Water Conditioning & Purification Magazine

Pipe repair

Sunday, November 15th, 2020

Internal Pipe Technologies’ Aquapea, now available in North America, is a free-swimming, efficient method of non-intrusive, in-line pipe repair that bonds to all pipe materials. The patented polymer-based technology is comprised of a specially formulated polymer material that, when mixed, starts a curing process; at its core is a polypropylene flotation and plugging methodology. A single pea works its way through piping systems (with the force of the leak) and plugs the pinhole.
(888) IPT-6649
www.internalpipetech.com
info@internalpipetech.com

Soft starters

Sunday, November 15th, 2020

Siemens introduces First Soft Starters with integrated safe torque off (STO) functionality. Features include integrated motor protection function that ensures fast, reliable shutdown and a restart interlock feature and failsafe digital input to help ensure user safety. Products are SIL 3- and PL e-compliant as well as ATEX- and IECEx-certified. The SIRIUS 3RW55 Failsafe soft starters are the first to feature the integrated STO function, which ensures that the motor comes to a complete standstill if an operator initiates an emergency shutdown.
www.usa.siemens.com

Touchless coolers

Sunday, November 15th, 2020

The International H2O® True Touchless System features Adjustable Proximity Sensitivity Sensors, from 0.5 to 6+ inches, as well as four primary functions: hot-water safety lock; hot-water dispensing; ambient or sparkling-water dispensing and cold-water dispensing. With the separately operating and simultaneously fully functional soft-touch sensor and True Touchless System, clients and customers may use either interface at their convenience and preference.
www.internationalh2o.com
sales@internationalh2o.com
(800) 982-8311

Product guide

Sunday, November 15th, 2020

Purolite Corporation’s latest product summary guide provides a broad overview of the characteristics and applications of the company’s ion exchange and specialty resin products. The 40-page interactive guide features over 300 products and is divided by product type, industry, application or brand. The table of contents contains links that can immediately take users to the desired section(s) within the guide. This update includes several products not featured in the last guide and new sections featuring organic scavengers, fine-mesh resins and products for condensate polishing, food and beverage, and metal plating.
www.purolite.com

Ultrasonic and vortex flowmeters

Sunday, November 15th, 2020

KROHNE introduces the OPTISWIRL 2100 vortex flowmeter designed for basic utility applications in the process industries and is an economical solution for the measurement of liquids, (wet) gases, saturated and super-heated steam where high accuracy is not required. Features include Advanced Vortex Frequency Detection (AVFD) technology for stable measurements with demanding process conditions from -40 to +464°F (-40 to +240°C); flange and sandwich versions with optional integrated nominal diameter reduction and remote option with converter installation up to 50 meters (164 feet) from the sensor.

OPTISONIC 6300 V2 ultrasonic flowmeter with a stationary, clamp-on design is ideal for a wide range of systems. It allows users to measure flow anywhere necessary, all while processes continue. New to the unit is a viscosity range of up to 200 cSt: no need for re-greasing due to solid coupling material, a next-generation signal converter for enhanced application range, Namur NE107 diagnostics and integrated thermal energy calculation. This product is suitable for diameters ranging from 0.5 to 160 inches (1.2 to 406.4 cm). It has a process temperature range of -40 to 392°F (-40 to 200°C). This flowmeter is constructed as a submersible stainless steel sensor rail (IP 68/NEMA 6P).
www.krohne.com

POU RO Systems and Arsenic Reduction

Sunday, November 15th, 2020

By Rick Andrew

One of the technologies commonly employed to help reduce arsenic levels in drinking water, particularly for those people who have private wells that are impacted by naturally occurring arsenic, is reverse osmosis. Because arsenic does occur naturally in groundwater, it is a relatively common issue that homeowners with wells can face. In fact, Wikipedia states that arsenic is the 53rd most abundant element in the Earth’s crust and comprises about 1.5 ppm of it.1 Because of this relative abundance, it is not uncommon for arsenic to be present at detectable concentrations in groundwater. And there are health concerns related to arsenic in drinking water.

According to Michigan Department of Environment, Great Lakes and Energy, long-term exposure to low levels of inorganic arsenic in drinking water is known to cause human health problems including cancer, thickening and discoloration of the skin, problems with blood vessels, high blood pressure, heart disease, nerve effects including numbness and/or pain, and interference with some important cell functions.2 Because of these health effects, any public or private drinking water supply drawn from wells in aquifers with arsenic contamination at a level higher than 10 µg/L will need treatment in order to comply with the US EPA maximum contaminant level (MCL). Due to the abundance of arsenic and its prevalence in groundwater, coupled with the health effects related to drinking water contaminated with arsenic, NSF/ANSI 58 includes requirements for testing and establishing claims related to arsenic reduction capabilities of POU RO systems.

