explore capital improvements, they can leverage their system model to determine the most cost-effective path forward. From an operational standpoint, cities can also ensure they are making the most of their system. Getting up and running with new software is less daunting than a city

Seminal papers are groundbreaking at the time of publication and remain influential many years later. I recently received word from the ASCE that my paper, “Battle of the Network Models: Epilogue,” published in the Journal of Water Resources Planning and Management, Volume 113, No. 2, 1987, has been selected to receive the Journal’s 2024 Seminal Paper Award. Here’s the story behind it if you are interested. In the early 1980s, many papers were being published on optimal pipe sizing in water distribution systems. It was hard to compare the methods. At that time, there was a television show, “Battle of the Network Stars,” where various TV stars would compete with one another in various little “athletic” events. The show ran from 1976 through 1988. I thought that would be a good name for a conference session and paper that I called “Battle of the Network Models.” I drew up a pipe network called “Anytown” and sent it out to everyone working in this area. We had a series of sessions at the ASCE Water Resources Planning and Management Conference in Buffalo, New York, in 1985 that brought together many of the top people in the field. I wrote the summary