Facts About Your Water
Are there bacteria in my water?
Water, air, food and our environment in general are not sterile. In fact, our immune systems need a certain degree of contact with germs to develop defense mechanisms to guard our health (the basis for inoculations and immunities). However, we should be sanitary and safe from harmful levels of microorganisms.
The Philadelphia Water Department tests the biological quality of the tap water delivered to our customers to make sure it is sanitary and safe. We add chlorine to disinfect our water (free it of harmful organisms).
As a result of our effective water treatment processes, including the use of chlorine, the quality of public health in Philadelphia is high. Philadelphians do not suffer from the water-spread diseases present in many communities around the world. The Philadelphia Department of Public Health educates people on disease prevention, and makes sure that any diseases are treated early on to prevent their spread.
For most people with healthy immune systems, the natural microorganisms in water, foods and the air are not harmful. Those with special needs should consult their primary care physician who can contact us for more specific information.
Why are black particles in my tap water?
The most common cause of black particles showing up in tap water is the disintegration of rubber materials used in plumbing fixtures. Gaskets and o-rings can disintegrate over time and some pieces can collect in toilet tanks and around faucets.
Similar problems are often experienced in newly constructed or renovated buildings, as plumbers inevitably disturb the plumbing system when they do their work. A simple flush through the system may easily remedy the situation in most cases.
Can I get my water tested?
The Philadelphia Water Department consistently tests the water supplied to the city. At our water treatment plants, where the drinking water is produced, we continuously run tests throughout the day, every day. In addition, we collect tap water samples from throughout the city on a daily basis, and analyze the samples at our sophisticated central laboratory. Our water has a very consistent, high quality. We test it for you, to make sure it is safe and acceptable for drinking.
Industries may need to have additional testing done.
Our water quality data is readily available to our customers, as we publish a Water Quality Report every year. This report, available by calling the Water Department at
215-685-6300, could answer many of your questions.
How can I better understand the levels of elements in my water?
The Philadelphia Water Department's engineers and chemists measure and control what's in the water, or remove from the water undesirable components. Our customers can find out a great deal about these particles from our annual Water Quality reports.
Tap water ingredients, like chlorine and fluoride, are measured at parts-per-million or milligram-per-liter levels - these are interchangeable terms.
1 part per million is similar to making a line of quarters from Center City to Conshohocken, and then walking that line to find the one quarter that is flipped up heads instead of tails.
Other substances, such as trihalomethanes, are measured at parts-per-billion or micrograms-per-liter levels.
1 part per billion is equal to 1 green apple in a barrel containing 1 billion red apples.
Finally, we also test for potential contaminants at parts-per-trillion or nanogram-per-liter levels.
Such contaminants include the naturally produced chemicals that can give water a musty taste.
1 part per trillion is similar to 1 inch in 16,000,000 miles or 1 penny in 10,000,000,000 dollars.
How corrosive is my tap water?
Water is often said to be the universal solvent. Given enough time, it will dissolve almost anything, including materials used in water mains and building plumbing.
Water mains in Philadelphia are made of iron, while most of the plumbing is made of copper, with a minimal lead content. In a process called corrosion, these metals (lead, copper and iron) may dissolve from the pipes and get into your drinking water.
The Philadelphia Water Department takes corrosion seriously for two reasons. First, corroded pipes become weak and must be taken out of service. Second, the dissolved metals or corrosion products may degrade the quality of our drinking water (the water can taste metallic) or in the most serious cases they may become a health concern (as with lead).
Although the city's waters are not particularly corrosive in their natural state, the Philadelphia Water Department adjusts the quality of the water to keep corrosion as low as possible.
There are two ways that we optimize water quality to reduce corrosion. First, we make sure that the acidity, or pH, of the water is around 7.4 units. At 7.4, the water is slightly basic, rather than acidic. The other way that we optimize water quality to reduce corrosion is by adding parts-per-million levels of phosphates to the water at the treatment plants. The phosphate, in combination with the natural calcium and magnesium minerals in the water, coats the pipes internally to prevent the iron, lead and copper from escaping. Phosphate is simply made up of phosphorus (an essential element for all living beings) and oxygen. They are common in the environment, especially as nutrients for plants, and are very useful to us for reducing the corrosion of our pipes and your plumbing.