Forms of arsenic
It is important to understand that arsenic occurs in water in two different forms, also known as oxidation states. These are pentavalent arsenic, also called As(V), As(+5) and arsenate, and trivalent arsenic, also known as As(III), As(+3) and arsenite. These forms have different chemical properties and because of these different properties they respond differently to treatment technologies. Treatment technologies have varying effectiveness in treating water contaminated with arsenic, based on the form or oxidation state of the arsenic.

The general rule of thumb is that for most technologies, trivalent arsenic is more difficult to treat in drinking water than pentavalent arsenic. The good news is that trivalent arsenic can be quite easily and quickly oxidized to pentavalent arsenic through the use of typical disinfectant chemicals, the most common being free chlorine. Other oxidizing chemicals can also be used to convert trivalent arsenic to pentavalent arsenic. As per the rule of thumb, RO has limited effectiveness for treatment of trivalent arsenic; it’s much more effective in treating pentavalent arsenic. Accordingly, NSF/ANSI 58 includes requirements for claims of pentavalent arsenic reduction but not requirements for evaluation of trivalent arsenic reduction.

Claims of pentavalent arsenic reduction under NSF/ANSI 58 are limited to water supplies with a free chlorine residual present or water supplies demonstrated to contain only pentavalent arsenic. This approach in the standard is consistent with the typical approach to treatment of groundwater contaminated with trivalent arsenic by POU RO. A chlorination device just upstream of the POU RO is usually employed to assure that all of the arsenic present in the water is oxidized to the pentavalent form prior to being treated by the RO. This combination of technologies allows for effective oxidation of the trivalent arsenic to pentavalent arsenic, which in turn is effectively treated by the POU RO system.

Because of the issue of trivalent and pentavalent arsenic and the use of chemical oxidation as pretreatment, the topic of arsenic treatment in groundwater can be confusing to end users, especially homeowners. Recognizing the potential for confusion, NSF/ANSI 58 requires specific information to be included in product literature for POU RO systems that have pentavalent arsenic reduction claims. This information is required in the form of an Arsenic Fact Sheet included with the performance data sheet, which:

  • describes the forms of arsenic present in groundwater
  • explains that the system treats only pentavalent arsenic
  • refers to the use of free chlorine to oxidize trivalent arsenic to pentavalent arsenic
  • emphasizes the importance of testing the water periodically to verify system performance
  • highlights the importance of proper system maintenance, including replacement elements

With all of this information included, the Arsenic Facts Sheet provides a useful and readily available guide for end users to understand how their treatment systems function and what steps must be taken to maintain them.

Testing POU RO for reduction of pentavalent arsenic
NSF/ANSI 58 describes the test method for reduction of pentavalent arsenic by POU RO in great detail, beginning with the composition of the test water. This test water is created beginning with RO/DI water, to which sodium chloride is added to achieve a concentration of 750 mg/L. Pentavalent arsenic is added to this water at a concentration of either 50 ug/L or 300 ug/L. In either case, the system must reduce the arsenic to ≤ 10 µg/L.

Beyond the test water, the method also specifies how the POU RO system is to be operated. The test is conducted with the system operated over the course of a week. This operation incorporates sampling and operational cycles that are designed to cover a variety of usage patterns. By varying the usage patterns, the test can assess the impact of those usage patterns on the overall performance of the system. For example, for a typical POU RO system with a storage tank and automatic shut-off valve, there are operational cycles that test arsenic reduction when:

  • starting with the storage tank full, completely emptying the storage tank and taking a sample, followed by allowing the tank to refill
  • starting with the storage tank full, emptying the storage tank to the point where the automatic shut-off valve is activated and taking a sample, and then allowing the tank to refill from this point
  • starting with the storage tank full, drawing five percent of the daily production rate of the unit and sampling, then allowing the tank to refill
  • a 48-hour stagnation with no water drawn from the storage tank, followed by completely emptying the tank and taking a sample, and then allowing the tank to refill

Whenever samples of treated water are collected, samples of the challenge water are also collected. These treated and challenge water samples are analyzed to determine the effectiveness of the treatment. The standard requires that the average value for all of the treated water samples, as well as 90 percent of the individual treated water samples, must be ≤ 10 µg/L arsenic.

Solutions for private well owners impacted by arsenic
Dealing with problem well water is a relatively common challenge for rural homeowners. When the problem is arsenic contamination, things can become a bit more complex and also can have health implications. Fortunately, the POU/POE industry provides proven solutions for private well owners. One of those proven solutions for contamination with arsenic is POU RO treatment. The proof comes through testing and certification to NSF/ANSI 58 for arsenic reduction. The testing provides confidence in arsenic reduction performance and the certification adds ongoing assurance of this performance, plus requirements for a clear explanation of the nature of arsenic contamination, the function of the POU RO system and the responsibilities of the homeowner to properly maintain the system to assure it continues to provide effectively treated drinking water.

