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EO 011.05

EO 011.05. Microbial Water Sampling TP10. Microbial Water Sampling. References: CFP 213, Health Manual, Chapter 3, Section 325 – Water Sampling Ministry of the Environment Ministry of the Environment - licensed labs

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EO 011.05

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  1. EO 011.05 Microbial Water Sampling TP10

  2. Microbial Water Sampling References: • CFP 213, Health Manual, Chapter 3, Section 325 – Water Sampling • Ministry of the Environment Ministry of the Environment - licensed labs • Health Canada, Guidelines for Recreational Water Quality Guidelines for Canadian Recreational Water Quality - 2009 Health Canada Consultation Document

  3. Microbial Water Sampling General: • Water samples are taken for bacteriological examination or chemical analysis. The frequency of such sampling is laid down in DFHP Instruction4400-98 Water Supplies Sampling and Sterilization.

  4. Microbial Water Sampling As a routine: • bacteriological sampling is carried out monthly; and • chemical examination (mineral analysis) is not performed unless considered necessary by the medical services after consultation with other technical services concerned.

  5. Microbial Water Sampling General: • In special circumstances (epidemiological investigations), sampling may be carried out on a large scale. Such sampling, with plotting of sampling points on a map of the distribution system, can be invaluable in pin-pointing a cross-connection or other source of pollution. In all circumstances, a written record of samples and results reported is essential to the sanitary control of a water supply system.

  6. Microbial Water Sampling Water Sampling Procedure: • Bottles – use only clean sterilized glass or plastic bottles with glass or bakelite stoppers. All bottles used for bacteriological analyses will be obtained from the provincial laboratories where bottles are properly sterilized and prepared for sampling tests. Laboratories place sodium thiosulphate in bottles to neutralize chlorine residual in samples (0.01 ml of a 10 percent solution of sodium thiosulphate).

  7. Microbial Water Sampling Water Sampling Procedure: Sampling from Tap: • after testing the chlorine residual • close the tap • heat the outlet with an alcohol or gasoline torch to destroy any contaminating material on the lip of the faucet • Flush the tap long enough to draw water from the main • Do not use rubber hose or other temporary attachments when drawing sample from tap.

  8. Microbial Water Sampling Water Sampling Procedure cont’d: Sampling from Tap: • Use bottle containing sodium thiosulphate • Without removing the protective cover • remove bottle stopper and hold it • Do not touch bottle mouth or sides of stopper • Fill bottle three-quarters full • Replace cap and carefully fasten protective cover

  9. Microbial Water Sampling Transport & Storage: • Transportation and Storing Samples – because biological changes occur rapidly, it is essential to provide the fastest practicable transportation to the laboratory. When possible, samples for bacteriological analysis sent to the laboratory from appreciable distances should be iced. Advice should be obtained from the laboratory on the necessity for icing samples.

  10. Microbial Water Sampling CF - Sampling Frequency: • The demonstration of the presence of any pathogenic organism in drinking water constitutes grounds for the rejection of the water supply unless effective remedial treatment and disinfection are applied immediately. • The overall microbiological quality of drinking water is evaluated by measuring its total coliform content.

  11. Microbial Water Sampling CF - Sampling Frequency: Water shall be sampled for coliform estimation at the following minimum frequency: • for a population under 2,000 – one sample of treated water is required every two weeks and one sample of raw water monthly; and • for a population over 2,000 – a weekly sampling of treated water is required plus one additional sample per month for each 1000 increase in population, and one sample of raw water is required during the first and third week of each month.

  12. Microbial Water Sampling MPN Method & MF Method: The desirable standard in all cases is no coliforms. The minimum standard depends on the laboratory method used, and is as follows: • MPN Method – at least 95 percent of the samples in any consecutive 30 day period should be negative for total coliforms. None of the samples positive for total coliforms should have an MPN index greater than 10 per 100 ml;

  13. Microbial Water Sampling MPN Method & MF Method cont’d: • MF Method – at least 95 percent of the samples in any consecutive 30 day period should be negative for total coliforms. None of the samples positive for total coliforms should have an MF count greater than 65 per 200 ml or 15 per 500 ml portions.

  14. Microbial Water Sampling Accredited Laboratory: • Effective October 1, 2003, the Safe Drinking Water Act, 2002 (SDWA) requires that all laboratories be appropriately licensed by the Ministry of the Environment (MOE) for specific tests should they wish to perform testing of Ontario drinking water.  On June 16, 2003, Ontario Regulation 248/03 (Drinking Water Testing Services) under the SDWA became law and requires that licensed laboratories and regulated drinking water system owners and operating authorities adhere to strict drinking water sample collection, handling and transport protocols and procedures.

