New Emphasis on Sediment Quality Objectives Water Board, SCCWRP, SFEI RMP Annual Meeting 2007

Water Board Policy Development 1989 Legislature amended Water Code –Sec Sediment Quality Objectives –“reasonable protection of beneficial uses” November Water Board hearing Chemistry - Biology – Toxicity Process driven by Scientific Steering Comm

Conceptual Framework Direct Effects Severity of Effect Potential for Chemically Mediated Effect Station Assessment BenthosToxicityChemistryToxicity Three lines of evidence (LOE) needed to assess direct effects of sediment contamination

Toxicity Line of Evidence

Benthic Community LOE - Steps Compile Data –Standardize taxonomy –Calculate abundance and other metrics Calculate Benthic Indices –Benthic Response Index (BRI) –Index of Biotic Integrity (IBI) –Relative Benthic Index (RBI) –River Invertebrate Prediction and Classification System (RIVPACS) Combine Index Scores

Benthic Community LOE - Steps Compile Data –Standardize taxonomy –Calculate abundance and other metrics Calculate Benthic Indices –Benthic Response Index (BRI) –Index of Biotic Integrity (IBI) –Relative Benthic Index (RBI) –River Invertebrate Prediction and Classification System (RIVPACS) Combine Index Scores

Chemistry Line of Evidence

Sediment Quality Lines of Evidence RESPONSE CHEMISTRY (Exposure) TOXICITY (Toxicity) BENTHOS (Disturbance) Equivalent to reference or control condition (1) Minimal Exposure NontoxicReference Slight change of uncertain statistical significance (2) Low Exposure Low Toxicity Low Disturbance Reliable difference generally regarded as significant (3) Moderate Exposure Moderate Toxicity Moderate Disturbance Highly reliable response of high magnitude (4) High Exposure High Toxicity High Disturbance

Direct Effects Station Assessment Unimpacted Likely Unimpacted Possibly Impacted Likely Impacted Clearly Impacted Inconclusive Six assessment categories 64 LOE Combinations 6 Assessment Categories MLOE Integration Framework

MLOE Conceptual Framework Direct Effects Severity of Effect Potential for Chemically Mediated Effect Station Assessment BenthosToxicityChemistryToxicity

Severity of Effect NontoxicLow ToxicityModerate Toxicity High Toxicity ReferenceUnaffected Low Effect Low Disturbance UnaffectedLow Effect Moderate Disturbance Moderate Effect High Disturbance Moderate Effect High Effect Benthos Toxicity

Potential Effects are Chemically Mediated NontoxicLow ToxicityModerate Toxicity High Toxicity Minimal Exposure Minimal Potential Low Potential Moderate Potential Low Exposure Minimal Potential Low Potential Moderate Potential Moderate Exposure Low Potential Moderate Potential High Exposure Moderate Potential High Potential Chemistry Toxicity

MLOE Conceptual Framework Direct Effects Severity of Effect Potential for Chemically Mediated Effect Station Assessment BenthosToxicityChemistryToxicity

Station Categories Unimpacted - no significant adverse impacts. Likely Unimpacted - some uncertainty from small disagreement among the LOE. Possibly Impacted - Small impacts or LOE disagreement cause substantial uncertainty. Likely Impacted - Evidence persuasive, some disagreement among LOE. Clearly Impacted - clear and severe adverse impacts Inconclusive - Large disagreement among the LOE

Station Assessment UnaffectedLow EffectModerate Effect High Effect Minimal Potential Unimpacted Likely Unimpacted or Inconclusive Low Potential Unimpacted Likely Unimpacted Possibly Impacted Moderate Potential Likely Unimpacted Possibly Impacted or Inconclusive Likely Impacted High Potential Likely Unimpacted or Inconclusive Likely Impacted Clearly Impacted Potential that Effects are Chemically Mediated Severity of Effect

Sec 305 (b) Report Test

Common Approach in Regions RegionToxicityBenthosChemistry NorthEohaustoriusRBI CA LRM CSI SFBEohaustorius RBI, IBI, RIVPACS, BRI CA LRM CSI SouthEohaustorius RBI, IBI, RIVPACS, BRI CA LRM CSI Common Tools: Eohaustorius, RBI, CA LRM & CSI

Results

LOE Responses (% Area) RegionResponseBenthosToxicityChemistry NorthAffected27171 SFBAffected SouthAffected Affected: Moderate or High response

Chemistry:Toxicity Relationships

Effect of Tool Differences on % Area Estimates RegionResponseToolsBenthosMLOE NorthAffectedAll2718 NorthAffectedCommon2718 SFBAffectedAll3896 SFBAffectedCommon85100 SouthAffectedAll2338 SouthAffectedCommon3640 Affected Benthos: Moderate or High response Affected MLOE: Possibly, Likely, or Clearly Impacted

RMP Response Implement Sediment Triad Regional Consensus on Indices Assessment of Toxicity Causes

Sediment Chemistry Classification Steps Compile Data –Calculate sums, estimate nondetects Calculate Chemistry Indicators (SQGs) –Chem-Tox: CA LRM (maximum probability of toxicity) –Chem-Benthos: CSI (weighted mean score) Combine Indicator Scores to Determine Chemistry LOE Category

Toxicity Classification Steps Compile Data –Normalize to control response –Statistical significance tests Apply Toxicity Classification Criteria –Amphipod survival (Eohaustorius estuarius) Determine Toxicity LOE Category

Statewide Condition

California Regions North 139 km 2 11% n = 27 SFB 1020 km 2 79% n = 40 South 135 km 2, 10% n = 314 Total = 1295 km 2

North 139 km 2 San Francisco Bay 1020 km 2 Unimpacted Likely Unimpacted Possibly Impacted Likely Impacted Clearly Impacted Inconclusive South 135 km 2 Regional Condition