References

  1. Arsenic. Wikipedia. https://en.wikipedia.org/wiki/Arsenic#:~:text=Arsenic%20is%20a%20chemical%20element,Arsenic%20is%20a%20metalloid
  2. Arsenic in Well Water. Michigan Department of Environment, Great Lakes and Energy. https://www.michigan.gov/documents/deq/deq-wd-gws-wcu-arsenicwellwater_270592_7.pdf

About the author
Rick Andrew is NSF’s Director of Global Business Development–Water Systems. Previously, he served as General Manager of NSF’s Drinking Water Treatment Units (POU/POE), ERS (Protocols) and Biosafety Cabinetry Programs. Andrew has a Bachelor’s Degree in chemistry and an MBA from the University of Michigan. He can be reached at (800) NSF-MARK or email: Andrew@nsf.org

Wildfires and Water Quality

Sunday, November 15th, 2020

By Kelly A. Reynolds, MSPH, PhD

Wildfires in 2020 have reached record proportions in North America. These events are not only damaging to people, structures and land, but also dramatically impact source-water quality. Future predictions indicate worsening conditions and the need for proactive water treatment management.

A record year
California has recently experienced five of the top 20 largest wildfires in the history of the state. In the current year, over 8,400 wildfires have burned over four million acres in the Golden State, doubling the previous record and destroying over 9,200 structures and killing 31 people.1 The California August Complex Fire, which started on August 10, has burned over a million acres and was still only 75-percent contained at the time of this writing. Further, over 16,000 firefighters continue to work on containing another 23 major blazes. With fire season typically spanning from August to November, experts fear these numbers could continue to increase. Dry, windy conditions, above-normal temperatures and no rainfall in the forecast continue to drive the risk of additional wildfires throughout the state.

Other western areas of the United States and Canada are also at risk. According to the National Interagency Fire Center’s Coordination Center, “above normal significant fire potential is expected across much of California, Arizona, eastern Nevada, Utah, Colorado Rockies and southern Wyoming in October” with elevated fire-activity risks expected in November and into the winter for Oklahoma and Texas. The majority of fires in 11 US states are on US Forest Service or national park lands, including protected regions of Washington, Idaho, Wyoming, Colorado, Arizona and Montana. Likewise, approximately 80 percent of US freshwater resources also originate on forest lands. High-quality water from forested-source watersheds benefits from natural rainfall, storage and filtration, a process valued at $4.1 trillion US (2013 dollars) per year.2

Devastating effects
Many of the western wildfires were started by lightning. Others were accidental or suspected arson. All were further exacerbated by drought conditions. In much of the western US, an earlier than usual snowmelt and disappointing monsoon season intensified already dry regions. Climate change and wildfire mismanagement are also blamed for contributing to the crisis. Structures ever-encroaching on remote forest regions and fire-suppression strategies are additional controversial issues that likely contribute.3

Wildfires have a devastating impact on surrounding ecosystems, affecting soil, water and air-quality measures. After the flames are extinguished and the air clears, source waters continue to be polluted from land runoff and erosion contaminants choking lakes and streams and taxing municipal treatment works. According to the US Geological Survey, municipal water providers spent over $26 million on water quality treatments to remove wildfire-associated debris following two Colorado fires.4

The use of fire retardants can lead to an increase in chemicals (such as phosphates, nitrates and nitrites) and promote algal blooms in reservoirs. Changes in water chemistry can disrupt established biofilms in plumbing, leading to leaching of lead, copper and microbes or the formation of cancer-causing DBPs. Heavy metals and residuals from burned structures and melted plastics are additional sources of hazardous chemicals that can reach the water supply. Following the 2002 Hayman Fire in the Colorado Rocky Mountains, concentrations of arsenic, aluminum, cadmium, iron, lead and mercury were two to 2,500 times higher than normal.2

Treatment difficulties
In 2018, the Water Research Foundation (WRF) released Wildfire Impacts on Drinking Water Treatment Process Performance: Development of Evaluation Protocols and Management Practices.5 Researchers evaluated the effects and treatability of source waters impacted by wildfires in consideration of treatment plant operations and costs, while providing recommendations and a framework for water quality and treatment assessment. Changes in source water quality require corresponding responses in treatment works that can be difficult to synchronize. While eroding soil, ash, sediment and other fire debris from land runoff can be physically filtered from water supplies, other contaminants require advanced treatments.

