Carcinogen in Valley Water

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An average water sample in Phoenix has the highest level of chromium-6, a suspected cancer-causing agent, among water utilities that have more than one million customers. Chromium-6 is a chemical compound that was made famous in a movie about environmental activist Erin Brockovich. Phoenix water services director Kathryn Sorensen and assistant water services director Troy Hayes will talk about chromium-6 in Phoenix water.


TED SIMONS: COMING UP NEXT ON ARIZONA HORIZON, A NEW REPORT RAISES QUESTIONS REGARDING THE SAFETY OF PHOENIX'S WATER SUPPLY. ALSO, HEAR ABOUT A PROGRAM THAT HELPS YOUNG PEOPLE BECOME FIRST GENERATION COLLEGE STUDENTS. AND WE WILL HE HOW ONE VETERAN USED WRITING TO HELP HIM DEAL WITH PTSD. THOSE STORIES NEXT ON ARIZONA HORIZON. ARIZONA HORIZON IS MADE POSSIBLE BY THERE CONTRIBUTIONS FROM THE MEMBERS OF ARIZONA PBS. THANK YOU.

TED SIMONS: APPLE HAS CONSTRUCTED A MASSIVE SOLAR POWER PLANT OUTSIDE OF FLORENCE THAT WILL SELL POWER TO S-R-P TO OFFSET THE POWER APPLE USES AT THE DATA CENTER IN MESA. DETAILS WERE SECRET UNTIL THIS WEEK. S-R-P WILL PAY WHOLESALE OR MARKET PRICE FOR ENERGY GENERATED AT THE SOLAR PLANT AND THE DEAL WILL NOT NEGATIVELY IMPACT S-R-P CUSTOMERS.

TED SIMONS: A REPORT SHOWS AN AVERAGE WATER SAMPLE IN PHOENIX HAS THE HIGHEST LEVEL OF CHROMIUM-6 AMONG U-S WATER UTILITIES THAT SERVE MORE THAN ONE MILLION CUSTOMERS. CHROMIUM-6 IS A CHEMICAL COMPOUND AND SUSPECTED CANCER CAUSING AGENT AND MADE FAMOUS IN A MOVIE ABOUT ENVIRONMENTAL ACTIVIST ERIN BROCKOVICH. HERE TO TALK ABOUT CHROMIUM-6 IN THE PHOENIX WATER SUPPLY IS THE CITY'S WATER SERVICES DIRECTOR KATHRYN SORENSEN AND ASSISTANT WATER SERVICES DIRECTOR TROY HAYES. THANK YOU FOR BEING HERE. LET'S LAY THE GROUNDWORK HERE. WHAT IS CHROMIUM-6?

KATHRYN SORENSEN: IT IS A NATURAL OCCURRING ELEMENT OF THE EARTH'S CRUST. ACCORDING TO THE WATER ASSOCIATION IT IS THE 21ST MOST COMMON ELEMENT. IT IS PARTICULARLY COMMON IN THE SOUTHWEST RESULTING FROM LOCAL VOLCANIC FORMATIONS HERE IN THE EARTH.

TED SIMONS: THE DIFFERENCE BETWEEN CHROMIUM-6 AND CHROMIUM?

TROY HAYES: CHROMIUM-6 IS JUST AN OXIDIZED FORM. THERE IS CHROMIUM-3 AND 6 AND OTHER VERSIONS. IT IS HOW IT OXIDIZES.

TED SIMONS: IS THERE A DIFFERENCE AS FAR AS HARMFUL EFFECTS TO HUMANS OR DO WE KNOW?

TROY HAYES: CHROMIUM-6 IS ON A LIST WITH THE E-P-A AND THE STATE OF CALIFORNIA WHERE THEY ARE TRYING TO IDENTIFY HEALTH EFFECTS OF CHROMIUM-6. THE STATE WENT TO IDENTIFY A LIMIT THEY WILL ALLOW IN WATER SYSTEMS OF TEN PARTS PER BILLION. THE EPA REGULATES TOTAL CHROMIUM AT A HUNDRED PARTS PER BILLION. ITS STARTING TO EVOLVE AND STARTING TO MOVE TO REGULATE CHROMIUM-6. THEY ARE TRYING TO COLLECT THE DATA AND THAT IS WHAT THE DATA CAME OUT IS ABOUT.

TED SIMONS: IT IS INTERESTING YOU WOULD TALK ABOUT CHROMIUM-6 AND EVERYONE IS WORRIED ABOUT CHROMIUM-6 BUT IT IS NOT MEASURED AND JUST A PART OF CHROMIUM.

KATHRYN SORENSEN: RIGHT. AS TROY WAS SAYING THE EPA ONLY REGULATES TOTAL CHROMIUM. THEY ARE LOOKING AT REGULATING CHROMIUM-6. AS PART OF THE PROCESS, MAJOR UTILITIES MONITOR THEIR SYSTEMS TO TAKE A LOOK AT HOW MUCH CHROMIUM-6 EXISTS WITHIN OUR DRINKING WATER SYSTEM TO PROVIDE THOSE SAMPLES TO THE EPA SO THAT SCIENTISTS CAN REALLY EXAMINE THE DATA AND DECIDE WHAT STEPS TO MAKE NEXT.

