Appendix 7.1          Methodology for Ecological Risk Assessments

 

Assessment Approach

 

1.1               Ecological Risk Assessment (ERA) consisted of the following phases:

l           Problem Formulation

l           COPC Identification and Selection of COC

l           Exposure Characterization

l           Ecological Effects Characterization

l           Risk Characterization

 

1.2               The assessment approach for ERA was based on the approach suggested in the Study Brief, which is very similar to the assessment framework documented in Guidelines for Ecological Risk Assessment by USEPA (1998).  The Guidelines consist of three phases: problem formulation, analysis phase (including evaluation data and models; characterization of exposure; characterization of ecological effects), risk characterization (including risk estimation; risk description).

 

Problem Formulation

 

1.3               The following tasks were accomplished in this phase:

·               Establish objective of the assessment

·               Establish scope of the assessment

·               Establish focus of the assessment

·               Construct Site Conceptual Model

·               Define assessment endpoint(s)

 

1.4               The objective, scope and focus of the risk assessments have been discussed in Section 7 of the EIA report.

   

    Site Conceptual Model

 

1.5               The SCMs adopted in the risk assessments were presented graphically in Figures 7.1 to 7.2.  As seen in the figures, there are 3 types of exposure pathway in terms of completeness and significance, namely “exposure pathway complete and significant”, “exposure pathway complete, but insignificant or significance unknown” and “exposure pathway incomplete”.  For the exposure pathway “complete and significant”, it means that contaminants can be up-taken by receptors through that pathway and the amount of uptake can be considerable to contribute to the risk level.  This type of exposure pathway was considered in the risk assessment.

 

1.6               For the exposure pathway “complete, but insignificant or significance unknown”, it means that contaminants can be up-taken by receptors through that pathway but the amount of uptake is not sufficiently large to affect the risk level or the amount of uptake through that pathway is uncertain for determining the risk level.  This type of exposure pathway was not considered in the risk assessment.  For the “incomplete exposure pathway”, it means that the contaminants cannot be up-taken by the receptor through that pathway because there is no complete route for the contaminants to reach the receptor.  This type of exposure pathway was not considered in the risk assessment.

 

1.7               The SCMs were presented in text as shown in Tables 1 to 2.

 

Table 1         SCM for Ecological Risk Assessment – Aquatic Life

Contaminant Source:

Effluent from the outfall of SCISTW

Receptor:

Aquatic life

Complete and Significant Exposure Media and Pathway:

·         Direct contact of seawater

·         Gill uptake of seawater

 


Table 2         SCM for Ecological Risk Assessment – Marine Mammals

Contaminant Source:

Effluent from the outfall of SCISTW

Receptor:

Marine Mammals (dolphin/porpoise)

Complete and Significant Exposure Media and Pathway:

·         Ingestion of seawater

·         Consumption of contaminated food

 

1.8               Direct contact (i.e. dermal exposure) with seawater was considered as a complete but insignificant pathway for marine mammals which have lungs, and therefore avoid the osmotic problem that occurs from saltwater.  This is different from fish, which have gills that are relatively permeable to water.  In addition, to obtain an osmotic balance with the surrounding saltwater, marine mammals must excrete water rather than take it in through dermal absorption to maintain an osmotic balance (Schmidt-Neilsen (1990) as in SSDS EIA (1998)).  Therefore, the dermal exposure pathway was considered to be a “complete but insignificant pathway”. 

 

    Assessment Endpoint

 

1.9               The assessment endpoint for the ERA – Aquatic Life is defined as protection of aquatic life at population level from chronic exposure to contaminants produced in disinfection process from SCISTW.  The measurement endpoint for the ERA – Aquatic Life is the surface water concentration for a particular COC that is unlikely to produce adverse effects to any aquatic organisms over long-term chemical exposure. 

 

1.10           The assessment endpoint for the ERA – Marine Mammals is defined as protection of marine mammals from chronic exposure of contaminants produced in disinfection process via the ingestion of diluted effluent from SCISTW and the dietary ingestion of food over a relatively long period of time.  The measurement endpoint for the ERA – Marine Mammals is the dose chemical doses that are unlikely to produce adverse effects to dolphins or porpoises over long-term chemical exposure. 

