Basic HTML Version
MERC ER02-10
8
Toxicity Summaries
Residual Chlorine
Analysis
- Levels of residual chlorine (or total residual oxidants -
TRO) were below the permissible discharge limit of 0.10 ppm in all TF treated samples. Values
ranged from 0.06 ppm to below the method detection limit (MDL) of 0.02 ppm.
Chronic Toxicity
- Results showed that ballast water discharge was not chronically toxic
to either mysids or sheepshead minnows. All samples, however, were chronically toxic to the
marine algal species
Isochrysis galbana
with a statistically significant inhibition in growth in
treated ballast discharge compared to controls.
Disinfection By-Products (
µg/l
)
Control Treated
BW
Treated RDL/MRL
T0
T0
T0
TF
Trihalomethanes
0
91.2
ND
293
0.5
Trichloromethane
< 0.5
< 0.5
ND
< 0.5
0.5
Bromodichloromethane
< 0.5
2.7
ND
3.8
0.5
Dibromochloromethane
< 0.5
20.7
ND
28.2
0.5
Tribromomethane
< 0.5
67.8
ND
261
0.5
Haloacetic Acids
0
87.4
ND
197
1.0
Monochloroacetic acid
< 2.0
< 2.0
ND
< 2.0
2.0
Dichloroacetic acid
< 1.0
1.2
ND
< 1.0
1.0
Trichloroacetic acid
< 1.0
< 1.0
ND
< 1.0
1.0
Bromochloroacetic acid
< 1.0
5
ND
< 1.0
1.0
Monobromoacetic acid
< 1.0
4.5
ND
< 1.0
1.0
Dibromoacetic acid
< 1.0
72.2
ND
< 1.0
1.0
Tribromoacetic acid
< 1.0
4.5
ND
197
1.0
Other
ND
Sodium chlorate
< 10
340
ND
340
10
Sodium bromate < 50.0
< 50.0
ND
< 50.0
50.0
Monochloroacetonitrile
<0.5
<0.5
ND
<0.5
Dichloroacetonitrile
<0.5
<0.5
ND
<0.5
0.5
Monobromoacetonitrile
<0.5
<0.5
ND
<0.5
Dibromoacetonitrile
<0.5
18
ND
<0.5
0.5
BW = backwash; RDL = reporting detection limit; MRL = method reporting limit