1. Ambient Water Toxicity Surveys
A. Ronald MacGillivray, Ph.D.
Environmental Toxicologist
Delaware Estuary Science Conference 2007

2. Advantages of Ambient Water Toxicity Testing
Assesses point sources and non-point sources
Assesses mixtures (cumulative effects)
Assesses toxicants with no chemical specific water quality standards and/or are not being monitored by chemical analysis
Water Quality Modeling indicates a potential exceedance of DRBC Water Quality Criteria for Chronic Toxicity in segments of the survey area based on reported toxicity in NPDES dischargers to the estuary
Other program conducting ambient water monitorin SF Bay program

3. Previous DRBC Ambient Water Toxicity Studies
Survival of all test organisms not affected
Sub-lethal chronic toxicity suggested at different sampling stations and in different species over the study period
EPA reviews conclude data inconclusive, recommend further study (possible confounding factors e.g., salinity effect)

4. Chronic Toxicity Workgroup Developing Consensus On Test Species and Study Design
DNREC – Rick Greene
NJDEP – Betty Jane Boros-Russo/Michelle Mooney
DRBC – Ron MacGillivray
DRBC – Tom Fikslin
EPA–RIII – Brian Trulear
EPA–RII – Jim Ferretti
PADEP – Mike Boyer
EPA-RIII – Dave Russell
DuPont, Haskell Lab – Bob Hoke
Rohm & Haas Co. – Steve Brown
PWD – Linda O’Donnell
AAT – Chris Nally
EPA – ORD consultation

5. Objectives
To assess if chronic toxicity, as measured in laboratory controlled experiments, is present in the river water samples collected.
To develop appropriate toxicity tests for the estuary.

6. Freshwater Test Species
Pimephales promelas
fathead minnow
Ceriodaphnia dubia
water flea
Pseudokirchneriella subcapitata
green algae

7. Salinity Tolerant Test Species
Menidia beryllina
inland silverside (5 to 32 ppt)
Americamysis bahia
mysid shrimp (10 to 30 ppt)
Freshwater to brackish water 0 to 15 ppt.
Ocean salinity (35 ppt)
Hyalella azteca
amphipod (0 to 15 ppt)

8. June Survey (sites T4 to T16)
2005 Sites mid-channel
June Survey (sites T4 to T16)
September Survey (sites T1 to T7)
16 fixed stations
81 miles (RM 50 to 131)
68 composite sample over 8 samples days.

9. June Survey Conditions graph by Dr. N. Suk
Delaware River at Trenton flow between 5000 and 6750 cfs during the survey.
Rainfall occurred between the first and second sample day.
Samples were taken on slack low tide.

10. Niskin sampler to analytical lab sample bottle

11. Transfer to cubitainer for transport to tox lab

12. Ambient Water Toxicity Tests
Expose test species to
100%, 75%, 50%, 25%, and 12.5% ambient water
Test Duration - 4 to 10 days (species specific)
Test for survival and growth or reproduction
Compare to controls
Chronic Toxicity Workgroup identified appropriate species and methods (DRBC, states, EPA, industry, tox lab, other interested parties – PWD)
Study conducted by AAT, Inc. to collect supporting data on Americamysis bahia acclimation to 10 ppt. (Poster Nov 2005 – SETAC-NA Annual Mtg)
Hyalella azteca in a 10-day water only test (standard tox test is in sediment)
Menidia Beryllina is not routinely used by NPDES program in basin states but is the species of choice for other estuarine programs such as MWRA Boston Harbor Discharge Toxicity Monitoring (Switch from Cyprinodon variegatus, sheepshead minnow)