 

Identification of COPC and Selection of COC

 

            Identification of COPC  

 

1.11            A total number of 35 chemicals were identified as COPCs in the risk assessments.  The COPCs included 9 chlorination by-products (CBPs) regulated by USEPA National Primary Drinking Water Standards; 25 priority pollutants[1] (which may contain potential CBPs) regulated by the USA National Pollutant Discharge Elimination System (NPDES)[2]; and total residual chlorine (as disinfectant residue).  The list of COPCs was presented in Table 3.

 


Table 3        List of Contaminants of Potential Concern

CBPs regulated by USEPA National Primary Drinking Water Standards

Priority Pollutants listed in NPDES Permit Application Testing Requirements (40 CFR 122, Appendix D, Tables II to V), which may contain CBPs

Disinfectant Residue

Chloroform

Methylene chloride

Total residual chloride

Bromodichloromethane

Carbon tetrachloride

 

Dibromochloromethane

Chlorobenzene

 

Bromoform

1,1-dichloroethane

 

Chloroacetic acid

1,2-dichloroethane

 

Bromoacetic acid

1,1-dichloroethylene

 

Dibromoacetic acid

1,2-dichloropropane

 

Dichloroacetic acid

Tetrachloroethylene

 

Trichloroacetic acid

1,1,1-trichloroethane

 

 

1,1,2-trichloroethane

 

 

Trichloroethylene

 

 

2-chlorophenol

 

 

2,4-dichlorophenol

 

 

p-chloro-m-cresol

 

 

Pentachlorophenol

 

 

2,4,6-trichlorophenol

 

 

Bis(2-chloroethoxy)methane

 

 

1,4-dichlorobenzene

 

 

Hexachlorobenzene

 

 

Hexachlorocyclopentadiene

 

 

Hexachloroethane

 

 

1,2,4-trichlorobenzene

 

 

Alpha-benzene hexachloride

 

 

Beta-benzene hexachloride

 

 

Gamma-benzene hexachloride

 

 

1.12           Unlike other conventional human health/ecological risk assessments for air pollution source (e.g. incinerator) and contaminated land/groundwater, a look-up table of contaminants/list of possible COPC for CBPs risk assessment in effluent was not identified from local and overseas authorities.  Moreover, according to the review of local and overseas practice, list of “regulated CBPs in sewage effluent” was not identified.

 

1.13           Hence, a conservative approach was adopted in this Study to include all the regulated CBPs in drinking water plus the 25 priority pollutants (may contain potential CBPs) regulated by NPDES as COPCs, although these pollutants are not regulated due to the concern of generation during chlorination process.

 

1.14           The NPDES practice was adopted because it contains the most comprehensive list of regulated pollutants for effluent discharge, based on the review of practice in the USA, the United Kingdom, Australia, Canada, China and Hong Kong.  Moreover, the purpose of NPDES is to ensure the US National Water Quality Criteria are complied by regulating pollutant concentrations in effluent discharge directly to surface water, in order to protect the human health and aquatic life. 

 

1.15           Therefore, the 35 COPCs identified for the risk assessment include all documented potential CBPs/disinfectant residue which are regulated due to their potential to cause impact to human health and/or ecological resources.  The list of identified COPCs (which the COCs for risk calculation were selected from the list) was considered sufficiently comprehensive to assess the potential risk to human health/ecological resources due to chronic exposure to the contaminants produced in the disinfection process in the effluent discharges.

 

1.16           The dechlorination agent - sodium bisulphite was not considered to pose an ecological risk issue but a physical stress related to water quality impact arising from dissolved oxygen uptake.  Hence, chemical species (sodium, bisulphite, sulphite and sulphate) associated with sodium bisulphite were not identified as the COPCs in ERA. 

 

Selection of COC

 

1.17           The concentrations of the identified COPCs in chlorinated/dechlorinated (C/D) CEPT effluent from SCISTW (for assessment scenarios 1 to 4), secondary treated effluent from Shatin/Tai Po Sewage Treatment Works (for assessment scenario 5) and ambient seawater (2 sampling locations) were determined by chemical analysis works.  The COC selection and determination of COC effluent concentrations for risk assessments were based on the chemical analysis results and the following rules.     

 

Rules of COC Selection

 

Rule A – COPCs without relevant toxicity values, standards or criteria were not selected as COCs for risk assessments.