Weeks following the 2017 Tubbs Fire in Santa Rosa, CA, residents continued to smell chemicals in their tap water. The smell turned out to be benzene in the water, a known carcinogen that is regulated by US EPA. The federal limit is five ppb but California set a more stringent standard at one ppb. Initial testing in Santa Rosa found concentrations of eight ppb, well above California’s standard and even the higher federal standard. Additional testing reportedly resulted in some sites testing positive at levels of 40,000 ppb of benzene in the water (US EPA’s hazardous waste threshold is 500 ppb).6 The source of the benzene was not definitively identified; contaminated air, melted plastics and burning structures have all been suggested factors. The contaminants appeared to be stuck in the plumbing and distribution system, which required continuous flushing and even replacement of service lines to fix the problem. A similar scenario was documented in Paradise, CA following the 2018 Camp Fire. This time homeowners reported symptoms of nausea, light-headedness and other symptoms after showering in potentially contaminated water.

Other impacts of fire on water quality include changes in water flow and pressure due to fire-hydrant releases or power outages. During pressure losses, contaminants may be drawn into distribution pipes or water may sit stagnant at certain points in the line. Changes in water taste, odor and color may indicate a problem but many harmful contaminants cannot be detected by human senses, even at unsafe levels.

Prepare at the point of use
Wildfires are unpredictable and subsequent contamination potentials are difficult to foresee. Post-fire residuals in the environment threaten safe water supplies, the ecosystem and public health. History supports that adjusting water treatment works to handle the massive influx of contaminants may be problematic, resulting in delayed action and delivery of water that exceeds regulatory health standards. At-risk regions should consider how tap-water supplies are affected and prepare for treatment at the point of use while supporting natural resource management groups.

How you can help
For information on how you can donate to help those affected by wildfire disasters or who are working on strategies to prevent and control wildfires, contact the Center for Disaster Philanthropy at www.disasterphilanthropy.org

References

  1. Welcome to Daily Wildfire Report. https://www.fire.ca.gov/daily-wildfire-report/. Accessed October 12, 2020.
  2. Bladon KD, Emelko MB, Silins U, Stone M. Wildfire and the future of water supply. Environ Sci Technol. 2014;48(16):8936-8943. doi:10.1021/es500130g
  3. ‘Wake-up call’: wildfires tear through drought-plagued US south-west. The Guardian. https://www.theguardian.com/us-news/2020/aug/26/wildfires-us-south-west-colorado-arizona-new-mexico-utah. Accessed October 12, 2020.
  4. USGS. Water Quality After Wildfire. https://www.usgs.gov/mission-areas/water-resources/science/water-quality-after-wildfire?qt-science_center_objects=0#qt-science_center_objects. Accessed October 12, 2020.
  5. Wildfire Impacts on Drinking Water Treatment Process Performance: Development of Evaluation Protocols and Management Practices. The Water Research Foundation. https://www.waterrf.org/research/projects/wildfire-impacts-drinking-water-treatment-process-performance-development. Accessed October 12, 2020.
  6. How Wildfires Are Contaminating The Water Supply With Benzene, Other Hazardous Chemicals. Here & Now. https://www.wbur.org/hereandnow/2020/10/02/wildfires-water-contamination. Accessed October 12, 2020.

About the author
Kelly A. Reynolds is a University of Arizona Professor at the College of Public Health; Chair of Community, Environment and Policy; Program Director of Environmental Health Sciences and Director of Environment, Exposure Science and Risk Assessment Center (ESRAC). She holds a Master of Science Degree in public health (MSPH) from the University of South Florida and a doctorate in microbiology from the University of Arizona. Reynolds is WC&P’s Public Health Editor and a former member of the Technical Review Committee. She can be reached via email at reynolds@u.arizona.edu

Water Quality Impact from California Wildfires

Sunday, November 15th, 2020

By Shannon Murphy

Living in the southwestern United States since the summer of 2003 has brought to me heightened awareness and (unfortunately) first-hand experience to the news and the effects of wildfires. This year seems to be an unusually aggressive season pertaining to wildfires, starting with the latest 2019-2020 Australian fire (known as Black Summer) and now into the most recent 2020 wildfire season in the US. In California, a state of emergency was called on September 28 in response to significant wildfires burning throughout the state, especially in Napa, Sonoma and Shasta counties. (California ranks the highest in terms of properties at risk to undergo damage due to wildfires).1

Cost associated with these fires are staggering, in which for all of the 2018 wildfire season cost $24 billion (USD), overtaking the previous record set in 2017 of roughly $16 billion, all primarily associated with buildings and infrastructure, as well as firefighting costs. In Australia this past wildfire season, there were over 46 million acres burned, which led to roughly 6,000 structures being destroyed, with significant loss to wildlife in the regions affected.

