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Category: Water Chemistry

Factors that Contribute to Drinking Water Quality

factors affecting water quality

 

Q: What factors contribute to the quality of a city’s drinking water?  It appears according to a recent report, 10 U.S. cities with the worst drinking water, that Florida has two cities which show up on the list (Jacksonville and Pensacola). For a peninsula, you would think the quality would be better. How does the natural Floridan aquifer affect the quality of the water (other than providing a sandy taste)?

 

A: The two biggest factors that contribute to the quality of a city’s drinking water are 1) the source of the water and 2) what treatment methods are employed before sending the water out.

Jacksonville has a lot of disinfection by-products in the water.  It’s hot there and biological contaminants will grow pretty easily in the water so the city uses disinfectants such as chlorine to reduce the growth of microorganisms.  The chlorine will react with organic matter that is present in nearly all water systems to produce disinfection by products.  According to Jacksonville’s website their water comes from a limestone aquifer so the source of water isn’t bad, they just use chlorine to keep biological contaminants out.

Pensacola has the deck stacked against them with their source water.  There the water comes from 32 sand and gravel aquifers, which many organic contaminants can easily leach through to get into the water table.  The water utility tries to clean up the water with a lot of adsorption media but it’s expensive to treat a lot of water that’s going to be used in toilets and for watering your lawn.

 

Find this question and others I’ve answered on Quora.  

All About Lead: Keeping your water safe

All About Lead is part of a series.  To be updated on when the next installment please subscribe to my mailing list.

The ability to have clean drinking water is something most residents in the United States take for granted.  When you’re in a situation where your water isn’t clean, it’s colored, smells weird, whatever, you feel helpless.

This isn’t supposed to happen.  This is America!  Not India.  Not Haiti.  We’re supposed to have clean water.  

It’s hard to see contaminants in water with our eyes; things like lead and cryptosporidium aren’t visible to the naked eye.  

With the on-going crisis in Flint, Michigan, lead is a hot topic these days.  There is a lot of information out there about the problem, but very little information about the actions people who are living with lead water can take to protect themselves.

In this three-part series I’m going to address the history of lead in plumbing distribution, the science behind why Flint is now full of lead, and what actions people can take to remove lead from their water.  

Let’s get started.

 

The History of Lead in Plumbing

The History of Lead in Plumbing

Most of us know that lead is bad so it’s hard to fathom the possibility of there being lead in the water.  In fact, lead is one of the best studied toxic-substances and we know more about the negative health effects than almost any other chemical.  This abundance of information however is unfortunately due to lead’s predominate use throughout history starting in the Roman Empire and extending through the 1990s.  

In Plumbo Nos

The Roman Empire is credited with being the first regime to mass-distribute lead due to their massive mining operations.  Lead itself does not occur in an elemental state but is a by-product of silver and gold mining.  It is readily available, easy malleable, is resistant to corrosion, and is easy to melt at low temperatures making it an ideal material for creating products out of.  

The Romans used lead extensively.  The used it to create plates and silverware, cooking utensils, urns for wine, makeup, and indoor plumbing.  In fact, the word plumbing itself is derived from Latin.

Plumbum.

That’s Latin for lead.  

Plumbum.

Fond of bathing, the Romans constructed great aqueducts to transport water from miles away to baths and recreation centers.  They were the original plumbers, lead workers who were responsible for measuring and laying out pipe, soldering, installing, and repairing the infrastructure that moved water around cities such as Rome and Pompeii.  

It should be noted that not all plumbing was created out of lead, some were created using terra cotta pipes.

With the decline in the Roman Empire so came the decline in plumbing.  Bath houses came to be viewed as places of debauchery and cleanliness decreased in value.  

It wasn’t until the mid-1800s when diseases like typhoid and Cholera were rampant that the link between bacteria and disease was discovered by Louis Pasteur.  Plumbing, especially to keep clean water isolated from wastewater, became of increasing importance. 

