Certified by the State of Colorado to Analyze Potable Drinking Water Samples for Total Coliforms & E. coli
Non Compliance Testing
Public Water Systems
Murray-Brown Laboratories maintains certification by the State of Colorado Department of Public Health and Environment (CDPHE) to analyze public drinking water compliance samples for total coliforms & E. coli by the Colisure Method (SM 9223 B) which are collected and submitted by Public Water Systems (PWS) in their efforts to satisfy the requirements of the Total Coliform Rule (TCR) under the Safe Drinking Water Act (SDWA).
The purpose of the TCR is to monitor for the presence of microbes, specifically coliform bacteria, and to determine whether the drinking water in the distribution system of a PWS is potentially contaminated with pathogens.
The purpose is to test the water distribution system NOT the plumbing of an individual building.
Therefore, all precautions should be taken to eliminate collecting a sample which may yield a positive result due to the potential for contamination some faucets have (see FAQ 2).
Production Facilities or Home Owners
In the world of food preparation, water isn’t just for drinking. It’s added to recipes, sprayed on facility equipment, and used to wash employee hands. The water from your pipes will touch nearly every surface in your production room – which means it needs to be as clean and safe as possible.
Because of this manufacturers of goods should perform regular tests on the water in their facility to check for the presence (or more desirably, the absence) of total coliforms and E. coli in their facility’s water source in order to assess the quality of water coming into contact with foods and/or goods produced.
Home owners or others may also desire to assess the quality of their water which may come into contact with humans in various ways.
Samples being collected from a production facility or home to assess water which may be directly consumed by humans, or come into contact with goods destined for human consumption, must be collected from a representative tap which supplies such water, no matter its condition.
Ingestion of pathogens in drinking water may result in gastroenteritis, hepatitis, myocarditis, paralysis, acute hemorrhagic conjunctivitis, meningitis, and/or other negative health impacts.
The presence of either of the pathogenic-indicating organisms otal coliforms or generic E. coli demands that an investigation promptly ensues to determine how the contamination occurred, followed by action taken to correct the fault in the water system, followed by resampling to verify the action taken has been effective.
We are here to help with sample collection, analysis, and result interpretation.
MBL is qualified to collecting drinking water samples for both compliance and non-compliance purposes which are to be analyzed for total coliforms and E. coli.
Upon request and by appointment, MBL can collect drinking water samples if you so desire.
If you are a Public Water System, you must provide the exact sample location according to your Monitoring Plan, including the Site Name and Site Address.
Please contact us to discuss the price and availability of this service.
If you desire, you may collect your own drinking water sample; we can supply all the materials are instructions for doing so.
Obtain a Drinking Water Sample Collection Kit from Murray-Brown Laboratories containing:
- collection bottle, sample label, sterile sample bag, gloves
- PDF MBL Drinking Water Sample Collection Instructions
- PDF MBL Drinking Water Sample Submission Form
Record the following information in your on-site sample log book and on the MBL Drinking Water Sample Submission Form:
- Name of system (PWS site identification number, if available)
- Unique Sample Identification (if any, as indicated on the PWS Monitoring Plan, i.e. “Bathroom Sink”)
- Sample Site Location (including physical address)
- Sample type (i.e. Routine Compliance, Repeat Compliance, or Special Purpose Non-Compliance)
- Date and time of collection
- Analysis requested
- Disinfectant residual, if applicable (samples for compliance purposes)
- Name of sampler
- Any remarks
Following the Sample Collection Instructions, aseptically collect and transport the sample.
Selecting what faucet, including its type, location, and the water source which feeds it, to collect a water sample from depends upon why the sample is being collected.
- If the sample is being collected for compliance purposes under the Total Coliform Rule, then the purpose is to test the water distribution system NOT the plumbing of an individual building. Therefore, all precautions should be taken to eliminate collecting a sample which may yield a positive result due to the potential for contamination some sampling sites have by selecting a Low Contamination Risk Faucet (see blue box below).
- If, however, the sample is being collected for non-compliance purposes from a production facility or home to assess water which may be directly consumed by humans, or come into contact with goods destined for human consumption, then the sample must be collected from a representative tap which supplies such water, no matter its condition. If such testing does reveal the presence of coliforms and/or E. coli, it would be appropriate to conduct an investigation to determine the cause, develop, and implement appropriate corrective action, and follow up with repeat samples to confirm the success or failure of the corrective action taken.
Faucet Selection for Samples Collected for Compliance Purposes
The TCR requires each small community drinking water system to sample for coliforms according to a written plan, (PWS Monitoring Plan) which must be made available to the CDPHE. Having a written sample collection protocol helps ensure that all sampling is done correctly, even when assignments of water system personnel change.
The plan specifies where in the distribution system routine samples will be drawn in order to ensure that they are “representative” of the water supplied to every customer. Representative samples that accurately reflect the quality of the finished water are crucial because, if coliforms are in the water supply, they may not be found uniformly throughout the distribution system. The sampling plan also designates repeat sampling sites to be used if a sample drawn from a routine sampling point tests positive for coliforms. The purpose of sampling is not to draw “clean” samples, but to identify any coliform contamination so it can be dealt with promptly. Because of this, it is important to identify dead ends and trouble spots in the distribution system for sampling locations.
When defining the Plan, sampling site locations, including specific faucets, which, according to their location or condition, have a high potential for contamination should be avoided as they may result in a positive result that is not truly representative of the water quality in the distribution system:
Low Contamination Risk Faucet
Water taps used for sampling should be free of aerators, strainers, hose attachments, mixing type faucets, purification devices, and should be in good repair (no leaks). Avoid collecting samples from kitchen or utility sinks with swing arm necks, or from swivel-type faucets that have a single valve for hot and cold water. It is not a good idea to collect water samples from: new plumbing & fixtures or those repaired recently; outside taps or hoses, faucets that have leaky packing material around the stem; faucets that supply areas, such as janitorial or commercial sinks, where bacterial contamination is likely; faucets close to or below ground level; faucets that point upward; faucets that have treads on the inside of their spouts; faucets connected to cisterns, softeners, pumps or pressure tanks.
Sample Collection Requirements from EPA Manual for the Certification of Laboratories Analyzing Drinking Water: