Why Is Water Testing Necessary?

Coliform Bacteria in Drinking Water

Public water systems are required to deliver safe and reliable drinking water to their customers 24 hours a day, 365 days a year. If the water supply becomes contaminated, consumers can become seriously ill. Fortunately, public water systems take many steps to ensure that the public has safe, reliable drinking water. One of the most important steps is to regularly test the water for coliform bacteria.

What are coliform bacteria?

Coliform bacteria are organisms that are present in the environment and in the feces of all warm-blooded animals and humans. Coliform bacteria will not likely cause illness. However, their presence in drinking water indicates that disease-causing organisms (pathogens) could be in the water system. Most pathogens that can contaminate water supplies come from the feces of humans or animals. Testing drinking water for all possible pathogens is complex, time-consuming, and expensive. It is relatively easy and inexpensive to test for coliform bacteria. If coliform bacteria are found in a water sample, water system operators work to find the source of contamination and restore safe drinking water. There are three different groups of coliform bacteria; each has a different level of risk.

Total coliform, fecal coliform, and E. coli

Total coliform, fecal coliform, and E. coli are all indicators of drinking water quality. The total coliform group is a large collection of different kinds of bacteria. Fecal coliforms are types of total coliform that mostly exist in feces. E. coli is a sub-group of fecal coliform. When a water sample is sent to a lab, it is tested for total coliform. If total coliform is present, the sample will also be tested for either fecal coliform or E. coli, depending on the lab testing method.

Total coliform bacteria are commonly found in the environment (e.g., soil or vegetation) and are generally harmless. If only total coliform bacteria are detected in drinking water, the source is probably environmental. Fecal contamination is not likely. However, if environmental contamination can enter the system, there may also be a way for pathogens to enter the system. Therefore, it is important to find the source and resolve the problem.

Fecal coliform bacteria are a sub-group of total coliform bacteria. They appear in great quantities in the intestines and feces of people and animals. The presence of fecal coliform in a drinking water sample often indicates recent fecal contamination, meaning that there is a greater risk that pathogens are present than if only total coliform bacteria is detected.


Drinking Water Testing

I waited the 48 hours for the bacteria test and it was a perfect purple and remained that way for several days. However, I forgot to dispose of it and at day 10 it was not a perfect purple anymore, it had turned yellow. Is that normal since so much time had gone by and should ignore or is it something I should be concerned about?

It is normal for the test to change color after the test period is over. It does not mean anything at all since the kit has run its course.

Will the bacteria test tell me if I have E.coli?

No. The bacteria test is a general scan for coliform bacteria. However, E. coli is a coliform type of bacteria.

I recently purchased your home water test kit to test my water. Is the powder in the bacteria sample toxic?

The kit contains no bacteria. It is just a few nutrients in powder form

Does your drinking water test kit test for chloramine?

Yes. The Total Chlorine test detects free chlorine and chloramine.

Does the Drinking Water Test Kit measure water hardness?

Yes. It measures water hardness and alkalinity.



Lead is a potent neurotoxin that impairs children’s intellectual development and alters their behavior and ability to concentrate. The impacts of lead exposure during childhood are permanent. There is a strong scientific consensus that any amount of lead exposure during childhood is harmful.

Lead-based paint has historically been the main source of exposure for American children. Yet even the lower levels of lead exposures now measured in American children cause intellectual impairment and behavior problems.

Lead contamination of drinking water remains a problem for many communities across the U.S., posing a serious risk to children’s health. Since lead levels vary from one house to another, it is difficult to estimate how many people have contaminated water in their homes.

Why is lead in drinking water?

Pipes made of lead were once used in hundreds of cities, most commonly in water lines installed before the 1930s. In 2016, the American Water Works Association estimated that 15 to 22 million Americans drink water from a system with lead-based service lines. Lead pipes are also found inside most homes built before 1930, and lead-based plumbing solder was used to join metal water pipes until 1986. Maintenance and replacement of a home’s plumbing or partial replacement of lead water pipes can increase levels of lead in water.

Is there a safe level for lead in water?

Lead exposure is an especial risk during children’s first six years, when their brains are developing and their blood-brain barriers are not yet fully formed. Babies fed formula mixed with unfiltered tap water are at highest risk of ingesting lead in drinking water.


Drinking Water Quality

Drinking water quality, however, can be affected by the condition of a building’s inside service. To safeguard tap water quality, property owners and building managers are advised to carry out proper maintenance of inside service and regular cleaning of water storage tanks.

Drinking Water Standards

The WHO Guidelines are prepared and updated through the participation of numerous authoritative institutions and hundreds of experts from a wide range of developed and developing countries, and represent the consensus opinion based on worldwide scientific and medical studies. The WHO Guidelines are authoritative, scientific and evidence-based and many developed countries worldwide make reference to them to monitor and control the quality of drinking water.

Water Quality Monitoring

The WSD has developed a comprehensive and extensive water quality monitoring regime through a series of physical, chemical, bacteriological, biological and radiological examinations covering the HKDWS and the additional parameters for water quality surveillance and operational monitoring.

Water quality throughout the entire water treatment, supply and distribution system is systematically monitored by means of physical, chemical, bacteriological, biological and radiological examinations of water samples taken at catchment, intakes, receiving point of DJ water


Consumer Resources & Drinking Water

Consumer Concerns About Emerging Contaminants

Eighty two percent of consumers report that they are concerned about the negative effects emerging contaminants may have on their health. Contaminants of most concern include pesticides and herbicides followed by prescription/OTC drugs and detergents.

Consumer Guide to Fluoridation Products and Fluoride

Fluoride comes from the naturally-occurring element fluorine and is added to drinking water for the public health benefit of reducing tooth decay.

U.S. Drinking Water Filtration and Treatment Survey

NSF International conducted a national consumer survey of 1,106 American adults, which showed gaps between consumers’ concerns, knowledge and actions related to their drinking water. Though they are concerned about potential contaminants in their drinking water, the majority of Americans surveyed don’t take steps to better understand what’s in their drinking water and they don’t look for independently certified water filters and treatment options.

Bottled Water

How and why bottled water is regulated is not common knowledge and can be confusing. Like other bottled beverages, bottled water is regulated by the U.S. Food and Drug Administration (FDA) as a food product and must adhere to strict quality and labeling guidelines. Many states also have strict requirements for bottled water produced and/or sold within their borders.

PFOA/PFOS in Drinking Water

Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic (PFOS) acid are part of a group of chemicals commonly referred to as perfluoroalkyl substances (PFASs) or perfluorinated compounds (PFCs). PFOA and PFOS are man-made chemicals that up until 2000 had been widely used in the manufacturing of many industrial and consumer products such as paper and cardboard food packaging, insecticides, electronics, stain repellants, paints, plumbing tape, firefighting foam and non-stick cooking surfaces.