|
Good afternoon,
Here in Los Angeles County, sewage discharges affecting drinking water are not much of a concern, but sewage discharges affecting recreational beaches are a huge concern. What Ms. McLellan suggested is correct, there should be some measure of preemptive warnings during rain events and sewage overflows. When we do have a rain event (a rare event in Southern California :) ), we issue a Rain Advisory advising all swimmers, surfers, and beach users to avoid ocean water contact. The bacteria levels go through the roof during a rain event so the advisories are warranted. The advisory remains in effect until 72 hours after rainfall ends. We know from years of data that bacterial levels return to "normal" within 72 hours.
In the event of a sewage discharge that makes it into the ocean, we close the affected portion of the beach until samples indicate that the bacterial levels are within standards. In the event of a closure, we don't allow anyone into the ocean, and folks usually obey the signs. We put closure information on our website, hotline, and closure signs are posted at the affected beach. It also helps that closures are usually covered in the local media so people might know in advance if their favorite beach is closed. In addition, local NGOs will also have closure information on their websites. The affected beaches are usually opened within a couple of days when the bacterial levels have dissipated due to dilution and tidal activity.
Eric Edwards R.E.H.S.
Chief Environmental Health Specialist County of Los Angeles Department of Public Health Water Quality Program 626-430-5420 eedwards@ph.lacounty.gov >>> <mclellan@uwm.edu> 01/15/2008 8 30 >>> Hi everyone, Just to give some comment on this study, since I am somewhat familiar with it, and am currently working with these authors on a larger effort. I think the study tackles a very important issue that, to date, we could only speculate on, e.g. are there measurable adverse health outcomes during sewage overflows? I think the authors do a good job in recognizing that this is a very preliminary study, and limited by the number of cases and sewage overflow events that occurred (there are approximately 0-3 per year in this study area). A larger sampling may or may not show the same effect. Also, drinking water might not be the only route of exposure during sewage overflows. Many small tributaries are receiving waters for SO, and beaches could also be impacted. It would be interesting to include recreational exposures along with drinking water. In addition to sewage overflows, during storm events alone we have detected human viruses, suggesting unrecognized sanitary sewage inputs (e.g. illicit cross connections to the stormwater system, or deteriorating infrastructure). I would not be surprised if there are subsequent adverse health effects (perhaps at a lesser level) from storm events in general. I think it's important to conduct such studies, even if they are limited, so we have a better foundation for decision-making. Until we know more, preemptive warning during sewage overflows seems like a logical measure for protection of public health. Sandra McLellan Associate Scientist Great Lakes WATER Institute University of Wisconsin-Milwaukee 600 E. Greenfield Ave. Milwaukee, WI 53204 Quoting Shannon Briggs <briggss4@michigan.gov>: > PEDIATRICS Vol. 120 No. 6 December 2007, pp. e1472-e1475 > (doi:10.1542/peds.2007-0283) > > FOR ABSTRACT > http://pediatrics.aappublications.org/cgi/content/abstract/120/6/e1472 > > > Pediatric Emergency Department Visits for Diarrheal Illness Increased > After Release of Undertreated Sewage > > Ryan L. Redman, MD(a), Cheryl A. Nenn, MS(b), Daniel Eastwood, MS(a) > and Marc H. Gorelick, MD, MSCE(a) > > (a) Emergency Department, Medical College of Wisconsin, Milwaukee, > Wisconsin > (b) Friends of Milwaukee's Rivers, Milwaukee, Wisconsin > > CONTEXT. Contamination of local waterways may occur through release of > partially treated sewage. The Environmental Protection Agency has > recently reviewed regulatory standards for this practice. However, the > health effects of these events have not been well studied. > > OBJECTIVE. Our goal was to identify any increase in visits to a > pediatric emergency department for diarrheal illness after sewage bypass > into Lake Michigan. > > METHODS. The study was conducted as a retrospective, observational > time-series analysis in a tertiary care children's hospital emergency > department with an annual volume of 45000 visits. We collected data for > 2002-2004 pertaining to the daily number of emergency department visits > for children (aged <19 years) for diarrheal illness (using specified > International Classification of Diseases, Ninth Edition codes as a > reference). Daily diarrheal illness visits were the dependent variable > in a time-series model. The primary independent variable was the > occurrence of a sewage-bypass event in the 3 to 7 preceding days. > Potential confounders included the season and daily rainfall. Separate > models were created for visits from people living in zip codes that used > Lake Michigan drinking water and those who used other water sources. > > RESULTS. Over the 3-year study period, there was a mean of 5.0 ± 3.8 > (SD) daily visits for diarrheal illness from people who lived in zip > codes that used Lake Michigan drinking water and 1.2 ± 1.4 (SD) from > outside that area. There were 6 sewage-bypass events identified. After > adjusting for the season and rainfall, there was a significant increase > of 2.5 to 2.7 visits only from people who lived in zip codes that used > Lake Michigan drinking water after the 2 largest of the 6 bypass events. > > > CONCLUSIONS. Emergency department visits for diarrheal illness > increased significantly after 2 events of release of partially treated > sewage into area waterways. These data suggest a potentially harmful > effect of such practices. > -------------------------------------------------------------------------------- > Key Words: gastrointestinal infections environmental health > > Abbreviations: EDemergency department ARIMAautoregressive integrated > moving average ICD-9 International Classification of Diseases, Ninth > Edition CHWChildren's Hospital of Wisconsin CIconfidence interval > -------------------------------------------------------------------------------- > Accepted May 10, 2007. > > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > beachnet is hosted by the Great Lakes Information Network: > http://www.great-lakes.net > To unsubscribe from this list: send mail to majordomo@great-lakes.net > with the command 'unsubscribe beachnet' in the body of your message. No > quotes or subject line are required. > About : http://www.great-lakes.net/lists/beachnet/beachnet.info > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * beachnet is hosted by the Great Lakes Information Network: http://www.great-lakes.net To unsubscribe from this list: send mail to majordomo@great-lakes.net with the command 'unsubscribe beachnet' in the body of your message. No quotes or subject line are required. About : http://www.great-lakes.net/lists/beachnet/beachnet.info * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * |