On The Job: Chemist Ensures Safe Water Flows To Your Home And Business

By Warren Tenney

Mark Xerxis is a chemist, but don’t imagine him behind a set of tubes, Bunsen burners and microscopes. Mark runs the metals lab within Scottsdale’s Water Quality Laboratory, which means assuring Scottsdale’s water never has a problem with elements such as arsenic, chromium, lead or copper. His main tool is something called an Inductively Coupled Plasma Mass Spectrometer. Mark gets up from his chair and writes the name on a white board. The piece of equipment looks like a giant copying machine with silver tubes venting out of the ceiling. Each morning it is Mark’s job to maintain, calibrate and optimize all the machines in his lab before running the daily samples, up to 60 a day.


Mark Xerxis runs the metals lab within Scottsdale’s Water Quality Laboratory.

Scottsdale and all the AMWUA cities take numerous daily samples from their drinking water systems, wells, or wastewater treatment plants. Mark tests Scottsdale’s samples for about 30 metals. The U.S. Environmental Protection Agency (EPA) regulates most of the metals that can be found in water. The lab also monitors for metals that could be regulated in the future, known as “emerging contaminants.” EPA will change the amount of metal permitted in water if it has new data to support a revised regulation. For example, in 2006 the EPA changed the level of arsenic permitted in American drinking water from 50 parts per billion to 10 parts per billion. That required new equipment in the treatment plants and new testing in the labs.

Preparing himself for all this responsibility didn’t come easy for Mark. He arrived in the United States – Arizona specifically – in 1987 at age 19 speaking only Polish. His mother and father were active in Poland’s anti-communism Solidarity Movement when the movement’s protests – as well as its members – were violently suppressed. First his mother, then his father, made their way to the United States as political refugees. Mark and his sister joined their parents several years later.

Mark entered North High School in the Phoenix Union High School District as a senior. He credits the school’s English as a Second Language program for teaching him English quickly and well enough to move on to Phoenix College. There he pursued chemistry, a science that had enthralled him since he was a young boy. He kept studying and earned a Bachelor’s of Science degree in Chemistry from Arizona State University.

“You see people come here (the United States) and surround themselves with people who don’t speak the language and they don’t need to learn it,” Mark said, who understands how hard it is to learn a new language but calls not learning English a mistake. “Eventually, it backfires.”

After several years working as a chemist in private industry, Mark applied and was hired to work in Scottsdale’s Water Quality Laboratory. That was 17 years ago. Mark’s colleagues are responsible for four other labs within Scottsdale’s main lab where they monitor for organic and inorganic compounds as well as microbial contaminants. Mark and his fellow scientists are cross-trained to step into each other’s labs and take charge when necessary.

Water treatment is always moving forward and new processes are regularly being tested. Mark’s favorite days are when he gets to evaluate something new, like a proposed water treatment system. It’s up to the lab’s scientists to provide data about the strengths and weaknesses of a new treatment option, which often requires more than scientific know-how. Mark’s job includes presenting his findings to the city’s technical group as part of the decision making process. Also, Mark often makes presentations to explain the results of his experiments at industry conferences to help other cities optimize their treatment and testing processes.


Mark mountain bikes year round, but his adventures don’t always go as planned.

Mark, 47, lives with his wife and four rescued dogs in Apache Junction. Once out of the lab, it’s likely you’ll find him in the mountains. Truth be told, he’s a bit wild in his off hours. Here’s an example: On the hottest day of each Arizona summer the scientist straps to his back a hydration pack filled with ice and water (tap water never bottled: “I think it’s a waste of money. I work in the field, I test water and I know it is completely safe to drink.”). Then he puts a charged cellphone in his pocket and at 3 p.m. goes for a 10-mile mountain bike ride in the desert – just because he can. This year it was 117 degrees when Mark did his annual ride in the Usery Mountains. While he claims to be impervious to the heat, Mark doesn’t hesitate to show you photos of the time he was test-driving a new bike and suddenly veered into a patch of notoriously painful Jumping Cholla cactus.

