baltimore harbor – toxic impairments, and tmdl endpoint(s)

Baltimore Harbor – Toxic Impairments,

and TMDL Endpoint(s)

Baltimore Harbor SAG

September 10th 2002

Today’s Presentation

• Introduction: Toxic impairment in Sediment & Water Quality

• Contaminated Sediment Evaluation Tools

• Baltimore Harbor Data

• Toxic TMDLs Endpoints

• Conclusions/Discussion

Statutes Protecting Sediment Quality

• CWA (101) “restore and maintain the chemical, physical, and biological integrity of the Nation's waters”– “provides for the protection and propagation of fish, shellfish, and wildlife, and

provides for recreation in and on the water”

• COMAR 26.08.02.02 Designated Uses

• Baltimore Harbor: Use I: Water Contact Recreation, and Protection of Aquatic Life. This use designation includes waters which are suitable for:– (1)(d) The growth and propagation of fish (other than trout), other aquatic life, and

wildlife

• COMAR 26.08.02.03-1 Toxic Substances Numerical WQ Criteria– (2)(b) The wholesomeness of fish for human consumption

– (2)(c) Fresh, estuarine, and salt water aquatic life from acute toxicity impacts

– (2)(d) Fresh, estuarine, and salt water aquatic life from chronic toxicity impacts

Toxic Impairment in Sediment & Water Quality

• Functions of Aquatic Sediment:– Habitat for bottom dwelling organisms– Substrate for aquatic plants– Hunting grounds for predators, scavengers– Sink for nutrients, contaminants

Contaminated Sediment Evaluation Tools

• Sediment Quality Standards for Metals: – Criteria (WA, FL, CA) – Promulgated and Enforceable

– Chemistry-based

• Sediment Quality Guidelines (e.g. Effects Range Median - ERM) for Metals– Guidelines (Not Enforceable)

– Chemistry-based

• Sediment Quality Triad– Weight of Evidence Guidelines

– Chemistry, Toxicity Testing, Benthic Community Data

– Requires Interpretation

Toxicity Testing

• Standard Methodology

• Uses Amphipod (Leptocheirus plumulosus)

• Acute Test – 10 Day – Mortality

• Chronic Test – 28 Day – Growth/Reproduction

Regulations and Approaches• No Federal Criteria:• EPA Guidance Approach: EQ Partitioning• Other Guidelines – Empirical Approach

– Effects Range Median/Low (ERM/ERL - NOAA Status & Trends)

– Probable/Threshold Effects Level (PEL/TEL - Ontario Ministry of the Environment)

– Apparent Effects Threshold (AET - Puget Sound – WA)

– Consensus Based Standards (Probable/Median/Threshold Effects Concentration) – GEOMEAN of 3 or more Guidelines

• Sediment Management Standards– Washington State – Stds similar to ERMs & PELs

Baltimore Harbor Data

Data Types

• Bulk Sediment Chemistry (82 Stations)– Metals – Organics (PCBs, Pesticides, PAHs)

• Bulk Sediment Toxicity Tests (Amphipod) –(15-20 Stations)– 10 Day Acute Tests– 28 Day Chronic Tests

• Benthic Community Analyses (15-20 Stations)• Fish Tissue Monitoring Data (8 Stations)

– Organics – PCBs – Heavy Metals – Cr, Pb, Zn

Total PCBs Impairment (ER-M = 180 ppb)

• Mean = 262 ppb• Range = 8 – 2150 ppb• Total 27/73 > ERM• (36.9 %)• 10 Sites = > 2 ERM• 4 Sites = > 3 ERM (Yellow)• 3 Sites = > 4 ERM (Brown)• 2 Sites = > 5X ERM (Red)• 1 Site = > 10X (Black)

Chromium Impairments(ER-M = 370 ppm)

• Mean = 357 ppm• Range = 8 – 1830

ppm• Total 18/73 > ERM• (24.7%)• 8 Sites = > 2 ERM• 2 Sites = > 3 ERM (Yellow)• 2 Sites = > 4 ERM (Brown)

Lead Impairments (ER-M = 218 ppm)

• Mean = 150 ppm• Range = 1 – 1000

ppm• Total 15/73 > ERM• (20.5%)• 1 Site = > 4 ERM (Blue)

