Understanding The EPA's Secondary Drinking Water Standards

 EPA's Secondary Drinking Water Standards

EPA's Secondary Drinking Water Standards

The Environmental Protection Agency is tasked with keeping us safe from contaminants in our drinking water. They have established National Primary Drinking Water Standards (NPDWRs) that set mandatory quality standards for a variety of drinking water contaminants. The regulations are legally enforceable and set Maximum Contaminant Levels (MCLs) to protect the public from consuming water that may be a health. A water test will tell you if you have contaminants in your well water.

In addition to these legally enforceable standards, the Environmental Protection Agency has established National Secondary Drinking Water Regulations that set non-mandatory water standards for an additional 15 contaminants.

What Are The Effects of the EPA's Secondary Contaminants?

There are some problems secondary contaminants can cause. They can be grouped into three categories.

Aesthetic Effects – including undesirable tastes or offensive odors.

Cosmetic Effects – these are not harmful and do not pose any health risk but are still undesirable.

Technical Effects – damage to water equipment or reduced effectiveness of treatment for other contaminants.

Let’s take a closer look at each of these effects.

Aesthetic Effects

Bad odors or tastes are useful indicators of water quality, but it’s important to remember that even odor-free water may not be safe to drink. Measuring offensive taste or odor is a subjective practice and identifying the culprit is not always possible. Some contaminant odors may be detectable even when present in small amounts. It can be expensive to fix and often impossible to identify or remove the odor-producing contaminant.

The EPA has set standards relating to odor and taste. These include Total dissolved solids, foaming agents, chloride, copper, iron, manganese pH, sulfate, and zinc.

Color can indicate dissolved organic material, inadequate treatment, or the production of excess amounts of disinfectant by-products. Inorganic materials such as metals are also a common cause. Detergent usually causes foaming when water has been agitated or aerated by faucets. Foaming is usually accompanied by a taste often described as fishy or oily. These tastes and odors may be caused by the breakdown of waste products rather than detergents themselves.

Cosmetic Effects

Skin discoloration is a cosmetic effect caused by ingesting silver. Called argyria, it does not impair body function and has never been caused by drinking water in the U.S. Today, many water treatment systems use some form of silver as an antibacterial agent, so this may be a potential problem in the future and deserves attention.

Another cosmetic effect is caused by excess exposure to naturally occurring fluoride, especially in infants and small children. Tooth discoloration and pitting can happen when infants are exposed to excess fluoride during the early stages of tooth growth.

Technical Effects

Corrosion and staining not only affect water aesthetically, but they can also potentially damage appliances and fixtures costing the homeowner money to repair or replace. Corrosive water can also taste metallic and show a red or blue-green coloration.

Scaling and sedimentation are other processes that can have an economic impact to the homeowner. The scale can build up inside hot water pipes, boilers and heat exchangers shortening their lifespan and restricting water flow.

Secondary Water Contaminant Treatment Options

While the Environmental Protection Agency does not enforce Secondary Drinking Water Regulations, they do recommend that homeowners monitor, test and treat for these contaminants.

Conventional treatments like filtration and aeration can remove metals like iron, zinc, and manganese. Granular Activated Carbon effectively removes most contaminants, which cause odor, color, and foaming. Treatments like distillation and reverse osmosis are effective at removing chlorides, total dissolved solids, and other inorganic substances. The best solution is to speak with a well-water professional at Skillings & Sons. They can help you determine the best treatment options for your situation.