In the summers, Mark works with high school students who intern at the laboratory. He likes to watch their eyes widen when they see the city’s array of equipment. Part of his job is to help them design an experiment and make a presentation to staff. One student decided to measure the metals in a cigarette so she could explain to her father the exact amount of metal he had taken into his body during his 20-year smoking habit. Mark said he has faith in the next generations of scientists to continue keeping cities’ water safe.

“It’s the best job there can be,” Mark said, calling himself just one member of a team that gets things done right. “It’s the people, the management, the science. Scottsdale has the best mix of everything. It’s very satisfying.”

For 47 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit amwua.org.

Putting Storm Runoff To Work

By Warren Tenney

Cities in the Phoenix Metropolitan area are experimenting with building methods to slow storm runoff and allow more of it to be absorbed into the ground instead of rushing into streets and down storm drains. Low Impact Development (LID) is an approach to land development – or redevelopment – that mimics the natural environment by encouraging rainwater to stay in place and to sink into landscaping and planters, soak through sidewalks and parking lots made of permeable pavement, pour off roofs into cisterns and rain barrels, even collect on rooftop gardens. LID practices aim to preserve, restore and create green spaces using soils, vegetation, and rainwater harvesting. The City of Tempe has just taken a big step forward in determining how to make LID work for desert cities.

Cities are taking a hard look at Low Impact Development methods for building streets, commercial developments and planned residential communities. The methods could reduce water used to irrigate landscaping, prevent street flooding, and allow cities to downsize expensive storm drain systems. For example, the City of Phoenix maintains an 895-mile underground storm drain system. During the Valley’s infrequent but often hard and fast rainstorms, runoff rushes into 18,641 catch basins cut out of Phoenix sidewalks and along streets or into grated dry wells often located in parking lots. Many of the storm drains eventually empty into the Salt Riverbed.

Last year, the cities of Mesa and Glendale, working with the consulting firm Logan Simpson, created the Low impact Development Toolkit, which offers technical variations of techniques that make the most out of storm runoff. Mesa and Glendale have used Low Impact Development techniques on several public projects and plan more. For example, Mesa used curb cuts that allow runoff to collect in shallow basins and irrigate street landscaping around Fiesta Mall, along Southern Avenue at Alma School Road. Glendale used permeable pavement in a 6-acre park-and-ride lot at 99th and Glendale avenues where water sinks through the pavement and into the ground.  

Now, Tempe is adding another piece of critical information about Low Impact Development in desert cities. Tempe, working with the Flood Control District of Maricopa County and contractor J2 Engineering & Environmental Design, used new technology to create a model that divided most of the city into 20-square-feet grids. New highly detailed topographical maps allow engineers to know how much grass, pavement and gravel are contained in each grid and if there are buildings or fences or walls. Then consulting engineers used computer-modeling techniques to determine what happened to runoff in each grid during the lightest to the heaviest rainstorms. Linking the grids has given the city the most accurate storm runoff data available. (These computer-modeling methods have been around for many years, but only within the last 5 years have typical computers been powerful enough to model entire cities.)


Tempe neighborhood as it is now.


Model of Tempe neighborhood with LID techniques.

Here’s the interesting part: Tempe and its consultant modeled a small portion of a neighborhood with a history of flooding problems by dividing it into even smaller 4-square-feet grids. The city then overlaid the model with different Low Impact Development techniques. This model produced the state’s most detailed and quantifiable data about the effect of Low Impact Development techniques on storm runoff. The small section of the neighborhood was modeled using different Low Impact Development methods, such as driveways made of permeable pavement and yards contoured to hold water and release excess water into permeable underground pipes. The model included street landscaping created with curb cuts and swales to hold stormwater and even a roof garden on a nearby school building. Runoff was measured using different combinations of Low Impact Development techniques and different percentages of homeowners using the techniques.

Here’s what the City of Tempe found out: If 50-75 percent of homeowners agreed to participate and applied the suggested Low Impact Development techniques to their property, flooding would be mitigated enough to downsize a proposed new storm drain system for the area. The city has concluded that retrofitting established neighborhoods with Low Impact Development techniques is possible and worthwhile. 

