The Arizona Department of Environmental Quality (ADEQ) has admitted that they don't know if the carcinogen methylene chloride has contaminated the water in the aquifer beneath the Page-Trowbridge radioactive/toxic waste dump or not.

      ADEQ made the disclosure in a flyer distributed at meetings with SaddleBrooke residents held Friday, October 20 at SaddleBrooke.  The ADEQ flyer informs readers that the groundwater beneath Page-Trowbridge could have a concentration of methylene chloride at twice the limit allowed by law and the ADEQ would not know it. 

Local residents more knowledgeable than ADEQ

       In August of this year Oracle residents, concerned that testing and reporting methods allowed by ADEQ were inadequate to assure of the water supply was safe, compelled the University of Arizona to conduct tests and report the results using accepted and common reporting methods. 

       While analysis of groundwater samples taken in August show that methylene chloride is not present in the groundwater beneath Page-Trowbridge, ADEQ has allowed the University of Arizona (U of A) to report the results of water tests using a method that would allow massive groundwater contamination in a concentration of twice the legal limit to go unreported. 

       The U of A owns the Page-Trowbridge landfill and is liable for any consequences should the landfill contaminate groundwater.  The U of A is responsible for monitoring the groundwater beneath the landfill to detect possible contamination.

       ADEQ has allowed the U of A to use this irregular reporting method for over 8 years, and has announced no plans to change it.

       Additionally, ADEQ has granted waivers allowing local water companies to bypass testing for methylene chloride contamination.  Some of these waivers have been in effect for over 3 years.  As an example, the Oracle water supply has not been monitored for methylene chloride contamination since the contaminant was detected at one or more Oracle wells in 1997.

       As of this writing, it is not known if the results of the citizen intiated tests done in August have been made available to ADEQ.

         Records of the U of A's montioring of groundwater at Page-Trowbridge show that the citizen initiated test in August is the only test in the last eight years that would have detected methalyne chloride below the limit set by federal law. 

EPA Superfund remediation sought

       The fact that ADEQ has permitted the use of a highly irregular reporting method allowing potentially massive groundwater contamination to go unreported, and because ADEQ has no plans to change the irregular reporting method, and because ADEQ has granted waivers allowing water companies to bypass testing for methylene chloride contamination for several years, local residents are left to wonder if the public trust placed in ADEQ to protect their water supply is well placed. 

       Concerned citizens in the area are seeking EPA Superfund status for the Page-Trowbridge radioactive/toxic waste landfill.

      The University of Arizona owns the Page-Trowbridge landfill and is responsible for periodically monitoring the groundwater for contamination by the landfill. 

       The U of A maintains four monitoring wells spaced hundreds of feet apart around the Page-Trowbridge radioactive/toxic waste landfill.  Water from these wells is sampled twice a year and analyzed to determine if the hazardous wastes buried at the landfill have begun to infiltrate the groundwater. 

       Reports with the results of the analysis of every test are sent to ADEQ.

ADEQ's admission

       The admission by ADEQ that they don't know if the water beneath Page-Trowbridge is contaminated with methylene chloride or not, is worded as follows:

"The most recent sampling events for which ADEQ has received copies are the April 26, 2000 and May 17, 2000 ground water sampling events.  None of the results for the chemicals tested were above the detection limits used by the laboratory and none of the results for the chemicals tested were shown above the Aquifer Water Quality Standards [AWQS].

"However, because the AWQS for methylene chloride is 5 ppb [ppb = Parts Per Billion] (ug/L) and the detection limit used by the lab was 10 ppb (ug/L), it cannot be determined from these results whether or not levels of methylene chloride between the AWQS and the detection limit were present."

ADEQ flyer, page 1

ADEQ flyer, page 2 (ADEQ admission on this page)

What ADEQ does know 

        Because ADEQ tells us that "None of the . . . chemicals tested were above the detection limits" and that "the detection limit used by the lab [for methylene chloride] was 10 ppb", ADEQ knows that the level of methylene chloride is 10 ppb or less. 

What ADEQ doesn't know

       ADEQ's statement that they do not know if methylene chloride contamination exists at levels between 5 ppb and 10 ppb, is an admission that ADEQ doesn't know the level of methylene chloride contamination in the water supply.

       Specifically, if ADEQ knew the level of methylene chloride contamination, then ADEQ would have to know whether the level of contamination was between 0 ppb and 5 ppb or between 5 ppb and 10 ppb. 

       For example, if the level of methylene chloride contamination was 9.99 ppb, ADEQ would be able to determine that the contamination level was between 5 ppb and 10 ppb.  Yet ADEQ tells the reader that "it cannot be determined . . .  whether or not levels of methylene chloride between the AWQS [5 ppb] and the detection limit [10 ppb] were present."

       Similarly, if the level of methylene chloride contamination was 1 ppb, ADEQ would be able to determine that the contamination level was not between 5 ppb and 10 ppb.  Yet ADEQ tells the reader that "it cannot be determined . . .  whether or not levels of methylene chloride between the AWQS [5 ppb] and the detection limit [10 ppb] were present,"

       Since ADEQ says that "it cannot be determined . . .  whether or not levels of methylene chloride between the AWQS [5 ppb] and the detection limit [10 ppb] were present," it follows that ADEQ doesn't know the level of methylene chloride contamination in the water supply. 

ADEQ doesn't know if  the water supply is contaminated or not

       ADEQ doesn't know if the the groundwater beneath Page-Trowbridge is contaminated with 9.99 ppb of methylene chloride or is completely free of methylene chloride.

