NC0085928_Chronic Toxicity Testing_20020315

of wArF,? Michael F. Easley
A Governor
P� Qy ATA William G. Ross,Jr., Secretary
C NCDENR North Carolina Department of Environment and Natural Resources
`c Gregory J.Thorpe, Ph.D., Acting Director
Division of Water Quality
March 15, 2002
Mr. Bob Hird
Cooper Environmental, Inc.
2300 Sardis Road North, Suite Q
Charlotte, North Carolina 28277
Subject: Chronic Toxicity Testing
NPDES Permit NC0085928
American Truetzschler
Mecklenburg County
Dear Mr. Hird:
Division of Water Quality (Division) personnel have reviewed your request to eliminate the chronic
toxicity test and limit at the American Truetzschler site in Mecklenburg County. We regret that at this
time we cannot grant your request. The toxicity record for this facility indicates three consecutive failures
in November and December and periodic failures over the past four years. Such a toxicity record indicates
that the discharge is indeed toxic to the aquatic biota. Although remediated groundwater may meet
federal drinking water standards, and thus not be harmful to humans, such "pure water" is actually toxic
to some forms of naturally present aquatic life. Should toxicity problems persist, you may wish to explore
a non-discharge system, which does not have toxicity requirements associated with it.
All permitted dischargers of complex wastewater in the state are required to perform self-
monitoring of aquatic toxicity of their wastewater. Currently this totals approximately 580 industrial and
municipal facilities. If you have questions about the Aquatic Toxicology program, please call Matt
Matthews at [phone], extension 256. If you have any questions concerning this permit, please
contact me at telephone number [phone], extension 551.
Sincer4ely, '
N talie V. Sierra
cc: Mooresville Regional Office/Water Quality Section
NPDES Unit
Central Files
Aquatic Toxicology Unit
Mr. Dirk Jaekel - American Truetzschler, Inc.
P.O. Box 669228
Charlotte, North Carolina 28266
•
N.C.Division of Water Quality/NPDES Unit Phone:[phone]
1617 Mail Service Center,Raleigh,NC 27699-1617 fax:[phone]
Internet:h2o.enr.state.nc.us DENR Customer Service Center:1 800 623-7748

Natalie Sierra
1 February 27, 2002
Page 3
problem, which was a faulty delay timer. CEI had ATI repair the system and then
immediately had PACE return to collect a third sample on January 26-28, 2000. This
sample passed the full range chronic toxicity test with a chronic value of 92.5%. ATI
reported that the system failed with an average of 71.3 % for the month of January
2000. As a result ATI received an administrative penalty and negotiated an acceptable
penalty payment with the NCDENR.
CEI collected an effluent system sample for the Ceriodaphnia Dubia chronic
toxicity test on February 29-March 3, 2000. The laboratory analytical results for this
sample period indicated a failed test result. Due to problems with chronic toxicity
testing in the past, CEI had two separate laboratories conduct the chronic toxicity
pass/fail test on the effluent sample. The effluent samples were collected on March 9
and 14, 2000. The samples were split and one sample was shipped to PACE and the
other was sent to ETT Environmental, Inc. (ETT) for analysis. Both laboratories
reported failed chronic test results. As a result, CEI contacted both Matt Heller,
NCDENR Regional project manager, and Kristy Robeson of the NCDENR, ESB and
requested that they allow ATI to turn off the remediation system and cease discharging
effluent water to the open ditch while CEI and ATI run additional toxicity tests to
determine the problem. They both agreed, and CEI turned the system off on March
17, 2000.
CEI had ETT run total and dissolved RCRA metals analyses on the failed March
9-14, 2000, effluent sample. The test results indicated that dissolved zinc was present
at levels, which might be toxic to the Ceriodaphnia Dubia. When CEI conducted
dissolved metal analyses in January 2000 on a sample that passed the Ceriodaphnia
Dubia chronic toxicity test, there was no dissolved zinc detected above the laboratory
detection limit. This was the initial indication that zinc may be the problem.
In order to determine if zinc was the problem, CEI had ETT run a bench scale
acute toxicity test on an effluent sample collected March 30 and 31, 2000, for both an
untreated sample and one sample with the addition of an ethylene diamine acetic acid
(EDTA) chelating agent that binds up dissolved zinc. The untreated effluent sample
was acutely toxic with all test organisms dying within 24 hours. The chelating agent
effectively bound up the dissolved zinc within the treated effluent sample and all test
organisms survived the 48-hour test.
On April 6, 2000, CEI conducted a zinc study of pumping wells RW-1, RW-2,
RW-3 influent and effluent, and surrounding perimeter monitoring wells MW-4, MW-

