7/6/2010

1

Total Maximum Daily Load for PCBs in 

the Houston Ship Channel

+

Survey and Snapshot of PCBs and 

Dioxin in the Houston Ship Channel 

and Galveston Bay System

University of Houston

Parsons

6/23/2010

Outline

• Total Maximum Daily Load for PCBs in the Houston Ship 

Channel

– FY09 PCB results from the Houston Ship Channel 

(HSC) and Galveston Bay.

– Effluent and Runoff Sampling Results

• Proposed Sampling Plan

– Survey of PCBs and Dioxin in the Galveston Bay System

– Snapshot of PCBs and Dioxin in the Houston Ship 

Channel and Galveston Bay
7/6/2010

2

Total Maximum Daily Load for PCBs in the Houston 

Ship Channel

Houston Ship Channel Segments

Houston

HSC

Galveston 

Bay
7/6/2010

3

FY 2009 PCB Sampling

• PCB ambient sampling

– Samples collected for water, sediment, and tissue in HSC and 

Upper Galveston Bay

• 47 sites samp ( p) led for water (dissolved & suspended)*

• 35 sites sampled for sediment 

• 30 sites sampled for catfish and 16 sites sampled for seatrout or 

Atlantic croaker.

• PCB runoff sampling

– 7 sites sampled once and 1 site sampled twice for water 

(dissolved & suspended (1-40 μm and >40 μm))*. 

• PCB effluent sampling

– 16 effluent sites sampled for effluent (dissolved & suspended)*. 

• PCB concentrations calculated as sum of 43 congeners; 

non-detects assumed as 1⁄2 MDL

*High-volume sampling technique

FY 2009 PCB Ambient Sampling Locations

Morgan's point
7/6/2010

4

QA/QC Summary

Media Analysis

Number of 

samples 

collected

Number of sample 

results obtained 

from laboratory

Number of sample 

results reviewed for 

QA/QC

% Results 

reviewed for 

QA/QC

Water TSS, DOC, TOC 81 81 81 100%

Sediment Grain size and Solids 

content 42 42 * *

Water PCB (209 Congeners) 174 174 174 100%

Sediment PCB (209 Congeners) 42 42 42 100%

S di t e men TOC 42 42 42 100%

Fish

PCB (209 Congeners), 

Lipid and Moisture 

content*

58 58 58 100%

*QA/QC not required

Summary Statistics for DOC and TSS

by Sample Type

Count Mean Median Minimum Maximum Standard 

Deviation

Ambient samples

DOC (mg/L)

48

6.3 6.3 2.3 15.5 2.3

TSS (mg/L) 31.8 30 2 93 20.6

Effluent samples

DOC (mg/L)

16

15.2 10.4 2.5 48.5 12.0

TSS ( /L) TSS (mg/L) 27 9. 17 2 137 34 6.

Runoff samples

DOC (mg/L)

9

7.6 7.3 5.6 11.5 1.7

TSS (mg/L) 115 99 63 221 57
7/6/2010

5

PCB Concentrations in Water (2009)

PCB Concentrations in Sediment (2009) 
7/6/2010

6

PCB Concentrations in Catfish (2009)

PCB Concentrations in Seatrout/Atlantic 

Croaker (2009)
7/6/2010

7

Comparison of Percent Stations Exceeding 

Water/Tissue Quality Standards 

Sampling Watera Catfishb Seatrout/Atlantic 

Croakerb

Stations sampled 32 45

2002-2003 Stations that exceed standard 12 36 Not sampled

Station exceedance (%) 38% 80%

2008

Stations sampled 37 26 19

Stations that exceed standard 15 19 16

Station exceedance (%) 41% 73% 84%

Stations sampled 48 30 18c

a WQS (0.885 ng/L)

b DSHS Health Assessment Comparison Value (47 ng/g)

c Species sampled

2009 Stations that exceed standard 28 24 16c

Station exceedance (%) 58% 80% 89%

* ∑43 congeners

PCB Concentration in Runoff (2009)
7/6/2010

8

PCB Concentration in Effluent (2009)

Correlations Between PCB and Water Column Parameters

DOC 

(mg/L)

TOC 

(mg/L)

TSS 

(mg/L)

Suspended 

PCB (ng/L)

Dissolved 

PCB (ng/L)

DOC (mg/L) 1

TOC (mg/L) .995** 1

TSS (mg/L) .165 .152 1

All unique 

combinations of 

station and sample 

type (n=73)

