HealthGoods

National Primary and Secondary Drinking Water Regulations

The US Environmental Protection Agency (EPA) sets Current Drinking Water Standards for drinking water. These standards are made up of the National Primary Drinking Water Regulations and the National Secondary Drinking Water Regulations. The Primary Standards set levels of contaminants that may pose a health risk when present in drinking water supplies and are known or anticipated to occur in public water systems. The Primary Standards contaminants are divided into Inorganic Chemicals, Organic Chemicals, Radionuclides and Microorganisms. The Secondary Standards are non enforceable guidelines that establish recommendations for contaminants that may cause cosmetic effects such as skin or tooth discoloration and aesthetic effects such as taste, odor and color.  The EPA recommends Secondary Standards to water treatment systems but does not require systems to comply. The Safe Drinking Water Act (SDWA) was passed in 1974 and has been amended in 1986 and 1996. Despite strict and comprehensive government guidelines, our drinking water can contain contaminants that pose serious health risks. 

The National Primary Drinking Water Standards establish a Maximum Contaminant Level (MCL) and a Maximum Contaminant Level Goal (MCLG) for certain water pollutants. The MCL is the maximum permissible level of a contaminant in drinking water which is delivered to any user in a public water system. These standards are established by considering contaminant impact on human health and what is technologically and economically feasible for removal by a treatment facility. The MCLG is the level of a contaminant at which there would be no risk to human health. This goal is not always technologically or economically feasible by a water treatment facility and is not enforceable.

If you have a well system for your home, you are responsible for your water quality and assuring it is safe for you and your family.  Generally, homeowners only test their well water after the well system is installed and may not do it again.  This initial test is usually a requirement for the local board of health and may not check for all the EPA Safe Water Drinking Act standards. Failure to check your water can be a dangerous gamble as ground and surface water is susceptible to contaminants at all times. Without a periodic comprehensive test of your drinking water, you may be putting yourself and your family at risk.

Primary Drinking Water Standards

Primary Drinking Water Regulations are legally enforceable standards that limit the level of specific contaminants that can adversely affect public health and are known or anticipated to occur in water. Units for the regulations are displayed in milligrams per liter (mg/L) unless otherwise noted. Milligrams per liter are equivalent to parts per million. These regulations take several forms:

• Maximum Contaminant Level (MCL) - The maximum permissible level of a contaminant in water delivered to any user in a public water system. MCL's are set as close to MCLG's as is economically and technologically feasible. These are enforceable standards.

• Maximum Contaminant Level Goal (MCLG) - The level of a contaminant in drinking water below which there is no known or expected risk to health. These MCLG's allow for a margin of Safety and are non-enforceable public health goals.

• Treatment Technique (TT) - A required process intended to reduce the level of a contaminant in drinking water.

• Maximum Residual Disinfectant Level (MRDL) - The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.

• Maximum Residual Disinfectant Level Goal (MRDLG) - The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.

Microorganisms

Note 1 - EPA's surface water treatment rules require systems using surface water or ground water under the direct influence of surface water to (1) disinfect their water, and (2) filter their water or meet criteria for avoiding filtration so that the following contaminants are controlled at the following levels:

Cryptosporidium: (as of 1/1/02 for systems serving >10,000 and 1/14/05 for systems serving <10,000) 99% removal.

Giardia lamblia: 99.9% removal/inactivation

Viruses: 99.99% removal/inactivation

Legionella: No limit, but EPA believes that if Giardia and viruses are removed/inactivated, Legionella will also be controlled.

Turbidity: At no time can turbidity (cloudiness of water) go above 5 nephelolometric turbidity units (NTU); systems that filter must ensure that the turbidity go no higher than 1 NTU (0.5 NTU for conventional or direct filtration) in at least 95% of the daily samples in any month. As of January 1, 2002, turbidity may never exceed 1 NTU, and must not exceed 0.3 NTU in 95% of daily samples in any month.

HPC: No more than 500 bacterial colonies per milliliter.

Long Term 1 Enhanced Surface Water Treatment (Effective Date: January 14, 2005); Surface water systems or (GWUDI) systems serving fewer than 10,000 people must comply with the applicable Long Term 1 Enhanced Surface Water Treatment Rule provisions (e.g. turbidity standards, individual filter monitoring, Cryptosporidium removal requirements, updated watershed control requirements for unfiltered systems).

Filter Backwash Recycling; The Filter Backwash Recycling Rule requires systems that recycle to return specific recycle flows through all processes of the system's existing conventional or direct filtration system or at an alternate location approved by the state.

Note 2 - more than 5.0% samples total coliform-positive in a month. (For water systems that collect fewer than 40 routine samples per month, no more than one sample can be total coliform-positive per month.) Every sample that has total coliform must be analyzed for either fecal coliforms or E. coli if two consecutive TC-positive samples, and one is also positive for E.coli fecal coliforms, system has an acute MCL violation.