Perspective
Forested land makes up over 766 million acres representing roughly 33 percent of the total land mass in the US. Additionally, roughly 53 percent of the US water supply is surrounded by this forest land.2 In the US over the past 10 years, (on average) there have been 64,000 wildfires, burning just under seven million acres every year. As of October 1, there have been over 44,000 wildfires across the country, burning nearly eight million acres in the current season, causing this to be an above-average burn season.

Of significant note, when looking at the numbers dating back to 1990, where there was a higher number of annual fires (nearly 79,000), the damage due to these fires was less than half (averaging just over three million acres burned) of what we have been experiencing in the last 10 years.3 In short, a growing number of Americans is being directly affected by the effects of these wildfires.
According to the US Department of of Interior, almost 90 percent of the wildfires that occur annually are caused by unintended human interaction (people as opposed to nature). All too often we hear about fires being caused by improper campfire management, cigarettes, off-road vehicle exhaust, fireworks. In the case of the deadliest and most destructive fire in California, a downed electrical power line was determined to be the cause.

Camp Fire and Paradise California
In 2018, a fire ignited by a faulty electrical transmission line started in northern California’s Butte County and quickly became the deadliest and most destructive wildfire in the state’s history. Covering nearly 155,000 acres and destroying almost 19,000 structures, the towns of Paradise and Concow were significantly impacted, having large portions of their towns lost due to fire. It was not until several months after the fire that I would start to understand the serious impact of wildfires on water distribution and quality. Following the fire, an associate living in the general area reached out in order to inquire about drinking water treatment for those affected, which led to a conversation with the Paradise Irrigation District manager in order to obtain additional information about general water quality there.

Restoring pressure
The City of Paradise and the Paradise Irrigation District worked for several months just to re-establish pressure within the distribution system. Due to the intense heat and significant number of buildings destroyed by the fire, the district had to work to get the water treatment plant up and running just to identify where there were leaks within the system. Initial repairs of damaged and open water lines (where visible) were initially conducted, followed by water plant start-up, which revealed more serious damage underground (due to the heat of the fire), as well as at the water mains and other distribution breaches.

Once identified, these areas were repaired and the process was started up again where the next group of leak points were identified. From there the district would repair again and then go through the entire process for the next several months until finally the treatment system was contained and able to hold pressure. Once the treatment system was back up and running, samples were taken of the water in order to establish overall quality. There were a number of factors in play which were impacting the overall water quality of the system.

VOC cocktail
Initial reports indicated significant levels of benzene in the water; however, there were also several other contaminants that were frequently mentioned as the ‘VOC cocktail.’ While inconclusive as to pinpoint from where the benzene was originating, several reports identified a few culprits, such as melted plastic service lines and burnt water meters; various burning materials from within the destroyed buildings were thought to be the main culprit. These various materials that were burning may have been sucked into the water distribution system during or after the fire, as system operators worked to get the system back up and pressurized. On average, benzene levels in the water tested around 31 ppb, with a few initial test results prior to continued flushing of the system coming in much higher than that. (Federally US EPA has set an MCL for benzene at five ppb; the MCLG is zero. The state of California’s regulatory level for benzene is even lower at one ppb.)

During a forest fire, especially during ones that burn hot, there are significant amounts of dissolved organic matter (DOM) that work their way into the source water. This significant increase in DOM creates a burden on the normal coagulation/flocculation or other settling equipment utilized during standard operation. (In a research study awarded by US EPA to Clemson University, a study of the effects of wildfires on drinking water was undertaken).4

Similar to what was observed in the Paradise Irrigation District, not only were there increases in detected benzene but also an increase in DBPs due to this excessive DOM loading. Water systems affected by wildfires need to be flushed and disinfection increased for the entire system. Increase of chlorine usage, in conjunction with this increase in DOM creates a perfect formula for DBPs developing within the distribution system. Free chlorine reacting with organic material results in the development of increased DBPs, especially in the form of trihalomethanes (chloroform–TTHM) and haloacetic acids (HAA).

Unfortunately, another aspect to significant burn is the sudden increase in nutrient-load within the ecosystem. With vegetation lost, runoff increases, which also leads to significant nutrient-loading in the water system. Frequently this results in increased algae-bloom within the watershed, especially as these fires typically occur during hot and low-rain seasons.

What we have learned
Not all wildfires are as severe as the Camp Fire, so not every community affected by wildfire will have the same results; however, the last few years have shed some light on issues created by wildfires and drinking water. First, we have a better understanding of what parameters to look for and what are the precursors. DBPs and other VOCs should be evaluated soon after a water system is up and running following a fire, especially if the fire is considered a significantly hot burn. Communities hit by wildfires have a wide array of issues to face. In cases where homes and other buildings are destroyed, just setting up shelter and finding clothes and food become a daily struggle. Initially, people turn to bottled water and tankers as their only water source for everything from drinking and cooking to bathing and laundry.

