**UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, DC 20460**  OFFICE OF PREVENTION, PESTICIDES, AND TOXIC SUBSTANCES

**DP Barcode: Chemical:**  Creosote **PC Codes:** 022003, 025003, 25004 **Case No.:** 0139 August 26 , 2008 **Memorandum: Subject:**  Ecological Risk Assessment for Creosote: Response to Public Comments **To:** Jacqueline McFarlane , CRM

Antimicrobial Division **From:** William Erickson, Ph.D., Biologist

RASSB/AD **Thru:** Norm Cook, Branch Chief

RASSB/AD RASSB has reviewed the public comm ents on the Updat ed Ecological Risk Assessment for Creosote. Comments on the ecological risk assessment were p rovided b y The Creosote Council; Be yond Pesticides; and the California Regional Water Quality Control Board , San Francisco Bay R egion . The comme nts and RASSB's response to those comments are provided below. **Comment (Creosote Council)**  **:** EPA needs to make better and more extensive use of the creosote ecological studies conducted b y Dr. Kenneth Brooks. The work of Dr. Kenneth Brooks established that use of creosote

- treated wood products (e.g., marine piling) in or near water does not pose an environmental hazard. **RASSB Response:**  The studies of Dr. Brooks are evaluated in the risk assessment including their strengths and limitations . RASSB disagre es with the Creosote Council's conclusion that creosote - treated wood products in or near water do not pose any environmental hazard. Dr. Brooks concluded that PAHs accumulating in sediments near aquatic pilings can pose a risk to aquatic organisms. He co ncluded that such impacts might be limited to within a few meters of asix

- piling dolphin structure in the So oke Basin of Canada. H owever, the footprint of potential

impact could be much more extensive where a larger volume of aquatic pilings was placed i n an aquatic environment. Elsewhere, Dr. Brooks ( 1995) has advocated not installing creosote

- treated aquatic structures in areas where current speeds are less than or equal to 1.0 cm/sec without further assessment. He stated that an individual project ri sk assessment should be required under certain conditions, including current speed, inter

- piling distances, proximity to existing creosote structures, and other factors . Clearl y, Dr. Brooks recognizes that creosote leaching from treated aquatic structures poses risk to some aquatic organisms. Elsewhere, as discussed in the risk assessment, creosote has been shown to have a significant and rapid impact on zooplankton communities (NOEC = 13.9 ppb), and 40

- ye ar - old creosote

- treated pilings caused hatching fa ilures and embryonic abnormalities in Pacific herring. Based on all available information, it is misleading to claim that creosote

- treated wood placed in the aquatic environment poses no hazard to aquatic organisms. Regarding risk to organisms in the wat er column of the Sooke Basin in Canada, Dr. Brooks states that water

- column concentrations of PAHs are extremel y low and not likely to be of concern for aquatic organisms . However, as d iscusse d in the risk assessment, water

- column concentrations were not measured until six months after aquatic pilings were installed. Microcosm studies (discussed in the risk assessment) demonstrate that water

- column concentrations of PAHs may be sufficientl y high in the first few days or weeks to cause adverse affects (lethal and sublethal) to aquatic organisms. RASSB also strongl y believes that the uncertainties in extrapolating PAH concentrations in pristine Canadian waters in winter may not adequately

reflect water

- column and sediment concentrations that might occur i n coastal Florida, Mississippi, Texas or other southern U. S. areas with different biotic and abiotic factors . Data from these areas would provide for a more refined risk assessment. As discussed in the risk assessment, environmental factors such as sali nity , temperature, pH, organic matter of sediments, water currents, tides, and others have been shown to influence both leaching of PAHs from treated wood and toxicity to aquatic organisms. **Comment (Creosote Council)**  **:** In1995 EP A waived all data requirem ents in favor of rel ying upon the public literature. **RASSB Response:**  EPA did not waive the data but did state that the registrant could use available published literature where appropriate. Although a field study from Canada (Sooke Basin) was subsequent ly

submitted, no literature or laboratory studies have been submitted to satisfy the standard ecotoxicity

tests required for all pesticides registered and reregistered under FIFRA. The data gaps are specified in the ecological risk assessment. However, RASSB realizes the difficult y in conducting standard ecological toxicity tests for creosote, because it is a mixture of a variety

of PAHs with differing toxicities in differing concentrations that change over time. RASSB believes that in lieu of standardiz ed laboratory tests, a field or simulated study might better address exposure and hazard concerns for aquatic organisms. RASSB will be working with the Creosote Council to determine appropriate means of testing. **Comment (Beyond Pesticides)**  **:** Emphasize th at an endangered species determination is legallyrequired.

**RASSB Response:**  The screening

- level ecological risk assessment identifies the taxa (e. g., saltwater invertebrates) at risk, based on exceedances of the acute and/or chronic level s of concern. As noted in the screening assessment, a refined listed

- species assessment will be conducted under Registration Review to assess risk to individual species in those taxa. The listed

- species assessment will be conducted in accordance with the OPPTS' overvie w document 1

. http://www.epa.gov/espp/ **Comment (** 

**California Regional Water Quality Control Board ,**  **SF Bay Region )**  **:** Recent research provides additional information about the hazards that PAHs in creosote pose to f ish. We have enclosed recent research papers on this topic. **RASSB Response:**  The information in these articles may be useful for further characterizing ecological risks of creosote , but there appears to be no new information that would change RASSB 's risk conclusions at this time . The information will be used, as deemed appropriate, when RASSB conducts a refined listed

- species assessment (including listed salmonids) or conducts an y additional ecological risk assessments for creosote

- treated structures
. **C omment**  **( California Regional Water Quality Control Board**  **, SF Bay Region**  **) :**  Important data needs include sufficient aquatic toxicity data to calculate acute and chronic risks to benthic organisms and sufficient aquatic toxicity data to calculate chronic risk to organisms (fish, invertebrates, plants) inhabiting the water column in both freshwater and saltwater. **RASSB Response:**  RASSB agrees that additional data are needed and identifies these data gaps in the ecological assessment. See also RASSB's response to the Creosote Council regarding the data requirements.

1 USEPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs, U.S. Environmental Protection Agency : Endangered and Threatened Species Effects Determin ations
. Office of Prevention, Pesticides and Toxic Substances , Office of Pesticide Programs , Washington, D.C.