United States
Environmental Protection
Agency
Risk Reduction
Engineering Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/SR-92/184 October 1992
EPA Project Summary
Toxicity Reduction Evaluation:
Case Histories at High Point and
Fayetteville, North Carolina
Francis A. DiGiano, Marilyn Maerker, Tory Champlin, and Maria Frey
This research focused on investiga-
tion of two important elements of the
toxicity reduction evaluation (TRE)
protocol proposed by the U.S. Environ-
mental Protection Agency (EPA): (1)
toxicity identification evaluation (TIE)
and (2) toxicity source evaluation (TSE).
The specific objectives of this research
were to challenge the TIE protocol with
target compounds to determine whether
toxic agents could be properly classi-
fied, apply the TIE and TSE protocols
to two case studies (High Point and
Fayetteville, NC) where pass-through
toxicity was highly variable, and inves-
tigate the potential for return activated
sludge to desorb acutely toxic com-
pounds.
Testing of the TIE Phase I protocol
with five target compounds showed that
false positive and false negative re-
movals of toxicity can occur. Elution of
the C18 solid phase extraction (SPE)
column with methanol/water fractions
(TIE Phase II) showed that a single toxic
compound is eluted in several fractions.
Only a weak relationship was found
between the polarity of compounds and
the elution fractions they appeared in.
Identification of the sources or nature
of acutely toxic compounds when
events were sporadic was not solved
in the High Point study. Modifications
were made to the refractory toxicity
assessment (RTA) protocol to simplify
its use. Also, the RTA protocol was
modified to use chronic toxicity as the
end-point rather than acute toxicity.
Four TIEs at the Fayetteville, NC facility
showed that passage of samples
through a C18 SPE column completely
eliminated acute toxicity. Other tests
implied that ammonia contributed tox-
icity, but the presence of toxicants other
than ammonia was indicated by removal
of toxicants by the C18 column. In three
TIEs, most of the toxic substances ap-
peared in the 80% to 85% methanol
fractions from the C18 column. RTA
tests suggested that five industries
potentially contributed toxic substances
to the waste stream. Return activated
sludge was not found to be more toxic
than whole effluent in the case histories
examined. However, a sample from an-
other treatment facility indicated con-
centration and release of toxic agents
by biomass. The TIE Phase I protocol
can provide the proper direction for
further narrowing of potential toxicants
but more data are needed with mixtures
of target compounds to show reliability.
The RTA protocol should be stream-
lined to make it more practical to apply.
The development of "real-time" mea-
sures of aquatic toxicity is essential if
sporadic sources of toxic compounds
are to be eliminated.
This Project Summary was developed
by EPA's Risk Reduction Engineering
Laboratory, Cincinnati, OH, to announce
key findings of the research project
that is fully documented in a separate
report of the same title (See Project
Report ordering information at back).
Introduction
Effluent biomonftoring is the cornerstone
of water-quality-based permitting of
wastewater discharges as mandated by
Printed on Recycled Paper
-------
Francis A. DiGlano, Marilyn Maerker, ToryL Champlin, and Maria V. Freyare
with the University of North Carolina, Chapel Hill, NC 27599-7400.
Richard A. Dobba is the EPA Project Officer (see below).
The complete report, entitled "Toxicity Reduction Evaluation: Case Histories at
High Point and Fayetteville, NC," (Order No. PB92-222 231/AS; Cost:
$26.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
EPA/600/SR-92/184
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
------- |