essay on different sources of water

Sciencing_Icons_Science SCIENCE

Sciencing_icons_biology biology, sciencing_icons_cells cells, sciencing_icons_molecular molecular, sciencing_icons_microorganisms microorganisms, sciencing_icons_genetics genetics, sciencing_icons_human body human body, sciencing_icons_ecology ecology, sciencing_icons_chemistry chemistry, sciencing_icons_atomic & molecular structure atomic & molecular structure, sciencing_icons_bonds bonds, sciencing_icons_reactions reactions, sciencing_icons_stoichiometry stoichiometry, sciencing_icons_solutions solutions, sciencing_icons_acids & bases acids & bases, sciencing_icons_thermodynamics thermodynamics, sciencing_icons_organic chemistry organic chemistry, sciencing_icons_physics physics, sciencing_icons_fundamentals-physics fundamentals, sciencing_icons_electronics electronics, sciencing_icons_waves waves, sciencing_icons_energy energy, sciencing_icons_fluid fluid, sciencing_icons_astronomy astronomy, sciencing_icons_geology geology, sciencing_icons_fundamentals-geology fundamentals, sciencing_icons_minerals & rocks minerals & rocks, sciencing_icons_earth scructure earth structure, sciencing_icons_fossils fossils, sciencing_icons_natural disasters natural disasters, sciencing_icons_nature nature, sciencing_icons_ecosystems ecosystems, sciencing_icons_environment environment, sciencing_icons_insects insects, sciencing_icons_plants & mushrooms plants & mushrooms, sciencing_icons_animals animals, sciencing_icons_math math, sciencing_icons_arithmetic arithmetic, sciencing_icons_addition & subtraction addition & subtraction, sciencing_icons_multiplication & division multiplication & division, sciencing_icons_decimals decimals, sciencing_icons_fractions fractions, sciencing_icons_conversions conversions, sciencing_icons_algebra algebra, sciencing_icons_working with units working with units, sciencing_icons_equations & expressions equations & expressions, sciencing_icons_ratios & proportions ratios & proportions, sciencing_icons_inequalities inequalities, sciencing_icons_exponents & logarithms exponents & logarithms, sciencing_icons_factorization factorization, sciencing_icons_functions functions, sciencing_icons_linear equations linear equations, sciencing_icons_graphs graphs, sciencing_icons_quadratics quadratics, sciencing_icons_polynomials polynomials, sciencing_icons_geometry geometry, sciencing_icons_fundamentals-geometry fundamentals, sciencing_icons_cartesian cartesian, sciencing_icons_circles circles, sciencing_icons_solids solids, sciencing_icons_trigonometry trigonometry, sciencing_icons_probability-statistics probability & statistics, sciencing_icons_mean-median-mode mean/median/mode, sciencing_icons_independent-dependent variables independent/dependent variables, sciencing_icons_deviation deviation, sciencing_icons_correlation correlation, sciencing_icons_sampling sampling, sciencing_icons_distributions distributions, sciencing_icons_probability probability, sciencing_icons_calculus calculus, sciencing_icons_differentiation-integration differentiation/integration, sciencing_icons_application application, sciencing_icons_projects projects, sciencing_icons_news news.

• Share Tweet Email Print
• Home ⋅
• Science ⋅
• Nature ⋅

Different Sources of Water

Uses of Seawater

Some sources of water are obvious, like lakes and rivers, while others, like glaciers, are a bit more removed from everyday experience. With so many people living near water, it sometimes seems unlikely that water shortages could be a serious problem. Understanding the sources of water available for human use reveals how limited freshwater actually is. Despite the overwhelming amount of water on earth, very little of it is suitable for consumption. New research and technology are currently seeking answers to this dilemma.

TL;DR (Too Long; Didn't Read)

In addition to visible sources of water like oceans and rivers, vast quantities of water are stored as groundwater and in polar ice.

Ground Water

Ground water refers to any source of water that lies beneath the soil layer. Ground water can exist in the soil itself or between rocks and other materials. Most communities obtain their water from underground aquifers, or rock formations capable of holding large amounts of freshwater. Only 3 percent of the water on earth is considered freshwater, with a mere 30 percent of that small amount being found as groundwater. Pollution, seawater contamination and overuse threaten this valuable resource.

Surface Water

Sources of surface water can include any above-ground collection of water such as rivers, lakes, ponds and oceans. Some sources of surface water are also fed by underground aquifers. Surface water accounts for 80 percent of the water humans use.

Ocean Water

Although ocean water makes up nearly 97 percent of all water on earth, it is not a viable source of potable water unless salt and other impurities are removed. Desalination, the process by which salt is removed from water, is a rapidly growing practice. While salt and other microscopic particles can be removed from water in a variety of ways, the most promising method is through reverse osmosis. This process forces saltwater through filters with microscopic pores that remove salt and other microbes. Reverse osmosis requires large amounts of energy, making it a very expensive process.

Ice Caps and Glacial Melting

Of the 3 percent of earth's water considered freshwater, 70 percent of that small amount is currently locked in glaciers and ice caps. In theory, frozen glacial and ice cap water could be melted and used, but the amount of energy needed to melt and transport vast quantities of ice make it economically impractical. Glaciers and ice caps also play vitally important roles in the regulation of earth's climates and global temperatures, making their preservation very important.

Related Articles

Is hydropower a non-renewable or renewable resource, desert biome environmental problems, methods for desalination, what are water currents, how does water get cleaned, common uses for h2o, list of fun facts about the water cycle, why do we need to conserve water, what is the purpose of simple distillation, how to calculate the mass of a solid, can i use dehumidifier water, the average rainfall in a fresh water ecosystem, pros & cons of desalination plants, why is the water cycle important to humans & plants, why is it important to recycle water, types of water ecosystems, the importance of saving water, persuasive speech topics on water, negative effects of solar energy.

• Environmental Protection Agency: Groundwater
• Environmental Protection Agency: Surface Water Contamination
• The Library of Congress: Science Referencs Services: Desalination

About the Author

Kendra Young has been a professional educator and science curriculum writer since 2005. She also works as a faculty advisor and content reviewer for the National Science Teacher’s Association. Young holds a Master of Education in instructional design, and is completing a Master of Science in geology.

Find Your Next Great Science Fair Project! GO

We Have More Great Sciencing Articles!

What is the meaning of sources of water?

Water is a precious and natural resource on the planet earth. It is found all around us. Nearly two-thirds of the Earth’s surface is filled with water. Every living organism existing on our planet requires water for its survival, including plants, animals, birds, insects, etc.

Water is considered the most precious resource and essential requirement of life. All living things rely on water, and without which, there would be no life.

We humans can survive without food for a day or two, but we cannot stay without drinking water for a short amount of time because our body needs it for different types of life processes.

Explore more: Water

Uses of Water

We all use water for drinking, cooking, bathing, cleaning, washing, etc. Factories and large industries use water in large quantities for producing various products required for human welfare. Farmers also use water for irrigating and cultivating crops. Thus, water is necessary for many activities; therefore, it is an essential requirement of life.

Sources of Water Meaning

Water is a valuable natural resource found in different forms in our environment .

As per the Earth’s geography, there is a lot of water all around us, but it is not fresh water and not suitable for human use.

The available natural water is not pure forever. Excluding rainwater, all other water sources comprise salts and minerals deposits dissolved in it. These salts make the water impure, which is not fit for consumption.

There are two primary sources of water – surface water and groundwater.

The primary water sources used for drinking, cooking, washing, farming, and other commercial uses are surface water, groundwater, and collected rainwater.

These primary water sources depend on rainfall and snow, which form a part of the hydrological cycle.

Rivers, streams, lakes, and ponds are the main form of surface water. The amount of available surface water depends mainly on rainfall. When rainfall is limited, surface water supply will vary considerably between wet and dry seasons and between years.

Surface water like reservoirs and dams generates hydroelectric power and supplies water for agricultural, municipal, industrial uses, and other commercial purposes.

Rainwater is also an essential water source, although on a relatively small scale. Collecting rain from roofs or other hard-surfaced areas and storing it until it is needed can provide a valuable water source for many purposes.

Explore more: Rainwater Harvesting

Stay tuned to BYJU’S Biology to know more about water, sources of water, scarcity of water, and different measures taken to preserve water.

Frequently-Asked-Questions-on-What-is-the-meaning-of-sources-of-water?

Frequently Asked Questions on What is the meaning of sources of water?

Where does the water come from for drinking.

Drinking water comes from groundwater or seawater, which are natural water sources.

What are the natural sources of water?

The natural sources of water are:

• Surface water (seawater)
• Above surface water (rain)
• Underground water (springs)

What are the primary sources of drinking water?

The primary sources of drinking water are cisterns, springs, and wells.

The majority of household wells are found in rural areas.

What are the primary sources of surface water?

Rivers, lakes, ponds and tanks are the four primary surface water sources.

Why is water essential to the human body?

Water serves as an essential nutrient to our body, and it plays a vital role in the following:

• Lubricates joints
• Maintains the body temperature
• Removes toxins and other wastes from the body
• Moistens the tissues of the eyes, nose and mouth
• Transportation of nutrients and oxygen to different cells, tissues and organs.

Which Indian states have the highest utilisation of groundwater?

In India, groundwater utilisation is very high in certain regions such as Punjab, Haryana, Rajasthan, and Tamil Nadu.

Related Links:

• Water Cycle
• Back to the oceans
• Disappearing Act of Water
• How Can We Conserve Water?
• Water for all – Importance of water

Leave a Comment Cancel reply

Your Mobile number and Email id will not be published. Required fields are marked *

Request OTP on Voice Call

Post My Comment

• Share Share

Register with BYJU'S & Download Free PDFs

Register with byju's & watch live videos.

Importance of Water Essay for Students and Children

500+ words essay on importance of water.

Water is the basic necessity for the functioning of all life forms that exist on earth . It is safe to say that water is the reason behind earth being the only planet to support life. This universal solvent is one of the major resources we have on this planet . It is impossible for life to function without water. After all, it makes for almost 70% of the earth.

However, despite its vast abundance, water is very much limited. It is a non-renewable resource . In addition, we need to realize the fact that although there is an abundance of water, not all of it is safe to consume. We derive some very essential uses from the water on a daily basis.

Significance of water

If we talk about our personal lives, water is the foundation of our existence. The human body needs water for the day to day survival. We may be able to survive without any food for a whole week but without water, we won’t even survive for 3 days. Moreover, our body itself comprises of 70% water. This, in turn, helps our body to function normally.

Thus, the lack of sufficient water or consumption of contaminated water can cause serious health problems for humans. Therefore, the amount and quality of water which we consume is essential for our physical health plus fitness.

Further, our daily activities are incomplete without water. Whether we talk about getting up in the morning to brush or cooking our food, it is equally important. This domestic use of water makes us very dependent on this transparent chemical.

In addition, on a large scale, the industries consume a lot of water. They need water for almost every step of their process. It essential for the production of the goods we use every day.

If we look beyond human uses, we will realize how water plays a major role in every living beings life. It is the home of aquatic animals. From a tiny insect to a whale, every organism needs water to survive.

Therefore, we see how not only human beings but plants and animals too require water. The earth depends on water to function. We cannot be selfish and use it up for our uses without caring about the environment.

Get the huge list of more than 500 Essay Topics and Ideas

A world without water

Water is not only required for our survival but for a healthy and happy life as well. Everyone has seen the scenario of water-deprived countries like Africa, where citizens are leading a miserable life. It is time for everyone to wake up and realize the urgency of conserving water.

In other words, a world without water would make the human race impossible to last. The same can be said for all the animals and plants. In fact, the whole earth will suffer without water.

Firstly, the greenery will soon diminish. When earth won’t get water, all the vegetation will die and turn into barren land. The occurrence of different seasons will soon cease. The earth will be caught in one big endless summer.

Furthermore, the home of aquatic animals will be taken from them. That means no fishes and whales for us to see. Most importantly, all forms of living organisms will go extinct if we do not conserve water right away.

In conclusion, unnecessary usage of water must be stopped at once. Every single person must work to conserve water and restore the balance. If not, we all know what the consequences are going to be.

{ “@context”: “https://schema.org”, “@type”: “FAQPage”, “mainEntity”: [{ “@type”: “Question”, “name”: “Why is water important?”, “acceptedAnswer”: { “@type”: “Answer”, “text”: “Water is essential for survival for all living organisms. We need it to lead a healthy and happy life.” } }, { “@type”: “Question”, “name”: “What will happen to earth without water?”, “acceptedAnswer”: { “@type”: “Answer”, “text”:”Without water, the earth will turn barren. The vegetation will die and so will the living organisms including humans, plants and animals.”} }] }

Customize your course in 30 seconds

Which class are you in.

• Travelling Essay
• Picnic Essay
• Our Country Essay
• My Parents Essay
• Essay on Favourite Personality
• Essay on Memorable Day of My Life
• Essay on Knowledge is Power
• Essay on Gurpurab
• Essay on My Favourite Season
• Essay on Types of Sports

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Download the App

Freshwater Ecosystem

The world's demand for fresh water is high, though there is a limited supply. How can we be more responsible with this crucial resource and its ecosystems?

Biology, Ecology, Conservation, Earth Science

Mountain Stream

A mountain stream flowing through Inverpolly, Scotland.

Photograph by Education Images

Every living thing on Earth needs water to survive, but more than 100,000 species, including our own, need a special kind of water that can only be found in certain places and is in very rare supply: fresh water. The plants, animals, microbes, rocks, soil, sunlight, and water found in and around this valuable resource are all part of what is called a freshwater ecosystem. Less than three percent of our planet’s water is fresh water, and less than half of that is available as a liquid; the rest is locked away as ice in polar caps and glaciers. For these reasons, freshwater ecosystems are a precious resource. Where is Fresh Water? Fresh water starts out as water vapor that has evaporated from the surface of oceans, lakes, and other bodies of water. When this vapor rises, it leaves salts and other contaminants behind and becomes “fresh.” The water vapor collects in drifting clouds that eventually release the water back to Earth in the form of rain or snow. After fresh water reaches the ground through precipitation , it flows downhill across a landscape called the watershed to lakes, ponds, rivers, streams, and wetlands . But fresh water can be found in less-obvious places, too. More than half of all fresh water on our planet seeps through soil and between rocks to form aquifers that are filled with groundwater. The top surface of an aquifer is called the water table , and this is the depth where wells are drilled to bring fresh water into cities and homes. Studying Freshwater Ecosystems On the volcanic island nation of Iceland, explorer Jónína Herdís Ólafsdóttir studies freshwater ecosystems that develop from groundwater seeping into fissures . These fissures are large cracks, which are caused by the tectonic plates underneath the country shifting and pulling the bedrock apart. The crystal blue water in these fissures is barely above freezing temperature. Wearing scuba gear, Olafsdóttir drops into the water and collects biological samples, recording notes about the species of fish, crustaceans, algae, and other microbes that she finds. She was one of the first scientists ever to describe the biodiversity in these Icelandic fissure ecosystems. Scientists who study freshwater ecosystems are called limnologists. Limnologists want to learn what creatures live in an ecosystem and how they interact with each other through the ecosystem’s food web , as well as how they interact with their environment. This knowledge can help the researchers know when a freshwater ecosystem is healthy and when it may be in danger. Balancing Change Freshwater ecosystems naturally share resources between habitats. The ecosystems in rivers and streams, for example, bring salts and nutrients from the mountains to lakes, ponds, and wetlands at lower elevations, and eventually they bring those nutrients to the ocean. These waterways also enable migrating species, like salmon, to bring nutrients from the ocean to upstream freshwater ecosystems. Lakes and ponds, on the other hand, can exchange nutrients in a seasonal cycle. Cold water is denser than warm water, so it sinks to the bottom, where a fairly steady temperature is maintained. However, as the air temperature drops with the arrival of winter, the water that is closest to the surface may drop below the temperature of the water at the bottom of the lake, causing it to sink and the warmer bottom water to rise. The same process happens as floating surface ice melts into very cold water in the spring. During these periods, nutrients are churned from the floor and brought to the surface. It is normal for ecosystems to encounter change. Temperatures may fluctuate, populations may rise and fall, and rain may bring an abundance of water, then taper during drought. The plants, animals, and microbes in healthy freshwater ecosystems are resilient and have adaptations that allow them to adjust appropriately until ideal conditions resume. However, if any element of the ecosystem varies too far outside of the norm, the balance of the whole system can start to fail. Signs of Danger Humans use fresh water in many ways, but these activities can be dangerous for freshwater ecosystems when we are not careful. Overfishing, pollution, and disruption of the landscape through projects like dams and deforestation are just a few ways we can put these ecosystems—and ultimately, our own access to fresh water—at risk. When the changes we cause are too great or too sudden, then ecosystems struggle to bounce back. An example of this kind of sudden change is when an invasive species enters an area, which happened in 2009 near the city of Madison, Wisconsin, when the spiny water flea ( Bythotrephes longimanus) was detected in Lake Mendota. The spiny water flea, native to Russian and European lakes, came to North America in the 1980s with cargo ships that had traveled across the Atlantic and down the St. Lawrence River to the Great Lakes. Eventually, these tiny stowaways were carried over land to Lake Mendota, and that is where they unleashed a cascade of havoc. Spiny water fleas love to eat Daphnia pulicaria plankton, which are important to the Lake Mendota ecosystem, because they eat green algae that would otherwise grow out of control. D. pulicaria is also a key food source for fish in the lake. As the population of spiny water fleas increased, algae began to overgrow and lower the oxygen content of the water, causing the fish to die and the lake water to grow murky. Ten years later, spiny water fleas are still thriving in Lake Mendota and now, a new invasive species, the zebra mussel ( Dreissena polymorpha ), is taking over the lake floor. Once an invasive species becomes established in a freshwater ecosystem, it is nearly impossible to get it out. Scientists like Canadian aquatic ecologist Dalal Hanna can help avoid disasters like these by studying ecosystems and identifying points of human interaction that might cause trouble. Hanna has researched freshwater fish in African streams and birds that live near freshwater ecosystems in Canada. Today, she is developing useful measures and management strategies so communities can gauge how to balance their need for “ecosystem services” like drinking water, recreation, and flood prevention with the health of the freshwater ecosystems upon which they rely.

