United States
                     Environmental Protection
                             Office of Water
               Number 18
               Winter 1997
SEPA   Contaminated
                     Sediments   News
  3 ORD Activities—
  "\ff        x,
    SedimentToxicity Test
    for the Ammonia
    Tolerance of the Marine
    Bivalve Mulinia lateralis

    Sediment £ffe,ct

  g Regional*:
   .Activities'.'1:.   ,  '
    •Manistique River/
    Harbor Dredging
    Sediment Management
    in Hawaii
    Creature Feature
  "J Activities Timeline
 CS News is produced by the >~
 EPA Office of Science and
 Technology (OST) to exchange
 Information on contaminated ' >
 s&dimente and to increase
 •communication among
 interested parties. To obtain'  •
 copies of Oils report or to
 contribute information, contact
 Jane Marshall Farris, EPA
 OST, mail code 4305,401M ,
 StreetS.W., Washington, DC
 20460 at ,(202) 260-8897.

 To be added to the mailing list
 or to make changes to your
 address, please fax your
 request to Jane Marshall Farris
 at (202) 260-9830.
                     EPA Holds National Conference  on
                     Sediment Bioaccurnulation
       More than 400 persons attended
        the National Sediment
        Bioaccumulation Conference,
cosponsored by EPA's Office of Science
and Technology and Office of Research
and Development, on September 11-13,
1996 in Bethesda, Maryland.

The conference featured presentations by
national experts in seven sessions. Attend-
ees heard about recent advances in ap-
proaches for assessing bioaccumulative
sediment contaminants and for integrating
assessment results into EPA decision mak-
ing. They also had the opportunity for dia-
logue with panelists during question-and-
answer periods at the end of each session.

The first day of the conference focused on
measuring bioaccumulation and on inter-
preting and applying the results of assess-
ments. The second day included sessions
on modeling the bioavailability of sedi-
ment contaminants and on conducting hu-
man health-based and environmentally
based risk assessments. On the last day of
the conference, an EPA program panel ad-
dressed how the results of bioaccumulation
assessments are being used in Agency de-
cision making. The panelists represented
the Agency's Superfund, NPDES, and
Dredged Material Programs, as well as
programs hi the EPA Office of Pollution
Prevention and Toxics and the EPA Office
of Science and Technology.

Conference Feedback
EPA received complimentary feedback
from numerous conference attendees.
Many appreciated the Agency's organizing
and sponsoring the event on a national
scale. They identified areas of interest for
future conferences, such as sediment reme-
diation, nonpoint source sediment contami-
nants, dredged material disposal, and envi-
ronmental indicators of sediment quality.

Attendees said some session topics—par-
ticularly sediment test methods, bioavail-
ability of sediment contaminants, bioaccu-
mulation modeling, and ecologically based
risk assessment—should be expanded into
an entire conference.

Conference Proceedings
A conference proceedings should be avail-
able by late spring of 1997. Conference at-
tendees will receive a copy. Once the pro-
ceedings are available, a notice on how to
obtain the proceedings through NCEPI will
be published in the newsletter. Other infor-
mation on the proceedings may be obtained
from Leanne Stahl, EPA Office of Science
and Technology, 202 260-7055 (or
stahl.leanne@epamail.epa.gov). @

Screening Values

for  Tributyltin  in

Marine  Sediments

rTlhe EPA Region 10 Superfund
  •  Program, with support from
 -M. an interagency workgroup,
recently completed an evaluation
of various approaches for deriv-
ing an effects-based screening
value or clean-up level for tributyltin
(TBT) in marine sediments.

This effort was initiated to assist EPA in
recommending a cleanup approach for
TBT-contaminated sediments at Superfund
                   Continued on page 2

No. 18

* TBT Screening Values
-Selocted for Sediments at Superfund Sites
r - in Puget Sound __
Screening Valuo
Screening Valua
Screening Valus
(ug TBT/L)
{ug TBT/kg OC)
(*1 ImerititM water Is porewater extracted from whole
tb) Assuming 2% TOC, tho lower screening value Is
approximately equivalent to 2B.1 ug TBT/kg (dry weight) and the
higher screening value Is equivalent to 351 ug TBT/kg (dry
Weight). Bulk sediment analyses quantify the TBT concentrations
In both pofewaler and tho sediments.
TBT VALUES Continued from page I

sites in Puget Sound, Washington. Re-
sults are detailed in a final report, Recom-
mendations for Screening Values for
  Tributyltin in Sediments at Superfund
  Sites  in Puget Sound,  Washington
  (EPA 1996).

