Water Quality in Norristown, PA
Norristown's water has 10 contaminants above health guidelines. We recommend using a certified water filter.
Utility
NORRISTOWN WATER SYSTEM
People Served
822,600
MCL Violations
0
Last Updated
Sep 23, 2025
Quick Summary
Contaminants Detected
⚠️ Contaminants Above Health Guidelines (10)
Chlorine (Total)
What is Chlorine (Total)?
Chlorine is a chemical element with the symbol Cl and atomic number 17. It is a yellow-green gas at room temperature and is a strong oxidizing agent. Chlorine is commonly used in water treatment to kill bacteria and other pathogens, making water safe for drinking.
Health Effects
Exposure to chlorine can cause respiratory issues, skin irritation, and eye irritation. Ingesting high levels of chlorine can lead to gastrointestinal distress and other serious health problems.
Affected Organs
Common Sources
Chlorine (Free)
What is Chlorine (Free)?
Chlorine is a chemical element with the symbol Cl and atomic number 17. It is a yellow-green gas at room temperature and is a strong oxidizing agent. Chlorine is commonly used in water treatment to kill bacteria and other pathogens.
Health Effects
Exposure to chlorine can cause respiratory issues, skin irritation, and eye irritation. Ingesting chlorine can lead to gastrointestinal distress and other serious health problems.
Affected Organs
Common Sources
Chlorine Dioxide
What is Chlorine Dioxide?
Chlorine dioxide is a chemical compound with the formula ClO2. It is a yellowish-green gas at room temperature and is used primarily as a bleaching agent and disinfectant. Chlorine dioxide is effective in killing bacteria, viruses, and other pathogens in water.
Health Effects
Exposure to chlorine dioxide can cause respiratory issues, skin irritation, and eye damage. Ingesting chlorine dioxide can lead to nausea, vomiting, and diarrhea. Long-term exposure may result in more severe health effects, including damage to the respiratory system.
Affected Organs
Common Sources
Trichloroacetic Acid (TCA)
What is Trichloroacetic Acid (TCA)?
Member of haloacetic acids (HAAs) that form as byproducts when chlorine reacts with organic matter
Health Effects
Health protective benchmarks for TCA in drinking water have been developed based on liver toxicity and carcinogenicity observed in animal studies. EPA has classified TCA as a possible human carcinogen. Developmental toxicity has also been associated with exposure to TCA based on evidence from animal studies.
Affected Organs
Common Sources
Total THMs
What is Total THMs?
Group of contaminants that form in drinking water systems when a disinfectant, typically chlorine, reacts with organic matter
Health Effects
Drinking water standards for total THMs are based on evidence of carcinogenicity in human and animal studies, as well as liver and kidney toxicity observed in animal studies. Individual THMs have been further associated with developmental, immune, spleen, and genotoxicity.
Affected Organs
Common Sources
Chloroform
What is Chloroform?
Member of trihalomethanes (THMs) that form in water treated with chlorine and is generally the most abundant THM formed in drinking water
Health Effects
Health protective benchmarks for chloroform have been developed based on kidney and liver carcinogenicity observed in animal studies, and liver toxicity observed in occupational studies. The EPA classifies chloroform as a probable human carcinogen based on animal evidence, and there is additional epidemiological evidence that may increase the risk of colon and bladder cancer in humans. Results from animal studies also suggest that exposure to chloroform can cause liver, developmental and immune toxicity. Acute exposure to low levels of chloroform will cause nervous system toxicity.
Affected Organs
Common Sources
Dibromoacetic Acid (DBA)
What is Dibromoacetic Acid (DBA)?
Member of haloacetic acids (HAAs) that form as byproducts when chlorine reacts with organic matter
Health Effects
Health protective benchmarks for DBA are based on carcinogenicity and liver toxicity observed in animal studies. The EPA has classified DBA as a probable human carcinogen. Results from animal studies also suggest that kidney, immune system, spleen and developmental toxicity are associated with exposure to BDCM. BDCM has been shown to produce DNA changes (genotoxicity) in laboratory studies.
Affected Organs
Common Sources
Dibromochloromethane
What is Dibromochloromethane?
Member of trihalomethanes (THMs) that form in water treated with chlorine
Health Effects
Health protective benchmarks for DBCM have been developed based on liver toxicity and carcinogenicity observed in animal studies. EPA has classified DBCM as a possible human carcinogen based on animal evidence, while IARC (International Agency for Research on Cancer) says it is unclassifiable as a human carcinogen. Kidney toxicity has also been associated with DBCM based on evidence from animal studies. DBCM has been shown to produce DNA changes (genotoxicity) in laboratory studies.
Affected Organs
Common Sources
Chlorite
What is Chlorite?
Chlorite is a chemical compound that is a derivative of chloric acid. It is often found in drinking water as a byproduct of chlorine disinfection processes. Chlorite can also occur naturally in some water sources.
Health Effects
Exposure to chlorite can lead to various health issues, including irritation of the skin, eyes, and respiratory tract. Ingesting high levels of chlorite can cause gastrointestinal distress and may affect red blood cell function, leading to methemoglobinemia, a condition where the blood cannot carry oxygen effectively.
Affected Organs
Common Sources
Chloramine
What is Chloramine?
Chloramine is a chemical compound formed when ammonia is added to chlorine in water treatment processes. It is used as a disinfectant to kill bacteria and other pathogens in drinking water.
Health Effects
Exposure to chloramine can cause respiratory issues, skin irritation, and gastrointestinal problems. Long-term exposure may lead to more serious health effects, particularly for individuals with pre-existing health conditions.
Affected Organs
Common Sources
Understanding the Data
This data comes from your local water utility testing. The bar charts compare detected levels against health guidelines (HGL). Contaminants above the health guideline are shown by default and may require filtration. All other tested contaminants are within safe levels and can be viewed by expanding the section above.
Recommended Water Filters for Norristown
Based on Norristown's water quality data, these NSF-certified filters are recommended to remove contaminants above health guidelines.

Tupperware Brands Corp.
Nano Nano Nature Water Filtration System
NSF Certified:
Capacity
13251 gal
Filter Life
44 mo
Flow Rate
0.9 gpm
Removes 11 contaminants:
Asbestos, Chloramine, Chlorine (Free), Chlorine (Total), Chlorine Dioxide +6 more

Access Business Group International LLC, DBA Amway
100186F 100186F
NSF Certified:
Capacity
13201 gal
Filter Life
44 mo
Flow Rate
0.9 gpm
Removes 13 contaminants:
Asbestos, Chloramine, Chlorine (Free), Chlorine (Total), Chlorine Dioxide +8 more

Tupperware Brands Corp.
Nano Nano Nature TPW2-C1 Household Water Purification System
NSF Certified:
Capacity
13251 gal
Filter Life
44 mo
Flow Rate
0.9 gpm
Removes 11 contaminants:
Asbestos, Chloramine, Chlorine (Free), Chlorine (Total), Chlorine Dioxide +6 more

Omnipure Filter Co.
ELF ELF 1MPF
NSF Certified:
Capacity
500 gal
Filter Life
2 mo
Flow Rate
1.67 gpm
Removes 6 contaminants:
Chlorine (Free), Chlorine (Total), Chlorine Dioxide, Cryptosporidium, Perfluorooctanesulfonic acid +1 more
Frequently Asked Questions
Norristown's water has 10 contaminants above health guidelines. We strongly recommend using a certified water filter to reduce exposure to these contaminants. Check our filter recommendations below for NSF-certified options that can remove the specific contaminants found in Norristown's water.