Drinking Water - A Conversation With Professor James Salzman
Rarely do we reach to turn on our kitchen faucet (tap) wondering whether it will produce water. It’s similarly rare to consider whether the water coming from the tap could harm us. And how many of us can trace back the path that water has taken to get to our home - beyond our local municipality to its true point of origin? When you think about it, there are a lot of circumstances where it’s hard to connect the dots when it comes to drinking water. At Edstrom, questions like this are always on our minds, so we were particularly excited when we read the book ‘Drinking Water: A History’ by Professor James Salzman.
James Salzman is the Donald Bren Distinguished Professor of Environmental Law, with joint appointments at UCSB and UCLA. In Drinking Water, Professor Salzman presents readers with a multifaceted look at historic and contemporary topics surrounding an indispensable resource – the water we drink. Throughout the book, Professor Salzman both informs readers and challenges them to carefully consider many issues surrounding our drinking water. Renowned for his scholarship on the topic, he has provided commentary for C-SPAN, NPR (National Public Radio) and Slate magazine, among others. We had the pleasure of speaking with Professor Salzman, who touched on topics from his book, including chlorination, the role of drinking water in the birth of epidemiology, the regulation of our drinking water, and the vulnerability of drinking water and its infrastructure.
DRINKING WATER – LEARNING FROM HISTORY
There is a lot to be learned from the history of drinking water. The provision of safe drinking water is something that every society in human history has faced. Many of the questions raised by the engineers of ancient Babylonia still resonate today. It’s understood that every sizable human settlement must ensure it has access to drinking water. To do so, it has to accomplish three things: it has to protect the water source, transport the water safely, and allow for final delivery in a manner that makes it safe to drink. Though in considering this, it’s important to recognize that what we consider to be safe has changed over time, and that safety can be put in jeopardy from a variety of different sources.
CHOLERA, SNOW, AND THE BROAD STREET PUMP
The idea that contaminants in water could affect health is fundamental to the basis of epidemiology. The story of John Snow and the Broad Street Pump is relevant as the first major example of public health being affected by contaminants in water. John Snow was a 19th century physician that had disagreed with the widely accepted Miasmatic Theory of Disease. This theory held that diseases were spread by breathing contaminated air. Snow was trying to prove that cholera was actually a waterborne disease.
In 1854, there was an outbreak of cholera in the Soho area of London. Snow decided to plot a map of where the cases were occurring, which had never been done before. He found that the cases were centrally located around a particular water pump. Learning this, John Snow convinced local health authorities to shut down the pump and remove the handle, thereby stifling the spread of the disease.
CHLORINE – OVERCOMING DISEASE
The use of chlorine to treat drinking water is considered one of the public health triumphs of the 20th century. When chlorination was first put to use, there was early opposition due to a lack of understanding of what caused waterborne diseases. The Germ Theory of Disease adopts two basic tenants: specific diseases are caused by specific microorganisms in the air and water, and the same germs reproduce from bearers of the same disease.
When the germ theory was accepted and chlorination was used more widely, what had been scourges of disease like cholera and typhoid, disappeared almost overnight. And the way in which the use of chlorinated drinking water spread was quite clever. Because water treatment was a local government decision, the Interstate Commerce Commission (ICC) in the US required that interstate common carriers such as buses, trains or ferries had to provide chlorinated drinking water to passengers. So the ICC said that if common carriers were transporting water, that water needed to be chlorinated. This is what drove the adoption of chlorination of drinking water in the US, and reduced the opportunities for waterborne diseases to spread.
WHO’S WATCHING OVER YOUR WATER?
Many countries in the world have adopted the World Health Organization (WHO) guidelines for safe drinking water*. In the United States, there are two government agencies tasked with keeping public drinking water safe – The Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA). The EPA regulates the quality of the water coming from taps. This is done in accordance with the Safe Drinking Water Act of 1974. For tap water, there are over 100 substances like arsenic and lead that are regulated under the Safe Drinking Water Act. The Act is a law that works in three steps. First, it determines which contaminants the law will regulate and which it will not based on risk assessment for public drinking water systems. It then assigns the contaminants posing the greatest risk Maximum Contaminant Level Goals (MCLGs), which is the highest allowable concentration of the contaminant that will allow for an adequate margin of safety. For many contaminants like carcinogens, that number is zero. If there is a reason that the Maximum Contaminant Level Goal cannot be reached, then the EPA determines the Maximum Contaminant Level (MCL) permitted, and scores that level as close to its goal level as possible. In the third step, the EPA performs a risk assessment and cost evaluation of what would be necessary to achieve any prescribed reduction in contamination required to meet the MCL. If the contaminants do not exceed the MCL, the water is considered safe to drink by the EPA.
