Biomonitoring Recycled Water in the Santa Ana River Basin in Southern California

Abstract

The Santa Ana River (SAR) is the primary source of groundwater recharge for the Orange County Groundwater Basin in coastal southern California. Approximately 85% base flow in the SAR originates from wastewater treatment plants operated by three dischargers. An on-line, flow-through bioassay using Japanese medaka (Oryzias latipes) as a means of judging potential public health impacts was employed to evaluate the water quality of the surface water and shallow groundwater originating from the SAR. Three chronic (3-4.5 mo) exposures using orange-red (outbred, OR) and see-through (color mutant, ST-II) Japanese medaka as bioindicators were conducted to evaluate endocrinologic, reproductive, and morphologic endpoints. No statistically significant differences in gross morphological endpoints, mortality, gender ratios, and vitellogenin induction were observed in fish from SAR groundwater treatment compared to the group tested in solute reconstituted reverse osmosis-treated or granular activated carbon (GAC)-treated control waters. Significant differences were observed in egg reproduction and the time to hatch in SAR groundwater; however, total hatchability was not significantly lower. To evaluate the estrogenic activity of the surfacewater source of the groundwater, SAR surface water was evaluated for vitellogenin and gonadal histopathology in juvenile medaka with no effects observed. These results demonstrate that OR Japanese medaka may be a sensitive strain as an on-line monitor to predict potential impacts of water quality, but further studies are needed to elicit causative agents within the water mixture.

Evaluation of Chemical, Molecular, and Traditional Markers of Fecal Contamination in an Effluent Dominated Urban Stream

“…The Santa Ana River is divided geographically into Upper and Lower basins by a large flood control structure, Prado Dam, used to limit flow in the river during storms and provide base flow for groundwater recharge in the lower reaches of the river during dry weather periods . During dry weather, approximately 85% of flow in the Santa Ana River is disinfected tertiary treated wastewater effluent discharged from 12 wastewater treatment plants (WWTPs), each of which contribute a minimum of 3700 m 3 day −1 . A previous study suggested that the Middle Santa Ana River, located upstream of Prado Dam, may be impacted by untreated human sewage, based on the enantiomeric fraction (EF) of the pharmaceutical compound propranolol measured there .…”

Pesticide and Surfactant Mixtures Alter Sexual Differentiation in Japanese Medaka (Oryzias latipes)

“…15 Additionally, exposure to antiandrogenic chemicals has been shown to suppress the formation of masculine papillary processes in male medaka. 16,17 Recent papers have also well-described the reproductive toxicity of chemicals with androgen receptor antagonistic activity in medaka after exposure to EDCs during earlier life stages. 18−20 The Japanese medaka has been proposed by the USEPA 22 and OECD 23 as a model to assess sexual development following embryonic or larval exposure to xenobiotics.…”

“…Recent studies showed that exposure to pesticides and synthetic steroids in early life stages of fish alter gonad differentiation and secondary sex characteristics. ,− For instance, exposure to the synthetic progestin, dydrogesterone caused male bias in zebrafish, and phenotypic changes among multiple species of fish have been observed following exposure to 17α-ethinylestradiol, causing the transgenerational inheritance of altered phenotypes in Japanese medaka, Oryzias latipes . Additionally, exposure to antiandrogenic chemicals has been shown to suppress the formation of masculine papillary processes in male medaka. , Recent papers have also well-described the reproductive toxicity of chemicals with androgen receptor antagonistic activity in medaka after exposure to EDCs during earlier life stages. − …”

Site-Specific Profiles of Estrogenic Activity in Agricultural Areas of California’s Inland Waters

“…In vivo bioassays employing caged fish , flow-through aquaria , , static renewal , and intraperitoneal injection , have been used to assess the estrogenicity of specific contaminants, to compare the estrogenicity of municipal wastewater effluent , and to evaluate temporal and spatial variations of estrogenic contaminants in surface waters , . However, the large volume of water required and limited throughput of these assays has precluded their widespread use for bioassay-directed fractionation.…”