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Strategy of CWA
- 1. sewage treatment requirements
- 2. sewage effuluent standards
- 3. NPDES permit requirements
- 4. swimming water quality standards
- 5. monitoring
- 6. fines for failures to meet standards
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recreational use of water-disease transmission
- pathogen source
- environ
- pathogen survival
- exposure
- infection
- disease
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sewage-borne pathogens (3 major types)
- 1. bacteria
- 2. virus
- 3. protozoa
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EPA WHO strategy: use fecal indicator bacteria to establish WQ standards
- 1. pathogens
- 2. limit concentraion of fecal coliform, e. coli and enterococci in recreational water to safe level
- 3. monitor beach water for fecal bacteria and close beach
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positive impacts of EPA regulations
- 1. guidelines for all parties
- 2. fecal contamination focus
- 3. empowers agencies to prevent pollution
- 4. effective
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negative impacts of EPA regulations
- 1. not applicable to all states
- 2. non-sewage pathogens like leptospirosis, stapj and vibrio) are not covered by regulations
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enteric or sewage pathogens
- 1. transmitted by ingestion of water
- 2. pathogen is feces
- 3. addresed by WQ standards
- 4. monitoringed data available
- 5. data from epi studies
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non-sewage sources of pathogens
- 1. tranmistted y contact with water
- 2. pathogen source-urine, water, people
- 3. not addressed by WQ standards
- 4. methods not approved for monitoring
- 5. no data available
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Conclusions of EPA epi studies
- 1. set WQ standard based on concentrations of fecal bacterica in water to predic an acceptable health effects level
- 2. fecal indicator bacertia in recreational water predicts disease rate
- 3. not if its non-sewage source
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EPA 2 assumptions for WQ
- 1. only fecal bacteria is from feces or sewage
- 2. cannot multuple under envir conditions
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alternative fecal indicator for hawaii
- C. perfringens
- an anaerobi bacteria that grows in the intestines of man and animal but not in soil
- -survive as stable spore in sewage/ but cannot multiply
- -in hawaii based on exceeding ambient levels
- -reliably shows presence of sewage in environmental waters (streams, oceans)
- -used by hawaii doh
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principals of microbial ecology
- 2. conditions select for microbial populations in the environment
- -tropical is humid and waym
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leptospirosis
- 1. bacteria infected animals (rats)
- 2. rat urine transmission (asymptomatic)
- 3. incubation 0-30days
- 4. mild -flu- serious-kidney and liver failure
- 5. treatable with anti-biotics
- 6. 50% in hawaii
- not reportable since 1994.
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Alternative indicators?
- viruses not completly removed.
- -virus infectivity assays (can tell % of cells by volume)
- -protocol validation-detection of enteric viruses in sewage using molecular technology
- -detection of NoV GII in environmental waters
- -only testing sequence of a gene.
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