  What is TBT?
   A man-made organotin compound,
   TBT has many commercial, industrial,
   and agricultural applications. TBT has
   been widely used in marine paints as
   an effective means of preventing or
   retarding the growth of fouling organ-
isms such as barnacles and mussels on the
hulls of boats and ships.  It is this applica-
tion that is thought to represent the main
contribution of TBT to the marine and es-
tuarine environments in Puget Sound.
However, TBT compounds are also used
as biocides hi cooling towers, pulp and
paper mills, and textile mills, and as ac-
tive ingredients in wood preservatives,
disinfectant and antimicrobial cleaners
and shampoos, and toilet bowl cleaners.

Development of Agency  TBT
Screening Values
In the 1990s, EPA found TBT was ex-
tremely  widespread in sediments at three
Superfund sites located in highly industri-
alized urban embayments. To evaluate
these bulk sediment chemistry data, the
Agency developed a range of bulk sedi-
ment and interstitial water TBT screening
values. Interstitial, or pore, water is ex-
tracted or  centrifuged from whole bulk

Screening values were developed because
         there are no state or federal cri-
         teria for TBT, and it was neces-
         sary for Region 10 to move for-
         ward with sediment remedial
         design and remedial action at
         these sites. The range of screen-
         ing values allows for the site-
         specific selection of a cleanup
         level based on  the protective-
         ness that is considered appropri-
         ate for the given sediment man-
         agement decision.
                           The interstitial water screening
                           values for TBT are based on
                           chronic and acute water quality
                           effects data reported in the lit-
erature for concentrations of TBT (as the
ion). The report summarizes all available
TBT water quality effects data, including
test species, endpoints, and citations.

The sediment screening values for TBT
are derived using a sediment-water parti-
tioning approach. This approach is based
on a mathematical relationship between
TBT concentrations known to cause ad-
verse effects in water and an organic car-
bon-based partitioning coefficient. (A
Koc value of 25,100 L/kg was used.) This
mathematical relationship is shown here:
                                                                     [Sedl = [Water] * K
                                                               Sedoc    = organic-carbon normalized sedi-
                                                                       ment concentration (jag/kg)

                                                               Water    = effects concentration in water
                                                                       = organic carbon based partitioning
                                                                       coefficient (L/kg)
This equation was used to calculate a
range of organic-carbon normalized sedi-
ment TBT concentrations that would pre-
dict TBT concentrations associated with
minor adverse effects. Note that this ap-
proach assumes that TBT is in equilib-
rium between sediment interstitial water
and particulate organic carbon phases.

Because there  were no state or federal
critieria for TBT, Bulk Sediment TBT
concentrations normalized to organic car-
bon were developed as screening concen-
trations to predict minor or adverse ef-
fects. Two limited studies found that the
screening values reflected interstitial wa-
ter concentrations of TBT to within only
one to two orders of magnitude of actual

The organotin  compounds are unique,
and they partition between sediment and
water differently from other organic com-
pounds. For a number of organic com-
pounds, organic carbon normilization has
been shown to reliably reflect interstitial
water concentrations. For TBT, however,
the  interstitial water should actually be
collected and analyzed for TBT, instead
of using the original predictive concentra-
tions. (See Table of Screening Values.) A

disadvantage of this method is that rela- *
tively large amounts of sediment must be
collected to obtain a large enough quan-
tity of interstitial water for TBT analysis.
However, for organotin compounds like
TBT, this collection is necessary.

Results of Region 10's study suggest that
bulk sediment, and organic carbon-nor-
malized sediment TBT concentrations
may be poor predictors of the bioavail-
able fraction of TBT.  Thus, Region 10
strongly recommends that sediment
cleanup decisions at Superfund sites in
Puget Sound be based on TBT concentra-
tions in interstitial water, and on any as-
sociated biological effects testing.

Two recent sampling  efforts showed that
measured concentrations of TBT hi inter-
stitial water were lower than would have
been predicted using the sediment-water
partitioning approach and existing bulk
sediment data.

Recommendations for future work have
also been identified. Additional research
is needed on the environmental factors af-
fecting TBT partitioning behavior and the
degradation rates of TBT under varying
conditions (e.g., anaerobic vs. aerobic
conditions) and varying TBT concentra-
tions (e.g., moderate vs. high concentra-
tions). Also, to confirm the ecological
significance  of interstitial water "exceed-
ances" of TBT screening values,  appro-
priate biological effects tests should be
developed to assess the bioavailability of
TBT in sediments. Some data suggest that
several bioassay species commonly used
in effects test appear to be insensitive to
TBT, and/or test durations may be too
short. The uptake of TBT from sediments
to tissue appears to be fairly complex,
and there are limited studies on tissue
residue effects data for TBT.

