Water is not just a commodity or a utility; it is essential to life. Every time you open a tap or flush a toilet, there is a vast network of infrastructure at work behind the scenes to keep these processes flowing uninterrupted. Our most valuable resource goes through a complex journey from its natural source to your home or business. Understanding the journey provides insight into engineering, science, and environmental considerations required to sustain the operation of a Public Water System.
Drinking water can be broken into two basic components: treatment and distribution. Water must be taken from a source, surface water or groundwater, treated to meet drinking water standards and sent to customers through the distribution system. This is a very basic reduction of the process but will serve as a backdrop for this discussion.
Raw water comes from either a surface source: lake, river, or stream; or a groundwater source: wells tapped into an aquifer or similar groundwater structure. One of the primary environmental considerations is the condition of the source water itself. Infrastructure can impact surrounding habitats, and continued withdrawals can lower water levels if not carefully managed. Flow data paired with precipitation data allows water systems to maintain acceptable levels in the source water body. Under drought conditions, water systems implement usage restrictions to mitigate negative effects on the source water. The quality of the source water dictates the following step: treatment.
There are two main treatment types of drinking water: membrane and conventional.
Membrane treatment is less dependent on chemical reactions due to the nature of membrane filters. Membrane filtration technology, including reverse osmosis, utilizes semipermeable barriers to filter the water at a molecular level. There are four main membrane types, classified by pore size: microfiltration, ultrafiltration, nanofiltration, and reverse osmosis. Though they are less dependent on chemicals, the upkeep and power costs of such plants are what allows conventional treatment to remain a viable option for many water systems.
Conventional treatment is a combination of physical and chemical processes that involve using chemical coagulants and flocculants and specifically constructed basins to induce clarification of the water. This process causes solid particles to clump together and settle to the bottom of a basin. The clarified water on the top of this basin, known as the supernatant, is decanted from the basin and sent to be filtered. There is a multitude of different filter types, but they all serve the same purpose: physically removing smaller particulate matter that remains after the clarification process. After filtration, the water is disinfected with chlorine in one of its many forms. Once treatment is complete, the water must be delivered to customers through an extensive distribution network.
The distribution of drinking water requires miles of pipeline, storage tanks (both elevated and ground), and pumps that can move the water through the system and to homes and businesses throughout the service area. Pumps are required to move water from the source to the treatment plant and from the treatment plant into the distribution system. Depending on the layout and topography of a water system, there can be multiple pump stations to get water into or out of storage tanks. Elevated storage tanks also help maintain system pressure and provide reserve capacity during periods of high demand or emergency situations such as power outages or firefighting. The distribution system is what makes water available the moment a tap is opened. Pumping capacity, pipe size, and storage capacity must be carefully considered to meet the demand and requirements of the water system. If a water system is not equipped to meet demand, there could be an inadequate supply of water for the system.
From start to finish, the journey of drinking water is a remarkable combination of engineering, science, and environmental stewardship. The next time you open a faucet, consider the miles of pipeline, treatment processes, pumps, storage tanks, and dedicated professionals working behind the scenes to ensure safe, reliable water is available whenever you need it. Maintaining these systems requires continual planning, investment, and expertise, making modern water systems among the most important pieces of infrastructure supporting our communities and our way of life.
At JACOB | MARTIN, we are proud to support communities through the planning and design of infrastructure that helps make reliable public water systems possible.