An Introduction to Fecal Water Pollution

Transcription

1 Slide 1 An Introduction to Fecal Water Pollution for the Cohansey Area Watershed Association Salvatore Mangiafico Rutgers Cooperative Extension Environmental and Resource Management Agent This presentation introduces fecal contamination of water, with a focus on surface water bodies. It will cover the importance of fecal contamination, indicator organisms used to identify contamination, sampling and analysis of water, and pollution prevention and management.

2 Slide 2 Why is fecal contamination important? Sicknesses include: - eye and ear infections, and conjunctivitis - gastrointestinal illness - hepatitis a - meningitis, dysentery Photo by Amy MMP Hurley. Used with permission. Fecal contamination of water bodies is a concern primarily due to the potential for pathogenic organisms to be transmitted by contaminated water. There are a wide variety of pathogenic organisms that can survive and remain infectious in the aquatic environment. Diseases that could be caused by fecal contaminants include eye and ear infections, gastrointestinal illnesses, hepatitis, and serious illnesses like meningitis and dysentery.

3 Slide 3 Why is fecal contamination important? Sources of infection - recreation ingestion cuts nose, mouth, ears - drinking water note: most pathogens destroyed by treatment; wells polluted mostly by surface contamination - shellfish some bacteria Photo by Amy MMP Hurley. Used with permission. Infection can occur during recreational activities such as swimming, where there is some potential for ingestion of water, water contact with open wounds, or water contact with the nose, ears, or mouth. Infection from drinking water is also a concern, though in New Jersey public water supplies are treated to destroy any pathogens. Likewise, water from private wells is usually free from significant quantities of pathogens. However, the potential exists for wells to be contaminated by material from the land surface for example from a broken well seal. Eating shellfish from fecal contaminated water is also a concern.

4 Slide 4 Why is fecal contamination important? Pathogens - bacteria Salmonella, Aeromonas, Shigella, E. Coli **, and many others - virus norovirus (Norwalk) common gastroenteritis rotavirus children s diarrhea ** certain strains only, e.g. enterohemorrhagic E. coli O157:H7 Photo by Amy MMP Hurley. Used with permission. The pathogens of primary concern fall into four groups of organisms: bacteria, viruses, protozoa, and helminths. There are many potentially harmful bacteria species that could be found in fecal contaminated water. These include Salmonella (which can cause diarrhea, fever, and vomiting), Aeromonas (which can cause severe diarrhea and infection of open wounds), and Shigella (with symptoms ranging from mild diarrhea to serious dysentery).. Specific strains of E. coli known as enterohemorrhagic E. coli can also cause illnesses including diarrhea, colitis, and renal failure. It is important to note that only certain strains of E. coli like the O157:H7 strain that is discussed in news reports of foodborne illness are pathogenic.. Viruses include norovirus or Norwalk virus (a common and contagious cause of gastroenteritis) and rotavirus (a common cause of childhood sickness and diarrhea, sometimes requiring hospitalizations).

5 Slide 5 Why is fecal contamination important? Pathogens - protozoa Giardia and Cryptosporidium (gastrointestinal illnesses) cyst-forming - helminth flatworms, tapeworms, roundworms, nematodes eggs Photo by Amy MMP Hurley. Used with permission. Protozoa of concern include Giardia and Cryptosporidium, which can cause diarrhea, fever, and vomiting coined beaver fever in the case of Giardiosis. Both Giardia and Cryptosporidium can form protective cysts in the environment making them relatively long lived in environmental waters, with Cryptosporidium being fairly resistant to water treatments of chlorine and ozone.. Helminths are parasitic worms such as flatworms, tapeworms, roundworms, and nematodes, typically infesting the intestines. Their eggs are shed in fecal matter and can be found in contaminated water.

6 Slide 6 Why is fecal contamination important? Notes on pathogens - are found naturally in the environment in low levels - require infectious dose human waste contamination may be more of a concern that that from other animals because of potential pathogens, and there s some indication that domestic animal waste may be more a concern than that from wild animals Photo by Amy MMP Hurley. Used with permission. Many pathogenic organisms may be found in low levels in the environment naturally. Infection with any of them usually requires some infectious dose that is a certain quantity of the pathogen must be ingested or encountered for infection to be successful. Some fecal material for example from wildlife is likely to be found in any surface water body. Because of this, it is the amount of the contamination not its absolute presence often that is of concern.