Currently there are a number of initiatives within our industry that are bringing to light the concept of POE and POU final-barrier treatment options. A greater focus is underway to investigate small community Safe Drinking Water Act-compliance achievement through POU and POE systems. Looking for solutions for communities affected by 1,2,3-TCP is moving forward with an initiative to include this testing in Standard 53 for certification. Additional work will also need to be done to establish testing parameters for POE systems, since VOCs should be addressed for the whole-house POE systems.

Conclusion
Fires are projected to become bigger and more frequent, leading to an increased focus on their aftermath. As regulatory issues arise, especially for small rural communities, greater opportunities will become apparent where we, the water filtration industry, can step up and lend a helping hand to provide safe, clean and affordable water to these communities in dire need.

References

  1. “Facts + Statistics: Wildfires.” Insurance Information Institute. https://www.iii.org/fact-statistic/facts-statistics-wildfires
  2. Blackard et al. 2008. “Remote Sensing of Environment 112(4): 1658‐1677.“ US Forest Resource Facts and Historical Trends. 2012.
  3. National Interagency Fire Center (NIFC).
  4. “Fuel Reduction Techniques as Effective Forested Watershed Management Practices against Wildfire: Drinking Water Quality Aspects”. US EPA. https://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/10493/report/F

Arsenic Toxicity: Why and How to Remove It from Drinking Water

Sunday, November 15th, 2020

By Gary Battenberg

What is arsenic toxicity?
Arsenic toxicity, also referred to as chronic arsenicosis in humans, is well known and occurs when one is exposed to high levels of arsenic more than 0.05 mg/L. Arsenic is generally found in one of two chemical valence states: as arsenite AS+3 (ASIII) and arsenate AS+5 (ASV). Effects of arsenic ingestion in small amounts appear slowly and may take several years before poisoning becomes apparent. When ingested in large amounts, chronic arsenicosis manifests itself in many ways in different parts of the world.

Arsenic can be inhaled and may be taken up dermally through the skin. For example, those working in the smelting industry may be exposed to airborne inorganic arsenic which may be present in coke emissions. Therefore, it is prudent to wear appropriate breathing apparatus to prevent inhalation. Most plants now have air-emission scrubbers to eliminate toxic gasses and chemicals. Dermal exposure from wood products treated with chemicals containing arsenic can cause arsenic poisoning as well.

Where is arsenic prevalent?
Countries where high levels of arsenic have been confirmed in groundwater include the United States, Mexico, China, India and Taiwan. Western US states typically have arsenic levels that exceed 10 micrograms per liter (µg/L, ppb) compared to the rest of the US. Groundwater from artesian wells in villages along the southwest coast of Taiwan containing extremely high levels of arsenic are known to cause Blackfoot Disease. Patients afflicted with this disease suffer severe systemic arteriosclerosis with black, mummified dry-foot gangrene, which often requires amputation in lower extremities. Fortunately, implementation of treated tap water to these villages has resulted in a dramatic decrease in the severity of arsenic poisoning over the past 30 years.

What are symptoms of arsenic poisoning?
Health effects range from mild to very severe symptoms. What makes arsenic so dangerous is that it has no taste or odor, which means one can be exposed to it without knowing it. Some of the symptoms include:

  • Tingling of fingers and toes, red or swollen skin and changes such as lesions or warts
  • Muscle cramps and abdominal pain
  • Diarrhea, nausea, vomiting and persistent digestive problems
  • Persistent sore throat
  • Damage to cardiovascular and nervous systems
  • Endocrine disruptor

Arsenic has been shown to cause cancer of the skin, bladder, prostate, kidney, liver, lungs and nasal passages. The most common cause of arsenic poisoning is contaminated groundwater, where it is abundant in the earth and leaches from natural deposits. Additionally, arsenic seeps into groundwater from industrial plant runoff as well as from other sources, such as:

  • Living near industrialized areas, exposed landfills or waste sites
  • Breathing contaminated air containing arsenic from plants or mines that use arsenic
  • Breathing in smoke or dust from treated wood or waste products
  • Smoking tobacco products

Arsenic regulations and guidelines
US EPA, under authority of the Safe Drinking Water Act (SDWA), has set the maximum contaminant level goal (MCGL) for arsenic at zero mg/L as a health-based goal. The maximum contaminant level (MCL) establishes the highest level of contaminant that is allowed in drinking water. MCLs are enforceable standards that are set as close to MCLGs as feasible, using the best available technologies while taking costs into consideration. Current standards for arsenic are:

  • US EPA: MCL = 0.010 mg/L (or ppm) MCLG = zero
  • WHO Guideline MCL = 0.010 mg/L (10 µg/L or ppb)

The first rule in water treatment is to obtain an accurate and complete water analysis where health-related contaminants are known or suspected to be present in a water supply. A complete analysis will reveal background issues that may affect the performance of the treatment methods available for remediation. Effective, reliable and consistent arsenic removal can be achieved when accurate interpretation of a water analysis is rendered, which eliminates those treatment methods that don’t provide optimal results. This allows water treatment specialists to present viable options to prospective customers.