In contrast, bottled water in the US is considered a food product, and as such, falls under the jurisdiction of the FDA through the Food and Drug Act. It’s ironic that many people drink bottled water because they perceive it to be healthier than tap water. The fact is, bottled water is actually less regulated than tap water. Of the many studies that have been done, the findings often indicate that tap water is as clean as bottled water, and in about 1/3 of the cases, it’s even cleaner. Tap water is tested much more frequently than bottled water, and the notification requirements to the public are very different when there is a concern.
Regulating and enforcing the laws that pertain to drinking water is not a simple task. In the United States, there are over 60,000 chemicals that are in use, and that number is growing. Whether there is a real or only perceived risk from these chemicals is mostly undetermined. Only a small fraction of these substances fall under existing drinking water regulation. Many have the potential to pollute our drinking water in situations that vary from the runoff of agricultural pesticides, to the improper disposal of unused pharmaceuticals as they are flushed down the toilet.
SMALL DOSES... REALLY SMALL
Part of the difficulty in understanding whether there is a real or only perceived risk of certain contaminants in drinking water is that scientists are attempting to understand their impact on health in often extremely small concentrations. Technological advances have allowed for the detection of trace amounts of pollutants. These newly detectable concentrations have exceeded parts per million or parts per billion, and can now even register contaminants diluted to parts per quadrillion. Do these trace contaminants pose a risk to drinking water? Is there an insidious risk from ingesting trace amounts of these pollutants over time?
At present, the unsatisfying but truthful answer is that we do not know. As research allows us to discover more answers, new contaminants find their way into our waterways and present new questions for epidemiologists and toxicologists. Our ability to detect potentially harmful compounds in drinking water has grown faster than our ability to link very low levels of these compounds to a present or future health risk. And if risk is discovered, the removal of such minuscule amounts of contaminants from drinking water will neither be easy, nor cheap.
IS OUR DRINKING WATER VULNERABLE?
The idea of drinking water coming under attack really came into consideration in the US after the events of 9/11. There are thousands of miles of exposed water infrastructure across the United States. And there have been many movies created where a nefariouscharacter is seen dumping a test tube or vial of something into a treatment plant or reservoir. It turns out that, fortunately, it would be very hard to poison a water supply. The reason for that is simply dilution. Reservoirs are so large and contain so much water that you would have to drop in several truckloads full of poison in order to really threaten the water supply. That’s good news. However, there is so much drinking water infrastructure that targets are certainly vulnerable to explosives or similar destructive attacks. To counter this, there has been a lot of focus in recent years on the idea of hardening the water supply infrastructure and thereby making it less vulnerable to the risk of sabotage.
While this is a sensible conversation to have, what presents a more pervasive danger is our aging infrastructure itself. Most conversations about "our crumbling infrastructure" are related to roads and bridges. But it’s equally true for our pipes. Many cities in the United States have pipe systems that are 50 – 100 years old, and in some cases even older. Much of this infrastructure needs to be replaced, but no one wants to allocate funds towards this. The metaphoric ticking time bomb may prove more costly in the long run than the real thing.
WHO DO YOU TRUST?
Drinking water presents us with a situation that involves trust. Our current system of accessing drinking water puts faith in the notion that the government is getting it right, both in terms of regulation and the maintenance of the infrastructure. Very few people have the ability or means to test their own water on a regular basis. And so you have to trust that the government is doing their job in protecting us.
The circumstance of lead contamination that has occurred in Flint, Michigan gives us pause however. It’s easy to destroy trust, but it takes a long time to build it back up. It will take a very long time to rebuild the trust that was lost due to the events that happened there and the subsequent tragic results. It’s a history that will hopefully never be repeated.
Edstrom extends its appreciation to Professor Salzman for speaking with us. His book, Drinking Water: A History is available from Overlook Press and Amazon.
* For more information on the World Health Organization’s guidelines for drinking water, please visit their website: www.who.int/water_sanitation_health/dwq/guidelines/en/
Positive Results for Preparedness – Study Proves Sipper Sack® A Good Choice For Storing Water
With intense weather events occurring at a greater frequency, we agree with the idea that having a contingency action plan for animals in the vivarium is a necessity. Customers have asked us whether the Edstrom Sipper Sack® is a viable choice for disaster preparedness. As the ideal individual cage watering solution for mice and rats, the Sipper Sack clearly fits the bill. It provides a compact, portable unit whose small footprint allows it to be stationed nearly anywhere in the lab so sacks of water can be filled in advance of an impending storm. Simply fill the required number of sacks and then seal the port in the sacks with a removable plug until needed – replacing the plug with a drinking valve at the time of use. In terms of mechanical operation, the Sipper Sack is an elegant answer to the question of being ready for an emergency.
