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# Assessment of Antifouling Paint Use Indicators in California Marinas

Nan Singhasemanon CA Department of Pesticide Regulation

CAHMPC Annual Conference, Ventura 20082 

# Background

• Documentation of elevated copper at SIYB in San Diego Bay sparked follow

- up investigations



### • Dissolved copper (DCu) concentrations observed above W.Q. standards

– CA Toxics Rule (CTR)



### • SIYB TMDL identified boat AFPs as source



### • Main question

– do similar conditions exist elsewhere in CA?



### • DPR planned study under consultation w/ CSG, an interagency sub

- workgroup of MRBW



### • Study co

- funded by DPR, SWRCB & U.S. EPA3 

# AFP Use in CA

• ~ 180 AFP pesticide products registered



### • More than 90% utilizes copper

- based biocides Copper oxide , copper hydroxide, copper thiocyanate



### • Booster biocides are often co

- formulated Zinc pyrithione (a.k.a. omadine, ZnPt 2 ) Irgarol 1051 Sea

- Nine (a.k.a. DCOI)4 

# Study Objectives

• Determine occurrences & magnitude of AFP

- use indicators (i.e., Cu, Zn, & Irgarol/M1) in marina areas



### • Determine if indicators exceed established water quality standards, criteria, guidelines, or other relevant benchmarks



### • Determine if marina conc. of indicators are higher than background conc.5 

# Study Objectives (cont.)

• Determine if differences exist among AFP indicators in fresh, brackish, & salt water areas



### • Apply U.S. EPA’s Biotic Ligand Model (BLM) or other scientifically

- relevant models to estimate bioavailability & toxicity of copper.



### • Measure toxicity of marina waters w/ copper

sensitive species & endpoints



### • If toxicity exists, identify the likely cause6 

# Study Overview

• Selected 23 (medium

– large) CA marinas



### • Avoided marinas w/ potential interferences from adjacent sources



### • Sampled each marina 3 times (replicates) between July & October 2006



### • Water and sediment from 4 points inside marina area & 4 points outside of the marina area (local reference sites or LRS)



### • Took sub

- surface samples from center of fairway & half way down docks7 

# Marina Sampling Diagram8910 

# Monitoring Summary

• 67 of 69 total events sampled



### • ~ 600 water samples taken, ~ 7,000 individual analytical results (most feed into models)



### • Sediment from only 3 marinas collected (fresh water). Remainder of sediment worked cancelled due to safety & liability issues



### • Field & Lab QA/QC very good overall



### • Metals data within range of other studies11 

# Results

Dissolved Copper (DCu)12 Marina Median DCu Concentrations by Water Types13

Median DCu Concentrations by Marina Areas14 

# Findings

- DCu

• DCu ranged from 0.1

– 18.4 μg/L



### • Particularly elevated levels in Central & South Coast marinas

– except Alamitos Bay Marina



### • MdR Basins consistently very high in DCu



### • Low to Moderate levels in SF Bay Area & brackish water marinas



### • Very Low to Moderate levels observed in fresh water marinas15 

# Findings

- DCu (cont.)

• Salt & brackish water marinas ↑ fresh water marinas (higher use?)



### • Marina ↑ vs. LRS for marinas of all 3 water types (statistically significant)



### • Many salt & brackish marinas exceeded W.Q. stds. 16 of 17 marinas exceeded CTR chronic stds. (3.1 ppb) 10 of these 16 marinas also exceeded acute stds. (4.8 ppb)16 

# Findings

- DCu (cont.)

• 30% (118/388) of samples from salt & brackish water samples exceeded chronic stds.



### • 17% (67/388) of these exceeded acute stds. Thus, ecological risks may exist



### • Very few LRS samples (4) exceeded chronic stds.



### • For fresh water, none of the samples exceeded fresh water CTR standards Thus, ecological risks unlikely in fresh water marinas17 

# Results

Dissolved Zinc (DZn)18 Marina Median DZn Concentrations by Water Types19 

# Findings

- DZn

• Ranged from 1.0

– 66.6 μg/L



### • Marinas ranked similar to DCu Exception: Alamitos Bay (very low DZn)



### • Tends to be higher than DCu by factor of 2

– 4



### • Much higher DZn in salt water marinas compared to brackish & fresh water marinas



### • Marina vs. LRS is statistically significant for salt & brackish water marinas



### • Zn CTR fresh & salt water stds. never exceeded20 

# Results

Irgarol & M121 Irgarol & M1 Concentrations by Rounds22 

# Findings

- Irgarol/M1

• Irgarol & M1 detected in all 45 samples



### • Irgarol ranged from 12

– 712 ng/L



### • M1 ranged from 1.6

– 217.1 ng/L



### • Highest Irgarol & M1 conc. documented @ Loch Lomond Marina



### • Higher conc. in salt water marinas



### • Higher conc. in Round 1 (Summer) vs. Round 2 (Fall) (applications in summer? higher leaching?)23 

# Findings

- Irgarol/M1 (cont.)