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Production Managers

Program specialists, specialist, content production, last updated.

January 26, 2024

User Permissions

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text on this page is printable and can be used according to our Terms of Service .

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Related Resources

Home — Essay Samples — Environment — Water Conservation — Importance of Water Conservation

Importance of Water Conservation

• Categories: Water Conservation

About this sample

Words: 880 |

Published: Jan 30, 2024

Words: 880 | Pages: 2 | 5 min read

Table of contents

Introduction, the significance of saving water, methods of saving water, case studies/examples, challenges in water conservation and protection efforts, a. water conservation practices at homes.

• Installing water-saving fixtures and appliances, such as low-flow showerheads, faucets, and toilets.
• Fixing leaks and reducing water wastage by taking shorter showers, turning off the tap while brushing, and fixing dripping taps.
• Implementing efficient water usage habits such as using a broom instead of a hose to clean outdoor areas and washing laundry and dishes only with full loads.

B. Agriculture Water Management

• Implementing efficient irrigation techniques such as drip irrigation and precision irrigation, which reduce water wastage by up to 30%.
• Crop selection and rotation to optimize water usage by selecting crops that require less water and reducing water-intensive crops, such as rice and cotton.
• Using precision farming methods such as soil moisture sensors, weather forecasts, and crop modeling to optimize water usage.

C. Industrial Water Conservation

• Recycling and reusing water in manufacturing processes by using closed-loop systems.
• Implementing water-efficient technologies such as water-efficient boilers, cooling towers, and dry lubrication processes.
• Promoting water stewardship among industries by adopting best practices and engaging in water conservation efforts.

D. Government Policies and Programs

• Providing incentives for water-saving practices such as tax credits, rebates, and grants for installing water-efficient appliances and fixtures.
• Implementing water regulations and enforceable laws such as water pricing, water rights, and zoning regulations to ensure efficient water use.
• Educating and creating awareness among citizens through campaigns such as the WaterSense program, which educates consumers on water-efficient products.
• United Nations. (2021, March 22). Water and Sanitation. https://www.un.org/en/sections/issues-depth/water-and-sanitation/
• WaterSense. (n.d.). Water-Efficient Products. https://www.epa.gov/watersense/water-efficient-products
• Valsecchi, G. B., & Faggian, R. (2019). The Alliance for Water Stewardship certification program in the Netherlands: measuring the performance of a water sustainability standard for industries. Water, 11(12), 2608. https://doi.org/10.3390/w11122608
• Maheshwari, B. L. (2019). Rainwater harvesting impacts on crop yield: a review with a case study of Tamil Nadu, India. Water, 11(5), 1018. https://doi.org/10.3390/w11051018

Cite this Essay

Let us write you an essay from scratch

• 450+ experts on 30 subjects ready to help
• Custom essay delivered in as few as 3 hours

Get high-quality help

Prof Ernest (PhD)

Verified writer

• Expert in: Environment

+ 120 experts online

By clicking “Check Writers’ Offers”, you agree to our terms of service and privacy policy . We’ll occasionally send you promo and account related email

No need to pay just yet!

Related Essays

3 pages / 1670 words

5 pages / 2419 words

2 pages / 942 words

1 pages / 696 words

Remember! This is just a sample.

You can get your custom paper by one of our expert writers.

121 writers online

Still can’t find what you need?

Browse our vast selection of original essay samples, each expertly formatted and styled

Related Essays on Water Conservation

An essay about soil and water conservation aims to shed light on the importance of protecting our soil and water resources. Soil and water are two of the most vital natural resources on Earth. Soil provides essential nutrients [...]

There are numerous federal water conservation requirements. Thankfully, the Environmental Protection Agency has created a Water Conservation Strategy to meet the various requirements set by the government. The Water Conservation [...]

The incinerator is initially fired up with gas or other combustible material. The process is then sustained by the waste itself. Complete waste combustion requires a temperature of 850º c for at least two seconds but most plants [...]

The Konark temple in the state of Odisha is one of the most recognized tourist place in India. It is famous for its Culturally enrich large Sun temple at the beautiful Shore of Bay of Bangal. The temple is now not in its [...]

Nowadays Plastic is everywhere in today’s lifestyle. The disposal of plastic wastes is a great problem. These are non-biodegradable product due to which these materials pose environmental pollution and problems like breast [...]

By considering the environment as an exploitable external element, an organization can generate high profit for some time. China, for instance, is a developing country that has ignored the gravity of the environmental issues [...]

Related Topics

By clicking “Send”, you agree to our Terms of service and Privacy statement . We will occasionally send you account related emails.

Where do you want us to send this sample?

By clicking “Continue”, you agree to our terms of service and privacy policy.

Be careful. This essay is not unique

This essay was donated by a student and is likely to have been used and submitted before

Download this Sample

Free samples may contain mistakes and not unique parts

Sorry, we could not paraphrase this essay. Our professional writers can rewrite it and get you a unique paper.

Please check your inbox.

We can write you a custom essay that will follow your exact instructions and meet the deadlines. Let's fix your grades together!

Get Your Personalized Essay in 3 Hours or Less!

We use cookies to personalyze your web-site experience. By continuing we’ll assume you board with our cookie policy .

• Instructions Followed To The Letter
• Deadlines Met At Every Stage
• Unique And Plagiarism Free

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• v.11(41); 2021 Jul 19

Microbial diversity in full-scale water supply systems through sequencing technology: a review

College of Environmental Science and Engineering, Tongji University, Shanghai 200092 China, nc.ude.ijgnot@ztkywl321

State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 China

Jiping Chen

Zhongqing wei.

Fuzhou Water Affairs Investment Development Co., Ltd., Fuzhou 350000 Fujian China

Longcong Gong

Fuzhou Water Co., Ltd., Fuzhou 350000 Fujian China

The prevalence of microorganisms in full-scale water supply systems raises concerns about their pathogenicity and threats to public health. Clean tap water is essential for public health safety. The conditions of the water treatment process from the source water to tap water, including source water quality, water treatment processes, the drinking water distribution system (DWDS), and building water supply systems (BWSSs) in buildings, greatly influence the bacterial community in tap water. Given the importance of drinking water biosafety, the study of microbial diversity from source water to tap water is essential. With the development of molecular biology methods and bioinformatics in recent years, sequencing technology has been applied to study bacterial communities in full-scale water supply systems. In this paper, changes in the bacterial community and the influence of each treatment stage on microbial diversity in full-scale water supply systems are classified and analyzed. Microbial traceability analysis and control are discussed, and suggestions for future drinking water biosafety research and its prospects are proposed.

Drinking water microbial diversity influence in full-scale water supply systems.

Introduction

Water security is not only an ecological and environmental issue, but also an economic, social, and political issue that is directly related to national security. Safe drinking water is essential to public health and an integral part of effective policies to protect health. 1 However, as of 2017, billions of people worldwide still do not have access to safe drinking water and basic health services. According to the World Health Organization (WHO), 80% of human diseases and 50% of child deaths worldwide are related to drinking water quality. With the outbreak of COVID-19, the safety of microorganisms in the environment, especially in water, has become a greater concern. 2–4 Unlike chemical pollution, microbial pollution is proliferative, secondary, and infectious. The explosive proliferation of microorganisms can result in deterioration of water quality, and the presence of odor or toxins, 5,6 and induce secondary pollution. Water-mediated pathogenic microorganisms can be transmitted through diet, aerosols, and contact, endangering human health.

Culture-based methods are one of the most widely used traditional analytical approaches to evaluate the microbiological quantity of drinking water. However, due to the overlooked of some bacteria ( e.g. , viable but non-culturable (VBNC) bacteria), the culture-based method leads to an underestimation of the microbial density and diversity in drinking water. 7 As a result, nucleic acid-based approaches have been widely applied in recent investigations of drinking water distribution system (DWDS) microbial communities. 8,9 These culture-independent methods, such as sequencing technology, include internal transcribed spacer (ITS) fingerprints, terminal restriction fragment length polymorphisms (T-RFLP), 16S rRNA gene surveys, and metagenomics surveys, 10 which could not only detect low concentrations of microorganism (including VBNC), but also obtain microbial diversity information, providing a good technical support for the study of microbial fate.

Given the advantages, sequencing technology, especially high-throughput sequencing (HTS), is widely used to analyze microbial diversity in drinking water to obtain a more comprehensive understanding of bacterial ecology. This review paper summarize the findings of microbial community analysis in full-scale water supply system through sequence technology, especially from the perspective of biological safety of the tap water through distribution system, focusing on (i) the development of sequencing technologies and influence on the study the microorganism in water supply system; (ii) the microbial diversity and environmental impact on full-scale water supply systems using sequencing technology; (iii) evaluation of microbial safety in water source, water treatment process as well as the drinking water distribution system (DWDS); and (iv) proposed biosafety assurance measures for a full-scale water supply system. The goals of this review are to understand application of sequencing technology in the study of drinking water microbial communities, analyze the possible causes of microorganism safety problems in full-scale water supply systems, guide operational practices to obtain safe drinking water, and enhance future research on the drinking water microbiome.

Development of sequencing technology and its contribution to drinking water investigation

Development of sequencing technology.

Gene sequencing technology has developed in the last 50 years as a result of the pioneering Sanger and Coulson chain termination method. With the high cost and low throughput of first-generation sequencing technology, 11 continuous technological development and improvement yielded Roche's 454 technology, Illumina's Solexa technology, and ABI's Solid technology. The comparison of four generation sequencing technologies was list in Table 1 . Compared with first-generation Sanger sequencing, they offered high throughput 12 and fast sequencing, greatly reducing sequencing cost and expanding the scale of genomics research. 13 The timeline and comparison of commercial HTS instruments and costs since 2003 are shown in Fig. 1 . After the introduction of the Genome Sequencer 20 System by 454 Life Sciences in 2005, and the Genome Analyzer II by Illumina/Solexa in 2006, high-throughput sequencing companies were emerging, providing a solid foundation for the development of high-throughput sequencing and price reduction. However, second-generation sequencing technology was still costly, with a short-read length. Since 2008, single-molecule real-time (SMRT, PacBio) sequencing technology and the Heliscope (Helicos Biosciences) genetic analysis system have been developed, known as third-generation sequencing. In NGS method, DNA is broken into short pieces, amplified, and then sequenced. Third generation technologies do not break down or amplify the DNA: they directly sequence a single DNA molecule. Fourth-generation sequencing technology ( e.g. , Nanopore sequencing technology by Oxford Nanopore Technologies) was invented in 2014. 14 However, third- and fourth-generation sequencing technologies have relatively lower accuracy and have not been widely used as NGS. Currently, NGS technology is still the predominant sequencing technology in the market. The launch of Illumina's NovaSeq 6000 in 2017 brought the cost of sequencing under $100 per human genome, promoting widespread use of HTS in recent years in medicine, health, and environmental fields ( Fig. 1 ).

Sequencing technology application in water supply system

With the development of sequencing technology, especially high-throughput technology in recent years, analysis of drinking water microorganisms in relation to human health has been widely conducted. 15 As the analysis method has gradually shifted from traditional analytical approaches to sequencing analysis methods, the research and focus on the whole process of microorganisms in drinking water has also changed from the original quantity and species to the present diversity, transformation, and function. Searching related papers on the topic of “Water” and “Bacterial community” in Web of Science, the number of publications has reached 39540 (as of July 1, 2021), among which the number of annual increased papers reached more than 1000 since 2007. Searching related papers on the Web of Science with the topic of “Drinking Water” and “Bacterial Community”, the article number has reached 2708 (as of July 1, 2021), among which the growth rate of the increased papers number was largely improved from 2006 ( Fig. 2 ).

Here in this paper, the changes in microbial diversity from source water to tap water were categorized based on reported research which using sequencing technologies, as well as the health risks associated with these changes.

Impact on microbial diversity in full-scale water supply system

Water source effects, biological effects.

Although the microbial community changes during water treatment, especially in biological and disinfection processes, most microorganisms in drinking water are introduced from those in source water. The diversity of microorganisms in the source water directly affects the species of microorganisms in the drinking water. 16 Different water sources have different microbial community compositions, resulting in different bacterial communities in the final tap water. 17–21 Microbial communities are sensitive to changes in their environment and reflect the structure and function of aquatic ecosystems. However, due to the influence of upstream water input and water environment, changes in the water source microbial community are complicated. 22 The dominant microbial composition may be similar in different water sources, but the abundances may vary. 17 Delphine, 18 Pearce 23 and Henne 24 found the same microbial compositions, Actinobacteria , Bacteroidetes , and Beta-proteobacteria , in different source waters, in proportions of 40.9%, 22.7%, and 18.2% (Sep Reservoir and Pavin Lake); 19%, 25%, and 26% (Sombre Lake); 16%, 25%, and 20% (two reservoirs in the south of Braunschweig), respectively. The results also showed that the predominant bacterial phyla were Actinobacteria , Proteobacteria , and Bacteroidetes , in reservoirs in Shanghai 22 and Hong Kong, 25 with proportions of 46%, 36.6%, and 16.1%; 24.55%, 45.72%, and 14.56%, respectively. Gomez-Alvarez et al. 21 investigated bacterial composition in a metropolitan DWDS using groundwater (GW) and surface water (SW); the results showed that the bacterial diversity of tap water from SW and GW service areas was different, indicating that different source water quality parameters and treatment processes can result in different microbial diversity in the final tap water. As the biological diversity of drinking water sources directly affects the microbial diversity in drinking water, many studies have focused on microbial diversity in drinking water sources and its environmental impacts.

Chemical effects

Environmental factors such as temperature, 25–27 pH, 28,29 electrolyte type, 19,30,31 salinity, 32 dissolved particles, 26 dissolved oxygen (DO), 33,34 C/N ratio, 19 total nitrogen (TN), 25 total phosphorus (TP), 22 and organic matter 35,36 have been investigated, and verified to influence the composition of the microbial community in drinking water. Zhang et al. 30 investigated the bacterial communities during the outbreak and decline of an algal bloom in a drinking water reservoir. The results indicated that the bacterial communities were significantly correlated with conductivity, ammonia nitrogen, water temperature, and Fe. Kaevska et al. 26 found that actinobacteria negatively correlated with phosphorus, sulfate, dissolved particles, and chloride levels. Proteobacteria positively correlated with sulfate, dissolved particles, chloride, dissolved oxygen, and nitrite levels. Jiang et al. 22 found that the relative abundance of predominant bacteria was affected by environmental factors in source water, and the changes in chemical oxygen demand (COD), TN, and TP in source water were related to microbial diversity. Seasonality also affects the microbial diversity of the source water. Wei et al. 25 found that in a drinking water source in Hong Kong, the microbial community composition and distribution exhibit obvious differences in the dry season and the rainy season, suggesting that seasonal change, as a comprehensive influencing factor, may have a great impact on the microbial diversity of drinking water sources.

Organics effects

As early as 1996, Pierre et al. 37 reported the threat of dissolved organic matter (DOM) in water to bacterial regeneration and water treatment. DOM is a mixture of common compounds in drinking water that can affect the optimization and efficiency of water treatment unit operations, including coagulation, sedimentation, and membrane treatment, and serve as the main precursor of disinfection byproducts (DBPs). 38 Nescerecka et al. 35 found that bacterial proliferation in chlorinated SW samples was restricted mainly by phosphorus and organic carbon; in chlorinated GW samples, carbon was the limiting factor. Apart from some nutrients or DBPs precursors of organic matter, some pharmaceutical and personal care products (PPCPs) which had been widely detected in aquatic environment, 39 influence the proliferation of bacteria, such as antibiotics, 40,41 and environmental endocrine disruptors (EEDs). 42,43 Antibiotics that can screen, enrich, and induce antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) largely affect the stability of microbial diversity, which is a major concern. Deng et al. 44 investigated the antibiotic distribution and microbial diversity in water sources; the results showed that areas polluted with high levels of antibiotics had rich and highly diverse bacterial communities. Ofloxacin posed the main risk to aquatic organisms; the antibiotics in 11.5% of the samples posed resistance selection risks. In recent years, with antibiotics in source water, the investigation of ARGs in full-scale water supply systems has increased, as they may affect the disinfection process in drinking water treatment plants (DWTPs), and the microbial diversity in DWDSs and in tap water. Guo et al. 20 investigated sul I , sul II , tet(C) , tet(G) , tet(X) , tet(A) , tet(B) , tet(O) , tet(M) , tet(W) , and 16S rRNA genes in seven DWTPs in the Yangtze River Delta in China. All the investigated ARGs were detected in the source waters of the seven DWTPs; sul I , sul II , tet(C) , and tet(G) were the four most abundant ARGs. The total concentration of the sulfonamide or tetracycline resistance gene class was greater than 10 5 copies per mL. Additionally, Wu et al. 36 studied the influence of disopyramide on bacterial diversity in water; the results showed that the community density and diversity decreased significantly after the addition of disopyramide. In addition, the microbial communities in drinking water sources are affected by antibiotics in water sources.

