The Source Of Our Clean Water Supply

Clean water is one of the most basic human needs, yet one in four people worldwide does not have access to it. Unsafe water is responsible for over a million deaths each year, and it is a leading cause of infectious diseases such as cholera, dysentery, and polio. It is also a major contributor to malnutrition, particularly in children. In the United States, most tap water comes from reservoirs, lakes, rivers, or groundwater. Groundwater is naturally filtered as it moves through the soil, removing some germs and chemicals, while surface water is treated to meet federal and state purity standards before being pumped into homes. Watersheds, or basins, are land areas where rainfall collects and flows into streams, rivers, and eventually oceans. Forests play a crucial role in the water supply chain by naturally filtering rainwater and preventing pollutants from entering waterways. However, climate change and human activities such as agriculture, industrial processes, and improper waste disposal threaten the quality and availability of clean water.

Clean water sources

Clean water is one of the most basic human needs, yet one in four people worldwide does not have access to it, which is a major health risk. Unsafe water causes more than a million deaths each year and is a leading risk factor for infectious diseases, malnutrition, and childhood stunting.

Forests are essential in providing clean drinking water for millions of people. They naturally filter rainwater, preventing erosion and absorbing nutrients that would otherwise pollute waterways. Watersheds, or drainage basins, are land areas where rainfall flows to streams and rivers and then to outlets like oceans or bays. National forests and grasslands are home to watersheds that provide clean drinking water for millions of people. However, as the climate warms, the amount of drinking water that forests provide may decrease, and watersheds are also threatened by land use change, wildfires, insects, and disease.

To ensure clean drinking water, it is typically treated at water treatment facilities before being pumped and piped to homes. The Centers for Disease Control and Prevention (CDC) outlines a four-step water treatment process: coagulation and flocculation, sedimentation, filtration, and disinfection. Chemicals are added to neutralize and bind small particles, forming larger particles called floc, which then settle at the bottom of the water supply due to their weight. The clear water on top passes through filters to remove dissolved particles, and then a disinfectant is added to kill any remaining harmful substances. Fluoride may also be added to prevent tooth decay.

Water treatment processes

One of the initial steps in water treatment is coagulation and flocculation, where chemicals such as aluminum sulfate are added to the water to neutralize and bind small particles together, forming larger particles called floc. This is followed by sedimentation, where the floc settles at the bottom of the water supply due to its weight. The clear water on top then undergoes filtration, passing through various compositions and pore sizes to remove dissolved particles like dust, parasites, bacteria, viruses, and chemicals.

After filtration, disinfection is often the next critical step to ensure water safety. Disinfectants like chlorine, chloramine, or chlorine dioxide are added to kill any remaining germs, parasites, or bacteria. Additionally, fluoride may be added to the water to prevent tooth decay. Ultraviolet (UV) light or ozone can also be used for disinfection, either alone or in combination with chemical disinfectants. Adjusting the pH of the water is another important step, as it improves taste, reduces pipe corrosion, and helps disinfectants remain effective as water travels through the pipes.

In some cases, advanced technologies like granular activated carbon (GAC) and aeration processes are employed to remove specific contaminants. GAC has high removal efficiencies for certain volatile organic compounds (VOCs). Aeration processes, such as packed tower aeration (PTA) and multi-stage bubble aeration (MSBA), transfer contaminants from water to air, with the more volatile contaminants being removed more easily. Anion exchange treatment is another specialized process where negatively charged contaminants are exchanged with negatively charged ions like chloride on the surface of a synthetic resin.

These water treatment processes are carefully monitored and controlled by devices like programmable logic controllers (PLCs) and the Supervisory Collection and Data Acquisition (SCADA) system, ensuring that the water meets the required standards for safe drinking water.

Watersheds and water supply

Watersheds are an essential component of our water supply systems. A watershed is an area of land that drains all the streams and rainfall to a common outlet, such as the outflow of a reservoir, the mouth of a bay, or any point along a stream channel. Watersheds can vary in size, from as small as a footprint to large watersheds that encompass all the land that drains water into rivers flowing into the ocean.

The quality and quantity of water in our rivers, lakes, and other sources are influenced by the watersheds they are a part of. Watersheds consist of surface water, including lakes, streams, reservoirs, and wetlands, as well as the underlying groundwater. The streamflow and water quality of a river are impacted by activities occurring in the land area above the river's outflow point.