How hard is my water?
The hardness of water is determined by the calcium and magnesium carbonates naturally dissolved in it. Across the U.S., there are waters that are very soft (low in carbonates) and waters that are very hard (high in carbonates).
When using soft water, one's skin and hair feel soapy even after repeated rinsing. Hard water, on the other hand, makes the washing of clothes or the action of detergents more difficult. Very hard water leaves calcium scale or mineral deposits behind when it is heated up, and often needs to be softened.
Philadelphia's water is moderately hard, and it may vary throughout the city. Depending on natural conditions, hardness could be higher or lower. For example, during a drought the hardness of the water increases as the calcium carbonates in the natural waters become more concentrated.
Hardness is measured in milligrams per liter or parts per million. Some washing machines ask for the hardness in grains per gallon. Soft water has about 1 grain of mineral per gallon. Moderately hard water has about 3 to 7 grains of minerals per gallon. Very hard water has over 10 grains per gallon.
The hardness of Philadelphia's tap water is typically around 100 to 150 parts-per-million, which translate to about 6 to 9 grains per gallon.
How much fluoride is in my water?
The Philadelphia Department of Public Health guides the Philadelphia Water Department in adding fluoride to drinking water to prevent tooth decay. The natural water in this area contains minimal levels of fluoride so we add fluoride to the water at our treatment plants to reach the level recommended by the American Dental Association.
Among its water quality standards, the U.S. Environmental Protection Agency stands behind a limit on fluoride content in drinking water. There are some areas in North America where the natural levels of fluoride in water are too high, but this doesn't immediately concern Philadelphia.
The Water Department's goal is to maintain a consistent level of 1 parts-per-million (mg/L) of fluoride in Philadelphia's drinking water at all times.
I found white or gray particles in my faucet's aerator.
Particles can clog aerators and showerheads because of the small screens that often make up these fixtures. These screens may collect particles present in the water. The screens are called aerators because they break up the flow of water as it comes out of the faucet. The particles that get trapped on the aerators can come from a variety of sources. One of the most common sources is the hot water heater.
The same faucet delivers both hot and cold water in most homes. That is why material from the hot water heater can clog the cold water faucet.
There are dip tubes in heaters that direct the water to circulate and get heated. A dip tube is often made of polypropylene, a nontoxic plastic material. This plastic can break apart or disintegrate, and the small pieces can be carried away in the water to the faucet where they collect on the faucet's aerator.
I think I got sick from my tap water.
The Philadelphia Water Department understands your concern. We often hear about people getting sick from water when they travel to foreign countries. Water in foreign countries is often not cleaned or disinfected as it is in the United States.
The Philadelphia Water Department tests the water daily, and in some cases, every three hours or on a constant basis, to make sure that it is free of harmful microorganisms. Philadelphia's drinking water meets all state and federal safety requirements. The Water Department has an unblemished record in maintaining top quality water. We do not find people getting sick from drinking the city's tap water. There are so many other sources of germs that the concern over tap water in our city is minimal, although that is not true everywhere you may travel or for everyone you might speak to. The Philadelphia Water Department is working with the Philadelphia Department of Public Health to make sure that we maintain the healthfulness of water in our city.
Your primary care physician is your best contact for determining the cause of any sickness that you might have.
Should I Boil my tap Water?
In general, you should not boil your tap water. Your tap water, as delivered by the Philadelphia Water Department, is safe and does not need to be boiled in order to drink it. Boiling water increases the risk of scalding or burns. This risk is typically much more significant than any benefits you might receive from boiling the water.
If there was a need to boil water to rid it of microbial contaminants, such as Giardia, Cryptosporidium and harmful bacteria, then the rule of thumb is to bring the water to a rolling boil for one minute. For example, people who go camping in the mountains are advised to boil their spring water before drinking or cooling with it.