 

Rule B - COPCs detected in the C/D effluent were selected as COCs for risk assessment.  The highest value from the replicates of analysis was chosen as the effluent concentrations to use in the risk assessment calculations.  

 

Rule C – Non-detected COPCs with detection limit (for C/D effluent samples) exceeds the Concentration of Interest[3] (COI) were selected as COCs.  For these COCs, effluent concentrations used in the risk assessments are one-half of the detection limit, which is a standard approach accepted by USEPA.  

 

Rule D – COPCs with concentration in C/D effluent lower than the ambient seawater concentration were not selected as COCs.

 

Rules of COC Ambient Seawater Concentration Determination

 

Rule E – The highest COC concentrations found in the replicates of ambient seawater analysis were used to represent the background concentrations in the risk assessment calculations.

 

Rule F – For COCs that were not detected in the ambient seawater samples, the background concentration was set as zero.

 

1.18           Based on the chemical analysis results and above rules, COCs were selected for the risk assessments for Scenarios 1 to 4 and Scenario 5 and presented in Tables 4 and 5 respectively.

 


Table 4         Results of COCs Selection for Scenarios 1 to 4

 

Selected as COC for

 

 

 

COPC

ERA – Aquatic Life

ERA – Marine Mammals

Max.  Conc. in C/D CEPT Effluent (mg/L)

Max. Conc. in Ambient Seawater (mg/L)

Note

Total residual chloride

Yes

Yes

100

0

 

Chloroform

Yes

Yes

7

0

 

Bromodichloromethane

 

 

<5

0

 

Dibromochloromethane

 

 

<5

0

 

Bromoform

 

 

<5

0

 

Chloroacetic acid

Yes

Yes

4

0

 

Bromoacetic acid

 

 

<2

0

 

Dibromoacetic acid

Yes

Yes

4

0

 

Dichloroacetic acid

Yes

Yes

45.9

0

 

Trichloroacetic acid

Yes

Yes

22

0

 

Methylene chloride

 

 

<20

55

 

Carbon tetrachloride

 

 

<0.5

0

 

Chlorobenzene

 

 

<0.5

0

 

1,1-dichloroethane

 

 

<0.5

0

A

1,2-dichloroethane

 

 

<0.5

0

 

1,1-dichloroethylene

 

 

<0.5

0

 

1,2-dichloropropane

 

 

<0.5

0

 

Tetrachloroethylene

Yes

Yes

1.3

0

 

1,1,1-trichloroethane

 

 

<0.5

0

 

1,1,2-trichloroethane

 

 

<0.5

0

 

Trichloroethylene

Yes

Yes

2

0

 

2-chlorophenol

 

 

<0.5

0

 

2,4-dichlorophenol

 

 

<0.5

0

 

p-chloro-m-cresol

 

 

<0.5

0

 

Pentachlorophenol

 

 

<2.5

0

 

2,4,6-trichlorophenol

Yes

Yes

2

0

 

Bis(2-chloroethoxy)methane

 

 

<0.5

0

 

1,4-dichlorobenzene

 

 

<0.5

0

 

Hexachlorobenzene

Yes

Yes

<0.5

0

B

Hexachlorocyclopentadiene

 

 

<2.5

0

 

Hexachloroethane

 

 

<0.5

0

 

1,2,4-trichlorobenzene

 

 

<0.5

0

 

Alpha-benzene hexachloride

 

 

<0.5

0

 

Beta-benzene hexachloride

Yes

Yes

<1

0

B

Gamma-benzene hexachloride

Yes

Yes

<1

0

B

Note:   A) No available toxicity data for aquatic life

              B) Detection limit exceeds the concentration of interest for aquatic life

 


Table 5         Results of COCs Selection for Scenario 5

 

Selected as COC for

 

 

 

COPC

ERA – Aquatic Life

ERA – Marine Mammals

Max.  Conc. in Secondary Treated Effluent (mg/L)

Max. Conc. in Ambient Seawater (mg/L)

Note

Total residual chloride

Yes

Yes

<20

0

A

Chloroform

 

 

<5

0

 

Bromodichloromethane

 

 

<5

0

 

Dibromochloromethane

Yes

Yes

8

0

 

Bromoform

Yes

Yes

49

0

 

Chloroacetic acid

 

 

<2

0

 

Bromoacetic acid

 

 

<2

0

 