Treatment methods
There are several treatment methods available that are generally recognized as being effective in reducing arsenic to meet or exceed the maximum contaminant level. A look at some of the available methods may be helpful when sourcing effective arsenic remediation.
Where arsenic is present in municipally treated water with measurable free available chlorine (FAC), it will be in the oxidized state of arsenate. In this state, arsenic is easy to remove from water. Where the water is only treated with monochloramine (NH2CL), however, it has been found that all the arsenite may not be converted to arsenate. For municipally treated water with monochloramine, it is wise to obtain an arsenic speciation test to determine the concentration of each form. RO and distillation are the most prevalent technologies currently being used to remove/reduce arsenic from municipal and groundwater supplies. Other options include activated alumina, which exhibits a high affinity for arsenic, lead and fluoride. This media works in pH range between 4.0–10.0 with optimal pH at 5.0 for best results. Performance is flow-dependent so care must be used when specifying this treatment option.

Pre-coated or impregnated iron-based media will reduce both species from water when properly applied within application guidelines. These types of media have a specific service life based on the calculated capacity within a specific volume of media, relative to the total arsenic levels in the water. Strong base anion resins chosen for their selectivity have proven very effective at removing arsenic from water. Some anion resins are functionalized with hydrous iron oxide nanoparticles, which provide a very high affinity for arsenite and arsenate. Care in handling spent media for disposal is critical and it should comply with federal guidelines. Newer media can be processed to remove arsenic before the resin is taken to a land fill.

Manganese Greensand (which dates to the 1950s and is still used today in many water treatment plants) is the grandfather of treatment methods to remove iron, manganese, arsenic and radium. Many dealers today still use manganese greensand for pretreatment of problem water containing iron, manganese and hydrogen sulfide. In fact, many water wells across the US contain arsenic where pump depths approach and/or exceed 200 feet (60 meters). Arsenite is converted to arsenate, bound with the oxidized iron and held in the bed until regeneration removes the oxides and capacity is restored after regeneration. Use care when handling potassium permanganate (KMnO4) and follow the package instructions. The newer Manganese GreensandPlus provides the same capability as the original, with the added benefit that water temperature is no longer limited to 85°F (29.4°C) because the media substrate is silica-based.

There are some very exciting technologies in R&D as well as field testing which will soon be available. Advancements in treatment media such a proprietary filter paper are on the horizon. Organoclays and granular activate carbon (GAC) with arsenic selective sorbents have been in use now for over 10 years with very good success. Choices today for treatment methods are many. Be sure and clearly understand, however, the capabilities and limitations of the chosen treatment method with accurate interpretation of the complete water analysis. Identify those contaminants or conditions that reduce the effectiveness of the chosen technology, which may mean rejecting it because the method will not yield the desired results.

Arsenic is a very dangerous and damaging health-related contaminant, so it is very important to apply due diligence when sourcing, selling and servicing treatment products for arsenic remediation. Products should be certified to WQAS-200, NSF 53, NSF 58 and NSF 62 for arsenic reduction. These certifications give the dealer and consumer the assurance of effective remediation when properly installed and maintained with timely media or cartridge replacement according to manufacturer recommendations.

About the author
Gary Battenberg is a Business Development Manager-Senior for Argonide Corporation. Previously, he was Technical Manager, Water Treatment Department of Dan Wood Company. Prior to that, Battenberg was Technical Support and Systems Design Specialist with Parker Hannifin Corporation. His nearly four decades of experience in the water industry include a proven, successful track record in areas of sales, service, design and manufacturing of water treatment systems. Battenberg’s technology base covers mechanical and adsorptive filtration, ion exchange, UV sterilization, RO and ozone technologies. He has worked in the domestic, commercial, industrial, high-purity and sterile water treatment arenas. A contributing author to WC&P International magazine and a member of its Technical Review Committee since 2008, Battenberg was voted one of the magazine’s Top 50 most influential people in the water treatment industry in 2009. He can be reached by email at gary@argonide.com or by phone (407) 488-7203.