Natalie Sierra
February 27, 2002
Page 4
4D, and MW-7S. Ground water samples were collected and analyzed for total and
dissolved zinc by ETT. Based on these results it appeared that dissolved zinc was
present at concentrations that would be toxic to Ceriodaphnia Dubia. The zinc also
appeared to by naturally occurring in the subsurface waters and the concentrations
appeared to have increased since the remediation system start-up due to the
dewatering of the aquifer. The dewatering activity appears to have caused the zinc to
start precipitating out of the natural rock formations. The concentrations of total zinc
concentrations were observed at between 200 and 360 micrograms per liter 0µg/L) and
dissolved zinc was observed between 170 µg/L and 370 µg/L.
CEI collected effluent samples from the treatment system on April 27 and May
2, 2000. The effluent samples were analyzed for total and dissolved zinc. In addition,
ETT analyzed an effluent sample with the addition of a water softener (hydrogen ionic
exchange) and an effluent without the addition of the water softener (untreated
sample). The ETT laboratory results indicated that the adult Ceriodaphnia had 100%
mortality with the untreated water sample. The results of the treated sample showed
that all the adult Ceriodaphnia lived, however, reproduction was significantly lower
than the "control" sample, and therefore a "failed test" resulted. It appears that the
hydrogen ionic exchange water softener removed the zinc as well as other essential
ions necessary for the Ceriodaphnia Dubia to optimize reproduction.
Based on the ETT bench scale testing, CEI concluded that the ion exchange was
an effective way of removing the toxic zinc. However, the ion exchange is too effective
at removing anions and cations from the effluent sample (including calcium,
potassium, magnesium, sodium and chloride) so the water basically become "too pure"
for optimal reproduction of the test organism.
On May 25, 2000, CEI collected a representative sample of the effluent water to
run a second bench test. The sample was split into two and one sample analyzed
untreated for chronic toxicity. This sample showed a 100% mortality rate within 48
hours. The second sample was passed through an ionic exchanger and then trickled
through a limestone bed prior to conducting the chronic toxicity test. The results of
this test showed that all test organisms survived and reproduced comparably to the
control organisms. Therefore, CEI concluded that the treatment regime would be
effective.
In order to confirm the May 2000 test, CEI completed the fmal bench scale test
utilizing sodium cycle cation exchange resin and an alkalinity adjusting limestone bed.

Natalie Sierra
February 27, 2002
Page 5
On July 6, 2000 and July 11, 2000, CEI sampled the treatment system effluent. ETT
analyzed two water quality samples from the treatment system effluent. One water
sample was treated by sodium cycle cation exchange and subsequently placed through
a limestone bed and the other sample was analyzed without treatment. The ETT
laboratory results indicated a failed test for the untreated sample and pass for the
cation exchange and limestone washed sample. In addition, CEI sampled the
treatment system influent and effluent for the presence of dissolved and total zinc on
July 6, 2000. The ETT results again confirmed the presence of total and dissolved
zinc in the influent and effluent samples. These results confirm those that were
collected in May 2000.
On October 2, 2000 CEI and ATI submitted a request to modify the remediation
system to the NCDENR, DWQ. This modification request included the addition of two
(2) strongly acidic sodium cation exchange resin filters be added to the remediation
system after the air-stripper to remove zinc followed by a limestone filter to add
cations and anions back into the discharge water prior to discharge. CEI initially
planned to run half of the discharge water through the resin system and blend back in
the other half prior to discharge. The system modifications were approved on January
5, 2001. CEI proceeded to gather the required equipment and completed the
installation on August 11, 2001. CEI submitted the engineer's certification an August
11, 2001.
On August 28, 2001, CEI prepared the system for start-up and ran a batch
sample through the system. CEI collected a sample of the effluent water and had it
analyzed for total and dissolved zinc as well as for VOCs. The system was turned off
immediately after the batch sample was collected. The sample results indicated that
the total zinc levels were still too high to have a successful chronic toxicity analysis.
CEI reduced the bypass water to about 4 gallons per minute (gpm) and increased the
amount of discharge that runs through the resin at about 12 gpm. This made the
ratio of one-third bypass and two-thirds treated for water treated by the resin filters.
On September 19, 2001, CEI turned on the system long enough to sample the
effluent water for VOCs in accordance with EPA Method 601 plus cis-1,2
dichloroethene and for both total and dissolved zinc. Upon completion of the sampling
activities, CEI turned the system off. The analytical results did not indicate detectable
VOC concentrations with the exception of methylene chloride, which was flagged as a
common laboratory contaminant. The analytical report also indicated zinc
concentrations were within a range that CEI believed would pass the chronic toxicity
sampling parameters. CEI collected effluent water samples for chronic toxicity testing

