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New Hampshire Department of Environmental Services

Frequently Asked Questions

Bacteria Sampling Guidance

This guidance is for water system operators and sampling agents with specific questions on Total Coliform Rule (TCR) sampling, and does NOT list the many other requirements required by these rules. The TCR program is commonly referred to as the bacteria program. Please refer to the additional information links and contacts at the end of this fact sheet for other questions and compliance requirements.

  • What are the components of the bacteria monitoring schedule?
    The Master Sampling Schedule (MSS) contains an up-to-date bacteria schedule and can be found at NHDES OneStop Data. It will list your routine sampling location(s) and the frequency of routine bacteria sampling required for your system.
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  • What Analysis Request Forms should I use and how are they filled out?

    The Master Sampling Schedule contains links to all sampling forms for the water system. Many of the fields are pre-populated with the information we have in our database to ensure the correct information is submitted with the results.

    • The TCR Routine Analysis Request Form should be used for routine samples.
    • The TCR Repeat Form should be used for repeat samples after a positive bacteria result.
    • The GWR-Triggered Monitoring Form should be used for source samples after a positive bacteria result.
    • The General System Evaluation Sample (GSES) Form should be used for samples taken for treatment evaluation or any other samples used for general evaluation.

    Be sure to fill out the forms completely and accurately. Select the sample category, print the sample month and name of person who took sample(s). Sample sites should match those found on the Master Sampling Schedule and the date and time samples are taken must be listed.

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  • How do I change my bacteria sampling site?
    You should always submit a site change request BEFORE you take your routine bacteria sample(s). This will ensure that DWGB has the newly updated sampling site in our database and will be able to accept the sampling results. You may submit a site change request form found on our website (Sample Site Change Request FormMicrosoft Word Symbol). DWGB will review the requested site change and notify you when the change has been made.
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  • Why did I receive a reminder email?
    If you are an Owner, Operator or Primary Contact with an email address in our database you will receive an email notification in the middle of your scheduled sampling period as a reminder to collect your samples. If you have already sampled, please check with the DWGB regarding the status of the sampling results.
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  • How do I apply for a reduction in bacteria sampling?
    If your system has been placed on increased monitoring for bacteria and you have not installed disinfection or any other forms of bacteria treatment, you may request a sampling reduction by contacting our office in writing. The DWGB will review your request and will contact you in writing of the decision.
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  • How can I get sample bottles? Can they be mailed?
    You can order sample bottles on line at the One Stop site or phone the state laboratory at 271-3445. You can also query the accredited laboratories to find out which labs are accredited to analyze the samples you are required to take. Links for these two websites can be found at the bottom of this FAQ page.
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  • If results of my bacteria samples are positive for total coliform what must I do?
    Within 24 hours of receiving notice of a positive total coliform sample result, and prior to disinfecting the system, submit a set of three repeat samples for each positive sample. Systems that take samples on a quarterly schedule must submit three additional routine samples the following month. A letter containing detailed instructions is mailed to the water system immediately after NHDES receives the results from the laboratory.
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  • Where should I take my repeat samples?
    Repeat samples should be taken from the following sites:
    1. Sample location where the bacteria hit occurred.
    2. Within 5 service connections upstream of the hit site.
    3. Within 5 service connections downstream of the hit site.
    4. Groundwater source samples MUST be collected from each active source to be in compliance with the Groundwater Rule.
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  • What is an MCL?
    MCL stands for Maximum Contaminant Level. MCLs are health based standards and are the maximum permissible levels of contaminants which can be present in the water delivered to any customer of a public water system.
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  • When/Why do I have to boil my water?
    Boil Water Orders are issued when fecal contamination is found in water samples or when there is a significant loss of water pressure in the distribution system, typically as a result of power outages or water line failure. Boiling the water will kill most disease-causing organisms that may be present.
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  • I received a Boil Order Notice. What can the water be used for?

    Please see the following table for guidelines on water use during a Boil Order:

    Use Yes / No
    Drinking No
    Ice cubes No
    Brushing teeth No
    Baby's formula No
    Washing fruit/vegetables* No*
    Preparing food No
    Coffee, tea, lemonade, soda dispensers and coffee No
    Laundry Yes
    Watering grass or garden* Yes
    Washing hands see fact sheet
    Showers or baths see fact sheet
    Washing dishes see fact sheet

    *Note: fruits/vegetables must be washed using pre-boiled or bottled water before consumption For more details please see the DWGB fact sheet on Boil Order FAQs by using the link at the bottom of the page.

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  • Why do I have to provide Public Notice to the water system customers?
    Public Notification provides a mechanism for public water systems to keep their customers informed of drinking water violations or situations that may affect public health and is required by both Federal and State regulations.
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  • How do I provide Public Notice to the water system customers?
    • Each public notice form contains directions about how to issue the notice. If using the public notice template provided by DWGB, be sure to fill out each section completely, including the Certification page. The notice must be distributed according to the type of system you serve and both pages must be submitted to DWGB.
    • All public notice templates can be found on the Public Notice Forms page of our website. The information that you will need in order to properly fill out the forms can be found in your records, on the recent letter that you received, or you can contact the person that sent you the letter to aid you in the process of filling out the entire notice completely and correctly.
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  • We have taken compliance samples after our scheduled compliance period ended. Do we still need to provide public notice to the water system customers?
    Yes. The public notice will tell your customers that the system failed to sample within the designated compliance period. The notice will also tell customers the date that you sampled on.
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NH Department of Environmental Services | 29 Hazen Drive | PO Box 95 | Concord, NH 03302-0095
(603) 271-3503 | TDD Access: Relay NH 1-800-735-2964 | Hours: M-F, 8am-4pm

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