Unconventional water sources effects

In addition to SW and GW, in some areas of water shortage, rainwater, 45,46 and desalination water 47 are used as drinking water sources. For rainwater, researchers have used sequencing technology to study the microbial diversity of the water from these sources; the sequencing analysis indicated the presence of one or more fecal indicators, and potential bacterial and protozoan pathogens were detected in the roof-harvested rainwater (RHRW), suggesting that RHRW may not be suitable for drinking. Thus, improving the rainwater biosecurity was proposed through regularly cleaning roofs and gouges, pruning overhanging branches, and reducing the contamination of rainwater tanks by animal waste. For desalination water, the survival microbial pathogens are markedly reduced, especially when comminating with a high level of sunlight radiation. However, some pathogens, such as Vibrio cholerae , could still survive. Although most systems could remove the vast majority of microbial pathogens, in some circumstances, there is a significant potential for some pathogens transfer, 10 thus creates biosafety stress for subsequent processes. Hence, disinfection was recommended whenever possible in these water sources treatments.

The microbial diversity of water sources detected by sequencing technology were categorized in Table 2 . Microbial diversity in drinking water sources is influenced by environmental factors, including chemical factors (electrolytes, organics, pH, nutrients, antibiotics) and physical factors (temperature, seasonality, light irradiation). The microbial diversity in the source water also affects the chemical and physical characteristics of the water. In conventional treatment, the source water microbial community is important because it is the source, and the tap water microbial community is the sink ( Fig. 3 ). In studying the dynamic changes of microorganisms in water sources, physical, chemical, and biological properties must be considered together for systematic analysis to evaluate the microorganism diversity more comprehensively.

Drinking water treatment processes effects

Drinking water treatment is the key to preventing waterborne diseases and their spread. There is a potential relationship between bacterial community composition and the emergence of opportunistic pathogens; 48 problems encountered in drinking water treatment plants or water distribution may lead to the proliferation of conditioned pathogenic bacteria ( Mycobacterium , Pseudomonas aeruginosa , Legionella pneumophila , etc. ). 49–51 Currently, conventional water treatment processes (coagulation–flocculation, sedimentation, filtration, and disinfection) are widely used to purify drinking water in China. 52 In recent years, with the deterioration of source water quality, especially from an increase in organic matter, advanced treatment technologies such as ozone–biological activated carbon (O 3 –BAC) and membrane treatment have been applied. Understanding changes in the microbial community during treatment is vital for the management of DWTSs. Usually, O 3 –BAC and disinfection processes are regarded as the primary units influencing the microbial density and diversity; other units also have some influence. 53 A great change in the proportions of Actinobacteria , Proteobacteria , and Firmicutes during the treatment process was detected by Hou et al. , the proportion of Actinobacteria decreased sharply, and the proportions of Proteobacteria and Firmicutes increased and predominated in treated water. 54 During drinking water treatment processes, the microbial activity and bacterial diversity showed obvious spatial differences; the bacterial community changed significantly after chlorination disinfection, indicating that the disinfection process affected the bacterial community. In addition, the bacterial community structure of the finished water was like that of the biofilm on the GAC, indicating that the application of biological treatment technology can significantly change the microbial community composition inherited from the source.

Coagulation and sedimentation

Coagulation and sedimentation are the most common processes in water treatment systems to remove microorganisms, such as protozoa ( e.g. , giardia and crypto) and prokaryotes ( e.g. , cyanobacteria and bacteria). Here, we'll focus on the effects of the treatment on bacteria. With double electric layer compression, adsorption electric neutralization, adsorption bridging, and sediment trapping, the particulate matter and colloids, and the bacteria adhered to them, are removed from the source water. These processes are generally reported to have no obvious effect on the microbial community structure. 55,56 However, by monitoring the microbial density and diversity from the influent and effluent of each unit in the water treatment process, Hou et al. 54 found that each unit in the DWTP had an influence on microbial diversity. The removal of microorganisms from water by coagulation and clarification mostly refers to microorganisms that are easily adsorbed on suspended particles and colloids. Strengthening coagulation can greatly reduce the pressure of follow-up disinfection, reducing the cost of follow-up treatment, and reducing the generation of DBPs. Thus, the coagulation and sedimentation process must be considered for microbial safety assurance.

Filtration ( e.g. , sand filtration, microfiltration, GAC filtration, and BAC filtration) usually occurs after coagulation and sedimentation; its main function is to intercept the macromolecular solid particles and colloids in water. Filtration is used to remove the suspended matter that has not been removed by coagulation and sedimentation. With good adsorption and interception capability, the filtration process can significantly reduce suspended substances such as bacteria and viruses, further affecting the microbial diversity. 57,58 In addition, various biological processes ( e.g. , biofilm formation and shedding) can occur in filters, which could further affect the microbial community structure of the effluent. Bai et al. 59 verified that sand filtering produces a biofilm on the sand that can influence the water quality and microbial diversity. Shaw et al. 57 reported that microfiltration (MF) treatment is the most effective way to inhibit biofilm growth in a DWDS, and that a highly efficient post-treatment disinfection regime reduces the rate of post-treatment regrowth compared with conventional treatment. By investigating the metagenomic characterization of three biofilters (rapid sand filter, GAC filter, and slow sand filter) in a full-scale DWTP, Oh et al. found that the bacterial communities in biofilters were significantly different from those in source water and effluent; Bradyrhizobiaceae were abundant in GAC, whereas Nitrospira were enriched in the sand filters. The GAC community was enriched with functions associated with aromatic degradation, many of which were encoded by Rhizobiales . 60 Lee et al. 61 used q-PCR analysis to clarify ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) effects on ammonium oxidation in a pilot scale rapid sand filter system, the results showed that AOA and AOB were similar in abundance and AOB density set the observed ammonium removal rate. The results were consistence with Tatari et al. , 62 and they also put forward that Nitrospira should be the predominant NO 2 oxidizers. And rapid sand filters are microbially dense, with varying degrees of spatial heterogeneity, leading to in different results, even under very similar experimental setup. In GAC sand filter system, Nitrosomonas and Nitrospira are likely to be involved in nitrification processes, while Novosphingobium , Comamonadaceae and Oxalobacteraceae may be involved in denitrification processes. 63 Coincidentally, LaPara et al. 64 also found that AOB were prominent in the bacterial communities, and he most prominent population in the profiles was a Nitrospira spp., representing 13 to 21% of the community. By determining the composition of the bacterial community after the stable operation of biological activated carbon (BAC) particles, Zhang et al. 65 found that after nine months of operation, a stable bacterial community dominated by bacteria such as Pseudomonas sp., Bacillus sp., and Nitrospira sp. could effectively eliminate or reduce 41 chemicals in water.

O 3 –BAC

When the organic matter in the source water cannot be effectively removed using conventional processes such as coagulation, clarification, and filtration, advanced treatment technology, O 3 –BAC, is often used to minimize the precursor of disinfection byproducts. 66 However, with the removal of organic matters in DWTP, the leakage of bacteria which could be have been seeding of distribution system, becomes an important issue in this unit. Researchers have increasingly studied microbial diversity changes in the O 3 –BAC unit to determine which microbial consortia colonize filters and what metabolic capacity they possess to obtain the organic matter removal mechanism, based on excellent organic matter removal performance. The influent water quality, oxidative pretreatment, empty bed contact time (EBCT), and backwashing frequency can affect the redox environment of the system, influencing the microbial diversity of the effluent. 71,72 Soonglerdsongpha et al. 73 compared the O 3 –BAC effect on assimilable organic carbon (AOC) removal in three DWTPs in Japan and found that AOC increased after O 3 treatment, and BAC could remove 53–73% of the AOC from water, which may be attributed to the microbial community differences. The results were consistent with Liao et al. , 74 who also showed that the BAC filtration system effectively removes both dissolved organic carbon (DOC) and AOC. 76 Researchers also investigated the effects of temperature, 77 influent water quality, 76 types of activated carbon, residence time, 59 filtration depth, and the backwash process of activated carbon 92 on the microbial community in the effluent during the operation of O 3 –BAC.

Disinfection

The disinfection process is the last barrier to ensure the biological safety of drinking water; its influence on microbial diversity is the greatest in the water treatment process, thus determining the microbial communities in the subsequent units. In recent years, however, chloride-resistant bacteria and VBNC have often been detected in finished water after disinfection, which could result in biofilm formation 78–80 and pipeline corrosion 81,82 in the subsequent DWDS. Thus, researchers have studied changes in the microbial community during the disinfection process, focusing mainly on improving the efficiency of disinfection and controlling costs. The results showed that disinfection (chlorination, chloramination, and hypochlorination) has a significant impact on microbial diversity, 83,84 decreasing bacterial diversity and cultivability, transferring the culturable bacteria from predominantly Gram-negative to predominantly Gram-positive. 93 After disinfection, alpha- and beta- proteobacteria were dominant in chlorinated water. Betaproteobacteria was more abundant after chloramine disinfection than the other two processes. The studies also revealed that the richness, diversity, and evenness of bacterial communities were greater in winter than in summer. 94 Chlorination and chloramination are the two main types of disinfection treatments applied to inactivate pathogens in DWTPs; the efficiency differs based on the disinfectant type and dosage. 85 Williams et al. 86 compared the bacterial diversity of drinking water in the distribution system after chlorination and chloramination, and found that even after disinfection, numerous bacteria still appeared in the finished water. Although the predominant species in the bacterial community were the same, the microbial diversity was different, which may be due to the difference in the inactivation mechanisms. 81 The presence of resistant bacteria can accelerate biofilm formation in a DWDS. Researchers have proposed a joint disinfection process 81,82,87 and develop new disinfectants for the removal of resistant bacteria. 88–90 In addition, ozone, a strong oxidant is widely used for water treatment, the effect was investigated by Kotlarz et al. , 95 and the results showed that with the detachment of biofilm, the cell concentration in water sample for sequential ozone chambers increased, and biofilms downstream of the dead zone contained a significantly higher relative abundance of bacteria of the genera Mycobacterium and Legionella than the upstream biofilm. Different from other disinfection method, UV, as a physical disinfection method, is a promising green method and have positive effect on disinfection process when combined with other disinfection method such as UV/Cl 2 , 96,97 UV/SO 3 2− , 98,99 and UV/H 2 O 2 . 97,100 Ao et al. 101 investigated the impact of UV treatment on microbial control in DWTPs, the results showed that UV treatment showed high efficacy in inactivating chlorine-resistant microorganisms, and can mitigate microbial re-growth to some extent. Proteobacteria (relative abundance: 8.02–92.34%) and Firmicutes (1.38–86.87%) were the dominant phyla in UV irradiation samples. Other common phyla included Bacteroidetes (1.38–15.26%) and Actinobacteria (0.16–8.87%).

Drinking water treatment processes effects on its microbiome was counted in Table 3 . Generally, drinking water treatment processes have a significant impact on the microbial diversity in tap water. Microbial changes, whether in the traditional processes of coagulation and sedimentation or in subsequent filtration and O 3 –BAC, are adjusted in the disinfection process, resulting in (i) the culturable bacteria transfer from predominantly Gram-negative to predominantly Gram-positive; 93 (ii) alpha- and betaproteobacteria are dominant in water; (iii) chlorine-resistant bacteria ( e.g. , VBNC and ARB) may be hidden dangers in subsequent DWDSs. The influence of each unit in the DWTP on the microbial community is shown in Fig. 4 . Coagulation and sedimentation have minimal influence on the community; filtration is the key step shaping downstream microbiota. The O 3 –BAC and disinfection processes have the strongest effect in changing the microbial community.

Influence in DWDS

Mathieu et al. 102 have reviewed the bugs systematically found in drinking water distribution systems all over the world (bacteria, viruses, yeasts, fungi, protozoa, microcrustaceans, rotifers, and oligochaete worms), here, we will analysis and discuss several factors which influence the microbial diversity in DWDS, especially the fate of biofilm on pipes according to the results from HTS. Based on the microbial diversity analysis of finished water and tap water, a diverse core microbiome was shared between the two locations; however, the microbial community was changed in the DWDS, 103 which was attributed to the shedding of biofilms (the environmental reservoirs for pathogenic microorganisms) from the inner wall of the pipe, posing a potential threat to human health. 104 Microbial regrowth with spatiotemporal variation is a major concern in distribution, as the physicochemical and nutritional conditions provided by pipe walls are very different from those found during treatment. Recent studies have identified the microbial community and dominant species associated with many factors in the DWDS. These factors include pipe materials, hydraulic conditioning, spatiotemporal effects, and the quality of the treated water ( Fig. 5 ).

Pipe materials

To date, the influences of the material and design of DWDS on the biofilm growth on pipe wall have been widely investigated, and these studies have been deepened step by step with the innovation of detection technology. Aggarwal et al. 80 put forward that coupon material (cement, HDPE, and PVC) did not have a significant impact on biomass levels or composition of the biofilm communities in the chloraminated reactors, however, most researchers have given evident on that pipe materials seem to be the most influential factor, followed by spatial and temporal distribution. The pipeline materials influence the density, the formation potential, the formation rate of biofilms, and the microbial diversity. When the biofilm is peeled off from the pipe into the bulk water, it directly affects the microbiome composition in the water. To date, research on the influence of pipe network materials on microbial diversity in drinking water and pipe wall biofilms has focused mainly on cast iron pipes (municipal pipes), 105,110,112 stainless steel (municipal pipe network into residential area), 116,117 EPDM and PEX (household plumbing material), 107,113,114 copper pipe (hotel hot water pipe), 108,109,114,117 and CP, PVC, and PVCF pipe (household common plastic pipe material). 105,110,112,116,117 The results showed that the biofilm community structure was different due to the pipe properties, especially for metal pipes. Due to the metal release, the biological diversity in different metal pipes was significantly different, with a greater biological diversity than in plastic materials. 115 Studies have also shown that the microbiome compositions of biofilms differ in different plastic pipeline materials. The most extensive biofilm was found in HDPE pipes; bacteria adhered to mineral deposits or were immersed in the extracellular polymeric substance (EPS). On the PEX surface, although the bacteria did not form large aggregates, the quantity of bacteria was the greatest. PVC biofilms do not contain mineral deposits, but are composed of single cells rich in Pseudomonas aeruginosa , which is harmful to human health. 106 Roeder et al. 107 found that the biofilm population had greater diversity on growth-supporting materials such as ethylene–propylene–diene monomer (EPDM) than on cross-linked polyethylene. Biofilms are mainly composed of proteobacteria; their composition is influenced by the applied materials. Liu et al. 105 reported that hyphomicrobia and corrosion-associated bacteria were the most dominant bacteria in PVC and cast iron biofilms, indicating that the colonization of bacteria on the material surface was selective. Mycobacterium and Legionella spp. are common potential pathogenic bacteria in biofilms; however, their proportions were different for PVC and cast-iron pipes. The results also verified that different pipe materials (PVC and cast-iron) have significant effects on the microbial community, especially the bacterial composition. Metal materials such as copper have an antibacterial effect, 109 which can significantly reduce the microbial diversity downstream. The proportion of bacteria and eukaryotes was reduced by half. 108 The effects of pipe materials on the drinking water microbiome are presented in Table 4 .

Hydraulic conditions

A previous study 118 reported no statistical difference in microbial communities in biofilms under different hydraulic conditions; biofilms were considered to be a substrate independent of the external environment. However, in bulk water, species richness and diversity were significantly greater in low hydraulic regimes, suggesting that water hydraulic conditions can influence the fate of biofilms. With further excavating to discover the formation mechanism of the biofilm, it was found that the hydraulic condition is related to the formation and shedding of the biofilm, and the water quality in the DWDS. 119 Thus, it has a great influence on the microbial community of the biofilm and bulk water. Boxall et al. 120 conducted a large number of studies revealing a tendency for greater species richness and diversity with highly varied flow. A more cohesive biofilm structure may be more resistant to external shear stress and detachment. In addition, the flow rate variation during growth was positively correlated with the number of cells, but negatively correlated with the EPS-to-cell volume ratio and bacterial diversity. 121 The results were consistent with E. Tsagkari's findings, which showed that turbulence could enhance the growth of drinking water biofilms. 122 Some studies have focused on water discoloration. It was believed that discoloration is influenced by hydraulic conditions, 121,123 and related to the biofilm shedding in water, indicating that the hydraulic condition plays an important role in the diversity of microbes in drinking water. Additionally, some researchers also argued that the strength of the biofilm matrix is not dictated by the applied fluid shear but is merely coincidental because the EPS composition and density are dictated by other purposes such as a defense from biocides or as a cache of stored food. Thus, one would not expect the strength to increase with fluid shear.