The New World and Lead

Almost as soon as the first colonists settled in the United States the mining and smelting of lead began.  Lead was originally sought out for its use in ammunition and by 1621 the metal was being mined and forged in Virginia but it wouldn’t be until later that lead would be used to transport water.

Early water distribution systems were created using bored-out logs, usually from hemlock or elm trees.  In 1652 Boston unveiled the country’s first water distribution system using these hollowed out trees in order to provide water for firefighting and domestic use.  

There were several problems with using wooden pipes however.  Uneven ground would cause the pipes to sag, creating pockets of stagnant water that developed a woody taste over time.  As cities expanded more pressure was needed to move the water farther and farther and this would cause the wooden pipes to split.  

As wooden pipes ceased to be useful, a switch to iron was made.  The city of Philadelphia became a global leader in plumbing when it became the first city to distribute water using entirely cast iron pipes in 1804.  Other cities such as Chicago, New York, and Boston followed suit.  

As plumbing knowledge evolved, so did the ease of bringing water inside homes.  Instead of getting water from a pump in the street one could get water from a faucet inside your house.

 Designing piping to move water around cities was fairly easy and straightforward but when it came to connecting buildings to water mains things became more complex.  There were a lot of pipes and conduits in the streets so piping that was flexible was highly desirable.  

The connections from water mains to buildings are known as service lines and creating these pipes out of lead became the most practical solution for engineers.

Lead service line location

Lead in the 20th Century

By 1900, of the 50 largest cities in the United States all but six or seven of them has installed lead piping.  New York, Chicago, Philadelphia, Saint Louis and Boston all used lead services to varying degrees.  

Many local building codes mandated that lead service pipes be used for constructing service lines.  Lead is more durable to corrosion than iron piping and many of the lead pipes that were being used in 1900 are still in use today.  

A committee on service pipes submitted a preliminary report to Engineering News, a journal of civil engineering and construction that was issued weekly, on the use of lead service pipes in 1916.  The report stated:

Lead is in many respects the most satisfactory material to use for service pipes. Its pliability and its comparative freedom from corrosive action make it almost ideal from a mechanical standpoint. The cost of lead pipe of sufficient thickness safely to withstand the pressure is more than the cost of many other materials used for service, but in a paved street the greater duration of life probably more than compensates for the extra cost, and in places where the streets are occupied by other pipes and conduits the ease of getting over and under these obstructions with a flexible pipe is a great advantage.

The article continues:

The most serious objection to the use of lead pipe for services is the possibility that the water may dissolve enough lead from the pipe to cause lead poisoning. It is certain that many cases of lead poisoning have been caused by the use of lead services.  On the other hand, lead has always been used for services in most of the large places without any unfavorable effects.

Engineers knew lead pipes were bad and could poison people but didn’t understand why in some areas people became poisoned and in others people were fine.

It seems to be practically impossible to determine definitely in advance what the effect of any water on lead pipe will be, as the laboratory results fail in many cases to show the action which will occur in actual practice.  Tests of service pipes in use for a considerable period are the only safe guides.

This highlights a key point in the use of lead pipes.  

Not all lead pipes pose a health risk.  

Not all lead pipes pose a health risk.

If the water chemistry is good, with a pH that’s close to neutral and not overly corrosive water, then lead pipes can be perfectly safe.  

In the 1930s copper pipes or galvanized steel pipes began to replace most of the lead pipes in residential plumbing.  Solder, a material that’s used to join together metals like copper pipe, still contained lead until it was banned for plumbing applications in the 1980s.  

The importance of lead dissolved from lead service lines has received little attention until now because over time oxidation created a protective coating along the interior of the lead pipes.  This limited the amount of lead that would leach into the drinking water and could be ingested.  

This brings us to today, where residents in Flint, Michigan, have been struggling with lead contaminated water since the summer of 2014.  


In a couple weeks I’ll be sharing the science behind how Flint became full of lead.  To be one of the first to know when the next installment is available please subscribe to my mailing list. 