7 Slide 7 Indicator organisms The organisms we typically look for to indicate fecal contamination are indicator organisms - the indicator organisms themselves are not pathogenic - (enterohemorrhagic E. coli confuse issue) A good indicator is found only in the intestines; and survives but does not reproduce in the environment (Ferguson, 2003) Photo: Sal Mangiafico Ferguson, et al Fate and transport of surface water pathogens in watersheds. Critical Reviews in Environmental Science and Technology 33. Because there are a large number and wide variety of pathogenic organisms that could be a concern in water, routine screening for the presence of the pathogenic organisms themselves is not practical. Instead, indicators are used to determine the presence of fecal contamination in water. An ideal indicator organism would be one that is found naturally only in fecal matter so that its presence would necessarily indicate fecal contamination. Additionally, an ideal indicator organism would survive in the environment long enough for contamination to be detected for some length of time. In general, these indicator organisms themselves are not pathogenic, though in the case of E. coli some strains are pathogenic, as previously mentioned.

8 Slide 8 Total Coliform - found in feces, but also rotting wood, soil, etc. - good indicator for drinking water (because you don t want rotting wood or soil contamination in your water either) Fecal Coliform - all found in feces (except the exceptions) Indicator organisms - was standard, but relatively poor indicator of pathogens, so no longer standard for USEPA or NJDEP All of these are bacteria Photo: Sal Mangiafico The four commonly used indicator organisms are all types of bacteria. Total coliform bacteria are primarily found in feces but are also found in rotting wood and in soil. They are used as indicators in drinking water, since any source of these bacteria (feces, soil, or wood) would indicate contamination of a drinking water source.. Fecal coliform bacteria are found almost exclusively in feces, though there are exceptions. These bacteria used to be the standard indicator of fecal contamination of surface water. However, since their presence was a relatively poor indicator of pathogen presence, they are no longer used as the standard for either the U.S. EPA or the New Jersey Department of Environmental Protection.

9 Slide 9 Indicator organisms E. Coli (Escherichia coli) - all found in feces - current best indicator for fresh water for USEPA and NJDEP Enterococci - survive in salt water - now best indicator for coastal waters and beaches for USEPA and NJDEP All of these are bacteria Photo: Sal Mangiafico E. coli are found exclusively in feces and are the recommended indicator for fecal contamination for fresh water bodies for both the U.S. EPA and the New Jersey Department of Environmental Protection.. Enterococcus is a genus of bacteria that survive well in salt water, and are currently used as the best indicator for coastal waters and saltwater beaches by both the U.S. EPA and New Jersey Department of Environmental Protection.

10 Slide 10 Sampling and analysis - analysis usually done certified lab, but can be done by trained volunteers, etc. with kits and equipment Microbial Source Tracking (MST) - goal is to identify source of contamination - separate human from other animal contamination, sometimes to indicate more specific animal sources Photo: Sal Mangiafico Analysis for indicator organisms is usually done by a certified laboratory, though analysis could be accomplished by trained volunteers with test kits and equipment.. One topic of interest in analysis is microbial source tracking (MST), which is used to determine the source of fecal contamination, for example by indicating if contamination is from humans or other animals, and sometimes identifying the specific animal sources.

11 Slide 11 Sampling and analysis Microbial Source Tracking Quantitative polymerase chain reaction (qpcr) - used by Rutgers for Cohansey study - uses DNA genotype - uses a fecal bacterium Bacteroides - uses markers for strains of bacteria specific to types of animal: e.g. human vs. bovine vs. avian vs. porcine - can be rapid and relatively straightforward, but currently not used extensively for routine analysis Quantitative! Photo: Sal Mangiafico One technique used for microbial source tracking is qpcr, which stands for quantitative Polymerase Chain Reaction. This technique was used by Rutgers in studying the upper Cohansey River. It analyzes the DNA genotype of a fecal bacterium, Bacteroides, for specific markers that indicate the animal of origin. Common markers are for human, bovine (cattle), avian (birds), and porcine (swine) sources. In theory, the technique is relatively rapid, but currently it is not used extensively for routine analysis. One notable benefit of the technique is that its results are quantitative that is, it is able to determine the percentage of the Bacteroides bacteria in a sample that is from each animal source.