In addition to convenience and ease of operation however, another very important consideration is the maintenance of water quality over time while the water is being stored. Will the water quality in the Sipper Sack be affected by prolonged storage? To present our customers with an answer to this question, Edstrom has performed a test to see if the effect of the residual biocide chlorine would maintain its effectiveness in prohibiting biological growth in the Sipper Sack over an extended time frame.
MATERIALS AND METHODS
The test was performed on sterilized, clear Sipper Sack bags (Edstrom Part Number 7335-1010-452). Chlorine levels were measured with a digital chlorine test kit (Edstrom Part Number 2400-6685-001), utilizing free chlorine reagent packets (Edstrom Part Number 2400-6685-002). Sixty-five (65) Sipper Sack bags were filled with water containing an initial chlorine level of 3.00 ppm (parts per million) using the Sipper Sack filler station (Edstrom Part Number 7335-1000-501). After each Sipper Sack was filled, the injection port in the sack was sealed using an autoclaved Sipper Sack plug (Edstrom Part Number 1010-1710-530). Each of the sealed Sipper Sacks was then placed in a sealed container (Edstrom Part Number 2310-5445-002) with a dark liner bag to prohibit light penetration.
Each day a single Sipper Sack was drawn from the container to measure the abatement of chlorine over the 65 days of the test period. A water sample was drawn from the final Sipper Sack on the last day and was subjected to a Biological Activity Reaction Test (BART). The sample was observed for 7 days.
The BART test procedure did not indicate the presence of bacteria.
Free chlorine was detected throughout the entire test period of 65 days. At the completion of the test, the concentrations of free chlorine detected were 0.04 ppm in the sealed Sipper Sack prior to BART testing. With the absence of bacterial growth demonstrated by this test, the study conditions suggest that the Sipper Sack is viable for disaster preparedness plans where individual cage watering needs to be stored over an extended period of time.
To learn more about Sipper Sack, please go to our website www.edstrom.com or contact an Edstrom representative.
A Perfect Pairing – PulseCMC® and Edstrom Automated Animal Watering
In the busy vivarium environment, time and resources are always at a premium. Any means of heightening efficiencies or streamlining tasks is appreciated, simply because there’s so much to get done. Utilizing an Edstrom Automated Watering System is essential in working toward the goal of a more efficient vivarium. It consistently delivers high quality water to animals on demand, and does so every minute of every day of the year – with minimal human intervention. Edstrom Automated Watering Systems improve productivity, reduce ergonomic injuries and reduce variability in research. PulseCMC® facilitates the robust utility of the automated watering system, acting as its control center.
PulseCMC can be used to automatically flush segments of the room distribution system, or even manifold piping on individual cage racks. This is done on a programmed schedule to aid in maintaining high water quality. During a flush cycle, pressure is used to purge stagnant water out of the watering system, and fresh water is introduced in its place. PulseCMC makes this happen by operating on solenoids to control the pressure and flow of water. It can also be used to manually actuate solenoids in rapid succession to remove any errant debris that may interfere with the solenoid attaining a proper seal.
The PulseCMC watering configuration includes settings to accommodate all automated watering system designs. The architecture and design of each vivarium is unique, depending on the needs of the facility and its staff. Edstrom works in conjunction with facility management and their architectural partners to ensure that PulseCMC is configured properly for each customer, allowing for maximum productivity and efficiency.
To learn more about PulseCMC or Edstrom Automated Watering, go to our website www.edstrom.com or contact an Edstrom representative.
Q: My lab has recently purchased an Edstrom Handy Bottle Basket Filler to speed up our manual bottle filling operation. If our building had a power failure, would we still be able to use the unit to fill bottles?
A: Since the Handy Bottle Basket Filler has no electrical components, it would continue to function in the event of a power failure, assuming there is pressure in the water line. Alternately, the unit could be used if the water were gravity fed.
Q: If I were to request that Edstrom preform a water quality test, what kinds of contaminants do you test for?
A: Edstrom can perform several different types of water quality tests, depending on the nature of the concern. The standard water quality test that Edstrom performs includes 108 analyses, including microbiological, inorganics, radiological, metals, herbicides, and volatile organics. In addition, Edstrom can test for pseudomonas, silt density and silica, as well as test for the presence of Bisphenol A (BPA).
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