Additional information and copies of the
EPA report are available from Karen
Keeley, Superfund Site Manager, EPA
Region 10 Office of Environmental
Cleanup, ECL-111, Seattle, WA, 98101.
206 553-2141 (e-mail: keeley.karen@
epamail.epa.gov). O
    No. 18
Winter 1997

Sediment Toxicity Test for the
Ammonia Tolerance of the
Marine Bivalve Mulinia lateralis

Ammonia is a naturally occurring, and of-
ten a eutrophication-enhanced, chemical
constituent of many freshwater and ma-
rine sediments. At sufficiently high con-
centrations ammonia can also be an im-
portant sediment toxicant. Recent work at
AED-Narragansett has focused on the
ammonia tolerance of a new sediment
toxicity test using the marine bivalve
Mulinia lateralis.

Because this species is being considered
for regulatory use by EPA Region 6,
knowing its response to sediment ammo-
nia concentrations is important. M.
lateralis had LC50 and EC50 (growth) val-
ues of 0.6 and 0.3 mg/L unionized ammo-
nia, respectively. These values indicate
that the bivalve is among the most sensi-
tive marine toxicity testing species.
A second study assessed whether ammo-
nia concentrations in the M. lateralis ex-
posure chambers that contained natural
sediments with high interstitial water am-
monia concentrations would approach ef-
fects levels. It was shown that the pre-test
flushing procedure (i.e., overlying water
replacement 24 hours after sediment addi-
tion to exposure chambers) reduced over-
lying water ammonia concentrations to
well below the levels where toxicity
would be expected.

For further details please contact Peg
Pelletier (401 782-3131) or Rob Burgess
(401 782-3106), EPA Office of Research
and Development, Atlantic Ecology Divi-
sion, Narragansett, RI. ©

Sediment Effect Concentrations

A recent U.S. EPA publication, "Calcula-
tion and Evaluation of Sediment Effect
Concentrations for the Amphipod
Hyalella Azteca and the Midge
                      Continued on page 4

     No. 18
     Winter 1997
The SEC is the
concentration of a
chemical that is
associated with the
effect. Once the
probable cause(s) of
sediment toxicity has
been identified,
better decisions can
be made regarding
remediation options.
ORD ACTIVITIES Continued from page 3
Chironomus Riparius," describes proce-
dures for calculating and evaluating sedi-
ment effect concentrations (SECs) using
laboratory data on the toxicity of con-
taminants associated with field-collected
sediment to the amphipod Hyalella azteca
and the midge Chironomus riparius.

SECs are the concentrations of individual
contaminants hi sediment below which
toxicity is rarely observed and above
which toxicity is frequently observed.
SECs were used to classify toxicity data
for Great Lake sediment samples tested as
part of the U.S. EPA Great Lakes Na-
tional Program Office (GLNPO) Assess-
ment and Remediation of Contaminated
Sediments (ARCS) Program (Fox and
Tuchman  1996; Ingersoll et al. 1996).

Three types of SECs were calculated for
Hyalella azteca and for Chironomus
riparius: (1) Effect Range Low (ERL)
and Effect Range Median (ERM), (2)
Threshold Effect Level (TEL) and Prob-
able Effect Level  (PEL), and (3) No Ef-
fect Concentration (NEC; analogous to
Apparent Effect Thresholds).

The SECs were calculated using: (1) dry-
weight concentrations, (2) dry-weight
concentrations normalized to total organic
carbon concentrations (for non-ionic or-
ganics), or (3) dry-weight concentrations
normalized to acid volatile sulfide con-
centrations (for divalent metals). SECs
were calculated primarily for total metals,
simultaneously extracted metals, poly-
chlorinated biphenyls, and polycyclic aro-
matic hydrocarbons. The database's
ranges of concentrations in sediment were
too narrow to adequately evaluate SECs
for butyltins, methyl mercury, polychlori-
nated dioxins and furans, or chlorinated

Using SECs, about 60 to 80 percent of
the sediment samples in the database can
be correctly classified  as toxic or not
toxic, depending on the type of SEC
evaluated. ERMs and ERLs are generally
as reliable as paired PELs and TELs at
classifying both toxic and nontoxic
samples in the database. Reliability of the
SECs in terms of correctly classifying
sediment samples is'similar between
ERMs and NECs; but ERMs minimize
Type I errors (false positives) relative to
ERLs, and minimize Type II errors (false
negatives) relative to NECs. Correct
sample classification can be improved by
using only the most reliable SECs for
chemicals (those with a higher percentage
of correct classification).