12 Slide 12 Sampling and analysis Microbial Source Tracking Multiple Antibiotic Resistance (MAR) - has been used by NJDEP - uses phenotypic reaction to series of antibiotics - is necessarily a library-dependent process; that is, need to develop library from known samples in watershed - very good if calibrated for a watershed at a given time - but library may not be stable over time or in other areas or for large area. Often not quantitative Photo: Sal Mangiafico Another microbial source tracking technique is Multiple Antibiotic Resistance (MAR). This technique works by subjecting the bacteria in a water sample to a series of antibiotics. Some bacteria will be resistant to some of the antibiotics either naturally or by the bacterial population having developed resistance in the host animal. The profile of resistance is compared to a library of profiles where the same technique was applied to fecal samples of known origin. A match suggests the probable source of the contamination. The technique is the very reliable if the library of known samples was assembled in the same watershed as the unknown samples were collected, and was assembled recently. However, the technique has more limited liability if used with an out-of-date library or one developed in another location. The technique has been used for source tracking in New Jersey.

13 Slide 13 Microbial Source Tracking Sampling and analysis Optical brighteners - in sewage from detergents - false negatives or false positives possible Not quantitative Photo: Sal Mangiafico Optical brighteners are found in detergents, so their presence in water samples indicates contamination by human sewage. False positives have been reported for this technique, since optical brighteners could come from gray water discharges and laundry water with no sewage. Likewise the absence of optical brighteners would not necessarily eliminate human sewage as a potential contamination source.

14 Slide 14 Microbial Source Tracking Sampling and analysis Fecal coliform / streptococcus ratio - has been used by NJDEP - not recommended much anymore - ratio may not be stable in environment Not quantitative Most of these techniques are useful if used with some thought as to what the data mean There are lots of variations of these techniques Photo: Sal Mangiafico The ratio of coliform bacteria to streptococcus bacteria has been used to indicate the presence of human fecal contamination. While the technique has been used by in the past, it is generally no longer considered a reliable technique since the ratio of the bacteria may not be stable in the environment.. As final thoughts on the topic of microbial source tracking, it should be noted that there are variations on these techniques, and other techniques exist as well. Most microbial source tracking techniques can provide useful information, though each requires caution in interpreting the results.

15 Slide 15 Water quality standards for New Jersey Surface water [NJAC] New Jersey Administrative Code. No date. N.J.A.C. 7:9B Surface Water Quality Standards. For surface waters in New Jersey, permissible limits on fecal contamination are based on enterococcus bacteria for coastal waters (SC) including beaches and estuaries designated for primary contact recreation including swimming and shellfish (SE1); E. coli for fresh water bodies (FW); and fecal coliform bacteria for other estuary waters (SE 2 and SE 3).

16 Slide 16 Water quality standards for New Jersey Drinking water Obropta, C.C. and L.G. Evrard. Drinking Water Standards, FS New Brunswick, NJ: Rutgers Cooperative Extension. Regulations for drinking water systems in New Jersey are based on the presence of coliform bacteria in water samples.

17 Slide 17 Extent of the Problem in New Jersey 2008 Integrated Report 2010 Integrated Report: The most frequent causes of water quality impairment on the (d) List are pathogens, which include E. coli, Enterococcus, fecal coliform, and total coliform. Pathogens are the primary cause of recreational use impairment as well as shellfish harvesting restrictions. Sources of pathogens include nonpoint sources, stormwater discharges, combined sewer overflows (CSOs), and illicit discharges. [NJDEP] New Jersey Department of Environmental Protection New Jersey Integrated Water Quality Monitoring and Assessment Report. and [NJDEP] New Jersey Department of Environmental Protection New Jersey Integrated Water Quality Monitoring and Assessment Report. Fecal contamination of surface waters is relatively common in New Jersey. This map shows in red the watersheds that failed to meet standards for primary contact recreation such as swimming. Green indicates watersheds meeting standards, and yellow those that were not assessed. These data are from the 2008 New Jersey Integrated Report. Furthermore, the 2010 report indicates that fecal contamination is the most frequent cause of water quality impairment for waterbodies on the Impaired Waters list in the state.

18 Slide 18 Issues with fate and transport Transport and fate - overland flow is most important pathway - soils filter and biota in soils destroy - pathogens killed also by: desiccation, UV light, predation, competition - most don t settle out unless attached to sediments, but some bacteria and virus do preferentially attach to sediments - soil treatment not always perfect sandy soils, small viruses, anaerobic conditions Photo: Sal Mangiafico Overland flow of contaminated water is the primary pathway for fecal contamination to reach surface waterbodies. This could include water moving through storm drains and stormwater pipes and basins, as well as moving over the land surface. If water infiltrates into the soil, the pathogens are largely filtered out by the soil or destroyed by soil bacteria and other organisms. Most pathogens will be destroyed also by desiccation and exposure to the ultraviolet light in sunshine on the soil surface. Infiltration of water into the soil does not always completely remove all pathogens, however, since small bacteria and viruses may be able to move through pore spaces in the soil, particularly for sandy soils. Furthermore, some pathogens may be able to survive better in saturated soils as compared with aerobic conditions. Many pathogens have limited viability in environmental waters due to predation and competition by other microbes. In general, pathogens and indicator organisms may not settle out of water as sediment does. However, some bacteria and viruses may preferentially attach to sediments, and so can be settled out of waters in these cases.

19 Slide 19 Issues with fate and transport Indicator organisms are not the disease organisms may have different survival or transport Photo: Sal Mangiafico Another issue when considering the fate and transport of fecal pathogens is that the indicator organisms and the pathogens of concern may have different survival rates and transport properties in the environment.

20 Slide 20 Issues with fate and transport Bacteria --- typically short lived - E. Coli typically don t flourish outside host conditions, but some evidence they can grow in natural waters outside hosts in some conditions (Brooks 2004) - E. Coli 2 12 days for 99% reduction in natural waters, with faster die off in warmer water, but can survive > 260 days without predators and competition (Flint 1987) Photo: Sal Mangiafico Brooks, et al Fate and transport of pathogens in lakes and reservoirs. Environment International 30: FLint, K.P The long-term survival of Escherichia coli in river water. Journal of Applied Bacteriology 63: Bacteria including fecal pathogens and indicator organisms are typically short lived in the environment. E. coli typically does not flourish outside their hosts, but there is some evidence that they can grow in environmental waters outside their hosts in some conditions. One study suggested that the population of E coli in natural waters will be reduced by 99% in 2 to 12 days with faster die-off occurring in warmer water. However, this study also indicated E coli can survive from more than 260 days in the absence of predators and competition.

21 Slide 21 Issues with fate and transport Sediment or beach sand may serve as reserve of E. coli bacteria (Whitman and Nevers 2003) Photo: Sal Mangiafico Whitman and Nevers Foreshore sand as a source of Escherichia coli in nearshore water of alake Michigan beach. Applied and Environmental Microbiology. 69: There is also evidence that sediment and beach sand may serve as reserves for E. coli bacteria at freshwater beaches.

22 Slide 22 Issues with fate and transport Cryptosporidium - cyst forming, which can survive in environment (c. 18 months) (SDWF) Pathogens - may remain viable in organic matter and sediments (Brooks 2004) - also low T, not freezing, moist, may have advantage in anaerobic Photo: Sal Mangiafico [SDWF] Safe Drinking Water Foundation. No date. Detailed Information for Cryptosporidium. oridium.pdf. Brooks, et al Fate and transport of pathogens in lakes and reservoirs. Environment International 30: The protozoa Cryptosporidium and can form cysts that can last in the environment for perhaps 18 months. Other pathogens may remain viable in organic matter or sediments. In general, pathogens will remain viable longer in low temperature conditions above freezing, in moist environments, and they may survive longer in anaerobic conditions where they may outcompete predators and competition.