Does boiling improve the taste of tap water? It is unlikely that you will notice any taste difference. The primary reason for the taste of tap water is the chloramine (chlorine) that is in the water. This gives the water a slight chlorine taste. The chloramine is there to maintain the freshness of the water throughout the City. Chloramine is used because it is persistent. Boiling water for five minutes might only reduce the chloramine level by half. It will not get rid of the chloramine. Placing the water in the refrigerator in a water jug will help to reduce the chlorine taste since colder water has a less noticeable taste.
Why does my water appear milky?
If you have ever shaken up a warm bottle of soda, you know that all of the carbonation or carbon dioxide gas added in the production process wants to come out. If you open the top, the fluid will fizz up and over as the gas escapes to the air.
The same is true for tap water. When cold, such as during the winter, water is rich in oxygen. When it enters our homes, the water warms up and the oxygen wants to escape. You turn on the tap and, like shaking up that bottle of warm soda, the air fizzes up. As the glass of water sits, you will see the water clear from the bottom of the glass upward, as the air bubbles rise and escape to the air. All of these tiny air bubbles give the glass of water a milky appearance under natural or household lighting.
The air bubbles are not harmful and will quickly dissipate.
My water has a color to it, what should I do?
If your water has a brownish or rusty color, the color is a result of the presence of iron or rust. Most of the pipes in Philadelphia used to deliver water to your home are made of iron. Older mains can impart rust to the water. Newer mains are lined with cement to lessen the contact between the water and the iron mains. However, when there is an upset in the system such as a water main break, or when a valve is operated or water flow is changed, rust may be stirred up. When this happens, the water is unpleasant to look at and taste, but it is not harmful.
A rust problem is usually short-lived, and should be gone in a day or less once it is flushed from our water distribution system or your home plumbing. Do not wash clothes when water appears rusty because the rust will stain the fabric. Flush your cold and hot water, once the discoloration is gone, to make sure the rust does not accumulate or stay in your plumbing.
Should I buy bottled water or a home filter device?
There are numerous brands of bottled water, as well as a variety of home water treatment devices. Bottled water certified by the Pennsylvania Department of Environmental Protection is guaranteed safe and truthful about the source of water the bottling company claims to use. Labels must note where the water comes from, and when naming the product, the company must follow certain requirements to ensure that the name is not misleading.
The Philadelphia Water Department cannot recommend brands of products to buy. It is up to the customer to make a choice.
The main reason people might prefer bottled water is because bottled water does not contain chorine to control bacterial growth, and it therefore does not have the chlorinous flavor that tap water may have. But remember that bottled water can sit on store shelves for a long time before it is sold.
Home treatment devices are generally of little use in Philadelphia unless you have special needs, such as a laundry service that would benefit from softer water. Some carbon filters can remove the chlorinous flavor. Treatment systems must be properly maintained (filters changed in due time) or they will cause more problems than they prevent.
Home treatment devices should also be certified (for example, they should display an NSF seal) proving that they can do what they say they do.
Please refer to the Pennsylvania Department of Environmental Protection's web site at www.dep.state.pa.us for more information.
There is pink slime on my bathroom tiles!
Bacteria and molds grow well in moist environments, such as bathtubs, sink drains and bathroom tiles. A humidifier can also encourage mold growth.
These bacteria or molds are common and natural. They can be found in the air, in soil, in water, or on household surfaces. Orange and pink are common colors for many environmental bacteria such as, Pseudomonas and Flavobacterium.
Since the slime is caused by microbial growth on surfaces, cleaning and disinfecting using common household products along with good hard scrubbing are the best means for controlling the slime growth.
It is a good idea to stay on top of these slime growths and scrub them away as they appear, as they can be irritants to sensitive people.
What are the main characteristics of my tap water?
Chlorine in the form of chloramine (chlorine combined with ammonia) is added, first to disinfect the water and then to make sure that the water stays free of germs or harmful bacteria all the way to your tap. Chlorine levels in water vary from about 0.2 parts-per-million to 2 ppm depending on where you live relative to the water treatment plant, as well as the time of the year (chlorine is harder to keep in the water during the summer when the temperature of the water is high).