Making it work, however, would require a partnership between homeowners and the city and that needs more research. What is the best approach to engage and assist residents to apply Low Impact Development techniques to their yards?  What tools and information will they need?  Would rebates be an effective means to encourage homeowners to invest in revamping their landscapes and driveways, similar to turf removal incentives? 

For now, these Low Impact Development techniques would be most practical when used on public property, such as parks, streets and sidewalks, and when they are built into large new residential or commercial developments or redevelopments.

Quantifying the effect of Low Impact Development is a big step toward helping it to gain traction in desert cities.  Cities will be able to demonstrate the value of integrating these techniques into the community to better manage stormwater, reduce infrastructure costs, potentially offset landscape irrigation, and to enhance our built environment.

For 47 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit www.amwua.org.

Building Better Water Rates in an Uncertain World

By Warren Tenney

Running a public water utility isn’t like any other business. This is because water is essential to everyone, at every economic level. Also, a city water utility isn’t out to make a profit. It can’t simply raise its prices to cover the cost of rising expenses or decreasing revenue. An elected city council, board or regulating commission must approve rate changes and that doesn’t always come easily.

It is a massive undertaking to reliably deliver safe and affordable water directly to homes and businesses and costs are rising. Water utilities are facing higher energy costs and expensive new water quality regulations. This is in addition to the cost of ongoing operations, hiring and keeping the best professional staffs, and maintaining and expanding extensive infrastructure, including miles of pipes, pumps and reservoirs. In addition to the obvious costs, water utilities are faced with uncertainties that could impact their finances, such as severe drought or an economic downturn.image-copy

So understandably, building a reasonable, yet adequate, water rate structure  is a hot topic among water professionals. That’s why nearly 100 of them gathered at a workshop last month presented by AMWUA and the Alliance for Water Efficiency. The objective of the workshop was to share new tools, information, and resources to help water utilities develop and successfully set effective rates that work for the utility and their customers.  Well-crafted rate structures provide revenue stability for the utility, ensure water flows reliably and safely, and encourage the efficient use of water, while still being affordable for the customer.  That’s not an easy balancing act.   

Developing and setting effective rates is a complex process.  Water professionals must determine how much water customers will demand five or ten years from now, how much it will cost to provide it, and determine rates that will be equitable and still cover rising expenses.  Like any business, water providers will need to continue to keep customers informed about what it takes to deliver water to their homes and businesses and why rate increases are necessary.


Members of AMWUA’s Board of Directors – Phoenix Councilwoman Thelda Williams, Avondale Councilman David Iwanski (right) and Mesa Councilman Kevin Thompson (left) –  talk about the difficulty of raising water rates.

Finance staffs, water resources managers, conservation staffs, public information officers, utility directors, city managers, and elected officials all play a role.  At the workshop, these professionals learned about new tools to help manage uncertainty, heard first hand about the challenges elected officials face in approving rates, and gained insight into the success of the Tucson area’s Metro Water District in setting a rate structure that balances needed income, uncertainties, and affordability.  Expert staff from the Alliance for Water Efficiency shared strategies for aligning water rates, revenues and resources and led an in-depth training on the Alliance’s Sales Forecasting and Rate Model.

Learning is never over for water professionals. AMWUA cities’ staffs collaborate regularly to share information and experiences that help streamline and strengthen their ability to ensure reliable, sustainable, secure water supplies for the Valley’s residents and businesses.

The Alliance for Water Efficiency is a stakeholder-based nonprofit organization dedicated to the efficient and sustainable use of water in the U.S. and Canada.  AMWUA’s assistant director serves on the Alliance’s Board of Directors.  Information on the Alliance’s Financing Sustainable Water initiative is available at financingsustainablewater.org. 

For 47 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit www.amwua.org.