TED SIMONS: AND PHOENIX DOES MONITOR AND TEST FOR CHROMIUM-6?

KATHRYN SORENSEN: WE DO. WE TOOK ABOUT 80 SAMPLES AS PART OF THE LATEST ROUND. THE AVERAGE OF THE SAMPLES IS CLOSE TO WHAT WAS REPORTED BY THE ENVIRONMENTAL WORKING GROUP WE REALLY THINK THAT IS A GROSS MISREPRESENTATION OF THE AMOUNT OF CHROMIUM-6 THAT IS IN OUR WATER SUPPLY.

TED SIMONS: WHY?

KATHRYN SORENSEN: LET ME EXPLAIN. WE SUBMITTED 80 SAMPLES AND ABOUT 36 OF THE SAMPLES CAME FROM GROUND WATER WELLS. THE CITY OF PHOENIX DOESN'T USE THE GROUND WATER WELLS WHEN DELIVERING WATER TO OUR CUSTOMERS. MOST OF THE CHROMIUM-6 COMES FROM GROUNDWATER WELLS. GROUNDWATER ONLY MAKES UP 2% OF THE SUPPLY BUT THE NUMBER USED IN THE REPORT - WHAT THEY DID IS THEY TOOK ALL 80 SAMPLES AND AVERAGED THEM. 36 WERE FROM GROUNDWATER. SO THAT AVERAGE IS AS IF HALF OF PHOENIX'S WATER SUPPLY WAS MADE UP OF GROUNDWATER AND THAT IS NOT THE CASE AND ITS NOT REALLY A GOOD REPRESENTATION OF WHAT'S IN OUR SYSTEM.

TED SIMONS: WE HAVE GROUND WATER WHICH SEEMS TO BE HEAVIER WITH THE CHROMIUM-6 AS OPPOSED TO SURFACE WATER WHICH IS MOSTLY WHAT THE CITY OF PHOENIX USES FOR WATER; CORRECT?

TROY HAYES: CORRECT. ONLY 2% OF THE WATER SUPPLY IS FROM GROUND WATER AND 98% IS FROM SURFACE WATER. SURFACE WATER HAS VERY, VERY LOW CHROMIUM CONTENT AND WHEN THE TWO ARE INTRODUCED TOGETHER WHAT WE SEE IN OUR SYSTEM ARE THE NUMBERS ARE FAR LESS. THE PIPES YOU WOULD TURN THE TAP ON AND FLOW WATER FROM THE AVERAGE CHROMIUM LEVELS IS AROUND .39 OR .40. UPPER LEVELS WE SEE 1.6 THAT WE TEST OUT IN OUR SYSTEM. THAT IS WHERE WE FEEL THE NUMBERS ARE MISREPRESENTATIVE OF WHAT OUR CUSTOMERS ACTUALLY SEE.

TED SIMONS: SO WHEN THE REPORT SAYS IT IS THE HIGHEST IN THE U.S., 400 TIMES THE HEALTH GOAL SET BY CALIFORNIA. BUT IT IS STILL A GOAL TO TRY I WOULD IMAGINE TO ACHIEVE. YOU SAY NOT SO FAST.

KATHRYN SORENSEN: WE SAY IT IS NOT AN ACCURATE REPRESENTATION OF WHAT GETS DELIVERED TO OUR CUSTOMERS. IF YOU LOOK AT THE SAMPLES FROM OUR DISTRIBUTION SYSTEM- THAT IS THE MOST ACCURATE AND THOSE SAMPLES COME IN AT LESS THAN POINT FIVE PARTS PER BILLION, A VERY DIFFERENT NUMBER.

TED SIMONS: WHAT ABOUT THE IDEA OF EXPOSURE TO THIS WATER? IS IT ALSO 2% OF ALL PHOENIX WATER? OR JUST TAP WATER?

TROY HAYES: 2% IS NORMALLY ABOUT HOW MUCH GROUNDWATER WE USE. IT MAY VARY BUT NORMALLY SURFACE WATER IS THE PREDOMINANT SOURCE. YOU WILL NOT SEE MUCH VARIATION FROM YEAR TO YEAR BECAUSE PHOENIX IS PRIMARILY A SURFACE SOURCE SYSTEM.

TED SIMONS: ALL RIGHT. SO IS PHOENIX DRINKING WATER SAFE?

KATHRYN SORENSEN: ABSOLUTELY. PHOENIX TAP WATER IS SAFE TO DRINK AND PEOPLE REALLY NEED TO BE REASSURED OF THAT.

TED SIMONS: CAN IT BE SAFER?