23 Slide 23 Pollution Prevention and Management Humans - sewer infrastructure - CSO issues - good septic siting - alternative septic systems where needed - pet scoops - stormwater infrastructure Not exhaustive lists Wildlife Well protection Photo: Rutgers Cooperative Extension Water Resources Program Prevention of water pollution by human sewage can be accomplished by repairing any faulty sewer infrastructure and eliminating combined sewage overflow issues where they exist. Also, siting septic systems properly and using alternative systems when necessary prevent issues with decentralized wastewater treatment. Additionally, keeping pet wastes out of stormwater and having effective stormwater infrastructure are important.. Discouraging wildlife from frequenting areas around waterbodies may be helpful in minimizing water contamination from wildlife sources, as are other wildlife management techniques. Likewise, using buffers and riparian areas around waterbodies may be beneficial.. Protecting drinking water wells from surface contamination is critical for the prevention of drinking water contamination.

24 Slide 24 Pollution Prevention and Management Agriculture - manure management - stream fencing - livestock management - filter strips, buffers, wetlands - manure spreading management Not exhaustive lists Low Impact Development - like rain gardens and swales - for urban or suburban environments Photo: Rutgers Cooperative Extension Water - help by providing settling, Resources Program desiccation, UV light Best management practices for agriculture to prevent fecal contamination of waterbodies include manure management, such as good practices for the storage and spreading of manure; fencing livestock out of streams and ponds; livestock management, such as using proper density of grazing animals; and the use of filter strips and buffers to treat runoff before reaching waterbodies.. In the urban and suburban environments, the use of low impact development techniques such as rain gardens and swales help to treat runoff water by settling out solids, and destroying pathogens by desiccation and ultraviolet light.

25 Slide 25 Notes on septic systems Proper septic system very very effective at destroying pathogens Soil and biological activity destroy (cf. aeration, soil / gravel zone, etc.) Biggest problem is with system failure. Most states define as surfacing and backup (EPA 2000). That is, overland flow is the problem. Photo: Rutgers Cooperative Extension Water Resources Program [USEPA] U.S. Environmental Protection Agency Chapter1: Background and Use of Onsite Wastewater Treatment Systems. EPA600/R-00/ Properly functioning septic systems are very effective at destroying pathogens. Septic systems and leach fields are engineered to create zones a biological activity in which pathogens are eliminated. The most frequent and serious trouble with septic systems is system failure, which is typically defined as cases where sewage reaches the land surface or backs up into the dwelling. If sewage reaches the soil surface, it can move to waterbodies by overland flow.

26 Slide 26 Notes on septic systems But limitations include: - Siting: sand large pores can allow viruses and bacteria to pass clay too wet, limits aerobic zones wet soils closeness to wells shallow to groundwater (Meschke and Sobsey 1999) - Combination of soil and proximity to surface water or groundwater (EPA 2000) Photo: Rutgers Cooperative Extension Water Resources Program [Meschke and Sobsey Microbial Pathogens and On-Site Soil Treatment Systems. Chapel Hill, NC: University of North Carolina. Septic systems may not entirely destroy pathogens, however, if the system was improperly cited. Problems can occur with a soil that is too sandy, and so may have large pore spaces that allow the passage of some bacteria and viruses. Clay soils can also be problematic if their poor drainage limits aerobic zones. Likewise, wet soils, or poorly drained soils, can be problematic since they may remain anaerobic for periods of time. Septic systems in areas that are shallow to groundwater may allow viable pathogens to reach groundwater, and systems cited too close to wells may allow viable pathogens to reach the intake of those wells. These citing issues were more common in past decades when regulations in some areas may not have been as stringent or strictly enforced as they are now. Septic systems, therefore, may not be completely effective in cases where there is combination of improper soil conditions and proximity to either surface water or groundwater.

27 Slide 27 Notes on septic systems Examples - bacteria moving 50 meters through soil - viruses at 60 meters and 18 meter depth (Meschke and Sobsey 1999) [Meschke and Sobsey Microbial Pathogens and On-Site Soil Treatment Systems. Chapel Hill, NC: University of North Carolina. Photo: Rutgers Cooperative Extension Water Resources Program As examples for the potential for contamination of surface waterbodies or wells, studies have shown bacteria moving through soils a distance of 150 feet and viruses moving a similar distance through soil and to a depth of 60 feet.

28 Slide 28 Salvatore Mangiafico County Environmental and Resource Management Agent Cooperative Extension of Salem County 51 Cheney Rd, Ste. 1 Woodstown, NJ mangiafico@njaes.rutgers.edu