This Year’s Least Known Election Is One Of The Most Important

By Warren Tenney

Various races are competing for your attention on the ballot this election season. You know the high profile races for President of the United States, the U.S. Congress and the State Legislature. Yet, near the bottom of your ballot is one of the most important races – one that will directly impact you and your water. It is the election of five new members to the Central Arizona Water Conservation District Board of Directors. If you are wondering what that is, you are not alone.


The Central Arizona Water Conservation District (CAWCD) is the official legal name of the Central Arizona Project (CAP), the 336-mile canal that delivrs Colorado River water from Lake Havasu to Phoenix and Tucson. The CAWCD Board of Directors is responsible for maintaining the more than 30-year-old CAP canal. Board members also set rates charged to its customers (including Valley cities), determine the taxes you pay to finance the CAP system, and establish policies to manage CAP water.

The CAWCD Board is a 15-member board with 10 elected from Maricopa County, four elected from Pima County, and one from Pinal County.  This year, Maricopa County voters will elect five of the Board positions. You are electing them to a six-year term, the same as for U.S. Senate. It’s not a high-profile race, so you may have to do a little more homework on the candidates. It is worth taking the time.

The CAWCD has the authority to set two property taxes for Maricopa, Pinal and Pima counties. For the median priced home in Maricopa County – valued at $174,000 in 2016 -these taxes amount to roughly $24 a year.  These taxes are used primarily to repay the Federal government for constructing the CAP canal, operation and maintenance of the CAP system, and storage of Colorado River water for times of shortage. This is a nominal amount for the wise, long-term effort to keep our water future secure. 

During the next six years, many critical issues will be facing the CAWCD Board—in particular, setting the rates that utilities pay for Colorado River water delivered through the CAP.  Those costs are eventually passed on to you, the utility customer.  And those costs are likely to increase. Here are some of the reasons why.

1. The U.S. Bureau of Reclamation could declare an official shortage of Colorado River water as soon as 2018.  A shortage would initially result in less Colorado River water delivered to CAP’s agricultural customers. Cities would still receive their full allocation of Colorado River water under an initial shortage declaration but cities also would pay more for their water. CAP must continue to generate enough money to maintain its delivery system, so cities would pay more to make up for lost revenue from agriculture customers.

2. It takes a lot of energy to move and lift Colorado River water uphill.  Ninety percent of CAP’s power comes from the Navajo Generating Station located on the Navajo Indian Reservation near Page, Arizona. New land and coal leases will be in place in 2019, which will increase the cost of CAP’s delivery of Colorado River water.

3. CAP must determine how it will recover Colorado River water stored in underground aquifers by the Arizona Water Banking Authority.  If shortages do become more serious, municipalities would need that stored water, and recovery of that water by CAP could be expensive. 

4.   CAP rates are directly linked to the operation and maintenance of the canal.  As the CAP’s infrastructure continues to age, maintenance costs will rise.

The cities are key CAP customers. Maricopa and Pima County cities with CAP contracts provide water to more than 85 percent of Arizona’s population.  CAWCD Board and the cities receiving CAP water will be facing important issues over the six-year terms of the candidates you are electing.  It will be critical that we work together for solutions that ultimately ensure you have secure, safe water at a reasonable price.

The CAWCD Board is a voluntary non-paid, non-partisan position.  It truly is public service and it remains important not to mix partisan politics into water.  So, do a little research.  Talk to water professionals if you know any. Search online to find out more about the candidates and who and what groups are endorsing them. Make a well-educated selection.  Above all, please do not just randomly vote or pick names that sound good. Share what you have learned with family, friends, and co-workers so they can also understand the importance of the CAP election.

The Board of the Central Arizona Water Conservation District will be making a big imprint on your future and Arizona’s.  It is important to have Board members who are committed to the wise management of the CAP system to ensure Arizona has a strong water future.  This means having Board members who are active and engaged in all the issues facing CAWCD.

Here are the ten candidates who are running for the CAWCD Board with a link for those who have a campaign website.  Kudos to the candidates for running and for understanding the importance of CAP water to Maricopa County and the rest of Arizona.   