Philadelphia's water is moderately hard because the rivers from which we get the water contain calcium. We increase the hardness slightly as we add lime to adjust the acidity, or pH level of the water. These are natural minerals.
The acidity of Philadelphia's water is controlled at the treatment plant using lime to make sure that treatment works properly and to make sure that the water coming out of your tap is consistent and low in corrosiveness. The natural water's pH can change. The treatment plants control these changes so that we can supply water that is neutral in pH.
Fluoride is added to the water at 1 milligram-per-liter concentration for the prevention of tooth decay. This is done under the Philadelphia Department of Public Health's guidance. Some fluoride is natural in the water, but we boost it up a little more to keep it consistent and beneficial.
The U.S. Environmental Protection Agency and the Department of State require us to control the corrosiveness of our water to prevent lead and copper from leaching out of the plumbing materials into the water. We add parts-per-billion levels of a corrosion inhibitor, a phosphate, to the city's water to reduce the corrosion of the pipes.
What is that musty or earthy taste in my water?
Earthy and musty off-flavors in water occurs world wide, and aside from the chlorine flavor of tap water, are the most common flavors noticed by our customers. They come from nature and have no known health effects at their natural levels.
Earthy and musty odors can be found in natural waters and in soils, as well as in beets and in corn (because they are grown in contact with soil). In waterways, when certain algae grow in abundance in what we call an algae bloom, high levels of these odors can be produced. Certain types of soil bacteria that also grow in water produce these chemicals, but they are less common in our waters.
The treatment needed to remove earthy and musty natural flavors can cost thousands of dollars a day. The most common treatment is to add carbon to the water as it is being treated, to absorb or soak up the flavors. However, these problems usually come and go, lasting for a few days to a few weeks.
The level of these flavors in water can be as low as 5 nanograms per liter (that is 5 parts-per-trillion or 5 seconds in 320 centuries, or 5 pinches of salt in 10,000 tons of potato chips). Yet, highly sensitive people can still taste them. Sensitivity varies greatly among people. Many people are unable to detect one or the other flavor at their natural levels. Some people can detect both, equally well; the human senses are far more complex than anyone can understand.
Who controls my water's quality?
The U.S. Environmental Protection Agency in Washington, D.C. sets national drinking water standards to protect public health. These standards are enforced in our state by the Pennsylvania Department of Environmental Protection. On a monthly or annual basis, we submit water quality test results to the state to prove that we are providing water that meets all of the standards. In addition, if there were ever a serious water quality problem, the state would immediately be notified and they would oversee our response and corrective actions.
However, only a portion of what we do in testing water quality is driven by these federal or state requirements. We also perform tests not prescribed by federal and state laws. We test for the acceptability of the water's quality, not just for its potential to meet the standards. We conduct research to better understand the characteristics of the water from the rivers to the tap, and to find better ways to treat and deliver water to our customers. In order to do all of this, we have set our own goals for water quality - goals that are more stringent than the federal or state standards. We continue reviewing these goals as new information comes in from around the world, and as better technology and science are developed, so that we can continue to provide the best tap water at the least cost.
Why do water mains sometimes break?
Most of the water mains in Philadelphia are made of iron, which makes them affordable and reliable. These water mains can last a long time if they do what they were made to do, transport water from one place to another. Engineers know how to make good quality iron mains, how to design distribution systems made up of mains, and how to properly construct and protect those systems.
Eventually, the condition of the water main and its surroundings lead to cracks, joint failures or more serious breaks. This could happen after 200 years; most often it happens after 100 years, but sometimes within only 50 years. Ideally, a main would be repaired or replaced before it completely fails.
There are over 3,000 miles of water mains buried in Philadelphia's streets. This is more than enough to go all the way to Los Angeles, California. Imagine riding from here to California every year, checking the buried mains for leaks or problems that could lead to breaks. Our crews spend hundreds of hours in the field making sure all the mains are functioning correctly.