  15. Microbial Water Sampling MOE Ontario Laboratories: Safe Drinking Water Act, 2002 Safe Drinking Water Act, 2002, S.O. 2002, c. 32 Ontario Accredited Laboratories Ministry of the Environment - licensed labs

  16. Microbial Water Sampling Health Canada – Sampling Frequency: Frequency of microbiological sampling. There are a number of factors that can influence the microbiological quality of a recreational water body at any given time. These can include: • Type & periodicity of contamination events • Time of day • Recent weather conditions • Number of users frequenting the bathing area • Physical characteristics of the area

  17. Microbial Water Sampling Health Canada – Sampling Frequency: More frequent monitoring (daily as opposed to weekly sampling; weekly as opposed to monthly sampling) will have several advantages: • As a result of the significant day-to-day variation in faecal indicator counts that can be observed, even daily monitoring will not necessarily improve the ability of the current day's microbiological results to predict the next day's water quality.

  18. Microbial Water Sampling Health Canada – Sampling Frequency: • However, the additional information provided by increasing the number of samples will allow the responsible authorities to more easily observe water quality trends and to make more informed decisions regarding the area's overall suitability for recreation. Moreover, it will enable authorities to more quickly detect persistent water quality problems that may occur.

  19. GEO Mean Guideline • Both a maximum limit for the geometric mean faecal indicator concentration and a single-sample maximum limit are used. • Dual limits allows recreational water operators to better evaluate the water quality both in the short term and over the duration of the bathing season.

  20. Microbial Water Sampling Minimum Frequency • Recreational activities should be monitored at a minimum frequency of once per week during the bathing season as recommended by the U.S EPA in its “2002 Implementation Guidance for Ambient Water Quality Criteria for Bacteria”. • In areas where high bather densities are expected, increased monitoring is recommended. In such situations, the number of samples may be increased to permit the calculation of a weekly or even daily geometric mean (based on a minimum of five samples), if so desired.

  21. Microbial Water Sampling When sampling: • Consideration should also be given to the collection of samples for the purpose of characterizing event-driven episodes of pollution that may affect recreational waters - for example, immediately following periods of heavy rainfall or at times of greatest bather activity.

  22. Microbial Water Sampling When sampling cont’d: • Similarly, certain circumstances may permit a reduction in the recommended sampling frequency. These may include the existence of beaches in remote locations or in areas where primary contact recreational activities are not a regular occurrence or beaches that have historically demonstrated acceptable water quality.

  23. Microbial Water Sampling When sampling cont’d: • Once an understanding of water quality behaviour at a site has been achieved through relatively intensive monitoring and the use of an Environmental Health and Safety Survey, a reduction in sampling frequency may be justifiable and can help ease the burden of monitoring .

  24. Microbial Water Sampling When sampling cont’d: • Thus, if it can be determined that a recreational water area is of consistently good microbiological quality and is not considered to present a significant risk to the health and safety of its users, monitoring may be reduced to a frequency sufficient to verify that the conditions have not deteriorated.

  25. Microbial Water Sampling When sampling cont’d: • It may also be acceptable to reduce monitoring frequencies for recreational water areas that consistently demonstrate poor water quality results, but only where appropriate management actions are taken to discourage recreational use, and provided that the risks are clearly communicated to the public.

  26. EO 011.05 Recreational Water Sampling TP11

  27. Recreational Water Sampling When collecting sampling from Tanks, Pools, Lakes, and streams: • Remove stopper • plunge bottle mouth down, at least three inches below surface • Fill bottle, tipping it away from hand so water which has contacted hand does not enter the bottle` • Discard a quarter of the water and replace stopper

  28. Recreational Water Sampling Sampling from Swimming Pools Collect two samples: • one at side of pool near deeper end • one near the shallow end • Take samples while pool is in use, preferably during the heaviest bathing load. • Use bottle containing sodium thiosulphate.

  29. Recreational Water Sampling Lakes & Ponds • collect sample from a boat or pier about 25 feet from shore and preferably in water at least four feet deep. • Do not collect sample at shore. • Collect stream sample at point where water is flowing , not from stagnant pools. • In a meandering stream, collect sample at a point where flow velocity is normal.

  30. Questions?

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