The Impact of Holiday Spices on Water

Holiday Spices

The Puget Sound is a large ocean inlet along the northwest coast of the state of Washington on the Pacific Ocean.  Seattle is located on the sound and enjoys being the eighth largest port in the United States.  If you were to visit Seattle today you’d likely visit the Pike Place Market and enjoy the fish vendors tossing fish around, or walk along Pier 66 taking in the view of the city at night.  The water within the sound is a meaningful piece of Seattle and keeping the water clean is important to the prosperity of the city.

Scientists at the Center for Urban Waters within the University of Washington Tacoma are working to understand and quantify the sources, pathways, and impacts of chemical pollution in urban water systems.  One program at the center, called Sound Citizen, studies pollution involving fun compounds, such as cooking spices, and more serious pollution, such as emerging pollutants.  The pollution of cooking spices in water systems is an interesting research area as it’s not an area of pollution that most people think about.  Just like pharmaceuticals that end up in water after passing through the human body, many spices end up in local water systems the same way.  This project focused specifically on spices, acting as a way to help people see the connections between humans and natural environments.

Tracking the presence of cooking spices in the Pudget Sound allows researchers to track the holidays.  In the summer the water contains high amounts of methyl-vanilla, an ingredient found in waffles cones and kettle corn.  After Thanksgiving and Christmas the water is full of vanilla and thyme, entering the sound through the water treatment plants.  At the West Point wastewater treatment plant in Seattle researchers have measured an increase in spices such as cinnamon, vanilla, allspice, thyme and rosemary starting immediately after Thanksgiving and lasting through the New Year. Converting the amount of spices detected in the Puget Sound into the amount of baking spices needed to make chocolate chip, gingerbread and snickerdoodle cookies, researchers determined that about 250,000 cookies were being consumed each day during the 2008 holiday season.  At that time the average person in Seattle was eating two cookies per day!  The population of Seattle has increased by over 50,000 people since 2008 and the amount of spices in the Sound has also likely increased.

At this time the effects of an increase in spices on fish and wildlife have not been explored.  Salmon fish use open-water navigation and a keen sense of smell to find their way back to the very same stream in which they were born.  The spices being detected in the Sound are at levels that fish can easily smell.  Until more research is completed however, the effects of “pumpkin spice everything” on fish and wildlife remain unknown.

(Photo credit: Happy Holidays 2016)

The Top 5 Drinking Water Contaminants and How to Remove Them

Now that you know how to find out what is in your water, here are the the top five most common contaminants in drinking water.

1) Hard water

eagle-water-treatment-hard-water
Having hard water isn’t bad from a health perspective but it will wreak havoc on your appliances that use hot water. Hard water is comprised of calcium and magnesium which have dissolved into groundwater over the course of centuries. Having a low level of hardness is fine but once you start getting over 12 grains per gallon (205 parts per million) you may want to consider installing a water softener.

2) Iron

iron-water-stains culligan Tulsa
Iron is another common contaminant frequently present in drinking water.  Similar to hardness, iron is present in water due to the dissolution of minerals over the course of centuries. Again, having iron in your water is only bad from an aesthic effect. Iron exists in water in the ferrous form but once it comes into contact with oxygen iron changes form into ferric and becomes the bright red color most are familiar with.  On the bright side, most who suffer from high levels of iron also have very hard water and the water softener will also work to remove iron. Iron is a secondary contaminant for the EPA, who recommends that you keep your iron level below 0.3 ppm for optimum tasting water.

3) Lead

lead plumbing - certified home inspection

This contaminant is most frequently found in the drinking water for those who live in older cities such as Chicago and Washington DC.  Lead is introduced into the drinking water through the distribution system, picking up lead from pipes, solder, and fittings that all were once made with lead. Now the Safe Drinking Water Act (SDWA) requires that products like fittings must have a weighted average of less than 0.25% lead.  The only way to know if your water has lead in it is to test the water and the most accurate way to accomplish this is to have your water analysed by a certified laboratory.  There is no safe level of lead in water, but there is an EPA action level of 15 parts per billion which means that once that level is reached the water authority must take action to replace 7% of the portion of lead service lines they control each year. If you have lead in your water an undersink reverse osmosis system is going to provide the most benefit to you.

