| According
to recently released water quality reports from the Arizona Water Company,
dichloromethane (also called methylene chloride) was detected in the water
supply for Oracle, Arizona in 1997.
Dichloromethane
is a volatile organic compound that can potentially cause damage to the
nervous system and to blood, as well as liver damage and cancer.
The amount of dichloromethane detected was 0.6 parts per billion (ppb).
The Maximum Contaminant Level (MCL) allowed for dichloromethane, is 5 ppb.
Previous Arizona Water Company reports on the quality of the water in the
aquifer supplying Oracle did not specify the amount of dichloromethane
detected. Instead, previous reports only indicated that contaminant
had been not been detected in an amount greater than the maximum level
allowed by federal regulations.
The newly released reports, mandated by Safe Drinking Water Act of 1996,
list the individual contaminants found as well as the concentration of
each contaminant.
While the well supplying residents
of Oracle with their drinking water is approximately
4 miles from a landfill used for several decades to dispose of radioactive
and toxic chemical wastes, the latest reports from the Arizona Water Company
report claims that the likely source of the contaminant as resulting from
"discharge from pharmaceutical and chemical factories".
There has never been a pharmaceutical or chemical factory located any where
near the aquifer that supplies Oracle with drinking water.
In addition to Oracle, several other Arizona communities rely on water
from the aquifer beneath the Page-Trowbridge radioactive/toxic waste landfill.
These communities include SaddleBrooke, Catalina, Sun City Vistoso, Oro
Valley, Marana, Northwest Tucson Arizona as well as a proposed retirement
community of 6000 homes to be built by Robson Communities on their property
adjacent to the landfill. |
For example, the Lago Del Oro Water Company's well #16, used to supply
SaddleBrooke Arizona with water, lies approximately four and a half miles
south, south-east of the Page-Trowbridge radioactive/toxic waste landfill.
The
EPA fact sheet on dichloromethane lists photographic supplies as one of
the primary sources of the contaminant.
According to the University of Arizona, photographic chemicals were included
in the hazardous waste disposed of at Page-Trowbridge. The amount
and types of other toxic chemicals disposed of at Page-Trowbridge are unknown,
because record keeping on the wastes disposed of at the landfill did not
begin until 1978.
Oracle resident Cliff Russell said that detection of dichloromethane provides
early indication of groundwater contamination.
"Since dichloromethane is heavier than water and does not dissolve in water,
it tends to move ahead of other contaminants", said Russell. Russell
owned and operated a construction company that specialized in toxic waste
containment prior to retiring to Oracle.
The University of Arizona owns the Page-Trowbridge landfill and is responsible
for monitoring it for possible groundwater contamination.
The University has discounted earlier indications that the groundwater
under the landfill is contaminated with dichloromethane and several other
chemicals, by attributing the findings to errors made by the independent
laboratories hired by the U of A.
In spite of claiming that the detection of dichloromethane was the result
of lab errors, the U of A raised their reporting limits for dichloromethane
from 2.0 ppb to 10.0 ppb in 1992.
Raising the reporting limit by a factor of 5, enabled the University to
avoid listing the concentration of dichloromethane, and instead merely
indicate that the contaminant was "not detected at the Practical Quantitation
Limit PQL" . |