Note 3 - Fecal coliform and E. coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Disease-causing microbes (pathogens) in these wastes can cause diarrhea, cramps, nausea, headaches, or other symptoms. These pathogens may pose a special health risk for infants, young children, and people with severely compromised immune systems.

Disinfection Byproducts

Note 4 - Although there is no collective MCLG for this contaminant group, there are individual MCLGs for some of the individual contaminants:

Trihalomethanes: bromodichloromethane (zero); bromoform (zero); dibromochloromethane (0.06 mg/L). Chloroform is regulated with this group but has no MCLG.

Haloacetic acids: dichloroacetic acid (zero); trichloroacetic acid (0.3 mg/L). Monochloroacetic acid, bromoacetic acid, and dibromoacetic acid are regulated with this group but have no MCLGs.

Note 5 - MCLGs were not established before the 1986 Amendments to the Safe Drinking Water Act. Therefore, there is no MCLG for this contaminant.

Disinfection

Inorganic Chemicals

Note 5 - MCLGs were not established before the 1986 Amendments to the Safe Drinking Water Act. Therefore, there is no MCLG for this contaminant.

Note 6 - MFL is million fibers per liter.

Note 7 - Lead and copper are regulated by a Treatment Technique that requires systems to control the corrosiveness of their water. If more than 10% of tap water samples exceed the action level, water systems must take additional steps. For copper, the action level is 1.3 mg/L, and for lead is 0.015 mg/L or 15 parts per billion (ppb).

Note 8 -  In 1986, the Safe Drinking Water Act (SWDA) amendment restricted the use of lead solder, flux and pipes in public water systems. In 1996, another amendment to the SWDA requires that all pipe, plumbing fittings and plumbing fixtures distributed after August 6, 1998 intended to disperse water for human consumption be "Lead Free". The term "Lead Free" does not mean it is "Free From Lead" as would be understood by the average consumer. "Lead Free" is defined in section 1417 of the Safe Water Drinking Act as:

• Solders and Flux - may not contain more than 0.2% lead.

• Pipes, Pipe Fittings, Well Pumps and Fixtures (faucets, drinking fountains, water dispensers, etc) - may not contain more than 8.0% lead.

The Maximum Contaminant Level Goal (MCLG) for Lead is zero. This is the level of a contaminant in drinking water below which there is no known or expected risk to health. Plumbing fixtures with 8% or less lead content can leach Lead into drinking water. A voluntary standard, NSF Standard 61, Section 9, for endpoint devices, has been established to verify compliance with the "Lead Free" rule. The NSF Standard is designed to limit Lead leaching from plumbing fixtures to 11 parts per billion (ppb). The Action Level for Lead under the National Drinking Water Standards is 15 ppb. The NSF Standard assumes other sources for Lead will not exceed 4 ppb. Since a Community Water Supplier is allowed to provide drinking water up to 15 ppb and be in compliance with the National Primary Drinking Water Standard, the combination of a faucet that can leach Lead up to 11 ppb and a supply water of 15 ppb, could provide water at a level of up to 26 ppb Lead and still meet all federal requirements and far exceed the Maximum Contaminant Level Goal for Lead of zero. Click here for more information on Lead in Plumbing Products.

Organic Chemicals

Note 9 - Each water system must certify, in writing, to the state (using third-party or manufacturer's certification) that when acrylamide and epichlorohydrin are used in drinking water systems, the combination (or product) of dose and monomer level does not exceed the levels specified, as follows:

Acrylamide = 0.05% dosed at 1 mg/L (or equivalent)

Epichlorohydrin = 0.01% dosed at 20 mg/L (or equivalent)

Radionuclides

Note 5 - MCLGs were not established before the 1986 Amendments to the Safe Drinking Water Act. Therefore, there is no MCLG for this contaminant.

Secondary Drinking Water Regulations

National Secondary Drinking Water Regulations (NSDWRs or secondary standards) are non-mandatory water quality standards for 15 contaminants. EPA does not enforce these "secondary maximum contaminant levels" or "SMCLs." They are established only as guidelines to assist public water systems in managing their drinking water for aesthetic considerations, such as taste, color and odor. These contaminants are not considered to present a risk to human health at the SMCL's. Public water systems may test for these standards on a voluntary basis, however, states may choose to adopt them as enforceable standards.

The US EPA believes that if these contaminants are present in your water at levels above these standards, the contaminants may cause the water to appear cloudy or colored, or to taste or smell bad. This may cause a great number of people to stop using water from their public water system even though the water is actually safe to drink. Secondary standards are set to give public water systems some guidance on removing these chemicals to levels that are below what most people will find to be noticeable.

There are a wide variety of problems related to secondary contaminants. These problems can be grouped into three categories:

• Aesthetic Effects - undesirable Tastes or Odors, Color and Foaming

• Cosmetic Effects - effects which do not damage the body but are still undesirable such as Skin Discoloration, Tooth Discoloration & Pitting.

• Technical Effects - damage to water equipment or reduced effectiveness of treatment for other contaminants including Corrosivity and Scaling & Sedimentation.