The unfortunate effects of a broken main include the interruption of water service, damage to property, a messy street, and a temporary case of rusty water being delivered to our customers.
There are various contributing factors that could lead to a water main failure or break. These factors can act individually or in combination, and may themselves have several causes.
One complex factor is the cumulative force exerted on the iron water main. This force is the sum of forces from a number of sources and directions. The weight of the soil covering the main in the street, and whatever is on top of that on the ground, are the major components of this force. Wet soil that expands upon freezing can exert additional stress on the main. Vibrations may be set up as a result of nearby activities such as trucks riding down the street in the vicinity of the main. Metal expansions and contractions resulting from temperature changes may also affect the main.
Another complex factor is the erosion of the supporting soil beneath the buried main. Flowing water may wash away the special sand and soil laid beneath the main to help bear the above mentioned force. The movement of water in the ground can create small or large caverns under the pipe, in which case the force bearing down on top of the pipe must be taken by the pipe itself without the help of supporting material underneath. If these forces exceed its strength, the main breaks. These breaks most often occur at the weakest part of the main, the joint. Imagine trying to chop a pencil in half when it is lying flat on a desk. It is virtually impossible to do so due to the additional support provided by the desk. But if you place the pencil ends on books so that most of the pencil has air beneath it, it will not be hard to break it.
Underground water can come from various places, such as natural springs, leaks in a water main, or a customer's service pipe. Sometimes these leaks come from cracks in the mains, or most often start at the joints. Water mains are manufactured in lengths of about twenty feet and are joined together in the ground to form a main.
There are different ways that two sections of main can be joined together. Older joints are not as leak-proof or durable as newer joints, so the Philadelphia Water Department is working as fast as possible to replace them. PWD crews look for leaks, and our customer service representatives answer customer calls that pinpoint signs of leaks.
Another complex factor in main-breaking is corrosion. An iron main can corrode on the outside and on the inside. The Water Department carefully controls the quality of the water flowing through mains so that the water is not highly corrosive to the mains. Mains are now lined with special cement to place a barrier between the iron and the water to reduce the corrosion or rusting of the iron in the mains. Corrosion on the outside of a main can be caused by the many different conditions of the surrounding soil. PWD takes precautions to protect buried mains from their surrounding environment.
These are some of the principal factors, but they are not the only factors that act individually or in combination to lead to a main break. Other factors could include a street excavation that accidentally disturbs a water main, and the misuse of fire hydrants.
The above discussion is a simplified picture of why water mains sometimes break. PWD cooperates in national research efforts to better understand why mains break and how to prevent such failures. Generally, the older, more developed cities need to invest heavily in efforts to predict and prevent water main problems in order to manage their water main infrastructures.
Why does my tap water taste like chlorine?
Chlorine is added to water at the treatment plant to disinfect the water or rid it of harmful bacteria and germs. Chlorine is again added to the water before it leaves the treatment plant to prevent bacterial growth in the miles of pipelines from the plant to your home. There is always chlorine in the water but at very low levels.
In the 1970s, the Philadelphia Water Department began changing the way we add chlorine to the water supplied to the city. We began to combine chlorine (bleach) with ammonia to form a "chloramine" product. The chloramine product has less of a taste or smell than bleach chlorine. It also lasts longer, and does not cause the pipes to rust as in the case of bleach chlorine - so we have also reduced the rust problems in our water pipes.
Thus, in one sense, the taste of chlorine is a welcome taste. The presence of chlorine means that the water has been kept fresh.
There are ways to reduce the chlorine flavor in your tap water. A simple solution is to take tap water and store it in the refrigerator so that it is as cold as can be when you drink it. Colder water has less noticeable flavor. But you need to choose a good, clean storage jug as some plastics impart a plastic taste to water.
There are people who are very sensitive to flavors. They may find it more difficult to ignore the chlorine taste in their tap water, although we have found that most people cannot taste the difference between bottled water and tap water. In the end, your own personal preference determines if you like the taste of your tap water.
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