State Water Resources Control Board 

Office of Information Management and Analysis

1001 I Street • Sacramento, California 95814 • (916) 327-9848 

Mailing Address: P.O. Box 100 • Sacramento, California • 95812-0100 

 FAX (916) 341-5463 • http://www.waterboards.ca.gov

Linda S. Adams 

Secretary for 

Environmental Protection

Arnold Schwarzenegger

Governor 

19 July 2010 

Darrin Polhemus, Deputy Director 

Division of Water Quality 

1001 I Street, 15th Floor 

Sacramento, CA 95814 

Dear Mr. Polhemus: 

EFFECTS ON WATER QUALITY OF ALKYLPHENOL ETHOXYLATE SURFACTANTS 

Per your request in a letter to me dated 24 June 2010, below I have summarized a 

review of the alkylphenol ethoxylate (APE) surfactant data available from the Surface 

Water Ambient Monitoring Program (SWAMP). 

SWAMP Data 

Table 1 summarizes the data available from the SWAMP database. The North Coast 

Regional Water Board analyzed 226 water samples from eight different water bodies for 

the APE surfactants nonylphenol and nonylphenol ethoxylate between 2003 and 2008. 

Samples were collected two to three times per year during that period. Nonylphenol and 

nonylphenol ethoxylate were detected in 19 and 7% of the samples, respectively. 

Nonylphenol was detected at concentrations ranging from 0.6 to 8.7 μg/L, with the 

highest concentration detected in the Russian River. Nonylphenol ethoxylate was 

detected at concentrations ranging from 0.6 to 3.9 μg/L with the highest concentration 

detected in the Klamath River. 

Table 1. Summary of available SWAMP data for surfactants. 

Nonylphenol (μg/L) 

Nonylphenol ethoxylate 

Local Watershed (μg/L) 

Date Min Max Average Min Max Average

Smith River 2003-2008 0.62 3.70 1.77 1.22 2.13 1.68

Klamath River 2003-2008 0.62 3.70 1.77 1.92 3.85 2.89 

Trinity River 2003-2005 0.56 0.59 0.57 1.07 1.26 1.17 

Redwood Creek 2003-2005 0.73 0.83 0.78 0.54* 

Mad River 2008 0.602* 

Eel River 2003-2005 0.66 3.60 2.03 

Gualala River 2006 2.32* 

Big Sulphur Creek 2005 6.84* 

Russian River 2003-2008 0.85 8.72 2.86 0.55 1.23 0.77 

No. Samples Analyzed 226 226 

No. Detections 44 16 

*Only one record not an average value 
Darrin Polhemus - 2 - 19 July 2010 

Ecotoxicity 

Toxicology studies summarized in US EPA’s ECOTOX database indicate that 

nonylphenol is toxic to some early life stages of fish at concentrations below 1 μg/L 

(Kelly and Guilio, 2000) suggesting that the concentrations reported by the North Coast 

Regional Water Board SWAMP could be toxic to fish species. While nonylphenol 

ethoxylate appears to be much less toxic than nonylphenol, a few studies indicate that 

some invertebrate species (i.e., Hyalella azteca and fairy shrimp) are more sensitive 

with LC50 concentrations as low as 1.0 to 4.8 μg/L (Collyard et al., 1994; Brausch and 

Smith, 2007). Concentrations detected in North Coast surface waters could be toxic to 

these more sensitive species. 

Toxicity to algae, attributable to surfactants, also was detected in studies of urban and 

agricultural runoff conducted by the Central Valley Water Board in the mid-1990s. The 

algae cells in the toxic samples tended to collect along the sides of the test container at 

the water line, a phenomenon also observed in surfactant dosing studies. 

In addition to acute toxicity, the endocrine disrupting effects of the APE surfactants are 

of concern (as noted in the San Francisco Estuary Institute’s memorandum attached to 

your 24 June letter). 

Recommendations

The available SWAMP data, previous toxicity monitoring studies, and the toxicological 

literature demonstrate the potential for APE surfactants to impact aquatic life in 

California surface waters. As such, I recommend that toxicity tests be conducted to 

more fully evaluate the toxicity of these chemicals to multiple species (including algae) 

at environmentally relevant concentrations and exposure scenarios. Due to the 

surfactants’ tendency to adsorb to particles and test containers, the toxicity tests should 

be conducted as flow-through exposures. In addition, analytical methods should be 

refined to ensure that these chemicals can be detected at concentrations lower than the 

effect levels for the most sensitive species. 

Literature Cited 

Kelly, S.A., and R.T. Di Giulio. 2000. Developmental Toxicity of Estrogenic Alkylphenols 

in Killifish (Fundulus heteroclitus). Environ Toxicol Chem 19(10):2564-2570. 

Brausch, J.M., and P.N. Smith. 2007. Toxicity of Three Polyethoxylated Tallowamine 

Surfactant Formulations to Laboratory and Field Collected Fairy Shrimp, 

Thamnocephalus platyurus. Arch.Environ.Contam.Toxicol. 52(2):217-221. 

Collyard, S.A., G.T. Ankley, R.A. Hoke, and T. Goldenstein. 1994. Influence of Age on 

the Relative Sensitivity of Hyalella azteca to Diazinon, Alkylphenol Ethoxylates, Copper, 

Cadmium, and Zinc. Arch.Environ.Contam.Toxicol. 26(1):110-113. 
Darrin Polhemus - 3 - 19 July 2010 

If you have any questions regarding this information, please contact Karen Larsen at 

(916) 319-9769 or klarsen@waterboards.ca.gov. 

Sincerely, 

Valerie M. Connor, Ph.D. 

Deputy Director, Office of Information Management and Analysis 
Darrin Polhemus - 4 - 19 July 2010