bacteria meeting review
DESCRIPTION
Bacteria Meeting Review. Swimmable & Fishable Waters. Goal of Meeting. To gather information on the “human health” aspect of water quality in Chesapeake Bay (swimmable/fishable) Beach monitoring Monitoring of shellfish growing areas Learn about existing monitoring programs Who does it - PowerPoint PPT PresentationTRANSCRIPT
Bacteria Meeting Review
Swimmable & Fishable Waters
Goal of Meeting
1. To gather information on the “human health” aspect of water quality in Chesapeake Bay (swimmable/fishable)
• Beach monitoring
• Monitoring of shellfish growing areas
2. Learn about existing monitoring programs
• Who does it
• What indicators are used
Swimmable Water
Major causes of contamination discussed:
• Overflows at pumping stations and sewage treatment plants• Residential & commercial sewage overflows
• septic and sewer backups/failures/ overflows• Stormwater drainpipes• Pets (esp. dogs)• Boat holding tanks• Wildlife (waterfowl, raccoons, deer, etc.)• Bather contamination• Wastes from pets, farm animals• Improper manure management from pastures or crop fields
*Indicator bacteria can be found in decaying plant matter, soils, and sediments
Enteric organisms - found in fecal waste• Giardia• Cryptosporidium• Campylobacter • Salmonella• E. Coli• Hepatitis A• norovirus
Indigenous organisms - naturally occurring in environment• Vibrio• Mycobacterium
Monti 2007
Swimmable Water
Ideal indicators for microbiological pathogens
• Easy to measure• Fast results• Short lived• Not natural to water
bodies• Relate to sewage
constituents only• Reliable and
reproducible results
Farrell, AAC Health Dept 2007
Indicator organisms
1 Total coliforms2 Fecal coliforms3 Enterococci4 Other potential
indicators, caffeine, hormones, antidepressants etc
5 DNA (not really a screening test)
• Easy to measure 1,2,3• Fast results (none so far)• Short lived (1 and 2)• Not natural to water
bodies (1,2 and 4)• Relate to human sewage
only (1,2 and 4)• Reliable and reproducible
results (none so far)
Farrell, AAC Health Dept 2007
Methods
Two different methods in use for enterococci counts:
• Membrane Filtration• Enterolert
• The two methods may give different results; some controversy here
Swimmable Water
1. Maryland and Virginia monitor beaches throughout the swimming season
• mid-late May to early-mid September
2. Beach Monitoring and Reporting is guided by the Beaches Environmental & Coastal Health Act, 2000.
Swimmable Water
Tier 1:
frequently used beaches or beaches where risk may potentially be elevated by known pollution sources or impacts from rainfall shall be monitored weekly
Tier 2:
Less frequently used beaches, or beaches where risks of potential pollution impacts are minimal, shall be monitored biweekly
Tier 3:
All other beaches shall be monitored monthly.
Swimmable Water
Maryland county-level monitoring, excluding ocean-side counties:
• Weekly: ~39
• Twice monthly: ~44 (beaches or recreational waters)
• Monthly: ~100
Virginia county/district-level monitoring (ocean-side excluded):
• Weekly: 20
Swimmable
Freshwater Marine waters
Geometric mean (from 2 or more samples in same calendar month)
E. coli - 126/100 ml
Geometric mean (from 2 or more samples in same calendar month)
enterococci - 35/100 ml
Single sample maximum
E. coli - 235/100 ml
Single sample maximum
enterococci – 104/100 ml
EPA-guided thresholds for beach monitoring:
Swimmable
Available Data
MD:
Enterococci and e. coli since 2000
Fecal coliform before 2000 (reliable data back to 1985)
VA:
Norfolk beaches (9) monitored since the 1960’s
Additional beaches added 2003-2006.
Officially adopted EPA indicator and thresholds Jan 2003
Fishable
Maryland and VA both follow the guidelines of the National Shellfish Sanitation Program (FDA)
Standardized method of classification provided by NSSP
States conduct routine, standardized monitoring
Frequency and criteria thresholds based on classification
Fishable
Bacteriological standards are set by the NSSP
Fecal coliform or total coliform
Variety of standards and monitoring levels, depending on classification• Approved-Remote
• median or geometric mean• ≤ 14 MPN or MF/100 mL fecal coliform, • ≤ 70 MPN/100 mL for total coliform
• Conditionally Approved-PS…• Conditionally Approved-NPS…• Restricted-PS, shellstock source…• Restricted-NPS, shellstock source…• Prohibited…
Fishable
Fishable
Different types of monitoring:
“Adverse Pollution Monitoring”
“Systematic random sampling monitoring.”
Determined by reasons for conditional approval/restriction
Requirements for each are set by NPSS
Fishable
VA data:
2181 Seawater sampling stations in the main tributaries and subtributaries of Tidewater Virginia
Stations are generally sampled once per month
24,166 seawater samples analyzed in 2006
“goldmine of data to be analyzed”
MD data:
~900 stations throughout Maryland waters
Goal is to monitor 2x/month; 6x/year where no oyster resource
Database back to 1970; reliable back to 1985.
“available and very large.”
HABs - VA
1. Monitoring of specific Chesapeake Bay sites for HAB organisms Feb 1 – March 31:
• 18 stations sampled monthly for HABs in the Northern Neck• Dinophysis sp.
April 1 – October 30:• 51 stations are sampled monthly for HABs in water• One mid-summer sediment sample/station for evidence of
cysts• Water quality parameters recorded: temperature, salinity, DO
and turbidity
2. Monitoring of visible blooms any time during the year
3. Notification Hotline
HABs - MD
1. HAB monitoring for composition on a monthly basis
Microscope analysis and molecular probes for HAB community composition
Database back to 1998 for molecular monitoring; at least 1985 for microscope data
___ stations?
2. If HABs are encountered at long-term sites, then they’re reported
3. Notification hotline for public to call in with reports
can result in rapid response; spp identification; toxin analyses on an as-needed basis
Discussion
1. Beach and shellfish monitoring programs are standardized and guided by federal agencies/legislation
Criteria are already developed and are consistent across states
We would need to set goals for a restored bay
Are there/ or how can we determine acceptable levels of criteria violation for a “healthy” bay?