In studying the effects of time on the microbial diversity of drinking water, we considered short-term effects, such as water age or residence time, 124–126 and long-term effects, such as seasonal changes. 94,127,128 The results 112,129 showed that the residual chlorine and DO decreased with the age of the water; DOM, TOC, total bacterial count, and bacterial diversity increased. From the beginning to the end of the DWDS, the relative abundance of Rhizobium decreased, and the relative abundance of most other residues increased in varying degrees. Studies have also reported that a greater water age produces a greater relative presence of M. avium , which can increase the risk of human infection. 130 The results were consistent with those of Masters et al. 111 However, in some studies, the effect of water age was not significant. Hwang et al. 131 studied the water-like microbial community at five locations, indicating that at the sampling site and water age (<21.2 h), most of the time samples contained microbes. The composition had no significant effects.

Water stagnation

In contrast to municipal water supply systems, water stagnation is an important water supply system characteristic in buildings. In the urban water supply system, the flow in the urban area rarely stops completely due to the high-water demand. However, in buildings, water flow is often stopped for long periods of time, allowing long incubation times for bacteria, and enhancing the formation of biofilms on the inner walls of pipes. 125,132–135 Stagnation is still an issue in building design. Studying the effect of stagnation time can effectively guide the end-use of water to reduce the risk of microbial contamination. Green-building design often focuses on water conservation, which essentially prolongs water stagnation and accelerates the deterioration of water quality. 136,137 Studies have shown that the composition of the bacterial community changes dramatically, and the cell count increases by two orders of magnitude after six days of stagnation. 126 Moreover, the composition and content of microorganisms in household faucet water change greatly, even if stopped overnight. 138 Chen et al. 139 studied the effect of water stagnation on microbial pollution in a water purifier; the results showed that the growth of microorganisms in the water purifier was faster than in a DWDS, and the size of the microorganisms decreased with an increase in stagnation time. This suggests that microbial contamination caused by stagnation should be carefully considered in the design and usage guidance of building water supply systems (BWSSs) to ensure healthy drinking water.

Spatiotemporal effect

The spatiotemporal effect also changes the drinking water microbial community. 34,109,140,141 Bautista-de Los Santos et al. 142 observed significant changes in the bacterial community over a diurnal time scale and found that the degree and pattern of diurnal changes in the bacterial community in the DWDS were related to the presence/absence of low-content bacteria, and to changes in the relative abundance of dominant bacteria at each sampling site. Perrin et al. 143 found significant but moderate changes in bacterial community composition on large temporal and spatial scales in a drinking water distribution system in Paris. Potgieter et al. 94 found that α-proteobacteria and β-proteobacteria dominated the microbial community in drinking water after disinfection with different disinfectants. In addition, the richness, diversity, and evenness of the bacterial community were greater in winter than in summer. The spatial dynamics of the bacterial community exhibited distance attenuation. However, a survey on the microbial biogeography of drinking water in the Netherlands showed that the population exchange between the biofilm and the water matrix was limited; different DWDSs had different microbial communities, and the treated water had significant stability in time and space. 34

In addition, treated drinking water quality, including temperature, 132,144,145 suspended solids, 35,146 electrolytes, 28,125,147–149 disinfectants, 149 and organic matter 28 also influence microbial diversity in tap water. Sun et al. 28 reported that pH and COD were positively correlated with the relative abundance of Proteobacteria and Firmicutes . Ma et al. 148 reported that bacterial richness and diversity were positively related to SO 4 2− , Cl − , and HCO 3 − in the water supply, and negatively related to pH value. Chemical reactions other than microbial processes play a major role in the release of iron during the transition period of the water supply. Moreover, the role of residual chlorine in water quality cannot be underestimated. The disinfectant changes the bacterial community structure of the pipeline biofilm, and affects the water quality and the remodeling of the corrosion scale, further changing the kinetics of the corrosion process. 149

Prospects of microbial diversity analysis in drinking water biosafety

With the development of sequencing technology, in-depth characterization and evaluation has been conducted by researchers on microbial communities in DWDSs and BWSSs. Although microbiological safety assurance technology is relatively good, harmful bacteria such as pathogenic bacteria and ARB may still be detected in drinking water, posing a threat to public health. 150–154 It has been verified that every stage from the source to the tap has some influence on microbial diversity. Thus, researchers have conducted traceability analyses of microorganisms in tap water or estimated the impact on microbial conditions in drinking water based on existing water quality conditions to determine if emergency treatment methods are necessary. Marshall et al. 155 investigated the genotype similarities and geographic relationships of bacterial communities between humans and drinking water. The results indicated that drinking water may be a source of human Mycobacterium lentiflavum infection. Liu et al. 156 used the Bayesian “source tracing” method to determine the proportional contributions of source water, treatment water, and the distribution system in shaping the bacterial community in faucet water based on bacterial community fingerprints. The results showed that the source water had no obvious contribution to the bacterial communities of tap water and water in the distribution system. Loose sediments and biofilms show significant effects on phytoplankton and particle-related bacteria in faucet water, which are position dependent and subject to hydraulic changes. In addition, sequencing technology has been used to assess the safety of rural drinking water systems. The rich genetic footprint of pathogens in water samples from many reports suggests that the bacteria can be transmitted to humans. Thus, the importance of disinfection of raw water must be clearly communicated to rural communities to ensure the safe use of water. Studying the microbial community structure and its influence on drinking water is critical.

With the continuous improvement of sequencing technology in depth, accuracy, and economy, how and why the microbial diversity changes in the whole process of drinking water will be clearer. Future research may focus on the impact of new pollutants, traceability analysis and source control, as well as rapid detection and intelligent feedback.

This paper summarizes and clarifies the biological sequencing technologies applied in research on drinking water microbial communities, including the source drinking water quality, the treatment process, and the distribution system supply conditions, and indicates that all three steps can affect the tap water microbial community. A significant correlation was observed between the microbial populations in the source water and tap water, and the abundance of bacteria was largely affected by the treatment process and the distribution system condition. Thus, the microbiological safety assurance of drinking water must start from the source. The treatment process must be improved, the pipeline network route material must be carefully selected, and drinking water management should be strengthened from the factory to the client, to block the source (water protection), decrease the concentration (optimization of disinfection during DWTP), and control the flow (reduce growth in the DWDS). These mechanisms that need to be explored require the development of cheaper and more accurate biological sequencing technologies.

Author contributions

The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript.

Conflicts of interest

There are no conflicts to declare.

Supplementary Material

Acknowledgments.

This work was supported by the National Natural Science Foundation of China (51979194). We also thank the research on water quality stability characteristics and countermeasures of the Fuzhou Water Supply System (Project No. 20203000) from Fuzhou Water Group Co. Ltd.

