What are iron‐oxidizing Never dump anything down storm drains— it will go straight into the nearest waterway. bacteria? Sweep your driveway, sidewalks and gutters, and dispose of debris in a trash Why is my creek orange? Iron‐oxidizing bacteria are or yard waste bin. non‐harmful bacteria that Direct downspouts to landscaped areas, allowing rainwater to soak into the soil. The Story of produce their energy by oxidizing Avoid pesticides—use the least toxic 2+ 3+ Iron‐Oxidizing Bacteria the iron (Fe Fe ) that is alternative available. Take your car to the car wash instead of naturally present in some soils. washing it in the driveway. The oxidized iron gives the Help pick up trash along creek banks. bacteria their rusty color. The Check your car for leaks and recycle used motor oil and filters. bacteria grow in mats, or large Pick up after your pet. clumps, and will remain in a Contact MCSTOPPP and your local sanitary certain locaon unl a large pulse district before draining your pool or spa. of water washes them away or unl other environmental parameters change.

Marin County Stormwater Pollution Prevention Program (MCSTOPPP)

Primary Business Address: 1600 Los Gamos Dr., Ste. 350 San Rafael, CA 94903 Iron‐oxidizing bacteria growing on Phone: 415‐473‐6528 concrete just downstream of a stormdrain Website: www.mcstoppp.org outfall. Photographer Bené da Silva. E‐mail: [email protected] How to determine if iron‐ What should I do if I ind oxidizing bacteria are present iron‐oxidizing bacteria in my creek? Disnguishing features include: Although perhaps unsightly, these  Orange‐brown slime that may appear “fuzzy,” growing in the bacteria have been present in creek bed or on pipes that feed waterways for millions of years. Iron‐oxidizing bacteria in a downstream pool. into the creek. There is no evidence that the Photographer Bené da Silva.  An oily sheen on the water which, bacteria pose a threat to aquac unlike actual oil, will disperse into References: small parcles if disturbed, such as species, such as fish. In some parts of by throwing a pebble into the the country, these bacteria have City of Bellevue Ulies. (n.d.). Why is the water. been found growing in drinking wells water orange? [Fact sheet]. Bellevue, WA.

 Most oen occur in slow‐moving and are considered ‘nuisance,’ but Gwinne County Department of Water reaches of streams, and in lakes, are not listed as a drinking water Resources. [n.d.] Iron Bacteria [Fact sheet]. parcularly aer a rainstorm that Lawrenceville, GA. could cause iron‐rich sediments to contaminant by the U.S. leach into the creek or waterway. Environmental Protecon Agency. Gold Coast City Council. (2001). Iron bacteria [Fact sheet]. Queensland,  May produce a foul odor. It may be possible to reduce the Australia. presence of the bacteria by Example of the removing iron‐rich soils from the New Hampshire Department of oily sheen created Environmental Services. (1997). Iron by iron‐oxidizing affected area, but this method is bacteria. Photo bacteria in surface water [Fact sheet]. likely to be very expensive. courtesy of Concord, NH. Gwinnett County Department of Therefore, if the bacteria do not Water Resources. U.S. Environmental Protecon Agency. appear to be causing any major [2009]. Drinking Water Contaminants. disturbance, the best thing to do is Available from: hp://water.epa.gov/ let nature take care of it. drink/contaminants/#List.