Drinking Water: It's Your Responsibility Too
"What Do You Mean I Might Be Contaminating the Water?"
You can pollute your own drinking water without even realizing it. Elimination of cross connections will help protect the water we drink. The Safe Drinking Water Act of 1974 established national standards for drinking water. The State and Local Governments are responsible for the enforcement of these standards, and the supervision of the public water supply. It is the responsibility of Local Government to deliver safe drinking water to your tap.
What is a Cross Connection?
A cross connection is a direct or potential arrangement of drinking water piping that is or can be connected to a questionable source. An example is the common garden hose submerged in a swimming pool. Other examples are supply lines connected to boilers, process equipment, or bottom-fed tanks. When the proper conditions occur water can flow backwards (backflow) in a piping system allowing contaminated water to flow into the drinking water through a cross connection. There are two ways that contaminated water can backflow into the drinking water: back-siphonage or back pressure.
What is back-siphonage?
Back-siphonage is the reversal of normal flow in a system caused by negative pressure (vacuum or partial vacuum) in the supply piping.
What factors can cause back-siphonage?
Back-siphonage can be created when there is stoppage of the water supply due to repairs or breaks in the city main or increased demand at a location such as fire fighting.
What is backpressure?
Backpressure is the reversal of normal flow in the system due to downstream pressure being greater than the supply pressure.
What factors can cause a backpressure condition?
Backpressure can occur in any pressurized system such as boilers, elevated tanks, or recirculating systems. For example, a boiler operating under 15-20 lbs. pressure would backflow into the potable water anytime the supply is below 15-20 lbs. Sometimes all this requires is flushing the toilet!
What is the cross connection control program?
This is a combined cooperative effort between plumbing and health officials, municipalities, and property owners to establish and administer guidelines for controlling cross connections and implementing means to ensure their enforcement so that the public drinking water supply will be protected both in the city main and within buildings.
What is the most common form of cross connection?
Ironically, the ordinary garden hose is the most common offender as it can be easily connected to the drinking water supply and used for a variety of potentially dangerous applications.
What is the difference between pollution and contamination?
Pollution of the water supply does not constitute an actual health hazard, although the quality of the water is impaired with respect to taste, odor, or utility. Contamination of the water supply, however, does constitute an actual health hazard; the consumer being subjected to potentially lethal water borne disease or illness.
What is meant by "Degree of Hazard"?
The degree of hazard is a commonly used phrase utilized in cross connection programs and is simply a determination of whether the substance in the non-potable system is toxic (health hazard) or non-toxic (non-health hazard).
What is the difference between toxic and a non-toxic substance?
A toxic substance is any liquid, solid or gas which when introduced into the water supply creates, or may create a danger to the health and well being of the consumer. An example is treated boiler water. A non-toxic substance is any substance that may create a non-health hazard, is a nuisance or is aesthetically objectionable. Non-toxic substances pollute the potable water, for example: food, such as sugar, soda pop, etc.
Selecting the proper backflow prevention devise is mandatory. There are five basic methods or products that can be used to prevent backflow.
What are the five basic methods or products for protection against backflow?
- Air Gap
- Atmospheric Vacuum Breakers: which also includes hose connection vacuum breakers
- Pressure Type Vacuum Breakers
- Double Check Valve Assembly
- Reduced Pressure Principle Backflow Preventers
Are there any regulations regarding cross connections?
Yes, the State of Michigan Department of Environmental Quality, Administrative Rules for Michigan's Safe Drinking Water Act, Act 399, P.S. 1976, Part 14 Cross Connection, R 325.11403-5. Michigan Plumbing Code 2000, MIOSHA Health Rule Sanitation Standard 4201, Chapter IV General Work Place Requirements, Part II Sanitation, Section 2(a).
Yes. OSHA requires that no cross connection be allowed in a piping system unless it is properly protected with an approved backflow preventer.
Questions concerting cross connection control and backflow prevention may be directed to Charter Township of Independence at 248-625-8222 or the Michigan Department of Environmental Quality (MDEQ), Water Supply at 517-241-1242 or the Michigan Department of Labor, Plumbing Division at 517-322-1804.
The Charter Township of Independence Water Department is committed to providing quality, cost efficient service in the testing and delivery of safe drinking water to all residential, commercial and industrial users.
In order to ensure uncontaminated drinking water the Charter Township of Independence remains committed to its cross connection control program. This program is part of our effort to ensure a safe and dependable drinking water supply.
Questions regarding this program or other water quality issues may be directed to the Charter Township of Independence Water Department.