KATHRYN SORENSEN: CERTAINLY. IT IS ALWAYS POSSIBLE TO DO MORE. IT IS SOMETHING WE HAVE TO WEIGH AS A COMMUNITY. WE WELCOME THESE TYPES OF QUESTIONS AND DISCOURSE. EVERYONE HAS THE SAME GOAL AND THAT IS TO PROTECT PUBLIC HEALTH AND SAFETY. THERE IS MORE THAT CAN BE DONE AND WE LOOK AT THAT CAREFULLY AND MAKE SURE WE ARE DOING EVERYTHING WE CAN WITH THE LATEST TECHNOLOGY, THE BEST TREATMENT TECHNIQUES. WE ALSO TAKE A LOOK AT WHAT IS COST EFFECTIVE FOR OUR CUSTOMERS. THERE IS A NATURAL BALANCE THERE. WE ARE CAREFUL TO ERR ON THE SIDE OF CAUTION AND ALWAYS MAKE SURE THAT OUR WATER IS SAFE TO DRINK.

TED SIMONS: SHOULD PHOENIX RESIDENTS USE A PURIFIER?

TROY HAYES: THAT IS A PERSONAL PREFERRANCE. OUR WATER IS SAFE TO DRINK SO I WOULDN'T BE DOING IT FOR A SAFETY REASON. THAT IS ONE THING THEY CAN DO IF THEY DON'T LIKE THE TASTE. WHAT YOU WANT TO BE CAREFUL ABOUT IS SOME THINGS YOU MAY BE TRYING TO REMOVE MAY NOT REMOVE IT ALL.

TED SIMONS: SO BASICALLY YOU ARE WASTING YOUR MONEY?

TROY HAYES: COULD BE. THE FILTERS ON THE REFRIGERATOR REMOVE CERTAIN TYPES OF THINGS BUT NOT OTHERS.

TED SIMONS: WHAT ABOUT CHROMIUM-6?

TROY HAYES: IT IS NOT REMOVED.

TED SIMONS: IF YOU WANT A WATER PURIFIER TO SAVE YOU FROM CHROMIUM-6 IT WILL NOT DO IT?

TROY HAYES: IT WON'T.

TED SIMONS: AS FAR AS CHROMIUM-6 IS CONCERNED, THE ERIN BROCKOVICH FILM, PEOPLE ARE FAMILIAR WITH THIS. IT IS CANCER-CAUSING AGENT. WHAT IS PHOENIX DOING TO LOWER THIS LEVEL?

KATHRYN SORENSEN: WE ARE PRIMARILY BLENDING. FOR EXAMPLE, AS TROY MENTIONED EARLIER, THERE IS NOT A LOT OF CHROMIUM-6 IN SURFACE WATER. WE ARE PREDOMINANTLY A SURFACE WATER SYSTEM. SO WHEN WE DO PUMP OUR WELLS, WE ARE CAREFUL TO PUMP INTO MAJOR TRANSMISSION MEANS SO THE WATER IS BLENDED WITH THE SURFACE WATER WHICH IS LOW IN CHROMIUM. WE RAN MODELS ON THAT AND TOOK A LOOK AT HOW MUCH MIXING OCCURS WHEN WE PUMP OUR WELLS INTO THE MAJOR TRANSMISSION SYSTEMS THAT ARE FULL OF SURFACE WATER AND THE MODELING SUGGESTS WHEN WE DO THAT BLENDING THE LEVELS COME IN AT ABOUT .5 PARTS PER BILLION OR LESS. FAR LESS THAN CALIFORNIA'S MAXIMUM CONTAINMENT LEVEL OF TEN PARTS PER BILLION AND FAR LESS THAN WHAT WAS REPORTED BY THE RECENT REPORTS.

TED SIMONS: BASICALLY BLENDING OR GETTING AS LITTLE GROUND WATER INTO THE MIX AS POSSIBLE IS A FORM OF CLEANUP?

TROY HAYES: ESSENTIALLY YOU TAKE IT AS A DROP OF CHROMIUM IN AN OLYMPIC SIZE SWIMMING POOL AND ESSENTIALLY IT DELUDES THE CONCENTRATION DOWN. YOU PUT IT IN THE WATER SUPPLY WITHOUT ANY AND OVERALL IT IS DILUTED DOWN.

KATHRYN SORENSEN: AND THAT IS EFFECTIVE FOR US BECAUSE SOME OF THE BEST TECHNOLOGY IS ION EXCHANGE AND THEY REALLY ARE ABLE TO TREAT DOWN TO ONE PART PER BILLION. FOR US TO ACHIEVE .5 IS REALLY GOOD.

TED SIMONS: IT IS VERY INTERESTING TO KNOW THERE IS SUCH A DIFFERENCE BETWEEN GROUND WATER AND SURFACE WATER WITH THIS PARTICULAR ELEMENT. GOOD TO HAVE YOU BOTH HERE.
 

Kathryn Sorensen: Phoenix Water Services Director,
Troy Hayes: Assistant Water Services Director

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