       In other words, ADEQ doesn't have any idea if the water supply is contaminated with methylene chloride or not.

Twice the legal limit

       The maximum contamination level allowed for methylene chloride by federal law is 5 ppb.   The detection limit used for methylene chloride is 10 ppb.

      Because ADEQ tells us that "None of the . . . chemicals tested were above the detection limits" and that "the detection limit used by the lab [for methylene chloride] was 10 ppb", ADEQ knows that the level of methylene chloride is 10 ppb or less.  ADEQ just doesn't know what the actual level is.

       In other words, the groundwater beneath Page-Trowbridge could contain 9.99 ppb of methylene chloride, twice the amount of contamination allowed by federal law, and the ADEQ would not know it.

"...none of the ... chemicals tested were shown above the Aquifer Water Quality Standards"

       The ADEQ flyer says that  "the Aquifer Water Quality Standards for methylene chloride is 5 ppb" and also tells us that "none of the ... chemicals tested were shown above the Aquifer Water Quality Standards."

       At first, this may seem to contradict the statement by ADEQ that "it cannot be determined . . .  whether or not levels of methylene chloride between the AWQS [5 ppb] and the detection limit [10 ppb] were present". 

        How could ADEQ say that "it cannot be determined . . .  whether or not levels of methylene chloride between the AWQS [5 ppb] and the detection limit [10 ppb] were present" and also say that "none of the ... chemicals tested were shown above the Aquifer Water Quality Standards"?

       The key to understanding this apparent contradiction is understanding how water test results use the detection limit.

Detection limits and Water quality reports

      When contamination is found in an amount above the detection limit, the laboratory reports the specific amount found. 

       When contamination is found in an amount below the detection limit, the laboratory does not report the amount found, but merely reports that the contaminant was less than the detection limit. 

       In other words, when contamination is found in an amount below the detection limit, the laboratory does not show the amount found on the report. Because the detection limit for methylene chloride is 10 ppb at Page-Trowbridge, the reports do not show amount of methylene chloride detected in amounts less than 10 ppb.

       Because the reports from the tests on groundwater from the PageTrowbridge monitoring wells do not show the specific amount of methylene chloride detected, the ADEQ can report that, "none of the results for the chemicals tested were shown above the Aquifer Water Quality Standards," and be technically correct.

       While the ADEQ statement that "none of the ... chemicals tested were shown above the Aquifer Water Quality Standards" is technically correct, it is completely misleading.

       The reason that methylene chloride contamination was not shown to be above the Aquifer Water Quality Standards, is simply because the specific amount of methylene chloride contamination detected in groundwater from beneath Page-Trowbridge is not shown on the reports.

ADEQ has known of potential contamination for at over 8 years 

       ADEQ has known that the water beneath Page-Trowbridge could potentially be contaminated with twice the amount of methylene chloride allowed by law for 8 or more years.

      Earlier detection of methylene chloride and other contaminants at the Page Trowbridge monitoring wells have been dismissed by the U of A as errors made by the independent laboratories that analyzed the water sampled from the wells. 

       In spite of claiming that the detection of methylene chloride was the result of lab errors, the U of A, raised their reporting limits for methylene chloride by a factor of 5, from 2.0 ppb to 10.0 ppb, in 1992

       An attachment to a letter from ADEQ to the U of A dated July 27, 1993,  tells us that ADEQ was concerned about this unusually high limit, 7 years ago. 
 

Document showing ADEQ aware of irregular reporting method 8 years ago (Click on images for larger view)

       ADEQ has known that they don't know whether the groundwater beneath the Page-Trowbridge radioactive/toxic waste landfill is contaminated with twice the legal dose of methylene chloride or not for at least 8 years.

No corrective action taken

       As of this writing ADEQ has taken no action to address their long-standing concern regarding the unusually high detection limits for methylene chloride, other than write letters to the University of Arizona.  No enforcement or regulatory action has been taken by ADEQ to remedy the situation.

       The last letter the ADEQ sent to the U of A complaining about the unusually high detection limits was sent Sept. 1 of this year. 

No corrective action planned

       As of this writing, the ADEQ has not indicated that they have any plans to adopt normal and accepted reporting methods that will show massive groundwater contamination. 

ADEQ permits testing to be bypassed

       In addition to taking no action to remedy the situation at Page-Trowbridge which could result in the water supply being contaminated with methylene chloride at twice the legal limit, ADEQ has been allowing water companies that pump water from the aquifer under Page-Trowbridge to bypass testing for methylene chloride.

       1997 The Arizona Water Company detected the presence of methylene chloride in water samples taken from the aquifer, and reported these results to ADEQ. 

       The amount detected was 0.6 ppb, but could have been as high as 1.2 ppb, or 24% of the limit allowed by law for methylene chloride.

       ADEQ then granted waivers allowing The Arizona Water Company to forego any further testing for methylene chloride.

Why methylene chloride is regulated

       Methylene chloride is a volatile organic compound  that can cause cancer.  Other health effects of exposure to methylene chloride include damage to the nervous system and blood as well as liver damage. 

Any Exposure Potentially Dangerous

       The EPA has Maximum Contamination Level Goals, called MCLG's for each hazardous compound that they regulate.  The EPA sets the MCLG based on the amount of a contaminant that can be consumed without any risk to health. 

       The MCLG for methylene chloride is zero, which means that the EPA considers any exposure to methylene chloride potentially dangerous to health.