Alexandra Arboleda 

Jennifer Brown

Frank Fairbanks                  

Michael Francis

Thomas Galvin           

Ben Graff

Rick Heumann           

Jim Holway

Mark Lewis

Rory Van Poucke

Warren Tenney was elected twice to serve as a member of the CAWCD Board from Pima County. He served as Vice-President of the Board and as Chairman of the Board’s Finance, Audit & Power Committee. He resigned his board position in January 2016 to become Arizona Municipal Water User Association’s executive director.

For 47 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit http://www.amwua.org

Tempe Offers Residents And Businesses Online Access To Water Use

By Warren Tenney

Imagine watching your water consumption online in real time as easily as you access your checking account or medical records. By Spring 2017 about 5,000 City of Tempe homes and businesses will have online access to their hour-by-hour water use. Tempe will continue to add more customers until every Tempe business owner and resident with a water meter can monitor their water use by early 2019. The new water meter reading system is known as “advanced meter infrastructure” or AMI. While some cities are piloting AMI systems, Tempe is pursuing the most ambitious meter conversion in the Valley. Here are five things you should know about the system.

1. A giant step: There are two common ways most Valley cities read your water meter. The first: an employee drives past each home and a computer inside the vehicle reads each meter. The second: a water department employee drives into a neighborhood, parks a specially equipped van on a street or in a parking lot, and uses a computer to read each water meter within a half-mile or so. Some cities use a combination of both of these electronic systems, which are called “automatic meter reading” or AMR. Tempe tested but never committed to either of these AMR methods. Right now, Tempe water employees still read meters the old fashioned way – by opening the lid of your water meter box (which is usually in the ground in your front yard or in the alley), checking the dial, and entering a number into a handheld computer.  

2. How it will work: If your water meter is more than 7 years old, Tempe will install a new meter compatible with the new electronic system. If you have a newer meter, the city will place a new register on your existing meter. A network of “collectors and repeaters” will be attached mainly to city-owned light poles. This network will relay water use from each meter directly to a computer inside Tempe’s Customer Service Division for billing. The new system is flexible. In an emergency, such as a power or computer failure, Tempe would switch to an AMR system and each meter would be read by an employee from a specially equipped vehicle as it passes a home and business. Tempe selected a vendor to operate the system. The vendor also will be responsible for such things as system upgrades and data storage.

3. The rollout: Tempe’s 44,000 water meters are divided into four sections with about 10,000 to 11,000 meters in each. Each of these four sections has 20 routes consisting of varying numbers of meters, up to 1,000. The City will convert 5,000 meters within two sections by January. As each route is completed and tested, Tempe will notify water customers when they have the option of registering for an online portal that will allow them to watch their water use in real time on an hourly basis.

4. What the City gains: Tempe’s goals are improving water conservation and customer service. For example, monthly bills to customers are based on 30 days of water service, but that number can change. When meters are read manually, the number of days it takes to complete a route can vary because of unpredictable circumstances, such as sick days and rainy days. Adding one or two days of water usage to a bill can mean a noticeable increase in what customers pay that month. Fluctuating bills make it harder for customers to budget and often cause customer complaints and questions. The new system will provide Tempe with more accurate data within a uniform period of time, generating more uniform monthly bills. The new system also will provide data for planning purposes, such as tracking the water saved due to home and business water audits, rebates and other conservation programs. Tempe now has four regular employees and four temporary employees responsible for reading meters. Once the conversion is complete, the four regular employees will be assigned new responsibilities, such as fixing broken meters, responding to customer concerns, or completing disconnects.

5. What you gain: The AMI system helps to alert you sooner to a change in your water use. Being able to see patterns in your hourly water use gives you a better opportunity to pin point a problem.  For example, if your water use is suddenly higher than usual between 5 a.m. and 6 a.m. when the irrigation system is running, you know the first place to look for a leak.


Advances in technology continue to help residents use water more efficiently.  Water meters are key to accounting for water used by customers and in turn can help customers find leaks quickly. If you need help fixing leaks, AMWUA’s Smart Home Water Guide has the answers.

For 47 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit www.amwua.org.