A Conversation on Water Treatment Options for Municipalities
Kate Dietz, P.E., is a project manager for KSA and has experience in the design of water and wastewater treatment facilities, including conventional water treatment processes, filter design, low pressure membrane filtration design, chemical feed and storage system design, ultraviolet (UV)/hydrogen peroxide disinfection, and other taste and odor control strategies. Kate also has experience with wastewater treatment, including anaerobic digester design, tertiary filter design, and other methods of treatment. Kate graduated with a master of science degree in engineering, environmental and water resource engineering from the University of Texas at Austin. She also holds a bachelor of science degree in chemical engineering from Vanderbilt University. Kate is a member of the American Water Works Association (AWWA), the Water Environment Federation (WEF), and is currently the president of the Northeast Texas Section of the Water Environmental Association of Texas (WEAT).
Kate, tell us a little about your career in engineering and specifically your experience in both conventional and non conventional water treatment systems?
“I’ve been working on water treatment plant design and planning projects since very early in my career. I have experience with all of the conventional treatment processes as well as unconventional systems, like membrane filtration, and numerous advanced oxidation processes, including UV/hydrogen peroxide and processes for taste and odor control.
“I learned a lot on one of the larger projects on which I have worked. It entailed taking a 24 million gallon per day (gpd) water treatment plant from pilot study to full-scale design and construction. Being a part of this project gave me invaluable knowledge about all phases of water treatment expansion design. This includes conducting a pilot study on different manufacturers microfiltration/ultrafiltration membranes; modeling and calibrating the hydraulic profile for existing processes and determining the effect new processes will have on the overall hydraulic profile; design and implementation of granular activated carbon filters for taste and odor control; design of a low pressure membrane system utilizing siphon design to minimize power costs; and, most importantly, why it is important to look at both the detailed design aspects and the overall big picture.
“My education in chemical engineering, environmental engineering, and water resource engineering has helped me develop into the engineer I am today. A huge part of water treatment is water chemistry. I have a solid foundation in chemistry, so thinking this way comes naturally to me. However, the most rewarding part of my job is working with communities to understand their specific water challenges, which many times relates to their specific water chemistry at the Plant, and what can be done to optimize their treatment processes. Being a part of the solution is very rewarding to me personally.”
“First, it’s very important that each community has its own plan that centers on its specific short- and long-term needs and problems. Water resource planning requires looking 50 to 60 years down the road to first ensure that the community has adequate water supply and then treatment in phased expansions for their growing communities.
“I think a common misconception is that there is unlimited water available for growth. This is not the case, especially when drought conditions are present. This issue has come to the forefront of discussions lately as Texas has experienced such harsh drought conditions in many parts of the state. I’m glad to see that community leaders are starting to see what a precious resource clean drinking water is and that they are taking proactive steps to secure water resources for future generations.
“Another issue that is commonly overlooked is the completion of a water master plan. This “plan,” sometimes combined with a capital improvement plan (CIP), should take into account historic population growth, potential for additional growth, the amount of water available, and the current problems with water supply and distribution within the community. Doing this makes it possible to plan for future expansions of all aspects of drinking water systems – from supply to treatment and distribution.
“Another major issue is funding. Each community should take a hard look at the possibility of restructuring its rate plans to allow for sufficient funds to complete projects that are necessary to continue delivering clean drinking water to their communities.
“Which brings me to the last issue that is often overlooked: operating and maintenance budgets. Many of the funds available to communities are not enough to, for example, replace the filter media when necessary, which will eventually decrease the efficiency of the plant, making the plant unable to handle peak demand. Without sufficient funds in operations and maintenance, all of these improvements may make fairly simple media replacement very costly if a community waits too long.
“Many times, communities can save money in operating budgets by re-evaluating their chemical usage. It’s fairly common practice to “over-dose” chemicals (coagulants, polymer) with the mindset that if “X” amount works, then increasing it can only make the drinking water quality better. This is not the case. In fact, it is critically important to overall drinking water quality to find that “sweet spot” for your chemical dosage.”
“There are so many new, innovative technologies and water treatment techniques available to communities today. However, some of the newer conventional treatment technologies can be a lot for a conventional system's operator to handle. An evaluation of current and future staffing needs should be taken into account when developing a plan for either a water treatment plant expansion or a new water treatment plant.
“A new technology, like membrane treatment, is an efficient means of water treatment, providing a direct barrier to pathogens that could otherwise make it into the water system. With the recent drought conditions, there has been much talk about reclaimed water use for both indirect and direct potable use. A few cities with critical drinking water needs have had direct potable reuse systems approved by the Texas Commission on Environmental Quality (TCEQ). Direct non-potable reuse is being used in many cities across Texas as a dependable source for irrigation, such as Dallas and San Antonio.”
“I would say, as a general rule, if there are days during the high-demand season (summer) that a plant is operating at capacity, and the demand is increasing along with the growth in your community, it’s vitally important to begin planning for an expansion of the treatment system. Also, if a community has specific problems with its treatment system when it operates above a certain capacity, it is time to look at increasing the efficiency of that specific treatment process. It is never a good idea for any of treatment processes to be stressed when operating above the average daily demand.
“A current, up-to-date asset management plan and water system master plan will help communities determine the need for upgrades to water treatment plants or if a new water treatment plan is necessary. Taking into account the capacity of current resources and the useful age of the system is instrumental in determining the need for additional water treatment plant capacity through an expansion of the existing water treatment plant or a second water treatment plant. Many small communities with a conventional water treatment plant have options to upgrade and expand the capacity of their current water treatment plant without building a new one. However, if the resources aren't going to be sufficient to deliver water to future generations, a plan for a second, new water treatment plant should be considered.”
For more than 35 years, KSA has provided expert engineering planning and design and technology selection to 268 municipalities across Texas. Kate is one of our many water treatment experts available to talk with you.
Do you need help with your water treatment plant and systems? Why not ASK KSA, 877.572.3547, or contact Kate directly at firstname.lastname@example.org.