Natalie Sierra
February 27, 2002
Page 6
during the week of September 25-29, 2001. CEI also collected a grab sample for
analysis of total and dissolved zinc on September 25, 2001. The September 25, 2001
laboratory report indicated acceptable concentrations of zinc present. The Pace
Analytical report also indicated a passing chronic toxicity sample. Since the sampling
requirements had been successfully met for the set forth NPDES limits, CEI started
the treatment system operations on October 8, 2001.
On November 6th and 9th, 2001, CEI collected a sample of the effluent water and
had it analyzed for pass/fail chronic toxicity utilizing Ceriodaphnia Dubia at the 90
percentile. The laboratory analysis indicated that the results failed the chronic
toxicity test at 90 percent. As a result of this failed test, CEI and ATI conducted two
separate full range chronic toxicity test utilizing Ceriodaphnia Dubia. The first test
sample was collected on December 4th and 7th, 2001. The results of this chronic test
showed a chronic value of 76.5 percent, which is below the required 90 percent. This
test result was similar to the May 2, 2000 bench test results, which showed that the
Ceriodaphnia Dubia would live but not reproduce as well as the control. The test
conducted in May 2000 was done utilizing the sodium cation exchange resin, however
no limestone filter was used. This suggested that either the limestone residence time •
was not adequate for the current flow or that the limestone has ceased providing
enough cations to produce an environment suitable for the Ceriodaphnia Dubia to live
and reproduce.
CEI reduced the flow rate from 16 gpm to 6 gpm to increase the residence time
and maintained the mixture rate of two parts effluent run through the sodium cation
exchange resin to one part bypass water. CEI re-sampled the system effluent with the
reduced flow rate on December 18th and 21st, 2001. The results of this full range
chronic toxicity test revealed a second failed at a chronic value of 76.5 percent. Since
no change in chronic value was observed, CEI determined that the limestone was no
longer dissolving cations in the effluent water. CEI also sampled the effluent for water
quality parameters to help establish a proper ratio of calcium and magnesium as well
as other parameters such as total dissolved hardness, alkalinity, standard pH, and
sulfate. CEI decided to turn the system off on December 27, 2001 until a solution
could be achieved and to help reduce or avoid additional fines while a solution was
found. The system has remained off except for batch sampling that CEI has
conducted to try new filtration systems to provide more cations to the discharge water.
On January 23-25, 2002, CEI turned the system on long enough to get a
sample of effluent to test several new media and satisfy the NPDES requirement of a
second month full range chronic toxicity test. During this testing period, CEI
r

Natalie Sierra
February 27, 2002
Page 8
the sampling requirements of this NPDES system. ATI will continue to remove the
naturally occurring zinc by running the water through the sodium cation exchange
resin tanks and will also continue adding cations by forcing the discharge water
through a crushed limestone filter bed. ATI and CEI feel that it should not be required
to add the compost filter bed since the discharge water will pick up sufficient organic
mater and nutrients from the soil and surface debris (i.e. grass, leaves, decaying wood,
etc.) on its journey to the receiving stream.
Upon your review of the extensive work conducted by ATI, CEI requests that
you consider our request to terminate the chronic toxicity testing requirement in this
NPDES permit. Should you have any questions or need additional information please
contact me at [phone].
Sincerely,
COOPER ENVIRONMENTAL, INC.
Robert S. Hird, P.G.
Vice President Geology Division
\\2.docARCHIEVE\Geology\Projects\95067-AT\RequestNo Chronic 2 Doc.
CC: Dirk Jaekel, American Truetzschler
John Lesslie, NCDENR Mooresville
Andrew Pitner, NCDENR Mooresville