DOC 

(mg/L)

TOC 

(mg/L)

TSS 

(mg/L)

Suspended 

Total PCB 

(ng/L)

Dissolved 

Total PCB 

(ng/L)

DOC (mg/L) 1

Ambient 

samples only 

Suspended 

Total PCB 

(ng/L)

.034 .056 .067 1

Dissolved 

Total PCB 

(ng/L)

.085 .098 .044 .789** 1

(g)

TOC (mg/L) .961** 1

TSS (mg/L) -.045 -.126 1

Suspended 

Total PCB 

(ng/L)

.327* .415** .122 1

Dissolved 

Total PCB 

(ng/L)

.573** .628** .196 .790** 1

* Bolded and double

asterisked correlations are

significant (two tailed) at

the p=0.01 level and the

p=0.05 level for a single

asterisk

(n=48)
7/6/2010

9

PCB Homolog Profiles for Ambient, Effluent, 

and Runoff Samples

PCB Homolog Profiles for Ambient, Effluent, 

and Runoff Samples

0.40 Ambient

Effluent

Runoff

SUSPENDED 0.40 Ambient

Effluent

Runoff

DISSOLVED

0 00

0.10

0.20

0.30

0.10

0.20

0.30

Relative fraction

0.00

1 2 3 4 5 6 7 8 9 10

0.00

1 2 3 4 5 6 7 8 9 10

Chlorination Chlorination

• Dissolved phase is similar in most sample types: ambient, effluent, and runoff.

• Suspended phase shows a greater difference than was observed with the dissolved 

phase for all three sample types.
7/6/2010

10

PCB Partitioning

• Runoff samples show dominant 

PCB concentrations in suspended 

phase compared to ambient and

14

16

18

20

fficient (Kd)

Ambient

Effluent

Runoff

phase compared to ambient and

effluent.

• However, when the amount of 

sediment per volume is taken into 

account, ambient and runoff show 

no statistical difference.

• Partitioning levels increase with 

increasing chlorination in all three 

0

2

4

6

8

10

12

0 1 2 3 4 5 6 7 8 9 10

Unitless Distribution Coef

Chlorination

g

samples types, but the increasing 

trend not the same.

• Simple linear partitioning models 

normally used to describe this 

behavior may not always be 

adequate for effluent and runoff 

conditions

Proposed Sampling Plan 

- Snapshot of PCBs and Dioxin in the Houston Ship 

Channel and Galveston Bay

- Survey of PCBs and Dioxin in the Galveston Bay System
7/6/2010

11

Parameter In-stream Water Bed 

Sediment Tissue

TSS Y NA NA

Parameters of Interest

DOC Y NA NA

TOC Y Y NA

Solids Content NA Y NA

Grain size NA Y NA

Lipid content NA NA Y

PCB dissolved in water Y NA NA

PCB in suspended sediment Y NA NA

PCB i di t PCB in sediment NA Y NA

PCB in fish tissue NA NA Y

Dioxin dissolved in water Y NA NA

Dioxin in suspended sediment Y NA NA

Dioxin in sediment NA Y NA

Dioxin in fish tissue NA NA Y

Survey of PCBs and Dioxin in the Galveston 

Bay System - Selection Criteria

• Reference Conditions Reference Conditions

• Potential Sources

• Spatial Distribution

• Physiography and hydrography 

• Add-on opportunities on opportunities

• Secondary considerations
7/6/2010

12

Proposed 

Sediment and 

Fish Sampling 

L ti i th Locations in the 

Galveston Bay 

System

Snapshot of PCBs and Dioxin in the Houston Ship 

Channel and Galveston Bay - Selection Criteria

• Provides a framework for decision making for the 

PCB/dioxin constituents on a system-wide basis. 

• Includes snapshot of PCBs and dioxins in sediment and Includes snapshot of PCBs and dioxins in sediment and

tissue in the HSC and a snapshot of PCBs and dioxins in 

water in the HSC and Galveston Bay.

• Station selection based on high concentrations observed 

from 2002-2003, 2008 and 2009 sampling results. 

• Monitoring plan consists of collecting 25 high-volume water 

sampl 21 b tt di t l d t 21 ti les, 21 bottom sediment samples, and up to 21 tissue 

samples.

• Proposed locations may change.
7/6/2010

13

Proposed Sediment and Fish Sampling Locations 

in Houston Ship Channel

Proposed Water Sampling Locations in Houston 

Ship Channel and Galveston Bay