Calculating SECs using dry-weight con-
centrations—instead of using sediment
concentrations for PAHs and total PCBs
that have been normalized to TOC con-
centrations—resulted in  similar correct
classification of toxicity and similar Type
I and Type II error. The range of TOC
concentrations in the database was rela-
tively narrow compared to the ranges of
contaminant concentrations. Therefore,
normalizing dry-weight concentrations to
a relatively narrow range of TOC concen-
trations had little influence on relative
concentrations of contaminants among

The SECs were calculated from toxicity
tests with field-collected samples. Even if
a chemical concentration exceeds an SEC
generated from data derived from tests
with field-collected samples,  the chemical
may not have caused the observed effect.
Rather, the SEC is the concentration  of a
chemical that is associated with the ef-

Field-collected sediments typically con-
tain complex mixtures of contaminants.
Additional information is needed to iden-
tify the specific contaminants that were
responsible for the toxicity.

Confirmation of sediment toxicity due to
individual or groups of contaminants can
be determined by using Toxicity Identifi-
cation Evaluation procedures or by con-
ducting toxicity tests with spiked sedi-
ments. Once the probable cause(s) of
sediment toxicity has been identified, bet-
ter decisions can be made regarding re-
mediation options.

The SECs can be used as guidance for
evaluating contaminated sediment, but
there is no intent expressed or implied
that they represent U.S. EPA or National
Biological Service (NBS) criteria.

The SEC data discussed here (U.S. EPA,
1996), including the database on disk, are

available from Callie Bolattino, U.S.
EPA, GLNPO, 77 W. Jackson, Chicago,
IL (312 353-3490, fax -2018; email:

An electronic copy of U.S. EPA (1996)
including the database is also available on
the internet at the NBS home page at:

References Cited
Fox, R.G., and M. Tuchman. 1996. The
Assessment and Remediation of Contami-
nated Sediments (ARCS) Program. J.
Great Lakes Res. 22:493-494.
Ingersoll, C.G., P.S. Haverland, E.L.
Brunson, T.J. Canfield, F.J. Dwyer, C.E.
Henke, and N.E. Kemble. 1996. Calcula-
tion and Evaluation of Sediment Effect
Concentrations for the Amphipod
Hyalella azteca and the Midge
Chironomus riparius. J. Great Lakes Res.

U.S. Environmental Protection Agency.
1996. Calculation and Evaluation of Sedi-
ment Effect Concentrations for the Am-
phipod Hyalella azteca and the Midge
Chironomus riparius. EPA 905-R96-008,
Chicago, IL.»
    No. 18
Winter 1997
Region 5

Manistique River/Harbor
Dredging Project

The Manistique River/Harbor Site, in
northern Michigan, is 1 of 42 Areas of
Concern, where Water Quality Objectives
are not met. The site is hi the City of
Manistique on the southern shores of
Lake Michigan's Upper Peninsula, where
the Manistique River discharges into
Lake Michigan.

PCBs are the major contaminant of con-
cern, and three areas have PCB concen-
trations that exceed the 10 part per mil-
lion (ppm) cleanup level. Concentra-
tions generally are in the hundreds of
parts per million in the contaminated ar-
eas, with concentrations as high as 2,510
ppm (see table at right).

Approximately 18,000 pounds of PCBs
can be found within 127,000 cubic yards
of contaminated sediments. Surface water
sample analysis indicate that 105 pounds
of PCBs are being discharged annually
into Lake Michigan, and there is potential
for erosion of a greater volume of con-
taminated sediments during a large storm
or floods.

There is a fish advisory for carp, in which
PCB concentrations average approxi-
mately 6 ppm. Sport fish are affected by
PCB contamination.
Potentially responsible parties (PRPs)
consist of a paper company, an electric
utility, a local salvage yard, and compa-
nies that sent materials to the scrap yard.