• W. H. Organization, Guidelines for Drinking-water Quality , 4th edn, 2011 [ Google Scholar ]
• Khadse S. Gharami N. Sapate T. Int. J. Tech. Res. Sci. 2020; 5 :35–41. [ Google Scholar ]
• Keulertz M. Mulligan M. Allan J. A. Water International. 2020; 45 :430–434. [ Google Scholar ]
• Neal M. J. Water International. 2020; 45 :435–440. [ Google Scholar ]
• Shang L. Feng M. Xu X. Liu F. Ke F. Li W. Toxins. 2018; 10 :26. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Lebaron P., Cournoyer B., Lemarchand K., Nazaret S. and Servais P., Environmental Microbiology: Fundamentals and Applications , 2015, pp. 619–658 [ Google Scholar ]
• Lee D. G. Park S. J. Kim S. J. J. Microbiol. Biotechnol. 2007; 17 :1558. [ PubMed ] [ Google Scholar ]
• Prest E. I. Hammes F. Van Loosdrecht M. C. Vrouwenvelder J. S. Front. Microbiol. 2016; 7 :1–24. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Petrosino J. F. Sarah H. Ann L. R. Gibbs R. A. James V. Clin. Chem. 2009:856. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Zhang Y. Liu W.-T. Crit. Rev. Environ. Sci. Technol. 2019; 49 :1188–1235. [ Google Scholar ]
• Luo Y. Liao X. Wu F. X. Wang J. Curr. Bioinf. 2020; 15 :2–16. [ Google Scholar ]
• Van Dijk E. L. Auger H. Jaszczyszyn Y. Thermes C. Trends Genet. 2014; 30 :418–426. [ PubMed ] [ Google Scholar ]
• Salk J. J. Schmitt M. W. Loeb L. A. Nat. Rev. Genet. 2018; 19 :269–285. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Reuter J. A. Spacek D. V. Snyder M. P. Mol. Cell. 2015; 58 :586–597. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Vierheilig J. Savio D. Ley R. E. Mach R. L. Reischer G. H. Water Sci. Technol. 2015; 72 :1962–1972. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Kahlisch L. Henne K. Groebe L. Draheim J. Höfle M. G. Brettar I. Water Sci. Technol. 2010; 61 :9–14. [ PubMed ] [ Google Scholar ]
• Mucha A. P. Vasconcelos M. T. S. D. Bordalo A. A. Estuarine, Coastal Shelf Sci. 2004; 59 :663–673. [ Google Scholar ]
• Boucher D. Jardillier L. Debroas D. FEMS Microbiol. Ecol. 2010; 55 :79–97. [ PubMed ] [ Google Scholar ]
• Li W. Wang F. Zhang J. Qiao Y. Xu C. Liu Y. Qian L. Li W. Dong B. Sci. Total Environ. 2016; 544 :499–506. [ PubMed ] [ Google Scholar ]
• Guo X. Li J. Yang F. Yang J. Yin D. Sci. Total Environ. 2014; 493 :626–631. [ PubMed ] [ Google Scholar ]
• Gomez-Alvarez V. Humrighouse B. W. Revetta R. P. Santo Domingo J. W. J. Water Health. 2015; 13 :140–151. [ PubMed ] [ Google Scholar ]
• Jiang T. Sun S. Chen Y. Qian Y. An D. Sci. Total Environ. 2021; 769 :144698. [ PubMed ] [ Google Scholar ]
• Pearce D. A. Gast C. J. Lawley B. Ellis-Evans J. C. FEMS Microbiol. Ecol. 2010; 45 :59–70. [ PubMed ] [ Google Scholar ]
• Henne K. Kahlisch L. Brettar I. Hofle M. G. Appl. Environ. Microbiol. 2012; 78 :3530–3538. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Sun W. Xia C. Xu M. Guo J. Sun G. Front. Microbiol. 2017; 8 :1644. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Kaevska M. Videnska P. Sedlar K. Slana I. SpringerPlus. 2016; 5 :1–8. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Moitra M. Leff L. G. Hydrobiologia. 2015; 747 :201–215. [ Google Scholar ]
• Sun H. Shi B. Bai Y. Wang D. Sci. Total Environ. 2014; 472 :99–107. [ PubMed ] [ Google Scholar ]
• Joshi D. R. Zhang Y. Gao Y. Liu Y. Yang M. Water Res. 2017; 121 :338. [ PubMed ] [ Google Scholar ]
• Zhang H. Jia J. Chen S. Huang T. Wang Y. Zhao Z. Feng J. Hao H. Li S. Ma X. Int. J. Environ. Res. Public Health. 2018; 15 :361. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Kaestli M. O'Michelle D. Rose A. Webb J. R. Mayo M. Currie B. J. Gibb K. PLoS Neglected Trop. Dis. 2019; 13 :e0007672. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Zhang L. Gao G. Tang X. Shao K. Can. J. Microbiol. 2014; 60 :319–326. [ PubMed ] [ Google Scholar ]
• Zhang Y. Oh S. Liu W. T. Environ. Microbiol. 2017; 19 :3163–3174. [ PubMed ] [ Google Scholar ]
• Roeselers G. Coolen J. van der Wielen P. W. Jaspers M. C. Atsma A. de Graaf B. Schuren F. Environ. Microbiol. 2015; 17 :2505–2514. [ PubMed ] [ Google Scholar ]
• Nescerecka A. Juhna T. Hammes F. Water Res. 2018; 135 :11–21. [ PubMed ] [ Google Scholar ]
• Wu Q. Zhao X. Tian Q. Wang L. Zhao X. IOP Conference Series: Earth and Environmental Science. 2018; 113 :012144. [ Google Scholar ]
• Servais P. Laurent P. Gatel D. Appl. Mech. Mater. 1995; 781 :329–332. [ Google Scholar ]
• Rosario-Ortiz F. L. Snyder S. A. Suffet I. H. Water Res. 2007; 41 :4115–4128. [ PubMed ] [ Google Scholar ]
• Rosi-Marshall E. J. Kincaid D. W. Bechtold H. A. Royer T. V. Rojas M. Kelly J. J. Ecological Applications. 2013; 23 :583–593. [ PubMed ] [ Google Scholar ]
• Proia L. Lupini G. Osorio V. Perez S. Barcelo D. Schwartz T. Amalfitano S. Fazi S. Romani A. M. Sabater S. Chemosphere. 2013; 92 :1126–1135. [ PubMed ] [ Google Scholar ]
• Li D. Qi R. Yang M. Zhang Y. Yu T. Water Res. 2011; 45 :6063–6073. [ PubMed ] [ Google Scholar ]
• Radwan E. K. Ibrahim M. B. Adel A. Farouk M. Environ. Sci. Pollut. Res. 2020; 27 :1776–1788. [ PubMed ] [ Google Scholar ]
• Yuan K. Xiao S. Jiang X. Yang L. Chen B. Luan T. Lin L. Tam N. F. Y. Mar. Pollut. Bull. 2017; 122 :122–128. [ PubMed ] [ Google Scholar ]
• Deng W. J. Li N. Ying G. G. Environ. Geochem. Health. 2018; 40 :1–13. [ PubMed ] [ Google Scholar ]
• Ahmed W. Hodgers L. Sidhu J. P. S. Toze S. Appl. Environ. Microbiol. 2012; 78 :219–226. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Alves F. Köchling T. Luz J. Santos S. M. Gavazza S. J. Water Health. 2014; 12 :513–525. [ PubMed ] [ Google Scholar ]
• Belila A. El-Chakhtoura J. Otaibi N. Muyzer G. Gonzalez-Gil G. Saikaly P. E. van Loosdrecht M. C. M. Vrouwenvelder J. S. Water Res. 2016; 94 :62–72. [ PubMed ] [ Google Scholar ]
• Ji P. Rhoads W. J. Edwards M. A. Pruden A. ISME J. 2017; 11 :1318. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Lu J. Struewing I. Yelton S. Ashbolt N. J. Appl. Microbiol. 2015; 119 :278–288. [ PubMed ] [ Google Scholar ]
• Ashbolt N. J. Curr. Environ. Health Rep. 2015; 2 :95–106. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Zhang Y. Oh S. Liu W. Environ. Microbiol. 2017:3163–3174. [ PubMed ] [ Google Scholar ]
• Feng S. Zhang X. J. Chen C. Yang Z. Y. China Water & Wastewater. 2012; 28 :16–19. [ Google Scholar ]
• Li Q. Yu S. Li L. Liu G. Gu Z. Liu M. Liu Z. Ye Y. Xia Q. Ren L. Front. Microbiol. 2017; 8 :2465. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Hou L. Zhou Q. Wu Q. Gu Q. Zhang J. Sci. Total Environ. 2017; 625 :449–459. [ PubMed ] [ Google Scholar ]
• Poitelon J. B. Joyeux M. Welte B. Duguet J. P. Prestel E. DuBow M. S. J. Ind. Microbiol. Biotechnol. 2010; 37 :117–128. [ PubMed ] [ Google Scholar ]
• Lin W. Yu Z. Zhang H. Thompson I. P. Water Res. 2014; 52 :218–230. [ PubMed ] [ Google Scholar ]
• Shaw J. L. Monis P. Fabris R. Ho L. Braun K. Drikas M. Cooper A. Chemosphere. 2014; 117 :185–192. [ PubMed ] [ Google Scholar ]
• Albers C. N. Ellegaard-Jensen L. Harder C. B. Rosendahl S. Knudsen B. E. Ekelund F. Aamand J. Environ. Sci. Technol. 2015; 49 :839–846. [ PubMed ] [ Google Scholar ]
• Bai Y. Liu R. Liang J. Qu J. PLoS One. 2013; 8 :e61011. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Oh S. Hammes F. Liu W.-T. Water Res. 2018; 128 :278–285. [ PubMed ] [ Google Scholar ]
• Lee C. O. Boe-Hansen R. Musovic S. Smets B. Albrechtsen H. J. Binning P. Water Res. 2014; 64 :226–236. [ PubMed ] [ Google Scholar ]
• Tatari K. Musovic S. Guelay A. Dechesne A. Albrechtsen H. J. Smets B. F. Water Res. 2017; 127 :239–248. [ PubMed ] [ Google Scholar ]
• Feng S. Xie S. Zhang X. Yang Z. Wei D. Liao X. Liu Y. Chao C. J. Environ. Sci. 2012:1587–1593. [ PubMed ] [ Google Scholar ]
• LaPara T. M. Hope Wilkinson K. Strait J. M. Hozalski R. M. Sadowksy M. J. Hamilton M. J. Appl. Environ. Microbiol. 2015; 81 :6864–6872. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Zhang D. Biomed. Environ. Sci. 2011; 24 :122–131. [ PubMed ] [ Google Scholar ]
• Liu C. Olivares C. I. Pinto A. J. Lauderdale C. V. Brown J. Selbes M. Karanfil T. Water Res. 2017; 124 :630–653. [ PubMed ] [ Google Scholar ]
• Zeng D. N. Fan Z. Y. Liang C. World J. Microbiol. Biotechnol. 2013; 29 :1573–1584. [ PubMed ] [ Google Scholar ]
• Zhu I. X. Getting T. Bruce D. J. - Am. Water Works Assoc. 2010; 102 :67–77. [ Google Scholar ]
• Velten S. Boiler M. Koester O. Helbing J. Weilenmann H. U. Hammes F. Water Res. 2011; 45 :6347–6354. [ PubMed ] [ Google Scholar ]
• Soonglerdsongpha S. Kasuga I. Kurisu F. Furumai H. Sustainable Environ. Res. 2011; 21 :59–64. [ Google Scholar ]
• Liao X. Chen C. Wang Z. Wan R. Chang C. H. Zhang X. Xie S. Process Biochem. 2013; 48 :312–316. [ Google Scholar ]
• Lautenschlager K. Hwang C. Ling F. Liu W. T. Boon N. Koester O. Egli T. Hammes F. Water Res. 2014; 62 :40–52. [ PubMed ] [ Google Scholar ]
• Liao X. Chen C. Wang Z. Wan R. Xie S. Process Biochem. 2013; 48 :703–707. [ Google Scholar ]
• Kaarela O. E. Haerkki H. A. Palmroth M. R. T. Tuhkanen T. A. Environ. Technol. 2015; 36 :681–692. [ PubMed ] [ Google Scholar ]
• Bai X. Wu F. Zhou B. Zhi X. J. Water Health. 2010; 8 :593–600. [ PubMed ] [ Google Scholar ]
• Roeder R. S. Lenz J. Tarne P. Gebel J. Exner M. Szewzyk U. Int. J. Hyg. Environ. Health. 2010; 213 :183–189. [ PubMed ] [ Google Scholar ]
• Aggarwal S. Gomez-Smith C. K. Jeon Y. LaPara T. M. Waak M. B. Hozalski R. M. Environ. Sci. Technol. 2018; 52 :13077–13088. [ PubMed ] [ Google Scholar ]
• Li X. Wang H. Zhang Y. Hu C. Yang M. Int. Biodeterior. Biodegrad. 2014; 96 :71–79. [ Google Scholar ]
• Zhu Y. Wang H. Li X. Hu C. Yang M. Qu J. Water Res. 2014; 60 :174–181. [ PubMed ] [ Google Scholar ]
• Kelly J. J. Minalt N. Culotti A. Pryor M. Packman A. PLoS One. 2014; 9 :e98542. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Homonnay Z. G. Török G. Makk J. Brumbauer A. Major E. Márialigeti K. Tóth E. J. Basic Microbiol. 2014; 54 :729–738. [ PubMed ] [ Google Scholar ]
• Mi Z. Dai Y. Xie S. Chen C. Zhang X. J. Environ. Sci. 2015; 37 :200–205. [ PubMed ] [ Google Scholar ]
• Williams M. M. Domingo J. W. S. Meckes M. C. Kelty C. A. Rochon H. S. J. Appl. Microbiol. 2010; 96 :954–964. [ PubMed ] [ Google Scholar ]
• Ding W. Jin W. Cao S. Zhou X. Wang C. Jiang Q. Huang H. Tu R. Han S.-F. Wang Q. Water Res. 2019; 160 :339–349. [ PubMed ] [ Google Scholar ]
• Zhou W. Fu L. Zhao L. Xu X. Li W. Wen M. Wu Q. ACS Appl. Mater. Interfaces. 2021; 13 :10878–10890. [ PubMed ] [ Google Scholar ]
• Ahmed Y. Lu J. Yuan Z. Bond P. L. Guo J. Water Res. 2020; 179 :115878. [ PubMed ] [ Google Scholar ]
• Xiong P. Hu J. Water Res. 2013; 47 :4547–4555. [ PubMed ] [ Google Scholar ]
• Chao Y. Ma L. Yang Y. Ju F. Zhang X. X. Wu W. M. Zhang T. Rep. 2013; 3 :3550. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Qi W. Li W. Zhang J. Wu X. Zhang J. Zhang W. Front. Environ. Sci. Eng. 2018; 13 :15. [ Google Scholar ]
• Vaz-Moreira I. Egas C. Nunes O. C. Manaia C. M. FEMS Microbiol. Ecol. 2013; 83 :361–374. [ PubMed ] [ Google Scholar ]
• Potgieter S. Pinto A. Sigudu M. Du Preez H. Ncube E. Venter S. Water Res. 2018; 139 :406. [ PubMed ] [ Google Scholar ]
• Kotlarz N. Rockey N. Olson T. M. Haig S. J. Sanford L. LiPuma J. J. Raskin L. Environ. Sci. Technol. 2018; 52 :2618–2628. [ PubMed ] [ Google Scholar ]
• Wang C. Moore N. Bircher K. Andrews S. Hofmann R. Water Res. 2019; 161 :448–458. [ PubMed ] [ Google Scholar ]
• Min S. Hao Z. Bei X. Bao J. Environ. Sci. Pollut. Res. 2018; 25 :1–11. [ PubMed ] [ Google Scholar ]
• Qian X. Ren Y. Yu S. Chem. Eng. J. 2017; 330 :1203–1210. [ Google Scholar ]
• Zeng F. Cao S. Jin W. Zhou X. Ding W. Tu R. Han S. F. Wang C. Jiang Q. Huang H. J. Cleaner Prod. 2020; 243 :118666. [ Google Scholar ]
• Ao X. Chen Z. Li S. Li C. Lu Z. Sun W. J. Environ. Sci. 2020; 87 :398–410. [ PubMed ] [ Google Scholar ]
• Mathieu L., Paris T. and Block J. C., The Structure and Function of Aquatic Microbial Communities , 2019, vol. 7 , pp. 261–311 [ Google Scholar ]
• El-Chakhtoura J. Prest E. Saikaly P. Van Loosdrecht M. Hammes F. Vrouwenvelder H. Water Res. 2015; 74 :180–190. [ PubMed ] [ Google Scholar ]
• Wingender J. Flemming H. C. Int. J. Hyg. Environ. Health. 2011; 214 :417–423. [ PubMed ] [ Google Scholar ]
• Liu R. Zhu J. Yu Z. Joshi D. R. Zhang H. Lin W. Yang M. J. Environ. Sci. 2014; 26 :865–874. [ PubMed ] [ Google Scholar ]
• Rożej A. Cydzik-Kwiatkowska A. Kowalska B. Kowalski D. World J. Microbiol. Biotechnol. 2015; 31 :37–47. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Roeder R. S. Heeg K. Tarne P. Benolken J. K. Schaule G. Bendinger B. Flemming H. C. Szewzyk U. Water Practice & Technology. 2010; 5 :wpt2010082. [ Google Scholar ]
• Lu J. Buse H. Y. Gomez-Alvarez V. Struewing I. Ashbolt N. J. J. Appl. Microbiol. 2014; 117 :905–918. [ PubMed ] [ Google Scholar ]
• Gião M. S. Wilks S. A. Keevil C. W. BioMetals. 2015; 28 :329–339. [ PubMed ] [ Google Scholar ]
• Buse H. Y. Lu J. Lu X. Mou X. Ashbolt N. J. FEMS Microbiol. Ecol. 2014; 88 :280–295. [ PubMed ] [ Google Scholar ]
• Masters S. Wang H. Pruden A. Edwards M. A. Water Res. 2015; 68 :140–149. [ PubMed ] [ Google Scholar ]
• Wang H. Masters S. Hong Y. Stallings J. Falkinham J. O. r. Edwards M. A. Pruden A. Environ. Sci. Technol. 2012; 46 :11566–11574. [ PubMed ] [ Google Scholar ]
• Moritz M. M. Flemming H. C. Wingender J. Int. J. Hyg. Environ. Health. 2010; 213 :190–197. [ PubMed ] [ Google Scholar ]
• Inkinen J. Jayaprakash B. Ahonen M. Pitkänen T. Mäkinen R. Pursiainen A. Santo Domingo J. Salonen H. Elk M. Keinänen-Toivola M. J. Appl. Microbiol. 2018; 124 :611–624. [ PubMed ] [ Google Scholar ]
• Chao Y. Mao Y. Wang Z. Zhang T. Sci. Rep. 2015; 5 :10044. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Yu J. Kim D. Lee T. Water Sci. Technol. 2010; 61 :163. [ PubMed ] [ Google Scholar ]
• Jang H. J. Choi Y. J. Ka J. O. J. Microbiol. Biotechnol. 2011; 21 :115–123. [ PubMed ] [ Google Scholar ]
• Shi Y. Babatunde A. Bockelmann-Evans B. Webster G. Environ. Sci.: Water Res. Technol. 2019; 5 :977–992. [ Google Scholar ]
• Han B. Chen R. Shi B. Xu W. Zhuang Y. J. Water Supply: Res. Technol.--AQUA. 2018; 67 :12–21. [ Google Scholar ]
• Douterelo I. Sharpe R. L. Boxall J. B. Water Res. 2013; 47 :503–516. [ PubMed ] [ Google Scholar ]
• Fish K. Osborn A. M. Boxall J. B. Sci. Total Environ. 2017; 593–594 :571–580. [ PubMed ] [ Google Scholar ]
• Tsagkari E. Sloan W. T. Bioprocess Biosyst. Eng. 2018; 41 :1–14. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Douterelo I. Sharpe R. Boxall J. J. Appl. Microbiol. 2014; 117 :286–301. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Lautenschlager K. Hwang C. Liu W.-T. Boon N. Koester O. Vrouwenvelder H. Egli T. Hammes F. Water Res. 2013; 47 :3015–3025. [ PubMed ] [ Google Scholar ]
• Ji P. Parks J. Edwards M. A. Pruden A. PLoS One. 2015; 10 :e0141087. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Ling F. Whitaker R. Lechevallier M. W. Liu W.-T. ISME J. 2018; 12 :1520–1531. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Hwang C. Ling F. Andersen G. L. Lechevallier M. W. Liu W. T. Appl. Environ. Microbiol. 2012; 78 :7856–7865. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Pinto A. J. Schroeder J. Lunn M. Sloan W. Raskin L. mBio. 2014; 5 :e01135-14. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Wang F. Li W. Li Y. Zhang J. Chen J. Zhang W. Wu X. Front. Environ. Sci. Eng. 2018; 12 :6. [ Google Scholar ]
• Haig S. J. Kotlarz N. Lipuma J. J. Raskin L. Bailey M. J. mbio. 2018; 9 :e02354-17. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Ji P. Rhoads W. J. Edwards M. A. Pruden A. ISME J. 2017; 11 :1318–1330. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Alcocer-Yamanaka V. H. Tzatchkov V. G. Arreguin-Cortes F. I. Water Resources Management. 2012; 26 :1779–1792. [ Google Scholar ]
• Hallam N. B. West J. R. Forster C. F. Simms J. Water Res. 2001; 35 :4063–4071. [ PubMed ] [ Google Scholar ]
• Zhou S. L. Mahon T. A. Walton A. Lewis J. J. Hydrol. 2000; 236 :153–164. [ Google Scholar ]
• Nguyen C. Elfland C. Edwards M. Water Res. 2012; 46 :611–621. [ PubMed ] [ Google Scholar ]
• Rhoads W. J. Pruden A. Edwards M. A. Environ. Sci.: Water Res. Technol. 2016; 2 :164–173. [ Google Scholar ]
• Lautenschlager K. Boon N. Wang Y. Egli T. Hammes F. Water Res. 2010; 44 :4868–4877. [ PubMed ] [ Google Scholar ]
• Chen X. Wang Y. Li W. Zhao X. Ding Z. Environ. Res. 2020; 188 :109715. [ PubMed ] [ Google Scholar ]
• Hong P. Y. Hwang C. Ling F. Andersen G. L. Liu W.-T. Appl. Environ. Microbiol. 2010; 76 :5631–5635. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Liu R. Yu Z. Zhang H. Yang M. Shi B. Liu X. Can. J. Microbiol. 2012; 58 :261–270. [ PubMed ] [ Google Scholar ]
• Bautista-de Los Santos Q. M. Schroeder J. L. Blakemore O. Moses J. Haffey M. Sloan W. Pinto A. J. Water Res. 2016; 90 :216–224. [ PubMed ] [ Google Scholar ]
• Perrin Y. Bouchon D. Delafont V. Moulin L. Héchard Y. Water Res. 2019; 149 :375–385. [ PubMed ] [ Google Scholar ]
• Ling F. Hwang C. Lechevallier M. W. Andersen G. L. Liu W. ISME J. 2015; 10 :582–595. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Inkinen J. Jayaprakash B. Santo Domingo J. W. Keinnen-Toivola M. M. Ryu H. Pitkänen T. J. Appl. Microbiol. 2016; 120 :1723–1738. [ PubMed ] [ Google Scholar ]
• Liu G. Bakker G. L. Li S. Vreeburg J. H. G. Verberk J. Q. J. C. Medema G. J. Liu W. T. Dijk J. C. V. Environ. Sci. Technol. 2014; 48 :5467–5476. [ PubMed ] [ Google Scholar ]
• Dwidjosiswojo Z. Richard J. Moritz M. M. Dopp E. Flemming H. C. Wingender J. Int. J. Hyg. Environ. Health. 2011; 214 :485–492. [ PubMed ] [ Google Scholar ]
• Ma X. Zhang G. Li G. Wan Y. Sun H. Wang H. Shi B. Environ. Sci.: Water Res. Technol. 2018; 4 :644–653. [ Google Scholar ]
• Zhang H. Tian Y. Kang M. Chen C. Song Y. Li H. Chemosphere. 2019; 215 :62–73. [ PubMed ] [ Google Scholar ]
• Corsaro D. Pages G. S. Catalan V. Loret J. F. Greub G. Int. J. Hyg. Environ. Health. 2010; 213 :158–166. [ PubMed ] [ Google Scholar ]
• Huang K. Zhang X. X. Shi P. Wu B. Ren H. Ecotoxicol. Environ. Saf. 2014; 109 :15–21. [ PubMed ] [ Google Scholar ]
• Karkey A. Jombart T. Walker A. W. Thompson C. N. Torres A. Dongol S. Thieu N. T. V. Thanh D. P. Ngoc D. T. T. Vinh P. V. PLoS Neglected Trop. Dis. 2016; 10 :e0004346. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Delafont V. Mougari F. Cambau E. Joyeux M. Bouchon D. Héchard Y. Moulin L. Environ. Sci. Technol. 2014; 48 :11872–11882. [ PubMed ] [ Google Scholar ]
• Saleem F. Mustafa A. Kori J. A. Hussain M. S. Kamran Azim M. Microb. Ecol. 2018; 76 :899–910. [ PubMed ] [ Google Scholar ]
• Marshall H. M. Carter R. Torbey M. J. Minion S. Tolson C. Sidjabat H. E. Huygens F. Hargreaves M. Thomson R. M. Emerging Infect. Dis. 2011; 17 :395–402. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Liu G. Zhang Y. Van der Mark E. Magic-Knezev A. Pinto A. Van Den Bogert B. Liu W.-T. Van Der Meer W. Medema G. Water Res. 2018; 138 :86–96. [ PubMed ] [ Google Scholar ]

Essay on Water for Children and Students

Table of Contents

Water is a colourless and odourless substance that is essential for the survival of the living beings. It is derived from various sources including rivers, lakes, oceans and streams and has several uses.

Fill Out the Form for Expert Academic Guidance!

Please indicate your interest Live Classes Books Test Series Self Learning

Verify OTP Code (required)

I agree to the terms and conditions and privacy policy .

Fill complete details

Target Exam ---

Water constitutes of almost 71% of the Earth’s surface. On earth, it moves constantly via water cycle. This is the cycle of evaporation and transpiration, precipitation, condensation and runoff. Water is used in numerous ways and is vital to all living beings. Here are essays on water of varying lengths to help you with the topic in your exam. You can select any water essay according to your need.

Also Check: Essay on Environment

Long and Short Essay on Water in English

Essay on water 200 words.