• Irgarol range overlaps more sensitive phytoplankton endpoints Photosynthetic activity Reproduction/growth



### • Irgarol exceed aquatic benchmark values (i.e., 136 & 251 ng/L) protective of 90% of aquatic plant species



### • M1 never exceeded benchmark ( 12,500 ng/L)24 

# Results

Toxicity & Toxicity Identification Evaluation25 

# Findings

- Toxicity/TIE

• 8 of 47 samples (17%) exhibited statistically significant toxicity

• 7 of 8 toxic samples came from MdR; remaining sample from MBYH in Richmond

• TIE strongly points to metal (most likely copper) as the cause of toxicity

• Toxicity test/species used is commonly used. Water Boards view this as exceedance of narrative WQO.26 

# Results

Bioavailability & Predictive Toxicity Modeling27 

# Findings

- Modeling

• Fresh water

- BLM predicted 7 samples would have had DCu > 1 Toxic Unit (all from Sacramento Marina)



### • Salt & brackish water

- DOC Model predicted: 86 samples would exceed chronic toxicity threshold Of the 86, 54 would also exceed acute threshold


### • Comparison of DOC model to actual toxicity showed good agreement28 

# Findings

- Modeling (cont.)

• Salt & brackish water

- draft BLM predicted that some toxicity would still occur 67 samples would exceed M. galloprovincialis EC 50 

### • BLM & DOC model showed similar results



### • Comparison of BLM to actual toxicity showed good agreement



### • Both models still tend to slightly over

- predict toxicity when compared to actual toxicity, especially when close to EC 5029 

# Conclusions

• CTR fresh water Cu stds. are not threatened.



### • Water samples from CA salt & brackish marinas regularly exceed CTR salt water Cu standards. Reality

– beneficial uses are potentially impaired...



### • Considering study results, scientific literature, leaching estimates & marina surveys

- AFPs are likely the most significant source of Cu in salt water marinas, particularly during dry periods.30 

# Conclusion (cont.)

• Higher background DCu loads in S.F. Bay Area, brackish, & fresh water marinas account for a larger portion of marina DCu loads than Central & South Coast marinas. Bay Area SSO’s raised regional Cu stds. CTR still applies to other CA marinas



### • Toxicity (in a copper

- sensitive test) may not occur until DCu is well over current CTR stds. Over

- protective? Does this matter?31 

# Conclusions (cont.)

• Copper

- sensitive aquatic species in salt water marinas that exhibit high DCu conc. may be adversely impacted by exposure to Cu. i.e., MdR Front & Back Basins



### • DOC Model & BLM predict actual toxicity with good precision & are promising tools in assessing biological effects of copper.32 

# Conclusion (cont.)

• Zinc CTR standards are not threatened by marina concentrations of DZn. Non

- biocide applications of Zn may be important factors in determining DZn in salt water marinas.



### • Irgarol may be adversely affecting more

sensitive phytoplankton species in CA’s salt water marinas.33 

# Next Steps...

• DPR will pursue formal reevaluation for Cu AFPs & potentially other AFPs (ZnPt 2 , Irgarol, Sea

- Nine).



### • If approved, Cu AFP reevaluation will likely focus on mitigation , while non - Cu AFP reevaluation will likely focus on W.Q. assessment & biological impacts

. 

### • Registration status of reevaluated AFPs remains the same... unless DPR or registrants take actions during process34 

# Next Steps...

• AFP product market shifts are already taking place. Zn AFPs have increased in market place Less

- toxic AFPs are becoming more available



### • DPR has taken active role in supporting 2 projects that are evaluating feasibility & costs of alternatives to Cu AFPs.



### • Long

- term solution: availability & use of multiple biocides rather than one (i.e., Cu).35 

# Other Activities to Consider

• Federal risk assessment for CuO & ZnPt 2 

### • Discharge standards for military vessels (UNDS)



### • Changes to copper W.Q. criteria for aquatic life Current stds. based on criteria Will stds. be updated to include bioavailability?



### • Proposed NPDES permits for recreational & commercial vessels & countering federal bills



### • U.S. EPA proposal to clearly define and/or require additional data to allow for improved exposure & risk assessments for registration Leaching, non

- target toxicity, phytotoxicity studies36 

# Other Activities to Consider

• EU Biocidal Directive



### • SCCWRP Reg. 9 marina monitoring



### • Lower NPB marina monitoring



### • DBW SIYB biological impact study



### • 303(d) listings & TMDLs



### • Regional or statewide marina permits



### • Local mitigation projects37 

# Questions?

Nan Singhasemanon Staff Environmental Scientist/MAA Coordinator Environmental Monitoring Branch Surface Water Protection Program 1001 I St., Sacramento, CA 95812 nsinghasemanon@cdpr.ca.gov (916) 324

- 4122