Recent Site History & Investigations
After an Engineering Evaluation/Cost
Analysis (EE/CA) was conducted by the
paper company and the electric utility,
EPA recommended that the contaminated
sediments be dredged and disposed of at
a nearby PCB landfill. This
recommendation quickly be-
came controversial, with the
community and PRPs voicing
strong opposition to dredging.
They asserted that dredging
was not protective because
PCB-contammated sediment
would be resuspended in the
water during dredging, leaving
contaminated materials behind.
The opponents to EPA's rec-
ommendation countered that
capping contaminated sedi-
ments in the river and harbor
would be the most protective
and cost-effective remedy.
^-IVfejilstlqile^Rf^e^Hairbbf , Drainage Project '
fe§r. "
Near Manistique
Papers Facility
North Bay/U.S.
2 Highway
1,000 Feet
Upstream From
River Mouth
Cubic Yards of
10 ppm
., 0
1 27,000
After considering community input and
remedial alternatives, EPA selected a
"hybrid" remedy whereby the Agency
would conduct and pay for dredging a
relatively small area in the river, and the
PRPs would implement a capping rem-
edy. EPA began its dredging project dur-

                      Continued on page 6

     No, 18
     Winter 1997
EPA will continue to
improve the
efficiency of
dredging and water
treatment, employing
such techniques as
hydrocycloning to
enhance the
separation ofPCB-
materials from
     TlilJ popular jportfijh iin'ta lalmonM,
     but a cliar. (an you identify it?
             B si ojnjea-j
MANISTIQUE RIVER Continued from page 5

ing 1995, while negotiations for the PRPs
to implement capping were conducted.

EPA's project demonstrated that, by using
diver-assisted dredging techniques on the
sediment, which was described as "light
and fluffy," resuspension during dredging
was minimized. And by separating the
sawdust and woodchips that accounted for
the highest PCB' concentrations— about
1,000 ppm—from the sediments that had
PCB concentrations less than 1- ppm, dis-
posal costs were reduced. This is because
the sawdust and woodchips accounted for
only about 3 percent of the total volume of
contaminated material.

The Agency therefore reproposed a total
dredging remedy, which was supported by •
the PRPs and community. The PRPs
agreed to pay $6.4 million for EPA to fin-
ish dredging all the river and harbor sedi-
ments whose contamination exceeded the
cleanup level.

Before beginning its dredging activities in
1995, EPA designed and built or installed:

  • Sheet piling and silt barriers to pre-
   vent any releases of resuspended sedi-

  • An on-site water treatment plant to
   dewater dredged sediments and treat
   dredge water prior to its discharge
   back into the Manistique River.

  • Two 1.2 million gallon lagoons for
               storage of treated dredge
               The Agency also up-
               graded a pad for storage
               and additional sediment
               dewatering that was
               owned by the paper com-
               pany and previously used
               to store recycled paper.

               Dredging Progress
               During 1995 and through
               August 1996, EPA fo-
               cused its dredging activi-
               ties in the North Bay/
               U.S. 2 Highway area of
               the Manistique River.
 Since September 1995, approximately
 18,000 cubic yards of contaminated sedi-
 ments have been removed, dewatered
 and disposed of. Approximately 30 mil-
 lion gallons of dredge water have also
 been treated and discharged to the
 Manistique River.

 Short-term adverse impacts from dredg-
 ing were found to be negligible. Turbid-
 ity measurements of surface water imme-
 diately downstream of the dredging area
 have remained at background levels dur-
 ing all dredging activities.

 Future Activities
 EPA will continue to improve the effi-
 ciency of dredging and water treatment,
 employing such techniques as hydro-
 cycloning to enhance the separation of
 PCB-contaminated materials from
 noncontaminated sediments.

 The Agency has completed dredging
 Area B (North Bay/U.S. 2 Highway
 area) and will dredge Area C. Dredging
 of Area C is scheduled to begin in May

 For additional information, contact
 James Hahnenberg, Remedial Project
 Manager, Superfund Division, EPA Re-
 gion 5, 77 West Jackson Blvd. SR-6J,
 Chicago, IL 60604 (312 353-4213, e-
 mail: hahnenberg.james@epamail.epa.
Region 9

Contaminated Sediment
Management in Hawaii

Most dredging in the Hawaiian Islands
has been conducted by the Navy at Pearl
Harbor. Operating under a general per-
mit (GP) from the U.S. Army Corps of
Engineers, the Navy had disposed of all
sediments at the EPA-designated south
Oahu ocean dredged material disposal
site (or earlier ocean disposal sites in the
vicinity). Under the old GP, the Corps
had determined the suitability of all Pearl
Harbor sediments for ocean disposal
based on broad, one-time regional sam-

The old GP has expired, and today

project-specific sampling and analyses
(chemistry and bioassays) are required by
EPA and the Corps. This testing of the
specific sediments to be dredged is begin-
ning to identify areas of contamination
within Pearl Harbor that require alternate
disposal methods. (Contaminants found
include metals and organics such as
PAHs and PCBs.) However, no Confined
Disposal Facilities (CDFs) or other sites
capable of managing sediments deemed
unsuitable for unconfined ocean disposal
have been constructed in Hawaii. A re-
gional dredging team for the Hawaiian Is-
lands formed by EPA and the Corps has
begun discussions and planning for man-
aging contaminated sediments.

