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TIE and TMDL Approaches for Legacy Sediment Contaminants: Arsenic and Petrochemical Case Studies. BW Brooks, PK Turner, JK Stanley, WT Waller, TW La Point, R Palachek & JA Sullivan. Background to Study.
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TIE and TMDL Approaches for Legacy Sediment Contaminants: Arsenic and Petrochemical Case Studies BW Brooks, PK Turner, JK Stanley, WT Waller, TW La Point, R Palachek & JA Sullivan UNT Institute of Applied Sciences, Parsons Engineering Sciences, Inc, & Tx CEQ SETAC 2002
Background to Study • Study purpose: to assess presence and causes of aqueous and sediment toxicity in Texas rivers; • Develop approaches to sediment toxicity identification evaluations; • Focus on complex sites: Alligator Bayou and Finfeather Lake.
Alligator Bayou Study Site • A freshwater tributary upstream of a salt water barrier, near Port Arthur, TX. • Alligator Bayou receives discharges from municipal and industrial facilities, plus smaller amount of agricultural runoff. • An urban, industrial river.
Finfeather Lake Study Site • A small municipal waterbody located in Bryan, TX, upstream of Bryan Municipal Lake. • Historically, arsenic has been the parameter of concern due to surface and groundwater contamination.
Initial Acute or Chronic Dilution Toxicity Test Phase I TIE Treatments at Appropriate Dilution Level Thiosulfate EDTA SIR-3001 SIR-9002 Baseline Toxicity Test Aeration3 EDTA SIR-300 Filtration C18 SPE Ambersorb5634 Does TIE Treatment Statistically Improve Toxicity Relative to Corresponding Baseline Dilution Level? Yes Phase II Procedures Including Analytical Measures of Effective TIE Treatments to Screen for Suspected Toxicants Phase III Confirmation Procedures TIE Procedures in this Study
SIR-300 Resin • Used as a parallel TIE treatment to EDTA. • A cation exchange resin, styrene & divinylbenzene copolymer with iminodiacetic functional group in the sodium form, chelates divalent metal cations. • Reported affinity for metals: Hg2+>Cu2+ > V2+>Pb2+>Ni2+>Zn2+>Co2+>Cd2+>Fe2+>Be2+ = Mn2+>Mg2+ = Ca2+> Sr2+>Ba2+>Na2+. • We found Mg2+ and Ca2+ to be taken out.
Alligator Bayou: Effective Acute TIE Treatments Test Date Test Type/Station Organism Treatment(s) 08-2001 Porewater/10643 C. dubia Aeration + EDTA, C18 12-2001 Porewater/10643 C. dubia S300, EDTA, Aeration + EDTA 05-2001 Sediment/10643 H. azteca None 06-2002 07-2002 Porewater/14410 C. dubia C18 @48h; Filt, S300, A563@24hr 08-2002 Porewater/10643 C. dubia C18, A563 @48h; Filt, S300 @24hr
Water Quality Criteria Used To Calculate Alligator Bayou Station 10643, Porewater Acute Toxic Units. Metal Acute Criterion1 Source Al 991 TCEQ As 360 TCEQ Cd 104 TCEQ Cr 1000 USEPA Cu 48.6 TCEQ Fe 1000 USEPA Pb 269 TCEQ Ni 3348 TCEQ Zn 274 TCEQ 1Acute criterion (µg/L) based on water hardness of 280 mg/L (25% station 10643 porewater) where appropriate.
Metal Chemistry of Alligator Bayou Sediment Porewater TIE1 48-hour C. dubia test Metal Sed (mg/kg) 100%Base Aeration SIR 300 SIR 300 + Aeration Al 23700000 718 179 340 266 As 8130 ND ND ND ND Cd 636 ND ND ND ND Cr3 45400 11.6 ND ND ND Cu 42500 ND ND ND ND Fe 21800000 581 395 218 188 Pb 211000 75 31.4 29 25.3 Ni 17200 12.4 11.1 ND ND Zn 218000 16.3 13.2 ND 11.8 125% porewater dilutions
Metal Toxic Units of Alligator Bayou Sediment Porewater TIE1 48-hour C. dubia test Metal 25%Base Aeration SIR 300 SIR 300 + Aeration Al 180 44.7 85 66.5 As ND ND ND ND Cd ND ND ND 0.68 Cr3 2.9 ND ND ND Cu ND ND ND ND Fe 145.2 98.8 7.25 47 Pb 18.8 7.8 31.4 6.3 Ni 3.1 2.8 ND ND Zn 4.1 3.3 ND 2.95 125% porewater dilutions
Alligator Bayou: Results • TIE identified significant toxicity reduction at 25% porewater dilution using EDTA, SIR-300 and Aeration + EDTA, but not by Aeration treatments. • Toxicity reduction with these treatments suggests that metals are causative toxicants to Ceriodaphnia dubia. • Chemical analysis on baseline porewater, Aeration, SIR-300 and Aeration + SIR-300 samples indicates that SIR-300 reduced or removed Al, Cr, Fe, Pb, Ni, & Zn.
Finfeather Lake: Effective Chronic TIE Treatments Test Date Test Type/Station Organism Treatment(s) 07-2001 Porewater/11798 C. dubia None 09-2001 Porewater/11798 C. dubia SIR-300, SIR-900 02-2002 Porewater/11798 C. dubia SIR-300, SIR-900 03-2002 Sediment/11798 H. azteca SIR-900 06-2002 Porewater11798 C. dubia EDTA, SIR-300 06-2002 Porewater/11800 C. dubia EDTA
Water Quality Criteria Used to Calculate Finfeather Lake, Station 11798, Porewater Chronic Toxic Units Hardness (mg/L as CaCO3) Metal 60 mg/L1 80 mg/L 120 mg/L 128 mg/L Al NL NL NL NL As 190 190 190 190 Ba 1000 1000 1000 1000 Cd 0.7 0.9 1.2 1.25 Cr 100 100 100 100 Cu 7.9 10.6 14.3 15.17 Fe 1000 1000 1000 1000 Pb 1.3 2.02 3.2 3.45 Hg 1.3 1.3 1.3 1.3 Ni 102 136 183 194 Se 5.0 5.0 5.0 5.0 Ag 1.7 3.01 5.5 6.20 Zn 67.8 90.1 122 129 1Reconstituted moderately hard water after treatment with SIR 300 and calcium and magnesium reintroduced.
Finfeather Lake: Results • Consistent sediment toxicity to C. tentans and H. azteca; • SIR-300 and SIR-900 significantly increased C. dubia reproduction and H. azteca growth; • Cu, Zn and Pb (not As) are the major players; • Phase III TIE
Study Conclusions • Currently, TSWQS do not include applicable promulgated sediment criteria. • There are insufficient procedures or methods to manage Alligator Bayou sediment issues under the existing TMDL program. • Alligator Bayou will require an innovative approach to solving the sediment toxicity issue. • Real Issue: how to deal with “legacy” toxicants?!
Overall Recommendations • TIE and Resins/Adsorbent Media Look promising: Research needed for porewaters and whole sediments • TMDL approach to historical contamination: a valid approach? • How to link TIE and Sediment Triad?