Water On Tap What You Need To Know

Table of Contents

1. A Consumer's Guide To The Nation's Drinking Water

2. How Safe Is My Drinking Water?

3. Where Does My Drinking Water Come From And How Is It Treated?

4. How Do We Use Drinking Water In Our Homes?

5. What's Being Done To Improve Water Security?

6. What Can I Do If There Is A Problem With My Drinking Water?

7. How Safe Is The Drinking Water In My Household Well?

8. What You Can Do To Protect Your Drinking Water

Appendix A: National Primary Drinking Water Standards as of 10/03 (.pdf)

Appendix B: References

Appendix C: Sources of Additional Information

Appendix D: Glossary

.pdf version

Appendix D: Glossary
(.pdf version)

Aquifer
A natural underground layer, often of sand or gravel, that contains water

Coliform
A group of related bacteria whose presence in drinking water may indicate contamination by disease-causing microorganisms

Community Water System (CWS)
A water system that supplies drinking water to 25 people or more year-round in their residences

Contaminant
Anything found in water (including microorganisms, radionuclides, chemicals, minerals, etc.) which may be harmful to human health

Cryptosporidium
Microorganism found commonly in lakes and rivers which is highly resistant to disinfection.

Disinfectant
A chemical (commonly chlorine, chloramines, or ozone) or physical process (e.g., ultraviolet light) that kills microorganisms such as viruses, bacteria, and protozoa

Distribution System
A network of pipes leading from a treatment plant to customers' plumbing systems

Ground Water
Water that is pumped and treated from an aquifer

Inorganic Contaminants
Mineral-based compounds such as metals, nitrates, and asbestos; naturally occurring in some water, but can also enter water through human activities

Maximum Contaminant Level
The highest level of a contaminant that EPA allows in drinking water (legally enforceable standard)

Maximum Contaminant Level Goal
The level of a contaminant at which there would be no risk to human health (not a legally enforceable standard)

Microorganisms
Tiny living organisms that can be seen only under a microscope; some can cause acute health problems when consumed in drinking water

Non-Transient Non-Community Water System
A non-community water system that serves the same people more than six months of the year, but not year-round

Organic Contaminants
Carbon-based chemicals, such as solvents and pesticides, which enter water through cropland runoff or discharge from factories

Pathogen
Disease-causing organism

Public Water System (PWS)
A water system which supplies drinking water to at least 25 people, at least 60 days each year

Sensitive Subpopulation
People who may be more vulnerable to drinking water contamination, such as infants, children, some elderly, and people with severely compromised immune systems

Septic System
Used to treat sanitary waste; can be a significant threat to water quality due to leaks or runoff

Source Water
Water in its natural state, prior to any treatment for drinking (i.e., lakes, streams, ground water)

Surface Water
Water that is pumped and treated from sources open to the atmosphere, such as rivers, lakes, and reservoirs

Transient Non-Community Water System
A non-community water system that serves the public but not the same individuals for more than six months

Violation
Failure to meet any state or federal drinking water regulation

Vulnerability Assessment
An evaluation of drinking water source quality and its vulnerability to contamination by pathogens and toxic chemicals

Watershed
The land area from which water drains into a stream, river, or reservoir

Well
A bored, drilled or driven shaft whose depth is greater than the largest surface dimension, a dug hole whose depth is greater than the largest surface dimension, an improved sinkhole, or a subsurface fluid distribution system