13. June Freshwater Sites P. promelas fish NOEC C. dubia invertebrate
P. subcapitata
algae
T4 S of
Del Mem Br
100%
75% reproduction
(salinity effect?)
T5 N of T6
Oldman’s Pt
T7 Marcus Hook Creek
No significant effect on survival.
T4 to T7 dilution series
T8 to T16 single concentration
Controls - P. promelas and Selenastrum dilution water control and extra conductivity control at 1, 750 µS/cm (1.0 ppt salinity at 25oC)
Controls – Ceriodaphnia – 750, µS/cm

14. Single Concentration NOEC <100%
June
Sites
P. promelas
fish
NOEC
C. dubia
invertebrate
P. subcapitata
algae
T15 Florence
100%
T16 Biles Channel
Single Concentration NOEC <100%
Resampled three weeks later with Dilution Series NOEC = 100%
QAPP specifies qualitative single concentration tests and quantitative multiple dilution tests as confirmatory tests.

15. September Sites and Salinity (ppt) A. bahia mysid NOEC M. beryllina
fish
H. Azteca
amphipod
T5 N of Del Mem Br
3.4 – 3.9
100%
T6 Oldman’s Pt
2.2 – 3.1
T7 Marcus Hook Creek
0.9 – 1.6
75% growth
IC growth
T7 – A. bahia – mean dry weight at 100% = within acceptable criteria for a control at >0.2 mg

16. Conclusions
Identified a set of test species and modified toxicity testing methods appropriate for routine monitoring of the estuary.
The June and September 2005 toxicity surveys indicated overall, based on the measured toxicity endpoints, that the ambient water samples collected were not chronically toxic.

17. Future Direction
Shift from a developmental phase of identifying appropriate test species and methods to a monitoring phase with a continued focus on ambient toxicity testing of water.
Increase spatial and temporal coverage of the estuary (new focus on tributaries as well as main-stem)

18. Criteria for Prioritization of 2007 Tributary Sampling
Direct tributary to the Delaware Estuary in Zones 2 through 5
Segment of the tributary is listed for toxics in a state Integrated Assessment
History of sampling as part of a tributary monitoring program
Brandywine River and C&D canal do not strictly met this criteria but have a strong influence on the Delaware Estuary

19. 2007
Ambient
Toxicity
Survey

20. Ambient Copper Concentrations at Selected Sites June 2005 survey
Date
Site
Current USEPA Criteria
µg/L
Proposed USEPA Criteria
Measured Dissolved Cu
Applicable
DRBC
Regulatory Criteria
BLM
Site-specific Chronic WQC
6/6/05 T4 13
3.1
2.1
2.8
7.8 T5
4.8
4.2 2
8.3
7.6
T16
<1.4
16.8
6/8/05
11.1
12.9
6/10/05
12.4
27.0
Site - T4 (South of Delaware Memorial Bridge, salinity 1.35 ppt - saltwater criteria); T5 (North of Delaware Memorial Bridge, salinity <1 ppt); T16 (Biles Channel, salinity <1 ppt).
Measured dissolved Cu - Multiple-day composite sample of water from each sample day over the duration of the toxicity test for sites T4 and T5. Site T16 is a single day composite.
National Recommended Water Quality Criteria 2002, EPA-822-R
2003 Draft Update of Ambient Water Quality Criteria for Copper, EPA 822-R
USEPA Method 200.7
Applicable Regulatory Criteria - DRBC Water Quality Regulations Marine Chronic Aquatic Life Objective is 2.8 µg/L and Freshwater Chronic Aquatic Life Objective is 8.3 µg/L.
Site-specific chronic water quality criteria (WQC) derived from Biotic Ligand Model Windows Interface, Version 2.12 predicted site-specific acute water quality criteria divided by an acute chronic ratio of 3.23 from 2003 Draft Update Of Ambient Water Quality Criteria For Copper, EPA 822-R
Input parameters: temp, pH, DOC, Ca, Mg, Na, K, SO4, Cl, alkalinity

21. Water Quality
Dissolved copper did not exceed the applicable regulatory criteria or the site-specific water quality criteria predicted by the BLM for the sites and dates evaluated.