Drinking water regulations are some times called "interim" because research continues on drinking water contaminants. They maybe strengthened and new standards maybe established for other substances based on new studies. But in any case the NSDWA has to set up a timetable under which required to develop PRIMARY Standards for certain contaminants (will be amended later on) and to:

All water treatment plant operators need to be thoroughly familiar with the national standards that apply to domestic water supply systems.

These regulations are the goals and guideposts for the water supply industry.

The purpose is to ensure the uniform delivery of safe and aesthetically pleasing drinking water to the public.

Setting Standards

A standard is usually the maximum level of a substance that deemed acceptable in drinking water. The first step in setting of a standard is to study the human and animal health effect of a given chemical. These studies are normally performed using rats or mice. Based on these studies a " No Observed Adverse Effect Level "-(NOAEL) is established. A safe factor is added to NOAEL and the result is an acceptable daily intake limit of the chemical in question. The limit is adjusted to take into account the average weight and water consumption of the consumer, and the resulting figure is called the Maximum Contaminant Level Goal or MCLG. This level is set at zero for known or probable human carcinogens, and at a level where no adverse health effect would occur with a margin of safety for non carcinogens.

The MCLG represents a safe level of consumption based solely on its studies of health effects. It is however, a goal rather than an immediately achievable constituent limit. To develop more realistic enforceable limit, we have to revise the MCLG to take into account existing laboratory detection technology, cost, and reasonableness. After adjusting for these factors we set for Maximum Contaminant Level (MCL) as close to MCLG as is realistically feasible. The important difference between the two levels is that the MCLG is a non enforceable goal and the MCL is an enforceable standard.

We have to establish standards (MCL) for chemicals, pesticides, bacteria and viruses, radioactivity, turbidity, and trihalomethanes. Most of these substances occur naturally in our environment and in the food we eat. However the MCL apply whether the contaminant is from naturally occurring sources or from manmade pollution. Therefore the national drinking water standards set by this act reflect the levels we can safely consume in our water, taking into account the amount we are exposed to from these other sources.

Primary Drinking Water Standards

Primary Standards or MCLS are set for substances that are thought to pose a threat to health when present in drinking water at certain levels because these substances are of health concern. Primary standards are enforceable by law (in contrast secondary standards relate to cosmetic factors and are not enforceable.). A primary standard is usually expressed as a maximum contaminant level MCL. Some contaminants, such as pathogenic organisms, are very difficult or expensive to measure so using specific treatment techniques (disinfection or filtration for example) which are known to be effective in reducing the health risk of these contaminants. Under this category of primary standards are many microbial, inorganic and organic chemical contaminants.

Types of Water Systems

All of the drinking water regulations apply to all public water systems. It makes no difference whether the water system is publicly or privately owned. A public water system is defined as any system which:

1- Has at least 15 service connections, or
2- Regularly serves an average of at least 25 individuals daily at least 60 days out of the year.\

Any water system that provides service for fewer connections or persons than this is not covered by NSDWA. Certain other individuals and residences also are excluded. Such as those whose water is supplied by an irrigation, old mining, and industrial water system. However, regardless of size, all operators must strive to provide consumers with a potable drinking water.

Drinking water regulations also take into account the type of population served by the system and classify water systems as community and non community systems. Therefore, in order to understand what requirements apply to any specific system, it is first necessary to determine whether the system is considered a community or a non community system. A community water system is defined as one which:

Any public water system that is not a community water system is classified as non community water system. Restaurant, campground and hotels could be considered non community systems for purposes of drinking water regulations.

[Part I] | [Part II] | [Part III]

Notes: I end my contribution at this point due to other pressing engagements that I am involved with. But I will be very happy to answer any concern regarding the environment. My contribution based on my experience in Canada. I have no practical knowledge of the environment in Iraq. I left my beloved country 1975, Insha Allah I will visit my country next winter.

My contribution is for my mother and my brother who are both victims of the environmental conditions in Iraq, and to the inhabitants of the mass graves who were victims of the despotic dictatorship of Sad dam.

The author is a Biotechnologist and Environmentalist , has been working with the Canadian Government and Environmental Companies for the last 13 years, and can be reached at hsnatar@hotmail.com