Water, known to be the universal solvent, plays a key role in the survival of various forms of life on earth. It is used for various purposes such as drinking, cleaning, cooking, washing and bathing. Besides these domestic uses, major amount of water is used in the agricultural sector mainly for the purpose of irrigation. A substantial amount of this substance is also used in the industrial sector.

However, unfortunately despite being aware about the importance of water in our lives, people around the world are leaving no stone unturned in wasting water and deteriorating its quality. The techniques used for irrigation in many parts of the world including India are old and mundane and often cause immense loss of water. Several industries make use of a good amount of water however they end up throwing their waste in water bodies without realizing that the deterioration of water will ultimately lead to their own loss.

Also Check: Water Pollution

Many areas around the world are facing water deficit and many more are likely to face this problem in the times to come. It is time the government must take effective measures to store and save water and channelize it properly for appropriate distribution. The general public must also be sensitized on efficient use of water.

Essay on Water 300 Words

Water is one such substance without which we cannot imagine our life. Besides, quenching our thirst, this transparent chemical substance is used for several other purposes. It is used to accomplish several household tasks. Water is also used for agricultural purpose and is needed for industrial use. Here is a brief look at how it is used at different places.

Agricultural Use

It accounts for around 70% of the water used around the world. In agriculture, water is mainly used for the purpose of irrigation. In addition to this, it is also used for the raring of the livestock. Most of the water used for irrigation is extracted from rivers. Groundwater is also used for this purpose.

Rivers are thus said to be of great importance for the farmers. Not only do they provide water for irrigation but they also play a vital part in the water cycle.

Industrial Use

Industrial use of water includes water used for the purpose of washing, diluting, cooling, transporting, fabricating, manufacturing and processing of various products. Thermal power plants, engineering and pulp and paper industries are among the one that consume the maximum amount of water.

Domestic Use

At home water is used for many purposes. This mainly includes drinking, cooking, bathing, washing utensils, washing clothes, cleaning houses, cars and other vehicles, watering plants and for the purpose of sanitation.

Also Check: World Water Day

Each country has its own system of water supply to ensure water reaches every household so that the aforementioned basic needs of its citizens are met. While water is used as it is for cleaning, washing and bathing purpose, it needs to be purified before drinking as well as prior to using it for the purpose of cooking.

Water is vital for the survival of the mankind. However, unfortunately it is being wasted at a rapid speed around the world. Everyone should contribute his/her bit towards saving water.

Essay on Water 400 Words

Water is derived from various sources. Rivers, lakes, seas, oceans and rain are known to be some of the main sources of water. This free flowing and readily available colourless, odourless substance is needed for domestic, agricultural as well as industrial use.

Sources of Water

The sources of water are mainly divided into two categories – Surface Water and Ground Water. Rain water pours and collects on earth in the form of surface water as well as ground water. Here is a brief look at both these sources of water:

• Surface Water : It is found in rivers, lakes, reservoirs, streams, seas and other such sources. The water in lakes and rivers comes from rain and the melting of snow. The river water flows into the sea.
• Ground Water : It is found under the land. Water travels under the surface of the land by way of soil on the non-porous rocks and fills the opening in these rocks. The rocks that store and send out groundwater are known as aquifers. At times, the water stored in these rocks bursts in the form of springs due to high pressure. Ground water is also extracted by digging wells and tube wells.

Also Check: Essay on Importance of Water

Water Available for Human Use

Our planet is rich in water with around three-fourth of its surface being covered with water. However, only a small part (just about 2.7%) of the total resources of water is available for the human use.

Around 97.3% of water on earth forms a part of the oceans. It is salty and cannot be used for the purpose of irrigation or any other agricultural use. It is not even good for industrial or domestic use. Out of the 2.7% fresh water available on earth, the inland surface water that is the water available from sources such as rivers, lakes and ponds accounts for just about 0.02%. This water is crucial for the growth and survival of all forms of terrestrial and freshwater aquatic beings.

It is thus important to use it wisely. This point is emphasized time and again. However, its criticality is not yet recognized by the people. It is essential to understand the importance of saving water else we will have to learn it the hard way.

Many areas around the world get sufficient water supply. However, several others, especially those that are a part of the developing countries, face water deficit. The government of such countries must ensure proper supply of water to various areas and the people must use water wisely and avoid any kind of wastage to ensure the flow.

Essay on Water 500 Words

Water (chemical formula H 2 O) is a transparent chemical substance. It is one of the basic necessities for every living being be it plants or animals. Just as air, sunlight and food, water is needed for the proper growth and development of life on earth. Besides quenching our thirst, water is used for numerous other activities such as cleaning, washing and cooking to name a few.

Properties of Water

Water is mainly known for five of its properties. Here is a brief about these properties:

• Cohesion and Adhesion

Cohesion, also referred to as water’s attraction to other water molecules, is one of the main properties of water. It is the polarity of water by way of which it is attracted to other water molecules. The hydrogen bonds present in water hold the water molecules together.

Adhesion is basically water’s attraction between molecules of varied substances. This substance bonds with any molecule it can form hydrogen bonds with.

• Lower Density of Ice

The hydrogen bonds of water turn into ice when cooled down. The hydrogen bonds are stable and maintain their crystal like shape. The solid form of water which is ice is comparatively less dense as its hydrogen bonds are spaced out.

• Water’s High Polarity

Water has high level of polarity. It is known to be a polar molecule. It is attracted to other polar molecules and ions. It can make hydrogen bonds and is thus a powerful solvent.

• Water’s High-Specific Heat

Water can moderate temperature owing to its high specific heat. It takes a long time when it comes to heating up. It holds its temperature for long when heat is not applied.

• Water’s High Heat of Evaporation

This is another property of water that renders it the ability to moderate temperature. As the water evaporates off a surface it leaves a cooling effect on the same.

Avoid Wastage of Water

Water is required for most of the activities we indulge in our day-to-day life. It is necessary for us to conserve it else our planet will be devoid of fresh water in the years to come. Here are a few ways in which water can be conserved:

• Fix leaking taps immediately to avoid wastage of water without any delay.
• Avoid the use of shower while bathing.
• Keep your tap off while brushing your teeth. Turn it on only when required.
• Wash full loads of laundry instead of half. This will not only save water but save a substantial amount of electricity too.
• Do not leave the water running while washing dishes.
• Use rainwater harvesting system.
• Avoid using water hose for cleaning gutters. You can use brooms or other techniques instead.
• Use the right size of pans and other dishes while cooking and eating food. Avoid using those bigger than your requirement.
• Try to water your plants by hand rather than using sprinklers.
• Cover the pools so as to avoid water loss due to evaporation.

We must not waste water and contribute our bit towards its conservation. We must practice and promote activities and plans that help in conserving water and protecting its sources to meet the current and future demands of living beings.

Essay on Water 600 Words

Water is the most common liquid found on our planet. It is vital for the survival of every living being. Around 71.4% of Earth is covered with water. However, while most part of our planet is covered with water, fresh water that can actually be used for drinking, cooking and other activities is quite less. It is thus important to use this substance wisely.

Different Forms of Water

Water is present in three different forms on Earth – Solid, Liquid and Gas. Here is a brief look at these forms:

Solid : Water freezes at 0 degree to form ice which is its solid state. As water freezes, its molecules move apart and this makes ice less dense compared to water in its liquid state. This means that ice is lighter than the same volume of water in its liquid state. It can thus float on water.

Liquid : This is the most common form of water. Water in its liquid state is used in several ways including drinking, washing, cleaning, cooking, irrigating fields and processing and preparing various products in industries.

Gas : As water boils, it changes from liquid to gas, often referred to as water vapour. Vapours are always present around us. When the water vapours cool, they form a cloud.

What is Water Cycle?

Water cycle is the term given to the circulation of water on, below or above the Earth’s surface. It is the process wherein water circulates between land, oceans and atmosphere. This involves precipitation, snowfall, drainage in rivers, lakes and streams and its return to atmosphere by way of evaporation and transpiration. Water cycle is also referred to as hydrological cycle.

Water Scarcity in India

Like most of the other developing countries, many parts of India also face scarcity of water. People in the country do not get clean water for drinking and there is water deficit for the purpose of sanitization as well. None of the cities in the country receives piped water 24/ 7. It is supplied for just a few hours each day mostly for a couple of hours in the morning and an hour or two in the evening. The quality of water has deteriorated in most of the water bodies in the country. This is because of the discharge of industrial and domestic waste in water.

The scarcity of fresh water in the country is often attributed to lack of proper planning at the government’s end, corruption, increased rate of corporate privatization and increasing amount of human and industrial waste that is discarded into water. The situation is expected to worsen in the times to come as the population of the country is likely to increase to 1.6 billion by 2050.

Here is a look at some of the other causes of water scarcity in India:

• Traditional techniques of irrigation employed in our country cause a lot of water loss.
• Lack of proper planning and distribution of water among domestic consumers, agricultural sector and industrial sector.
• Decline in traditional water recharging areas.
• Urban development has choked the ground water resources.
• Increasing number of recreational activities associated with water.

While water is available on earth in abundance, it needs to be understood that the amount that can be put to use for various domestic, agricultural and industrial use is limited. It is essential to use it wisely so as to ensure it reaches every one and is also available in abundance for our coming generations. The government must employ effective techniques to save water and distribute it evenly in various areas across the country. The general public on the other hand must use it wisely to ensure that it is not wasted.

Related Topics to Save Water

Essay on Water FAQs

Why is water important.

Water is essential for life as it hydrates our body. It helps in digestion and regulates body temperature. Water supports cell function and blood circulation. It aids in nutrient transportation within the body. Water acts as a lubricant for joints and tissues. It helps remove waste and toxins from the body. Water is crucial for brain function and concentration. It supports healthy skin and prevents dehydration. Water is necessary for the growth of plants and crops. It plays a key role in various industries and daily activities.

How do you write a water essay?

Start with an introduction about the importance of water. Discuss the various uses and benefits of water. Explain its role in human health and ecosystem. Include facts, statistics, and real-life examples. Conclude by emphasizing the necessity of conserving water. What is water? A short paragraph: Water is a transparent, tasteless, and odorless substance that is essential for all forms of life. It covers about 71% of the Earth's surface and exists in three states: liquid, solid (ice), and gas (water vapor). Water plays a vital role in various natural processes, including weather patterns, nutrient cycles, and habitat maintenance.

What are the uses of water?

Water is used for drinking and quenching thirst. It is essential for cooking, cleaning, and personal hygiene. Water is used in agriculture for irrigation and crop production. It plays a key role in generating hydroelectric power. Water is used in industries for manufacturing and cooling purposes.

Why is water so important to our life?

Water is vital for our survival as it hydrates our body, supports cell functions, and regulates body temperature. It plays a key role in digestion, nutrient transportation, and waste removal. Additionally, water promotes overall health, supports brain function, and maintains healthy skin. Furthermore, water is essential for agriculture, industry, and energy production, making it indispensable for human civilization and ecosystem balance. In summary, water is a precious resource that is fundamental to life, health, and the sustainability of our planet.

Related content

Talk to our academic expert!

Language --- English Hindi Marathi Tamil Telugu Malayalam

Get access to free Mock Test and Master Class

Register to Get Free Mock Test and Study Material

Offer Ends in 5:00

How long do Medicare enrollees wait for care? Learn about this and more in our Medicare resource center.

Popular Searches

AARP daily Crossword Puzzle

Hotels with AARP discounts

Life Insurance

AARP Dental Insurance Plans

Suggested Links

AARP MEMBERSHIP — $12 FOR YOUR FIRST YEAR WHEN YOU SIGN UP FOR AUTOMATIC RENEWAL

Get instant access to members-only products and hundreds of discounts, a free second membership, and a subscription to AARP the Magazine.

• right_container

Work & Jobs

Social Security

AARP en Español

• Membership & Benefits

AARP Rewards

• AARP Rewards %{points}%

Conditions & Treatments

Drugs & Supplements

Health Care & Coverage

Health Benefits

Staying Fit

Your Personalized Guide to Fitness

AARP Hearing Center

Ways To Improve Your Hearing

Brain Health Resources

Tools and Explainers on Brain Health

A Retreat For Those Struggling

Scams & Fraud

Personal Finance

Money Benefits

View and Report Scams in Your Area

AARP Foundation Tax-Aide

Free Tax Preparation Assistance

AARP Money Map

Get Your Finances Back on Track

How to Protect What You Collect

Small Business

Age Discrimination

Flexible Work

Freelance Jobs You Can Do From Home

AARP Skills Builder

Online Courses to Boost Your Career

31 Great Ways to Boost Your Career

ON-DEMAND WEBINARS

Tips to Enhance Your Job Search

Get More out of Your Benefits

When to Start Taking Social Security

10 Top Social Security FAQs

Social Security Benefits Calculator

Medicare Made Easy

Original vs. Medicare Advantage

Enrollment Guide

Step-by-Step Tool for First-Timers

Prescription Drugs

9 Biggest Changes Under New Rx Law

Medicare FAQs

Quick Answers to Your Top Questions

Care at Home

Financial & Legal

Life Balance

LONG-TERM CARE

​Understanding Basics of LTC Insurance​

State Guides

Assistance and Services in Your Area

Prepare to Care Guides

How to Develop a Caregiving Plan

End of Life

How to Cope With Grief, Loss

Recently Played

Word & Trivia

Atari® & Retro

Members Only

Staying Sharp

Mobile Apps

More About Games

Right Again! Trivia

Right Again! Trivia – Sports

Atari® Video Games

Throwback Thursday Crossword

Travel Tips

Vacation Ideas

Destinations

Travel Benefits

Beach vacation ideas

Vacations for Sun and Fun

Plan Ahead for Tourist Taxes

AARP City Guide

Discover Seattle

25 Ways to Save on Your Vacation

Entertainment & Style

Family & Relationships

Personal Tech

Home & Living

Celebrities

Beauty & Style

TV for Grownups

Best Reality TV Shows for Grownups

Robert De Niro Reflects on His Life

Looking Back

50 World Changers Turning 50

Sex & Dating

Spice Up Your Love Life

Navigate All Kinds of Connections

Life & Home

Couple Creates Their Forever Home

Store Medical Records on Your Phone?

Maximize the Life of Your Phone Battery

Virtual Community Center

Join Free Tech Help Events

Create a Hygge Haven

Soups to Comfort Your Soul

Your Ultimate Guide to Mulching

Driver Safety

Maintenance & Safety

Trends & Technology

AARP Smart Guide

How to Keep Your Car Running

We Need To Talk

Assess Your Loved One's Driving Skills

AARP Smart Driver Course

Building Resilience in Difficult Times

Tips for Finding Your Calm

Weight Loss After 50 Challenge

Cautionary Tales of Today's Biggest Scams

7 Top Podcasts for Armchair Travelers

Jean Chatzky: ‘Closing the Savings Gap’

Quick Digest of Today's Top News

AARP Top Tips for Navigating Life

Get Moving With Our Workout Series

You are now leaving AARP.org and going to a website that is not operated by AARP. A different privacy policy and terms of service will apply.

Go to Series Main Page

7 Types of Bottled Water

Water, water, everywhere. is one variety healthier than others.

Andrea Wickstrom,

Standing in front of the water aisle in stores can feel overwhelming. Once we filled our glasses with the simplest drink that just flowed from the tap, but now the choices are dizzying: vitamin water, hydrogen water, sparkling water, electrolyte water.

Americans spent an estimated $49 billion in 2023 on bottled water and drank about 16 billion gallons , according to the Beverage Marketing Corp. That’s a lot of bottled-up H2O.

AARP Membership — $12 for your first year when you sign up for Automatic Renewal

Though it’s true that staying hydrated is crucial to overall health — and many older adults are dehydrated — it’s not clear whether spending extra money on something that’s included in your monthly water bill can make you any healthier.

6 Risks of Dehydration

Older people are at higher risk of dehydration, due in part to decrease in thirst. In some older adults, the loss of just 2 to 3 percent of body fluid can cause physical and cognitive problems. One study found up to 40 percent of older adults may be underhydrated. Dehydration is linked to diabetes, heart failure and stroke and can lead to:

See also,  Do You Really Need 8 Glasses of Water a Day?

How are all the drinking water choices different, and is one better than another?

In general, the United States has some of the world’s safest drinking water. Some U.S. water is safe to drink directly from the source, while water from other sources must be treated before consumption because of potential chemical and bacterial contamination.

On April 10, the Biden administration finalized limits on “forever chemicals” in drinking water, requiring utilities to reduce them to the lowest level that can be reliably measured. Government officials say these chemicals, called PFAS (polyfluoroalkyl substances), are linked to liver disease, heart disease and certain cancers. The administration has also proposed rules that would require cities to replace lead water pipes within 10 years.

An estimated 43 million Americans receive water from a private underground well. Well water can be cloudy, have a rotten egg odor from hydrogen sulfide, and leave rust stains. This water is not regulated, so homeowners are responsible for ensuring their supply is safe for drinking, usually through recommended annual testing.

Other than private well water, the U.S. Environmental Protection Agency (EPA) regulates and monitors public water supply and tests and treats the water.

