impairment assessment and conceptual model of legacy pesticides: ddt, chlordane, and dieldrin rmp...
TRANSCRIPT
Impairment Assessment and Conceptual Model of Legacy Pesticides:DDT, Chlordane, and Dieldrin
RMP Annual MeetingMay 4, 2004
Jon Leatherbarrow, Chris Werme, Mike Connor, Jay DavisSan Francisco Estuary Institute
Regulatory Status
Restricted/Banned
• DDT in the 1960s/70s• Chlordane and Dieldrin
in the 1970s/80s
SanPabloBay
SuisunBay
CentralBay
SouthBay
LowerSouthBay
Delta
CWA 303(d) List• 1994 Fish Advisory
(OEHHA)• All segments of SF Bay
listed as impaired
Carquinez Strait
Impairment Indicator – Fish2000 RMP Fish Monitoring Results
DDT
Pe
stic
ide
s in
Fis
h (
ng
/g)
0
20
40
60
80
100
120
Chlordane0
5
10
15
20
25
30
Dieldrin0
1
2
3
4
5
Fish Screening Value
POSSIBLEIMPAIRMENT
POSSIBLEIMPAIRMENT
IMPAIRMENTUNLIKELY
Impairment Indicator – Water2002 RMP Water Monitoring Results
No 2002 samples exceeded CTR water quality criteria for:
p,p’-DDEp,p’-DDDp,p’-DDTTotal ChlordaneDieldrin
0 10 20 30 40
Mas
s in
Bay
(kg
)
0
100
200
300
400
Years
60 kg
40 kg
20 kg
0 kg
DDT Forecast
1980 1990 2000
p,p'
-DD
E (
µg/
kg)
0
20
40
60
80
100
…and Historic Trends in Bivalves
Data Gaps and Potential Next Steps
1. Current trends in contamination? Sediment cores and continued fish monitoring
3. Pesticide loading & fate from tributaries? Central Valley; storms with Delta Outflow > 150,000 cfs Local Watersheds; clean-up, loading & BMP studies
4. Loading & fate of remobilized sediment in Bay? Further investigation; field studies, clean-up, bathymetry, modeling
2. Benefits from activities focused on reducing PCB contamination in the Bay?