Using the WQRF Contaminant Occurrence Map to Research Groundwater and Arsenic

Sunday, November 15th, 2020

By Kim Redden

If you’ve been in the water treatment industry for any length of time, you likely have heard about the need for a comprehensive national water quality dataset for private wells. Since private wells are not federally regulated, there is no national on-going data collection for these drinking water sources. As we’ve witnessed in California and plenty of other areas across the United States, private well water quality can be a potential concern for public health and corrected with proper POU/POE treatment. The objective to collect private well data at a national scale is quite a large undertaking and would require a somewhat complex network and funding to process samples. There are, however, some resources already available to research public water systems (PWS) using groundwater and some states provide private well data on their websites (such as this one from Wisconsin: https://www.uwsp.edu/cnr-ap/watershed/Pages/WellWaterViewer.aspx).

WQRF Contaminant Occurrence Map
The Water Quality Research Foundation (WQRF) has funded a national data collection effort and mapping tool for water quality occurrence data of public water systems. The data collection, statistical analyses and mapping tool were conducted and developed by Corona Environmental Consulting. The mapping tool is an illustration of the occurrence data and a way to make the information accessible to the public (www.WQRF.org/map). The project successfully collected data for 57 contaminants over a 10-year period, from January 2009 to December 2018. This data collection effort resulted in over 59 million data points, one of the largest datasets on water quality available.

The data collection focused on regulated drinking water contaminants that have an enforceable level (MCL or action level) above the health-based goal level (MCLG). The data collection also included secondary contaminants with aesthetic issues, including iron, hardness, manganese, pH, chlorine and chloramine. The data collection methodology included a call for information to all the states, as well as used US EPA’s Fourth Unregulated Contaminant Monitoring Rule (UCMR4) occurrence data. US EPA’s State Drinking Water Information System (SDWIS) was also used to collect data on system size, system type, source water and addresses to geolocate the data for the online mapping tool.

The scope of the data collection is public water systems; however, the mapping tool does allow users to customize the occurrence data shown by use of several different data filters, including source-water type. As a result, the mapping tool can be used to review groundwater data and how that may compare to surface water or groundwater under the direct influence of surface water for a specific contaminant. The map’s other data filters allow for the user to see occurrence based on various statistical summaries, year and PWS size and type.

Observations about arsenic
Data for arsenic was collected from 46 states, resulting in 596,013 data records from 64,694 public water systems. The researcher performed several different statistical analyses to compare what types of circumstances affect the occurrence of arsenic. Statistical analyses included all data collected and were not based on sample location, i.e. untreated or treated water. As a result, these analyses did not reflect a system’s compliance with drinking water standards or the water quality at a consumer’s tap. For the national 50th percentile or median, which could be considered an appropriate statistic to review what is typical, the arsenic concentration was non-detect. Further, if looking at the national 95th percentile for a representation of what is more a worst-case scenario, the arsenic concentration was 17 µg/L. As suspected, the data showed groundwater had the highest 95th percentile arsenic levels compared to other source waters (see Figure 1). A statistical analysis also compared arsenic occurrence and system size, and the analysis found that arsenic concentrations were highest for the very small systems compared to larger systems.

Using the Contaminant Occurrence Map
Of the 46 states that provided data, not all had data available for all the requested contaminants due to a variety of reasons. Therefore, white space on the map indicates no data available for that area and non-detect data points indicate that data was available with a non-detect result. As the data collection effort included regulated contaminants where the concentrations are compliant with the Safe Drinking Water Act (SDWA) but above non-enforceable health-based goals, it’s important to understand that occurrence data does not necessarily indicate a SDWA violation. The map displays statistical summaries for all the data collected to show occurrence. It is not designed to be used to track SDWA violations. SDWA compliance is calculated on a specific schedule and based on yearly running averages. Additionally, it’s important to note the address for each data point from SDWIS may be an office building and not the treatment plant itself, so state level or regional level is the most appropriate use of the map (as opposed to a zip-code level).

Conclusion
This new mapping tool may not fully close the data gap for wells, but it provides access to an immense amount of data for groundwater and customized searches for researching contaminants, systems and source waters. Additional data in the coming years will make it an even more effective tool for reviewing contaminant occurrences across the United States.

About the author
Kimberly Redden, WQRF Foundation Relations & Research Manager, has a Bachelor’s Degree in chemistry from North Central College and Master’s Degree in public health from Elmhurst College. She has worked for WQA since 2013 in Regulatory and Technical Affairs as well as the Professional Certification and Training Departments.

About the organization
The Water Quality Research Foundation, formerly the Water Quality Research Council (WQRC), was formed in 1952 to serve on behalf of the Water Quality Association (WQA) as a universally recognized, independent research organization. The mission of WQRF is advancing knowledge and the science of high quality, sustainable water. WQRF’s vision is water quality improvement through relevant research. https://www.wqrf.org/

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