Water that doesn’t taste or smell good may be confused with water that is not good for you. A safe amount of chlorine kills bacteria and viruses and keeps water pipes clean, but it doesn’t taste good. Chlorine can be removed with a filter.

“Water can sometimes have a bad smell, taste or appearance, but these features don’t usually last long or indicate a public health concern,” says registered dietitian Kourtney Johnson. “Chlorine, chemicals or a medicine-like taste or smell don’t typically mean there’s an immediate health threat.”

Tap water that doesn’t taste or smell good, as well as news reports of problems with the water coming from our faucets, may explain in part why millions of Americans turn to bottled water.

Bottled water

The U.S. Food and Drug Administration (FDA) strictly regulates bottled water production and distribution. The FDA has set out Current Good Manufacturing Practices (CGMPs) that require bottled water companies to maintain sanitary conditions throughout manufacturing and transportation, protect the approved water sources and test the final product.

Most Popular

AARP NEWSLETTERS

%{ newsLetterPromoText  }%

%{ description }%

Privacy Policy

ARTICLE CONTINUES AFTER ADVERTISEMENT

Some sparkling waters, seltzer waters, tonics and club soda aren’t included as bottled water under FDA regulations. They are considered soft drinks.

Although experts say bottled water is generally safe, there are a few concerns.

AARP® Vision Plans from VSP™

Exclusive vision insurance plans designed for members and their families

Filtered water may remove fluoride, which is safe to drink and helps prevent tooth decay. Sometimes, manufacturers will reintroduce minerals after purification.

Microplastics are substances used to give plastic bottles transparency, shape and flexibility. A possible link between plastics and disruption of the endocrine system and thyroid is under investigation.

“Growing evidence shows that microplastics negatively affect the endocrine, reproductive and immune systems, as well as bacteria found in the gut. The thyroid plays a role in regulating almost all organs in the body, and long-term exposure to plastics negatively affects its ability to regulate growth, development, metabolism and reproduction,” Johnson says.

Water Filters

Options to enhance the condition of your home’s well or tap water include:

• A whole house filtration system. 
• A filtered refrigerator water dispenser.
• A filtered countertop water pitcher or faucet attachment.
• A reverse osmosis system.

Here’s a breakdown on seven popular varieties of bottled water.

1. Spring water

Spring water originates from rainwater that moves underground and is filtered naturally by rock and minerals. After it is pushed up to the ground’s surface, the water is collected in springs. Per FDA regulations, when manufacturers bottle and sell it, it must have the same composition and quality as the spring water at its source.

The amount of minerals in spring water isn’t substantial, so it doesn’t provide additional health benefits compared with other water. However, many people enjoy the taste.

2. Mineral water

To be labeled mineral water, this type of bottled water must contain at least 250 parts per million total dissolved solids. It differs from other types of bottled water due to minerals and trace elements that are present at the water source. Minerals cannot be added later, according to FDA rules.

3. Alkaline water 

Multiple brands manufacture alkaline water, which is altered to a higher pH. Alkaline water can be more expensive than other bottled water, but studies have yet to prove its health benefits. Some claim it can neutralize acid in the bloodstream, give better workout recovery and help prevent disease. A 2021  Iranian study found it may improve bone density in postmenopausal women with osteoporosis. The science on these claims is limited, and studies are generally small or in animals, not humans. Larger studies are needed to evaluate any potential health benefits.

LEARN MORE ABOUT AARP MEMBERSHIP.

“The body does an incredible job at keeping our pH within a very tight and controlled range. Consuming more alkaline water will not shift your pH outside of its normal range,” says Jen Hernandez, a registered dietitian who specializes in helping people with kidney disease.

Some suggest drinking alkaline water may help those who suffer from acid reflux, but Hernandez is skeptical.

“Adding this type of water into a very acidic environment, like the stomach, which is supposed to be producing acid to help us with digestion and breaking down foods, is almost counterintuitive,” Hernandez says.

4. Water with vitamins

Some manufacturers enhance water with vitamins. This water usually comes in sugar-sweetened and sugar-free options. In some brands, a 20-fluid-ounce bottle has up to 27 grams of added sugar (50–100 percent of the daily recommended limit), so those watching sugar content should check labels. Sugar-free options use stevia, monk fruit or artificial sweeteners.

Vitamin-infused waters may contain more than 100 percent of the daily recommended value of vitamins B and C. These are water-soluble vitamins, meaning that the kidneys will excrete any excess in your urine.

“So you’re just going to pay for expensive urine at that point. ... Your body is going to say, ‘I don't need this quantity,’ ” Hernandez says. “It is ideal to get our vitamins from foods as they provide many other benefits and nutrients.”

5. Electrolyte water

Sports drinks are intended for athletes who lose a lot of fluid and electrolytes through sweat. Such drinks often aren’t necessary for moderate exercisers or sedentary people. Electrolyte water may be beneficial short-term under certain circumstances, such as when people are exercising for long periods, have prolonged exposure to heat or are ill with vomiting and diarrhea. Experts say regular water is usually sufficient for meeting moderate exercise hydration needs.

6. Hydrogen water

Hydrogen water is plain water with hydrogen gas added to it. The water can be bought with the hydrogen in it, or people can purchase hydrogen tablets to add to water at home.

Hydrogen water is gaining interest due to its potential health benefits. A 2024 review of studies found that it may have antioxidant and anti-inflammatory properties, as well as improve physical endurance. Most studies have been small, and research is mixed. Further rigorous research is needed to confirm any benefits.

7. Purified water

Plain bottled water is not merely tap water in a bottle, although some bottled water does come from municipal sources. To be labeled purified, the water goes into a production plant and through a process that can include distillation, deionization or reverse osmosis, according to the International Bottled Water Association . It is then sold in individual, sanitary, sealed containers.

Is one type better?

Most people get the electrolytes and minerals they need from food, not fluids. The amount in drinking water is relatively low and not enough to meet our dietary needs.

Is there a best daily drinking water? Some say the right water is the one you will drink. Many people enjoy the taste and convenience of bottled water and prefer it to tap water.

On the other hand, purified, highly regulated, readily available tap water is likely coming from your kitchen faucet. With additional home filters, cost-effective tap water is an excellent daily drinking choice, and there are no toxins from plastic bottles.

Having a pitcher of filtered tap water on the counter at home, in sight as a reminder, can be great for hydration needs, Hernandez says.

Hard Water Vs. Soft Water

Many households have soft water, but it isn’t a requirement. A water softener removes the water’s hardness, caused by calcium and magnesium, and replaces it with sodium.

Some may wonder if their soft water tastes salty. Some sources say that’s a myth; others say people with very discerning taste buds may notice it.

The amount of sodium in one 8-ounce glass of softened water is about 12.5 milligrams (the recommended daily intake is 2,300 mg). Soft water is safe for the general public, but those with strict low-sodium diets may need their doctor’s guidance on water selection.

To avoid drinking soft water, you can switch to a nonsalt-based softening system (using potassium instead) or add a reverse osmosis system to your kitchen supply. Other solutions include having the water softener hooked up to your hot water to reserve for laundry, bathing and cleaning.

Andrea Wickstrom is a registered nurse who has covered health and medical topics as well as health-related news for multiple publications including Next Avenue, Nurse Journal, HeartValveSurgery.com and Healthnews.

Discover AARP Members Only Access

Already a Member? Login

More From AARP

Best Exercise for Lowering Blood Pressure

New study finds this is #1

Quiz: Health Benefits of Gardening

Having a green thumb boosts your well-being

11 Natural Foods to Help Boost Your Metabolism

Some foods and spices can even help burn belly fat

Feel Revitalized With This 10-minute Chair Yoga Class

Learn various poses that help with flexibility and mobility

Recommended for You

AARP Value & Member Benefits

Learn, earn and redeem points for rewards with our free loyalty program

AARP® Dental Insurance Plan administered by Delta Dental Insurance Company

Dental insurance plans for members and their families

The National Hearing Test

Members can take a free hearing test by phone

AARP® Staying Sharp®

Activities, recipes, challenges and more with full access to AARP Staying Sharp®

SAVE MONEY WITH THESE LIMITED-TIME OFFERS

Different Sources of Energy Definition Essay

Energy can be transformed to a range of states. Energy in different states can be used for various physical works. Energy can be utilized in natural processes or in supplying services to the community. For instance, an inner combustion engine transfers the latent chemical energy present in petrol and oxygen into heat, which is next changed to kinetic energy for use by automobiles and a solar cell changes solar energy into electrical energy which can be used to power television or light a bulb.

Fossil fuels are products of decayed residues of ancient animals and plants. They consist of oil, natural gas and coal. Currently, they provide more than 90 percent of the world’s sum energy (Vas, 1998). Fossil fuels remain attractive for use today since they are cheap, easily distributed, easily available, and can directly generate heat and electricity. However, they emit hazardous substances to the environment. As a result, alternative sources like wind and hydro electricity which are less harmful to the environment are being explored.

Hydro electricity is produced by streaming water through turbines. In generation of hydro electric power, water is bunged up in dams. Big pipes run through the dam construction directing water to the turbines which are turned round by the power of water. The power stations then control the level of the water by opening and closing water gates that ferry water into the turbine quarters.

Hydropower has several benefits over other energy sources. It does not pollute the environment since water is a clean source of fuel. It is also a renewable source that is easily available. Impoundment hydropower builds dams and pools that offer various leisure opportunities, particularly boating, swimming and fishing. Hydropower installations are supposed to offer public access to the reservoir. Other benefits of using hydropower as a source of energy include: flood management and water supply.

On the other hand, hydropower has several limitations. Dams can be a cause of soil erosion and may cause threats to downstream animals and plants in case of floods. Also, developing hydro electricity power plants is really expensive.

The other alternative source of energy is wind energy. Wind energy is a reproducible source of energy that is fueled by the sun so as to produce electricity. Since the earth is enclosed by almost 70 percent water, there is a difference in the manner of heating between the land and the sea (Muljadi & Wang, 2004).

During the night, the air on top of water cools less fast than the air above land. The temperate air over the sea inflates and mounts up while the heavier, cooler air hurries in to replace it, generating winds. During the day, the opposite occurs. The land heats up quicker than the seas. The temperate air over the land inflates and goes up while the heavier, cooler air hurries in to replace it, generating winds.

Wind Energy produces electricity by utilizing blades on wind turbines to amass the kinetic energy of the wind. Wind turbines hold back the wind which streams above the airfoil formed blades causing lift, and making them to revolve. The blades are linked to a drive ray that revolves an electric generator thus generating electricity.

Wind energy is the most rapidly growing energy source in the world as it has several advantages (Farret & Simoes, 2006). The fact that it is fueled by wind makes it a clean source of fuel. It does not emit harmful substances in the environment and it is a renewable source of energy. Wind energy is cheap and easily available. Wind turbines can be constructed on agricultural estates or ranches, thus promoting the rural economy.

On the other hand, wind energy has some demerits. Despite the fact that wind power plants have somewhat less impact on the surroundings weighed against other common power plants, there is much distress over the noise created by the rotor blades. In other instances, birds have lost their lives by soaring into the rotors. However, these issues have been significantly reduced through technological upgrading and by locating wind plants appropriately.

From the above discussion, it is clear that the two alternative sources of energy, the wind and hydropower, compare with fossil fuels in many ways. First, all of them are sources of energy that are available in the world today. However, while the wind and hydropower are renewable sources of energy, fossil fuels are not renewable.

This is the major difference between them. Fossil fuels also emit greenhouse gases that are harmful to the atmosphere. There is also a difference in the way these sources are obtained. While wind energy and hydropower are obtained from the wind and water respectively, fossil fuels are obtained from decayed remains of ancient plants and animals.

In conclusion, energy is convertible to different states. Currently, the world is exploring alternative sources of energy that can suitably replace the common use of fossil fuels as the chief source of energy. This has been motivated by the fact that fossil fuel emits greenhouse gases which are harmful to the environment. Wind energy and hydropower are some of the alternative sources of energy that have been explored. However, each of these sources of energy has its own merits and demerits.

Farret, F.A. & Simoes, M.G. (2006). Integration of alternative sources of energy . New York: Oxford University Press

Muljadi, E. & Wang, C. (2004). Parallel operation of wind, turbine, fuel cell, and diesel . Melboume: Generation Sources.

Vas, G. (1998). Sources of energy . London: Sage

• Chicago (A-D)
• Chicago (N-B)

IvyPanda. (2018, October 12). Different Sources of Energy. https://ivypanda.com/essays/different-sources-of-energy/

"Different Sources of Energy." IvyPanda , 12 Oct. 2018, ivypanda.com/essays/different-sources-of-energy/.

IvyPanda . (2018) 'Different Sources of Energy'. 12 October.

IvyPanda . 2018. "Different Sources of Energy." October 12, 2018. https://ivypanda.com/essays/different-sources-of-energy/.

1. IvyPanda . "Different Sources of Energy." October 12, 2018. https://ivypanda.com/essays/different-sources-of-energy/.

Bibliography

IvyPanda . "Different Sources of Energy." October 12, 2018. https://ivypanda.com/essays/different-sources-of-energy/.

• Hydropower: in the Latin America
• Alternative Sources of Energy: Solar, Wind, and Hydropower
• Hydropower Dams and Their Environmental Impacts
• The Mechanics of Hydro Power Plant
• Hydro Energy Advantages and Disadvantages
• Solar-Powered Water Cooler System
• The Big Bang Theory: Experimental Evidence
• Hydroelectric Power: Benefits and Drawbacks
• Concept of Piety in Plato’s “Euthyphro”
• Renewable Energy Sources: Existence, Impacts and Trends
• Can you study paranormal scientifically?
• The Path of Light
• The Formation of Rainbows
• The Role of Lenses in Optics
• Saving Energy Dollars While Providing an Optimal Learning Environment

Essay on Uses of Water

Students are often asked to write an essay on Uses of Water in their schools and colleges. And if you’re also looking for the same, we have created 100-word, 250-word, and 500-word essays on the topic.

Let’s take a look…

100 Words Essay on Uses of Water

Introduction.

Water is a precious resource, vital for all forms of life. It’s not just for drinking but has many other uses.

Hygiene and Health

We use water for bathing, washing our hands, and brushing our teeth. It helps us stay clean and healthy.

Cooking and Drinking

Water is essential in our diet. We drink it to stay hydrated and use it in cooking our meals.

Agriculture

Farmers use water to irrigate crops. Without water, agriculture would be impossible.

Industrial Uses

Industries use water in manufacturing processes, cooling systems, and cleaning.

Water is also used for recreational activities like swimming and boating. It brings joy and fun.

Water is indeed a versatile resource. Its uses are vast and essential, making it a key element in our lives.

Also check:

• 10 Lines on Uses of Water

250 Words Essay on Uses of Water

Water, the universal solvent, is undoubtedly one of the most critical resources on Earth. It plays a pivotal role in various aspects of life, ranging from maintaining biological life to driving industrial processes.

Biological Significance

In biological terms, water is a fundamental component of all living organisms. It serves as a medium for various biochemical reactions, aids in nutrient transport, and regulates body temperature. Moreover, it is crucial for photosynthesis in plants, which is the basis for life on Earth.

Domestic Use

At home, water is indispensable for daily activities such as cooking, cleaning, and personal hygiene. It is not just a medium for cooking, but also a key ingredient in many recipes. In hygiene, it is the primary agent for washing, bathing, and sanitation.

Industrial Applications

In industries, water serves multiple purposes. It is used as a coolant in power plants, a solvent in chemical industries, and a raw material in beverage industries. Furthermore, it is essential in construction, where it is mixed with cement to make concrete.

Agriculture, the backbone of many economies, heavily relies on water for irrigation. It aids in the germination of seeds, growth of plants, and production of crops.

In conclusion, water is an irreplaceable resource with diverse uses in various sectors. As we continue to exploit this resource, it is vital to remember the importance of sustainable usage and conservation to ensure its availability for future generations.

500 Words Essay on Uses of Water

Water, a fundamental resource for life, is often taken for granted due to its ubiquitous presence. However, its multifaceted usage in various sectors highlights its indispensable nature. This essay will delve into the various uses of water, including domestic use, agriculture, industry, and energy production.

The most immediate use of water is for domestic purposes. This includes drinking, cooking, bathing, and sanitation. Water is vital for consumption as it aids in digestion, nutrient absorption, and detoxification. It is also essential for personal hygiene and cleanliness, preventing the spread of diseases. Moreover, water is used for other household chores such as washing clothes and dishes, gardening, and cleaning.

Agricultural Use

Agriculture is the largest consumer of freshwater, accounting for around 70% of global water use. Water is essential for crop irrigation, livestock rearing, and aquaculture. It aids in the growth of plants, maintains the health of animals, and is a crucial component in the production of various agricultural goods. Furthermore, water is involved in the transformation of raw agricultural products into consumable goods, underscoring its importance in food security and rural livelihoods.

Industrial Use

Industries are significant consumers of water. It is used in various industrial processes, including manufacturing, cooling, and cleaning. For instance, water is used in large quantities in the textile industry for dyeing and treatment of fabrics. In the food and beverage industry, water is a primary ingredient and is also used for cleaning and sterilization. Moreover, the pharmaceutical industry uses water in the production of medicines and other healthcare products.