Zinc Impairments (ER-M = 410 ppm)

• Mean = 640 ppm• Range = 40 – 2600

ppm• Total 50/73 > ERM• (68.5%)• 3 Site = > 2 ERM (Brown)• 2 Site = > 3 ERM (Red)• 3 Site = > 4 ERM (Blue)• 3 Site = > 5 ERM (Green)• 1 Site = > 6 ERM (Black)

Middle Harbor

• Impairing Substance(s): Zinc

• Mean [Zn] = 421 ppm 181; (N = 16); Range = 40-715 ppm

• ERM = 410 ppm

• 11/16 (69 %) of stations exceed ERM

• Toxicity: 1/6 (16.7%) demonstrated acute toxicity

• Station had Cd @ ~ 2x ERM and Cu > ERM

Bear Creek• Impairments: Cr, Zn, PCBs

• Cr– Mean [Cr] = 975 ppm 441; (N = 12); Range = 51.9 – 1831 ppm

– ERM = 370 ppm

– 11/12 (92 %) > ERM; 7/12 (58 %) > 3X ERM

• Zn– Mean [Zn] = 1749 ppm 601; (N = 12); Range = 69.8 – 2574 ppm

– ERM = 410 ppm

– 11/12 (92 %) > ERM; 10/12 (58 %) > 4X ERM

• PCBs– Mean [PCBs] = 309 ppb 299; (N = 11); Range = 8.2 – 1163 ppb

– ERM = 180 ppb

– 9/11 (82 %) > ERM; 1/11 (9 %) > 6X ERM

Bear Creek Cont’d

• Toxicity: 4/5 (80%) of stations tested demonstrated acute toxic effects in 10 d L. plumulosus assays

• 2/4 tests demonstrating toxicity also had Cd levels > ERM

• 1/4 tests demonstrating toxicity also had Pb levels > ERM

• 2/4 tests demonstrating toxicity also had Chlordane levels > ERM

• 3/4 tests demonstrating toxicity also had T PCB levels > ERM

Curtis Creek/Bay

• Impairments: Zn, PCBs

• Zn

– Mean [Zn] = 645 ppm 133; (N = 13); Range = 455 – 911 ppm

– ERM = 410 ppm

– 13/13 (100 %) > ERM; 1/13 (7.8 %) > 2X ERM

• PCBs

– Mean [PCBs] = 449 ppb 276; (N = 13); Range = 104 – 1088 ppb

– ERM = 180 ppb

– 11/13 (85 %) > ERM; 3/13 (23 %) > 3X ERM

Curtis Creek/Bay Cont’d

• Toxicity: 5/7 (80%) of stations tested demonstrated acute toxic effects in 10 d L. plumulosus assays

• 4/5 tests demonstrating toxicity also had Chlordane levels > ERM

• 4/5 tests demonstrating toxicity also had Cu levels > ERM

• 4/5 tests demonstrating toxicity also had Pb levels > ERM

• 5/5 tests demonstrating toxicity also had T PCB levels > ERM

• 4/5 tests demonstrating toxicity also had Hg levels > ERM

Northwest Branch• Impairments: Cr, Pb, Zn, PCBs

• Cr

– Mean [Cr] = 572 ppm 332; (N = 7); Range = 247 – 1119 ppm

– ERM = 370 ppm

– 5/7 (71 %) > ERM; 2/7 (29 %) > 3X ERM

• Pb

– Mean [Pb] = 366 ppm 297; (N = 7); Range = 154 – 1014 ppm

– ERM = 218 ppm

– 5/7 (71 %) > ERM; 1/7 (14 %) > 4X ERM

Northwest Branch Cont’d• Zn

– Mean [Zn] = 610 ppm 243; (N = 7); Range = 330 – 994 ppm

– ERM = 410 ppm– 5/7 (71 %) > ERM; 1/7 (14 %) > 2X ERM

• PCBs– Mean [PCBs] = 744 ppb 685; (N = 7); Range = 172 – 2148

ppb– ERM = 180 ppb– 6/7 (86 %) > ERM; 3/7 (43 %) > 4X ERM; – 2/7 (29 %) > 5 ERM; 1/7 (14%) > 11X ERM