Dibromoacetic acid

Yes

Yes

10

0

 

Dichloroacetic acid

Yes

Yes

3

0

 

Trichloroacetic acid

Yes

Yes

7

0

 

Methylene chloride

 

 

<20

55

 

Carbon tetrachloride

 

 

<0.5

0

 

Chlorobenzene

 

 

<0.5

0

 

1,1-dichloroethane

 

 

<0.5

0

B

1,2-dichloroethane

 

 

<0.5

0

 

1,1-dichloroethylene

 

 

<0.5

0

 

1,2-dichloropropane

 

 

<0.5

0

 

Tetrachloroethylene

 

 

<0.5

0

 

1,1,1-trichloroethane

 

 

<0.5

0

 

1,1,2-trichloroethane

 

 

<0.5

0

 

Trichloroethylene

 

 

<0.5

0

 

2-chlorophenol

 

 

<0.5

0

 

2,4-dichlorophenol

 

 

<0.5

0

 

p-chloro-m-cresol

 

 

<0.5

0

 

Pentachlorophenol

 

 

<2.5

0

 

2,4,6-trichlorophenol

 

 

<0.5

0

 

Bis(2-chloroethoxy)methane

 

 

<0.5

0

 

1,4-dichlorobenzene

 

 

<0.5

0

 

Hexachlorobenzene

Yes

Yes

<0.5

0

A

Hexachlorocyclopentadiene

 

 

<2.5

0

 

Hexachloroethane

 

 

<0.5

0

 

1,2,4-trichlorobenzene

 

 

<0.5

0

 

Alpha-benzene hexachloride

 

 

<0.5

0

 

Beta-benzene hexachloride

Yes

Yes

<1

0

A

Gamma-benzene hexachloride

Yes

Yes

<1

0

A

Note:  A) Detection limit exceeds the concentration of interest for aquatic life

         B) No available toxicity data for aquatic life

       

Exposure Assessment

 

Ecological Risk Assessment – Aquatic Life

 

1.19           COC exposure by aquatic life was characterized as the COC concentrations in seawater.  The COC concentrations in the seawater at the edge of the ZID and the edge of the mixing zone, which were determined by using dilution factors estimated in water quality modelling, were adopted as the COC exposure concentration by aquatic life. 

 

1.20           The risk of individual COCs was characterized by hazard quotient which was composed of COC concentration at exposure point as numerator and the derived COC-specific toxicity reference value (TRV) as denominator (more details were presented below).  Moreover, the averaging time of COC concentration used for hazard quotient calculation should match the averaging time of the TRV of the corresponding COC. 

 

1.21           Table 6 summarized the averaging time of different TRVs and the corresponding dilution factor for COC concentration calculation.

 

Table 6         Averaging Time of TRVs and Corresponding Dilution Factor

TRV Averaging Time

Dilution Factor at Edge of ZID

Dilution Factor at Edge of Mixing Zone

Daily

Minimum dilution factor in dry and wet season

Minimum dilution factor in dry and wet season

4-day

Minimum dilution factor in dry and wet seasona

Minimum 4-day average dilution factor in dry and wet season

Annual

Annual weighted average dilution factor

Annual weighted average dilution factor

“To be complied at least 90% of occasions”

10 %tile dilution factor in dry and wet seasonb

10 %tile dilution factor in dry and wet seasonb

Seasonalc

The lower value of weight average dilution factor estimated for dry season and that of wet season

The lower value of weight average dilution factor estimated for dry season and that of wet season

Note:        a Minimum dilution factor was adopted as a conservative estimate    

                                b Dilution factor exceeded 90% of the time (i.e. 10% of values are below this value)

                                c For COC without water quality standard/criteria, which TRV was derived from toxicity data

 

Ecological Risk Assessment – Marine Mammals

 

1.22           This phase would comprise the following tasks:

·          Water quality modelling

·         Exposure setting characterization, which consists of the following tasks:

o        Characterize potential marine mammals receptors

o        Calculate the COC exposure

 

Water Quality Modelling

 

1.23           The water quality modelling has been conducted in this assignment and the results obtained were used for the risk assessment.

