1. Total Coliform Rule (TCR)

2. General
The purpose of the TCR is to protect the water system from microbial contamination
TCR requires the water system to monitor for total and fecal coliform bacteria.
TCR applies to all community and non-community water systems

3. What is a coliform?
A group of bacteria that include both pathogenic and non-pathogen species
Gram negative, spore-forming rod shaped bacteria that ferments lactose at 35oC
Indicator organism
Always present in fecal contamination
More persistent in water than pathogenic bacteria

4. Definitions Bacteria Coliform Bacteria Pathogenic Bacteria
Fecal Coliform / E. coli
Pathogenic Bacteria
Routine Sample
Repeat Sample
Replacement Sample
Other Sample

5. TCR Test Methods Test volume is at least 100 mL
Test results are reported as either “Present” or “Absent” per 100 mL sample
Bacterial enumeration (counting) is not required

6. TCR Approved Test Methods

7. Who can take TCR samples?
Certified water treatment / distribution operators
Persons trained to collect samples by DHS / LPA
A certified laboratory technician

8. TCR Requirements:
Develop a sample siting plan (update at least every 10 years)
Collect routine, repeat and replacement samples as required by TCR for your water system
Notify DHS or your LPA (County Health Department) when there is an increase in coliform bacteria
Comply with the total coliform MCL

9. Other Coliform Sampling:
In addition to following your sample siting plan, take additional bacteriological analyses when:
After construction or repair of wells (following disinfection, but before return to service
After main installation or repair
After construction or repair of storage facilities
Whenever system pressure drops below 5 psi
These special samples are not used to compute MCL compliance

10. TCR Sample Siting Plan Location of routine samples
Chose sites that are representative of the distribution system including:
All pressure zones
Each water source
Each distribution reservoir
Sites should be rotated if representative sites exceeds the number of samples taken each month.

11. Sample Siting Plans
It is strongly recommended that locations repeat sample sites be included in the sample siting plan

12. Tips for Selecting the Best Sample Sites
Accessible
Above “big dog” height or otherwise protected
Consider dedicated sample taps
No leaking valves or packings
Good flow control
No bushes or vegetation
Can be flamed or cleaned
Can be flushed vigorously without causing problems with the homeowner

13. Repeat Sample Site Selection
1st Repeat site is the original location
Site 2 & 3 must be within 5 service connections upstream and 5 service connections downstream (further from source)
Chose repeat sites using the same criteria as routine sites
System taking less than 5 routine samples per month must take a 4th repeat sample at a location acceptable to DHS/LPA

14. Routine Sampling
Number of routine samples/month determined by system size
Minimum frequency of sampling is one per month for small systems (25 to 1000 population
Samples shall be collected at regular intervals throughout the month

15. Repeat Samples
When any routine, repeat or replacement sample is total coliform positive the water system shall:
Collect a repeat sample set within 24 hours of being informed of the positive sample
Repeat sample set is required for each positive routine, repeat or replacement sample

16. Repeat Sample Set Three samples (small systems take 4 repeat samples)
One sample from the original total coliform sample location
Other repeat samples shall be taken within five service connections upstream or downstream of original location.

17. Significant Rise in Bacterial Count
Significant rise in bacterial count occurs when :
System has a positive for fecal or E.coli
System fails the total coliform MCL

18. Significant Rise in Bacterial Count
When a system has a significant rise in bacterial count it must:
Contact DHS/LPA by the end of the day (no later than 24 hours)
Submit a review of water system conditions that could contribute or cause the problem
Implement emergency notification plan as directed by DHS/LPA

19. Total Coliform MCL
All routine, repeat and replacement samples taken in a calendar month are used to calculate MCL compliance
Special samples (after maintenance samples) are not used to determine MCL compliance
Special samples must be properly labled

20. Acute Coliform MCL An Acute MCL violation occurs when:
Any repeat sample is fecal coliform / E.coli positive, or
Any repeat sample following a routine fecal positive is total coliform positive

21. Total Coliform MCL
Systems in violation of the Total Coliform MCL shall:
Notify DHS/LPA within 24 hours
Notify consumers of water system