Planning Hawaii's First CDF
The first project-specific CDF to manage
contaminated  sediments hi Hawaii is be-
ing planned. The Navy proposes to con-
tain unsuitable sediments, from the recon-
struction of a submarine base, in a sheet
pile-lined fill to be incorporated into new
piers being built as part of this project.
Preliminary plans have been presented to
EPA and the Corps, and the Navy plans
to evaluate maximizing the CDF's capac-
ity to accommodate contaminated sedi-
ments  from other planned projects.

Managing Other Contaminated
Advanced planning also has begun for the
management of expected contaminated
sediments from the Ala Wai canal in
Waikiki. Based on recent sediment stud-
ies that show elevated chemical concen-
trations, EPA  and the Corps have deter-
mined that significant volumes of
sediment in the proposed design may be
found unsuitable for unconfined ocean
disposal. The  state and local agencies
have been urged by EPA and the Corps to
re-evaluate the engineering of the project
to minimize the amount of dredged mate-
rial generated and to begin exploring op-
tions for alternative disposal sites as part
of the environment assessment of this
project. In particular, EPA and the Corps
are working with the agencies to coordi-
nate the Ala Wai's dredging needs with
other potential projects that may have a
need for fill, and whose sites may be en-
gineered to appropriately manage the
contaminants present in the Ala Wai sedi-
ments. Limited availability of potential
upland sites on the Hawaiian Islands,
however, makes developing appropriate
facilities difficult. Therefore, there is
growing interest in Hawaii in manage-
ment concepts such as Confined Aquatic
Disposal and containerization techniques
(e.g., with geotextile bags).

For more information, contact Allan Ota,
U.S. EPA Region 9, San Francisco, CA
94105 (415 744-1980). O
    No. 18
Winter 1997
   G5G2 Activities Timeline

   February 9-12, 1997
   1997 International Containment Technology Conference
   St. Petersburg, Florida
   Sponsors: U.S. Department of Energy, DuPont Company,
   U.S. EPA

   For further information, contact:
   Loreen Kollar, Conference Coordinator
   Florida State University
   2035 East Paul Dirac Drive, 226 HMB
   Tallahassee, Florida
   Phone: 904 644-5524
   Fax: 904 574-6704
   e-mail: ICTCE@mailer.fsu.edu

   April 9-11, 1997
   Third Environmental Monitoring and Assessment Program
   (EMAP) Research Symposium "Developing New Tools to
   Meet the Nation's Monitoring Needs: The Evolution of
   Albany, New York
   Sponsor: U.S. EPA

   For further information, contact:
   Dr. Shabeg Sandhu
   NHEERL Building
   U.S. EPA EMAP Center. MD-87
   Research Triangle Park, NC 27709
   Phone: 919 541-3850
   Fax: 919 541-4621
   e-mail: sandhu.shabeg@epamail.epa.gov

   April 9-11, 1997
   Seventeenth Annual Hydrology Days
   Sponsored by American Geophysical  Union, Hydrology
   Section & the Front Range Branch American Society of
   Civil Engineers (ASCE), Water Resources Engineering
   Division, and the Colorado Section American Water Re-
   sources Association
   Colorado State University, Fort Collins, Colorado
   Abstract Submittal Deadline: March 7, 1997

   For registration/general information, contact:
   Janet Lee Montera (Hydrology Days)
   Civil Engineering Department
   Colorado State University
   Fort Collins, CO 80523
   Phone: 970491-7425
   e-mail: jmontera@vines.colostate.edu

United States
Environmental Protection
Agency  (4305)
Washington, DC 20460
Official Business
Penalty for Private Use
                                   Beginning in 1997 CS News will be primarily available via the INTERNET
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                                   If you would prefer to continue to receive CS News as a hard copy, please send
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                                     FAX (202) 260-9830 or E-mail farris.jane@epamail.epa.gov

                                   or mail this form to:

                                     Jane Marshall Farris, U.S. EPA MC4305, 401 M St., SW, Washington DC