 

Exposure Setting Characterization

 

Potential Marine Mammals Receptors Characterization

 

1.24           The following parameters will be characterized for both dolphins and porpoises receptors:

·           Contaminated water/seafood ingestion rate

·           Proportion of dietary prey item (shellfish and fish) in diet

·           Area use factor (the fraction of time for the receptor resides and feeds in the impacted area)

·           Body weight

 

1.25           Table 7 presented the parameter values of marine mammals receptors, which were adopted in Montgomery Watson (1998) “Strategic Sewage Disposal Scheme – Environmental Impact Assessment Study – Technical Note 4. Detailed Risk Assessment (Final Version).

 

Table 7                Parameter Values of Marine Mammals Receptors

Parameter

Value

Unit

Dolphin

Porpoise

Ingestion rate of food

0.065

0.075

kg food/kg body weight/d

Ingestion rate of water

12.5

12.5

ml water/kg body weight/d 

Body Weight

225

55

kg

Area use factor

0.25

0.15

fraction

Fraction of dietary prey item in diet (fish/shellfish percent)

90/10

50/50

percent

COC Exposure Calculation

 

1.26           The COC exposure would be calculated by the following equation, which is adopted from SSDS/EIAS DRA (1998). 

 

Dosei = {(IRfood x BW x Cfish x FPfish x AUF) + (IRfood x BW x Cshellfish x FPshellfish x AUF) + (IRwater x BW x Cwater x AUF)} / BW

 

                                                                                                                                                                                  Equation 1

Where

Dosei = Daily Dose of COC i (mg/kg/day)

Cfish/shellfish = COC concentration in fish/shellfish (mg/kg)

Cwater = COC concentration in seawater (mg/L)

IRfood/water = Ingestion rate of food or effluent (kg food/kg/day or L water/kg/day)     

BW = Body weight of receptor (kg)

AUF = Area use factor (fraction)

FPfish/shellfish = Fraction of dietary prey item in diet (fraction)

 

1.27           The COC concentration in the prey item (fish and shellfish) of the marine mammals would be calculated by the following equation, which is adopted from USEPA (1999b).

 

Cis = Ciw x BCFi x FCMi                                                                                                   Equation 2

 

Where

Cis = contaminant i concentration in fish/shellfish (mg/kg)

Ciw = contaminant i concentration in seawater (mg/kg)

BCFi = water-to-fish/water-to-invertebrate bioconcentration factor for contaminant i (L/kg)

FCMi = food chain multiplier of contaminant i (unitless)

 

1.28           Annual average COC concentrations at the edge of the ZID estimated by the water quality modelling were used for exposure calculation.

 

1.29           Bioconcentration factor and food chain multiplier for COCs were presented in Table 8.

 

Table 8                Bioconcentration Factor and FCM

COC

Water-to-fish

Bioconcentration Factora

Trophic Level 4 FCMb

Water-to-aquatic invertebrates Bioconcentration Factor

Trophic Level 3 FCMb

Total residual chlorine

N/A

N/A

N/A

N/A

Bromoform

13.3

1.0

6.60c

1.0

Bromodichloromethane

8.26

1.0

3.68c

1.0

Chloroform

6.92

1.0

2.82d

1.0

Dibromochloromethane

10.4

1.0

4.79c

1.0

Chloroacetic acid

0.26

1.0

0.11c

1.0

Dibromoacetic acid

0.82

1.0

0.31c

1.0

Dichloroacetic acid

1.13

1.0

0.41c

1.0

Trichloroacetic acid

2.66

1.0

0.88c

1.0

Tetrachloroethylene

82.8

1.0

43.5c

1.1

2,4,6-trichlorophenol

56.1

1.0

76.6c

1.1

Hexachlorobenzene

2400

1.0

2595d

1.0

Beta-BHC

168

1.0

89.1c

1.2

Gamma-BHC

168

1.0

79.6c

1.2

N/A: Not Available

Note: a Also refer to Table 8.

b The FCMs were developed using Kow values reported in USEPA (1995), as in USEPA (1999b).

c No recommended BCF value identified.  Regression equation was used to calculate the BCF values (Southworth et al. (1978), as in USEPA (1999b)).

d Recommended BCF value in USEPA (1999b).

 


Ecological Effects Characterization (for ERA – Aquatic Life)

 

1.30           The ecological effects of COC exposure to aquatic life were characterized by comparing the COC concentrations in the seawater at the edge of the ZID and the edge of the mixing zone to the TRV for aquatic life.  TRVs for COCs were derived from water quality criteria/standards for protection of aquatic life when available; for COCs without such criteria/standards, toxicity values obtained from the scientific literature were used to derive TRVs.  Details on the TRV derivation process were presented in Annex B; derived TRVs for risk calculations were presented in Table 9.  