Northwest Branch Cont’d

• Toxicity: 2./2 (100%) of tests demonstrated acute toxicity in L. plumulosus 10 d tests

• 1/2 tests demonstrating toxicity also had PCB levels > 11X ERM

• 2/2 tests demonstrating toxicity also had Cr levels > ERM

• 2/2 tests demonstrating toxicity also had Cu levels > ERM

• 2/2 tests demonstrating toxicity also had Pb levels > ERM

• 2/2 tests demonstrating toxicity also had Zn levels > ERM

• 1/2 tests demonstrating toxicity also had Hg levels > ERM

What Does the Data Tell Us?

• Certain heavy metals in sediment may cause toxicity to benthic organisms in some Harbor locations

• Certain organic compounds (including PCBs) may cause toxicity to benthic organisms in some Harbor locations

• PCBs in sediment accumulate in benthos – levels increase through trophic transfer, resulting in fish consumption advisories. PCBs may also contribute to toxicity at high levels

TMDL Endpoints

• Metals– Zinc– Lead– Chromium

• PCBs

Metals Endpoint• For Protection of Aquatic (Benthic ) Life• Proposed Threshold “ER40” = ERM + 10% MOS• ERM = Effects Range Median• NOAA Status & Trends Program• Marine & Estuarine Sediments• ERM = Effects are “Probable” (the concentration at which

adverse effects occur in 50% of studies)• Does not account for mitigation of toxic effects due to:

– Sulfide– Organic carbon

• These compounds sequester contaminants, decreasing bioavailability making the contaminated sediments present less toxic

Metals Endpoint cont’d• Contaminant reductions to the “ER40” level should result in

occasional impacts to aquatic life based on observations of sediment metals chemistry and toxicity in Harbor samples

• Reductions to the “ER40” threshold should be protective against impacts where mitigating conditions (presence of

sulfide or organic carbon) are lower or do not exist. • While the ERM may be protective against toxic impacts from

metals, an implicit margin of safety is required in the TMDL;

• A 10% MOS was determined by best scientific judgement, and incorporated to provide a safety margin against the impact of metals on aquatic life.

PCB Endpoint

• Human Health Based

• “Fishable/Swimmable”

• Fishable = Wholesomeness for Human Consumption

– Clean Water Act

– COMAR

• Departmental Interpretation = 4 meals/month

PCB Endpoint Cont’d

• HHSQT = Human Health Sediment Quality Threshold

• Use Field Collected Fish Tissue Data

• Use Field Collected Sediment Data

• Calculate Biota Sediment Accumulation Factor (BSAF)

• Combined with Risk Assessment Exposure Parameters

• Calculate Acceptable Sediment Threshold

• Acceptable = Sediment PCB Concentration that is expected to result in tissue concentrations that are lower than the upper level of the 4 meal/month advisory recommendation (77 ppb).

HHSQT Calculation

• HHSQT = R * BW * LT * 1000 CSF * ED * IR * BSAF * FL

• R = Risk Level = 1 in a 100,000 (10 –5)• BW = 70 kg (General Population)• LT = Lifetime = 70 years• CSF = Cancer Slope Factor (PCBs = 2)• ED = Exposure Duration = 30 years• IR = Ingestion Rate = 29.8 g/d (4 meals/month)• BSAF = Biota Sediment Accumulation Factor• FL = Fish Lipid (%)

What Is A BSAF?

• Biota Sediment Accumulation Factor • Relationship between PCBs in sediment and PCBs

in biota (worms, clams, fish)• Constraints

– Both Organism and its food are exposed– Sediment is representative of average surface sediment

of organism’s habitat

• Ratio Lipid Normalized PCBs in Fish

Organic Carbon Normalized PCBs in Sediment

HHSQT Data Requirements

• Sediment– PCB concentration– Organic Carbon %

• Fish Tissue– Species: white perch, bullhead, catfish– Fillet PCB Concentration– Lipid %

Process Summary• Data Assessment: Assess “Pathways of Concern”

• Impairments Based on Human Health (Cancer Risk) and/or

Aquatic Life (Benthic Toxicity)

• Development of TMDL “Endpoints”

• MODEL

• Loads

• Allocation (TMDL)

Questions

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