Groundwater, which is located below the Earth's surface in the spaces between rocks and soil, is an important source of drinking water for many communities. While groundwater is naturally filtered, removing some germs and chemicals, the effectiveness of this filtration depends on the depth of the groundwater and the local geology. Watersheds play a crucial role in protecting and maintaining the quality of this groundwater.

By preserving natural land cover, such as vegetation and riparian zones, watersheds can help maintain the natural flow regime and water levels in lakes and wetlands. Additionally, healthy watersheds can provide benefits to both the human communities and wildlife that depend on them. For example, a healthy watershed can positively impact water quality by filtering pollution, reducing treatment costs for drinking water sourced from surface water.

It is important to note that healthy watersheds are becoming less common, particularly in urbanized, farmed, or mined areas. However, some regions have successfully maintained or improved watershed health through effective water pollution control measures. Protecting watersheds from contamination with harmful germs, chemicals, and pollutants is crucial to ensuring a safe and sustainable water supply for communities.

Access to clean water

Clean water comes from two primary natural resources: surface water and groundwater. Surface water includes lakes, rivers, reservoirs, springs, and oceans, while groundwater is found beneath the Earth's surface in the spaces between rocks and soil. In the United States, 9 out of 10 people obtain their water from public water systems, which draw from these sources. The water is then treated to meet federal and state purity standards before being pumped and piped to homes.

To ensure access to clean water, it is crucial to protect watersheds and bodies of water from contamination. Watersheds are land areas where rainfall collects and flows into streams, rivers, and outlets like oceans or bays. National forests and grasslands are home to watersheds that provide clean drinking water for millions of people. However, agricultural pollution, waste, plastic, and other pollutants pose significant threats to water sources.

Individuals can also play a role in protecting water quality in their communities. This includes correcting common household mistakes that affect water quality, such as improper waste disposal, indoor nutrient pollution, outdoor storm drain runoff, and over-fertilizing. Additionally, it is important to be mindful of water consumption and the impact of human activities on water sources. By taking collective action, we can help ensure access to clean water for all.

Furthermore, it is worth noting that while improved drinking water technologies increase the likelihood of providing safe drinking water, it is not a guarantee. "Improved drinking water sources" refer to those with the potential to deliver safe water due to their design and construction, but the safety of the water is not tested at the time of the survey. Therefore, it is essential to prioritize water treatment processes and infrastructure development to ensure that everyone has access to clean and safe drinking water.

Protecting water quality

Correct Common Household Mistakes

Individuals can start by addressing common household mistakes that impact water quality. This includes proper waste disposal, reducing indoor nutrient pollution, and minimizing outdoor storm drain runoff and over-fertilizing. These simple actions can significantly reduce water pollution.

Support Environmental Initiatives

Get involved with environmental organizations, such as the National Environmental Education Foundation (NEEF), which provides resources and education on water quality protection. Participate in initiatives like Water Quality Month, which raises awareness about the importance of clean water and promotes ways to protect it.

Advocate for Policy Changes

Support policies and regulations that protect water quality, such as the Safe Drinking Water Act (SDWA) in the United States. This act regulates public drinking water supply and sets health standards to safeguard against pollutants. Stay informed about local and national policies that impact water quality and contact local representatives to advocate for stronger protections.

Practice Sustainable Agriculture

Agricultural practices can significantly impact water quality. Farmers can implement conservation techniques, such as cover crops, no-till farming, residue management, and nutrient management, to reduce sediment, chemical, and waste runoff into nearby water bodies. Programs like the National Water Quality Initiative (NWQI) and the Great Lakes Restoration Initiative (GLRI) offer resources and support to farmers adopting more sustainable practices.

Support Watershed Protection

Watersheds are crucial in maintaining water quality. Get involved with organizations like the U.S. Environmental Protection Agency (EPA) and local watershed protection groups to protect and restore watershed health. This includes efforts to reduce stormwater runoff, treat wastewater effectively, and educate communities about their role in preserving water quality.

By combining individual actions, community engagement, and policy support, we can effectively protect water quality and ensure clean water for current and future generations.

Frequently asked questions