Energy Production

Water plays a critical role in energy production. Hydropower, a renewable source of energy, relies on the flow of water to generate electricity. Furthermore, water is used in the cooling processes of thermal power plants and in the extraction and refining of oil and natural gas. It is also a vital component in the production of biofuels and in nuclear energy processes.

Environmental Significance

Beyond its practical uses, water is fundamental to the environment. It supports biodiversity by providing habitats for a myriad of species in rivers, lakes, and oceans. Water cycles also regulate the Earth’s climate and weather patterns. Furthermore, water bodies act as natural filters, absorbing pollutants and mitigating their impact on the environment.

In conclusion, the uses of water are multifaceted and far-reaching. From quenching our thirst to generating electricity, water is integral to life and societal functioning. As we continue to exploit this precious resource, it is imperative that we recognize its value and strive for sustainable usage to ensure its availability for future generations.

That’s it! I hope the essay helped you.

If you’re looking for more, here are essays on other interesting topics:

• Essay on Save Water
• Essay on Importance of Water
• Essay on If There Is No Water

Apart from these, you can look at all the essays by clicking here .

Happy studying!

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

Watch CBS News

EPA announces first-ever national regulations for "forever chemicals" in drinking water

By Tracy J. Wholf

Updated on: April 10, 2024 / 8:06 PM EDT / CBS News

For the first time ever, the Environmental Protection Agency announced Wednesday it is issuing a national regulation limiting the amount of certain per- and polyfluoroalkyl substances, known as PFAS , found in drinking water.

Commonly called "forever chemicals," PFAS are synthetic chemicals found nearly everywhere — in air, water , and soil — and can take thousands of years to break down in the environment.

The EPA has stated there is no safe level of exposure to PFAS without risk of health impacts, but now it will require that public water utilities test for six different types of PFAS chemicals to reduce exposure in drinking water. The new standards will reduce PFAS exposure for 100 million people, according to the EPA, and prevent thousands of deaths and illnesses.

"Drinking water contaminated with PFAS has plagued communities across this country for too long," EPA Administrator Michael S. Regan said in a statement Wednesday.

For public water utility companies to comply with the new drinking water standards, the EPA is making $1 billion available to states and territories to implement PFAS testing and treatment at public water systems. That money is part of a $9 billion investment made possible by the 2021 Bipartisan Infrastructure Law to assist communities impacted by PFAS contamination.

"President Biden believes that everyone deserves access to clean, safe drinking water, and he is delivering on that promise," said Brenda Mallory, Chair of the White House Council on Environmental Quality, in a statement.

PFAS have been in use since the 1940s, often to repel oil and water, and are heat resistant, which makes them popular for a variety of products. But according to industry documentation , manufacturers have known for decades that PFAS are toxic.

"They can be found in everything from nonstick cookware to cleaning and personal care products," said Regan during a press briefing. "But there's no doubt that many of these chemicals can be harmful to our health and our environment."

Research confirms that exposure to certain levels of PFAS in the environment can lead to a range of health issues, from reproductive problems, including decreased fertility, to developmental delays in children and low birth weight, as well as a suppressed immune system, increased cholesterol levels, impacts to the cardiovascular system, and certain types of cancer.

"I think the strongest data is for kidney cancer and then testicular cancer," Dr. Linda Birnbaum, former director of the National Institute of Environmental Sciences, told CBS News. "But evidence is growing for several other forms of cancer."

Critics argue the EPA didn't go far enough because there are more than 15,000 PFAS chemicals, and this standard only regulates six.

"I think that we need to begin addressing PFAS as a whole class of chemicals," Birnbaum said. "And we need to ask the question, do we really need them?"

The EPA estimates that of the 66,000 public water utility systems impacted by the standard, 6% to 10% may need to act to comply with the regulations. Operators will have three years to test for PFAS pollution, then an additional two years to identify, purchase and install necessary technology to treat contaminated water.

Erik D. Olson, senior strategic director of health at the Natural Resources Defense Council, tells CBS News that the EPA estimates it will cost about $1.5 billion "to treat all this water and to protect people's health. The benefits, in our view, far outweigh those costs."

Despite knowing the risks for several years, it's taken a significant amount of time to regulate PFAS on the federal level.

"There's just a huge amount of political opposition from the chemical industry and, frankly, from some of the water utilities, that don't want EPA to regulate these chemicals, because they know that once EPA cracks down on them, it's going to cost them a lot of money, and they don't want to spend that money," Olson said.

While the onus on clean up will come at the cost of the water utility companies, the new regulations do little to hold polluters accountable for the damage PFAS have done to the environment and human health. There have been several major settlements in recent years by chemical companies over PFAS contamination, a notable one being a $10.3 billion settlement reached by 3M in June 2023.

If you want to limit your exposure to PFAS in drinking water, you can ask your water utility how it is testing for the chemicals, or have your water tested by a state-certified laboratory using EPA-testing standards. There are several technologies available to purchase to filter PFAS from your home water source. As for PFAS found in other common goods, there are several running lists to help track which companies have banned PFAS from their products.

• Forever Chemicals

Tracy J. Wholf is a senior coordinating producer of climate and environmental coverage for CBS News and Stations, based in New York. She manages and produces content for all CBS News national platforms and supports CBS stations across the country.

More from CBS News

What is a long-term care insurance cash policy?

FDA announces recall of heart pumps linked to deaths and injuries

House sends Mayorkas impeachment articles to Senate

Marijuana tied to Chinese criminal networks infiltrates Maine

Rent went up sharply along the Wasatch Front in 2022. The data tell different stories about 2023.

A local brokerage report shows a one-year decrease, but other sources show rent continued to rise in the greater salt lake area..

(Trent Nelson | The Salt Lake Tribune) Apartments in Post District Residences were among a few thousand units to become available in 2023. Thousands more are expected to come online in 2024, and an expert says those new units will keep the average rent from spiking for a couple of years.

Renters in the Salt Lake City area paid more to their landlords in 2023 than they paid two years earlier, according to data from a Utah brokerage firm, two apartment-finding websites and the federal government.

What those sources don’t agree on is whether 2023 rents along the Wasatch Front were higher or lower than what people paid in 2022.

A brokerage report from CBRE shows rent in 2023 was up from 2021, but down compared to 2022 in most cities in Salt Lake County.

Yet data from Rent.com, Zillow and the federal government show rent consistently on the rise, even amid an increase in apartment construction.

The market is slightly down or flat across most of the Wasatch Front, said Dejan Eskic , a senior research fellow at the Kem C. Gardner Policy Institute who focuses on housing.

Eskic said he expects that to remain true for a couple more years, as thousands of units open in new apartment complexes in Salt Lake, Davis, Weber and Utah counties.

But Paul Smith , executive director of the Rental Housing Association of Utah, agrees with the national sources that show rents spiking again.

Last year was a settling year after big increases, he said, and 2024 is back to the trajectory set by a lack of housing.

Local report shows rent decreased or stayed mostly flat

Rent in 2023 was up from 2021 in all but five cities across the Wasatch Front, based on a report from CBRE on the multifamily market in the Wasatch Front.

But that report shows rent in 2023 was down — not up — in most cities compared to 2022.

CBRE data going back to 2013 shows rent generally increased an average of 6% along the Wasatch Front until 2020, when it increased by 1% in Salt Lake and Utah counties, by 3% in Davis County and by 5% in Weber County.

Rent then skyrocketed in 2021, increasing by at least 19% in all four counties.

A moderate increase returned in 2022, and then rent decreased or stayed about even in 2023.

In Salt Lake County as a whole, rent was down about 1% last compared to 2022, according to that report. CBRE also indicates a 2.4% two-year drop in rent in Davis County, mostly driven by a 9.1% decrease in rents in Layton.

The report does show one-year increases in Utah and Weber counties, of 0.3% and 1.2%, respectively.

Other sources show a continued spike

Three other data sources — Rent.com , Zillow and the federal government — show median or average rents increasing in Salt Lake City and the greater Salt Lake area despite a construction boom, particularly in Salt Lake City, where cranes still dot the skyline.

Data from Rent.com and Zillow are based on listings on those sites, and numbers from the U.S. Department of Housing and Urban Development are estimates.

Among 50 metropolitan areas for which Rent.com compiles data, Salt Lake City was one of 26 with a two-year spike in rent, 35 with a one-year increase and 33 with a monthly increase.

The data shows Salt Lake City rent is up 5.7% over Feb. 1, 2022, 0.6% compared to Feb. 1, 2023, and 1.4% compared to New Year’s Day.

Rent.com does not include data for other metropolitan areas in Utah.

Zillow goes into more detail with thousands of cities, not just metro areas, and measures the average market rent as of the end of the month.

According to that data, rent is up compared to two years ago in Ogden, Provo, Orem, Millcreek, South Salt Lake, West Valley City, Salt Lake City, Sandy, West Jordan, St. George and Lehi.

The data also show rent is up annually in Ogden, Provo, Orem, Millcreek, West Valley City, Salt Lake City, West Jordan, St. George and Lehi — but down year-over-year in South Salt Lake and Sandy.

Zillow also shows rent is up since January in Provo, Salt Lake City, Sandy, West Jordan and Lehi — but down month-over-month in Ogden, Orem, Millcreek, South Salt Lake, West Valley City and St. George.

Compared to Rent.com, Zillow shows a more pronounced spike in Salt Lake City, except for the monthly increase. The data shows a 7.5% two-year jump, a 2.7% one-year increase and a 0.6% increase month over month.

Finally, data from the U.S. Department of Housing and Urban Development shows a yearly increase in median rent across all types of units in seven metropolitan areas in Utah — Logan, Ogden-Clearfield, Box Elder County, Provo-Orem, St. George, Salt Lake City and Tooele County.

The largest increases are in Logan and St. George, which had double-digit increases in median rent for units from studios to four-bedroom apartments between 2023 and 2024.

CBRE data ‘better and timelier’

Smith’s observations have matched the data based on listings and estimates, with big increases in 2021 and 2022 that have leveled back to normal hikes in 2023 and 2024.

“Any time you have a couple of years with big increases, you usually have a settling year after,” he said.

That settling year was 2023, he said, with 2024 getting back to typical increases of 5% and 7% as the housing supply struggles to keep up with demand.

But the current construction boom is a case of “overbuilding,” Eskic said, with 7,300 units expected to come online this year, compared to an average somewhere in the mid-3,000s in previous years.

He said he doesn’t expect to see a rent spike again until 2026 or 2027, because of all the ongoing construction.

Eskic said he wasn’t sure why the other sources show increases, but said the CBRE data is based on people calling most apartment buildings in the market and asking them about vacant units and rents.

That results in “much better and timelier data,” he said.

While home prices are easy to track, Eskic said, rent is “kind of like the Wild West” because prices are based on listings, not what tenants are actually paying after concessions.

As of December, Salt Lake City had the highest portion of rental listings with at least one concession among the country’s 50 largest rental markets, according to Zillow data.

Landlord advice for renters

Smith advised renters to work to grow their income by 5% to 7% a year to cover inflation, including rent increases.

He said people who are struggling to meet that should look to four safety nets before talking to their landlord:

Personal resources, such as working more hours, getting a loan or selling pricier items — such as a big-screen television or four-wheeler.

Friends and family.

Churches, many of which, Smith said, will help people by giving them funds for one month of rent.

Community and government resources — including such nonprofits as Utah Community Action, and some counties that have rental assistance funds.

If people do need to negotiate with their landlord, Smith said, they should try to find a middle ground.

As a landlord, Smith said he “would work with someone who’s willing to negotiate.”

Renters, he said, should stress they would like to stay and let their landlord know what they could afford to pay if they can’t make the full increase fit into their budget.

Megan Banta is The Salt Lake Tribune’s data enterprise reporter, a philanthropically supported position . The Tribune retains control over all editorial decisions.

Editor’s note • This story is available to Salt Lake Tribune subscribers only. Thank you for supporting local journalism.

Donate to the newsroom now. The Salt Lake Tribune, Inc. is a 501(c)(3) public charity and contributions are tax deductible

RELATED STORIES

Utahns less confident about where the economy is headed, a report says, see how slc compares to other airports for on-time takeoff and landing, are more people moving out of salt lake county than moving in depends on who’s counting., with nhl arena as a goal, ryan smith and slc charge forward on new sports district, in utah’s 2024 u.s. senate race, these candidates are their own biggest campaign donors, danny ainge is ‘going big game hunting’ in hopes of improving utah jazz next season, the nhl in salt lake city makes perfect sense to these utah hockey pros, byu finds its next head coach in phoenix suns assistant kevin young, park rangers search for 2 vandals who toppled ancient rocks at lake mead, featured local savings.

Advertisement

What Solar Eclipse-Gazing Has Looked Like for the Past 2 Centuries

Millions of people on Monday will continue the tradition of experiencing and capturing solar eclipses, a pursuit that has spawned a lot of unusual gear.

• Share full article

By Sarah Eckinger

• April 8, 2024

For centuries, people have been clamoring to glimpse solar eclipses. From astronomers with custom-built photographic equipment to groups huddled together with special glasses, this spectacle has captivated the human imagination.

Creating a Permanent Record

In 1860, Warren de la Rue captured what many sources describe as the first photograph of a total solar eclipse . He took it in Rivabellosa, Spain, with an instrument known as the Kew Photoheliograph . This combination of a telescope and camera was specifically built to photograph the sun.

Forty years later, Nevil Maskelyne, a magician and an astronomy enthusiast, filmed a total solar eclipse in North Carolina. The footage was lost, however, and only released in 2019 after it was rediscovered in the Royal Astronomical Society’s archives.

Telescopic Vision

For scientists and astronomers, eclipses provide an opportunity not only to view the moon’s umbra and gaze at the sun’s corona, but also to make observations that further their studies. Many observatories, or friendly neighbors with a telescope, also make their instruments available to the public during eclipses.

Fredrik Hjalmar Johansen, Fridtjof Nansen and Sigurd Scott Hansen observing a solar eclipse while on a polar expedition in 1894 .

Women from Wellesley College in Massachusetts and their professor tested out equipment ahead of their eclipse trip (to “catch old Sol in the act,” as the original New York Times article phrased it) to New London, Conn., in 1922.

A group from Swarthmore College in Pennsylvania traveled to Yerbaniz, Mexico, in 1923, with telescopes and a 65-foot camera to observe the sun’s corona .

Dr. J.J. Nassau, director of the Warner and Swasey Observatory at Case School of Applied Science in Cleveland, prepared to head to Douglas Hill, Maine, to study an eclipse in 1932. An entire freight car was required to transport the institution’s equipment.

Visitors viewed a solar eclipse at an observatory in Berlin in the mid-1930s.

A family set up two telescopes in Bar Harbor, Maine, in 1963. The two children placed stones on the base to help steady them.

An astronomer examined equipment for an eclipse in a desert in Mauritania in June 1973. We credit the hot climate for his choice in outfit.

Indirect Light

If you see people on Monday sprinting to your local park clutching pieces of paper, or with a cardboard box of their head, they are probably planning to reflect or project images of the solar eclipse onto a surface.

Cynthia Goulakos demonstrated a safe way to view a solar eclipse , with two pieces of cardboard to create a reflection of the shadowed sun, in Lowell, Mass., in 1970.

Another popular option is to create a pinhole camera. This woman did so in Central Park in 1963 by using a paper cup with a small hole in the bottom and a twin-lens reflex camera.

Amateur astronomers viewed a partial eclipse, projected from a telescope onto a screen, from atop the Empire State Building in 1967 .

Back in Central Park, in 1970, Irving Schwartz and his wife reflected an eclipse onto a piece of paper by holding binoculars on the edge of a garbage basket.

Children in Denver in 1979 used cardboard viewing boxes and pieces of paper with small pinholes to view projections of a partial eclipse.

A crowd gathered around a basin of water dyed with dark ink, waiting for the reflection of a solar eclipse to appear, in Hanoi, Vietnam, in 1995.

Staring at the Sun (or, How Not to Burn Your Retinas)

Eclipse-gazers have used different methods to protect their eyes throughout the years, some safer than others .

In 1927, women gathered at a window in a building in London to watch a total eclipse through smoked glass. This was popularized in France in the 1700s , but fell out of favor when physicians began writing papers on children whose vision was damaged.

Another trend was to use a strip of exposed photographic film, as seen below in Sydney, Australia, in 1948 and in Turkana, Kenya, in 1963. This method, which was even suggested by The Times in 1979 , has since been declared unsafe.

Solar eclipse glasses are a popular and safe way to view the event ( if you use models compliant with international safety standards ). Over the years there have been various styles, including these large hand-held options found in West Palm Beach, Fla., in 1979.

Parents and children watched a partial eclipse through their eclipse glasses in Tokyo in 1981.

Slimmer, more colorful options were used in Nabusimake, Colombia, in 1998.

In France in 1999.

And in Iran and England in 1999.

And the best way to see the eclipse? With family and friends at a watch party, like this one in Isalo National Park in Madagascar in 2001.