 

Table 9         Derived TRVs for Aquatic Life

COC

TRV for ecological resources (mg/L)

Averaging Time

Total residual chloride

13 at edge of ZID, 8 at edge of mixing zone

Daily average

Chloroform

12

Annual average

Dibromochloromethane

34

Annual average

Bromoform

360

Annual average

Chloroacetic acid

32,000

Seasonal average

Bromoacetic acid

1,600

Seasonal average

Dibromoacetic acid

690

Seasonal average

Dichloroacetic acid

230

Seasonal average

Trichloroacetic acid

93,000

Seasonal average

Tetrachloroethylene

8.85

Annual average

Trichloroethylene

10

Annual average

2,4,6-trichlorophenol

12.1

Seasonal average

Hexachlorobenzene

0.03

Annual average

Beta-benzene hexachloride

0.046

Annual average

Gamma-benzene hexachloride

0.063

Annual average

 

Ecological Effects Characterization (for ERA – Marine Mammals)

 

1.31           The ecological effects of COC exposure to marine mammals were characterized by comparing the COC daily dose to the toxicity reference doses for the marine mammals, which were derived by reviewing the toxicological effects data from various scientific literature, database and guidelines.  Details on the toxicity reference dose derivation process were presented in Annex C; derived toxicity reference dose for risk calculations were presented in Table 10

 

Table 10       Derived Toxicity Reference Dose for Marine Mammals   

COC

Toxicity Reference Dose Derived (mg/kg/d)

Bromoform

12.5

Chloroform

3.75

Dibromochloromethane

10.0

Dibromoacetic acid

0.025

Chloroacetic acid

0.1875

Dichloroacetic acid

0.095

Trichloroacetic acid

0.45

Total residual chlorine

1.875

Tetrachloroethylene

6.7

Trichloroethylene

13.7125

2,4,6-trichlorophenol

169.5

Hexachlorobenzene

0.3

Beta-BHC

0.1125

Gamma-BHC

1

 


Risk/Hazard Characterization

 

Ecological Risk Assessment – Aquatic Life

 

1.32           The risk associated with the COCs to the aquatic life were characterized by COC-specific hazard quotients (HQs) and hazard index (HI), estimated by the following equations:

 

HQi = Conc. of COC i in effluent or seawater / TRV for COC i                                                                      Equation 3

 

            Where

HQi = Hazard Quotient for exposure to identified COCi

 

HI = Σ HQi                                                                                                                                                                                                                    Equation 4

 

Where

HI = Hazard Index, total hazard attributable to exposure to all identified COCs

 

Ecological Risk Assessment – Marine Mammals

 

1.33           The risk associated with the COCs to the marine mammals were characterized by COC-specific hazard quotients (HQs) and hazard index (HI), estimated by the following equations:

 

HQi = Daily Dose of COC i / Toxicity Reference Dose for COC i                                                               Equation 5

 

HI = Σ HQi                                                                                                                                                                                                                     Equation 6

 

Output of the Risk Assessment

 

Output of the ERA – Aquatic Life

 

1.34           The output of the ERA – Aquatic Life are listed as follows:

l              The hazard quotient of exposure to individual identified COCs (contributed by both HATS effluent and “background” COC concentrations existing in ambient seawater) by aquatic life at the edge of ZID

l              The hazard quotient of exposure to individual identified COCs (contributed by both HATS effluent and “background” COC concentrations existing in ambient seawater) by aquatic life at the edge of mixing zone

l              The hazard index of exposure to all identified COCs (contributed by both HATS effluent and “background” COC concentrations existing in ambient seawater) by aquatic life at the edge of ZID

l              The hazard index of exposure to all identified COCs (contributed by both HATS effluent and “background” COC concentrations existing in ambient seawater) by aquatic life at the edge of mixing zone

 

 

Output of ERA – Marine Mammals

 

1.35           The output of the ERA – Marine Mammals are listed as follows:

l            Hazard quotient due to exposure of identified individual COCs (contributed by both HATS effluent and “background” COC concentrations existing in ambient seawater) by consumption of contaminated seawater and seafood

l            Hazard index due to exposure of all identified COCs (contributed by both HATS effluent and “background” COC concentrations existing in ambient seawater) by consumption of contaminated seawater and seafood


