[ADEQ Media] ADEQ Issues Order to IBWC for Cadmium Water Quality Violations and Failure to Properly Manage Sewage Sludge
Mon Oct 25 11:18:41 MST 2010
PHOENIX - (Oct. 25, 2010) - A compliance order has been issued to the
U.S. International Boundary and Water Commission for discharging
wastewater containing elevated levels of the toxic metal cadmium into
the Santa Cruz River and more than twice the legal limit in biosolids
-- the sewage sludge residue from the wastewater treatment process --
spread onto nearby fields north of Nogales and for failure to test and
manage biosolids from the Nogales International Wastewater Treatment
The Arizona Department of Environmental Quality compliance order
requires IBWC to work with its Mexican counterpart to meet the limits in
IBWC's Clean Water Act permit by reducing cadmium being sent to the
Arizona treatment plant. It also requires IBWC to provide information to
ADEQ regarding the quality of biosolids generated at the treatment
"The state is telling the responsible federal agency, the IBWC, enough
is enough. We need them to step up to the plate and across the border to
prevent toxic wastewater and sludge and invest in 21st Century
infrastructure," ADEQ Director Benjamin H. Grumbles said.
Cadmium is a carcinogenic metal commonly found in industrial wastewater,
usually in the metal-plating industry. Continued exposure can lead to
kidney, lung and bone problems.
The NIWTP treats wastewater from both Nogales, Ariz., and Nogales,
Sonora. IBWC's Arizona Pollutant Discharge Elimination System (AZPDES)
permit established effluent quality requirements for discharges to the
Santa Cruz River under the Clean Water Act. In addition, the AZPDES
permit allows biosolids generated at the treatment plant to be applied
to agricultural land only under very specific conditions.
Until biosolids quality questions are fully resolved, IBWC is storing
the material at the treatment plant. Biosolids stored off-site in
anticipation of land application are being held for further testing.
ADEQ has issued seven notices of violation to IBWC since 1995 relating
to water quality and biosolids issues. ADEQ and IBWC entered into a
consent order in 1996 regarding effluent quality. Although IBWC made
improvements to the wastewater treatment plant in 2009, the designs did
not include treatment for metals found in industrial wastewater.
The International Outfall Interceptor (IOI) -- the IBWC wastewater
pipeline which connects Nogales, Sonora, to the NIWTP -- was breached
earlier this month just south of the border. Repair work on the IOI has
resulted in millions of gallons of wastewater being diverted into
Nogales Wash in Nogales, Ariz. Although most of the flows were diverted
back into the IOI, some flows have reached the Santa Cruz River, about
nine miles to the north.
The wastewater has been chlorinated on both sides of the border to
reduce the risk of pathogens and crews have been working around the
clock to repair the pipeline.
"Today's clean water order and the recent sewage pipeline break
underscore the need for action. Bipartisan, bi-national efforts should
focus on preventing pollution and investing in infrastructure," Grumbles
"News media interested in additional information on this or any other
topic concerning the Arizona Department of Environmental Quality should
contact the Office of Communications at (602) 771-2215 or via email at
To receive press releases by email: http://www.azdeq.gov/subscribe.html
Follow ADEQ on Facebook: http://www.facebook.com/azdeq
Follow ADEQ on Twitter: http://twitter.com/ArizonaDEQ
NOTICE: This e-mail (and any attachments) may contain PRIVILEGED OR CONFIDENTIAL information and is intended only for the use of the specific individual(s) to whom it is addressed. It may contain information that is privileged and confidential under state and federal law. This information may be used or disclosed only in accordance with law, and you may be subject to penalties under law for improper use or further disclosure of the information in this e-mail and its attachments. If you have received this e-mail in error, please immediately notify the person named above by reply e-mail, and then delete the original e-mail. Thank you.
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Media