4) Chlorine and chloramines

chlorine tabs - grand slam pools

Technically these are two separate contaminants but they act in many of the same ways.  In order to protect drinking water from microbiological contamination the drinking water treatment plant will frequently add a disinfectant such as chlorine or chloramine to the water.  This leads to drinking water typically having a concentration between 0.2 to 1 parts per million of chlorine.  The EPA has a maximum residual disinfectant level of 4 parts per million as an annual average.  If your water has a chlorine taste or odor, a simple carbon filtration system (such as a Brita filter) will be most effective at creating a more aesthetically pleasing water.

5) Disinfection Byproducts

water help disinfection by products

When water has high concentrations of total organic compounds (TOC) or other naturally-occurring matter in the water, disinfectants such as chlorine and chloramine themselves can react to form byproducts which may pose health risks.  It is widely understood that chlorination will produce chlorinated and brominated disinfection byproducts (DBPs) with potential carcinogenic effects on humans.  While there are 80+ known disinfection byproducts, the EPA only currently regulates 11 of them.  Other DBPs may be present in water at levels too low for detection, or the health effects may not be known.  Again, a simple carbon filtration system (such as a Brita filter) is useful for removing these organics from the water.

(Photo credits: Eagle Water, Culligan Tulsa, Plumbing Problems Today, Grand Slam Pools, and Water Help)

Determining Water Quality

Geothermal Field in Haukadalur

Geothermal Field in Haukadalur, Iceland

Water is one of the most fundamental, essential components of life. When it is pure, it is very simple: H2O. However, almost all of the available freshwater is no longer pure. It contains different physical, chemical, and microbiological contaminants which include bacteria, viruses, and toxic material such as heavy metals. This makes good water difficult to categorize and describe. In order to define the quality of water, especially drinking water, researchers or experts have developed many parameters to categorize the water and the various contamination levels within.  By doing so, people can now determine what water is clean and safe for drinking.

There are some general parameters such as temperature, color, total suspended solids (TSS), and turbidity to describe the physical appearance of water but this does not tell the whole story.  There are many biological characteristics and chemical characteristics, such as hardness, total dissolved solids (TDS), and pH that help to complete the picture. Once these characteristics are known, it is possible to determine what water treatment options can be employed to make the water more drinkable.

There are several possible ways one can determine the quality of their drinking water.  The easiest method is to obtain a copy of the drinking water quality report water suppliers are required to send to their consumers.  The drinking water quality report will outline what contaminants are in the drinking water and if the contaminants would affect their health.  If nothing is available for the drinking water you have, the Environmental Working Group has created a database for tap water throughout the United States.  Another option is to find a local independant lab to test the water.  This can be done by calling around to the water bureaus in your area and/or surrounding areas to see who they’d recommend. It also possible to test the water yourself with a single use test kit, but this option should really just be used to see if the water should be further analysed by a professional.

It’s important to keep in mind that due to the advanced analytical techniques required to test for many contaminants, it’s not feasible to test the water for everything that could be present.  Instead the water is tested for common drinking water contaminants or those suspected to be present in the water.

The United States Environmental Protection Agency (US EPA) maintains a list of legally enforceable standards called the National Primary Drinking Water Regulations.  These standards apply to public water systems and serve to protect public health by limiting the levels of contaminants in drinking water.  A National Secondary Drinking Water Regulation list is also maintained by the EPA to serve as a non-enforceable guideline for contaminants which cause aesthetic or cosmetic effects in drinking water.

Knowing what contaminants are present in your drinking water and where their levels fall in terms of the regulations, will help you determine what treatment methods (if any) are best for your situation.

(Photo: Kristen Brastad)

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