References  

 

For Ecological Risk Assessment – Aquatic Life

 

1.                  ANZECC (2000). Australian and New Zealand Guidelines for Fresh and Marine Water Quality.

2.                  CCME (2005).  Canadian Water Quality Guidelines for Protection of Aquatic Life

3.                  CDM (2002). Environmental and Engineering Feasibility Assessment Studies in Relation to the Way Forward of the Harbour Area Treatment Scheme – Proposed Water Quality Critieria.

4.                  CDM (2004).  Environmental and Engineering Feasibility Assessment Studies in Relation to the Way Forward of the Harbour Area Treatment Scheme – Working Paper No. 8 Ecological and Human Health Risk Assessment (Final).

5.                  IPCS INCHEM.  OECD Screening Information DataSet High Production Volume Chemicals.  Available online: www.inchem.org/pages/sids.html.

6.                  Montgomery Watson (1998).  Strategic Sewage Disposal Scheme – Environmental Impact Assessment Study – Technical Note 4. Detailed Risk Assessment (Final Version).

7.                  PRC National Guideline – Environmental Quality Standards for Surface Water (GB 3838-2002).

8.                  USEPA. ECOTOX Database.  Available online: www.epa.gov/ecotox.

9.                  USEPA. Water Quality Standards – State, Tribal & Territorial Standards. Available online: www.epa.gov/waterscience/standards/states.

10.               USEPA (1999b). Screening Level Ecological Risk Assessment Protocol for Hazardous Waste Combustion Facilities.

11.               USEPA (2004). National Recommended Water Quality Criteria.

12.               WRc Swindon (1999). Guidelines for Managing Water Quality Impacts within UK European Marine Sites.

 

For Ecological Risk Assessment – Marine Mammals

 

13.               ATSDR (1997). Toxicological Profile for Chloroform.

14.               ATSDR (1997). Toxicological Profile for Tetrachloroethylene.

15.               ATSDR (1997). Toxicological Profile for Trichloroethylene.

16.               ATSDR (1999). Toxicological Profile for Chlorophenols.

17.               ATSDR (2002). Toxicological Profile for Hexachlorobenzene.

18.               ATSDR (2003). Toxicological Profile for Bromoform and Dibromochloromethane.

19.               ATSDR (2005). Toxicological Profile for Hexachlorocyclohexane.

20.               CDM (2004).  Environmental and Engineering Feasibility Assessment Studies in Relation to the Way Forward of the Harbour Area Treatment Scheme – Working Paper No. 8 Ecological and Human Health Risk Assessment (Final).

21.               Montgomery Watson (1998).  Strategic Sewage Disposal Scheme – Environmental Impact Assessment Study – Technical Note 4. Detailed Risk Assessment (Final Version).

22.               NHMRC (2004).  Australian Drinking Water Guidelines 2004.

23.               Oak Ridge National Laboratory (1996).  Toxicological Benchmarks for Wildlife: 1996 Revision

24.               The Risk Assessment Information System. Available online: http://risk.lsd.ornl.gov/tox/tox_values.shtml.

25.               USEPA (1998).  Guidelines for Ecological Risk Assessment.

26.               USEPA (1999b).  Screening Level Ecological Risk Assessment Protocol for Hazardous Waste Combustion Facilities.

27.               WHO (2000). International Programme on Chemical Safety – Environmental Health Criteria 216.

28.               WHO (2004b). Guidelines for Drinking-water Quality (Third Ed.) – Volume 1.

 

 



[1] The 25 pollutants are regulated in NPDES due to their presence in industrial effluent but not their possible generation in chlorination process.  However, a conservative approach is adopted to study all these regulated chlorinated organic substances, which are documented as potential CBPs, in US drinking water and wastewater discharge.  

[2] The NPDES permit program controls water pollution by regulating point sources that discharge pollutants into water of the United States.  Industrial, municipal, and other facilities must obtain permits if their discharges go directly to surface waters.

[3] The COIs for human health were the standards for drinking/tap water while the COIs for ecological resources were based on the water quality criteria or toxicity reference value derived in this study.  The list of COIs are presented in Annex A.