High TVC count in mains water

Hi, we have had a high reading for TVC in our water. The water is mains water, how can this be corrected?

High based on what sampling and test method? Are these methods accredited? What are regulatory limits? In the US, elevated HPC is not a safety limit indicator (per EPA), but less than 500/ml is considered "quality".

Hi Slab, The results were done by an accredited lab, count was TVC >300cg/u which is the upper limit.

I'm trying to figure out how to correct this so further results will be lower.

How is your water sampled? Point of use, office bubbler, ice maker? Have you retested? Have you contacted your water dept to see if there was any negative pressure events on your supply?

I would sample again in the same manner, but perhaps increase number of samples to include various locations (hose bibs, hand washing sink, fill station, etc.)

If the results are high repeatedly then it could be a sanitation issue with equipment (soiled faucet aerator, ice maker float reservoir), maintenance working on plumbing, or a recently formed dead-leg in the system.

Hi, we have had a high reading for TVC in our water. The water is mains water, how can this be corrected?

Simple question - What is the free chlorine level ?

The water was tested at point of use, hand washing stations.

Tests were for Total aerobic colony 22°c & 37°c, coliforms, e.coli, presumptive CL perfringens, enterococci.

all other tests were <1 

The water was tested at point of use, hand washing stations.

 

Tests were for Total aerobic colony 22°c & 37°c, coliforms, e.coli, presumptive CL perfringens, enterococci.

 

all other tests were <1 

Should have checked free chlorine. (Location unknown but guess why it's routinely added in many countries.. )

I deduce the result was based on one sample. Can be meaningless unless there is a history(?).

What is the SOP for sanitizing the sample point prior to collecting the sample? Flaming with a propane torch used to be followed by running for at least a minute before grabbing the sample. 

Checking the free chlorine also sounds like a great idea to me. 

ken