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SG-W:/ More to ponder regarding the Dexter Twp Power Plant



This message comes from Harry Campbell, of the Huron River Watershed
Council, regarding issues with water to be used from the Ann Arbor WWTP.

Jeff Surfus
---------------------------------------
Recently there has been a lot of activity regarding the proposed power plant
in Dexter TWP. and potential impacts this operation may have. While I
believe everyone is rightly concerned about land use issues, I would like to
raise the issue of contaminant loading to the air phase via the utilization
of Ann Arbors Wastewater Treatment Plant (AA WWTP) discharge.  I would
suggest that these issues be addressed & resolved fully prior to acceptance
of the proposed project.   Concerns/questions include:


1)  Typically treated wastewater discharge is high in total dissolved and
suspended solids (TDS and TSS).  Is there going to be any treatment to
reduce TDS and TSS of the wastewater prior to pumping to the plant?  Will
treatment take place at the plant?  If not, there are issues with scaling in
the pipes and at the plant.  Scaling would weaken the transport pipes,
increasing potential failure rates.

2)  Along the same lines, the remaining water which would be sent back to
the plant would essentially be concentrated TDS and TSS water.  This should
be a concern for AA WWTP plant as this water could reduce their treatment
efficiency and increase treatment costs  incurred by AA WWTP.

3) Recently researchers with the USGS found detectable levels of
antibiotics, human drugs, and steroidal and sex hormones in surface waters
of the Grand Traverse watershed.  These compounds are of not only aquatic
life concern but also of human health.  The DEQ, or any other regulatory
agency, does not monitor for these compounds.   Wastewater discharge permits
do not require monitoring of these compounds.  Essentially, we have no idea
of the extent these compounds are present in the environment, yet, they pose
a  threat (to what degree the science can't tell us yet).  But, they are
often blamed for the 3-legged frog syndrome seen across the world.  This we
do know, however, research on wastewater treatment plant discharge has shown
these compounds to be present on a regular basis.  Therefore, we can safely
assume they are present in AA WWTP discharge.  Given the fact that Panda
will use the discharge for the cooling towers, this operation would result
in transfer of these contaminants from the water phase to the air phase.  It
is in the air phase where human health concerns would be greatest due to
exposure routes and frequency.

4) Typically one finds numerous organic compound species in treated
wastewater discharge.  While these chemicals are often low in concentration
and not regulated (too many and too expensive to measure), they do have the
potential to cause harm to aquatic life under the right conditions.  If you
used said wastewater for cooling processes, organics with low boiling points
would volatilize into the air phase, those with high boiling points would be
concentrated in the remaining water (distillation process).  This should be
a concern for the treatment plant and in terms of air pollution.  The plant
may receive high doses of organic pollutants when the plant sends their
water back and the cooling stacks could transferorganic (many of health
concern) into the air.  In fact, an air pollutionprofessor friend of mine
felt that these cooling stacks, based on sheer amount of water being
transporated, could be considered a major source of VOC pollutants.

5)  What type of pipe material for transporting the wastewater will be used?
Contaminants leaching into the aqueous phase from the pipes could be a
concern. Same can be said about any cleaning agents, lubrication agents,
coatings, etc. used.

6) What is the regional NOX/VOC ratio?  Which is the limiting constituent?
Would the plant air emissions alter the ratio or more importantly increase
the concentration of the limiting nutrient?  If so, downstream areas could
have smog problems.

7) The plant "life" is 30 to 50 years (with upgrades).  What is the pipe
life?  I believe Mr. Bagby did not fully address the concerns raised about
pipe failure.  In fact, he essentially brushed it off.  While it is true
that there are millions of pipes which don't fail, I believe the frequency
of failure will increase in the coming years (via neglect, age, etc.).  How
would PANDA ensure failure would not occur? What type of maintenance would
they perform and at what frequency?  What emergency plans would they have in
case of failure?  They should have their own team of emergency personnel.
They should not rely solely on the township, county, and state for emergency
response.

Harry Campbell





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