Chlorine Residual Measuring Video Transcript
Presented by the North Dakota Department of Environmental Health Municipal Facilities Division.
Follow the manufacturer’s recommendation for your chlorine meter.
Today we are going to cover the operation of the Hach Pocket Colorimeter II chlorine meter and the procedure for measuring total chlorine residuals in your water distribution system.
I will be using the EPA compliant Hach meter 58700-00 for the demonstration.
These chlorine residuals are to be taken in your distribution system at the same locations and at the same time as all compliance bacteria sampling, whether routine samples, repeat samples, or replacement bacteria samples.
With any special purpose bacteria sampling, the chlorine residual is not reported to the state. Only report compliance sampling and testing.
This is the meter itself, taking most of the components out-of-the-box. We have the operations or instructional manual. We have the packets containing the testing reagents.
This is your DPD reagent that is used for each particular vial to test for total chlorine.
We have two one inch round plastic sample vials that are used with the chlorine meter high range and we have two one inch round glass vials that are used with chlorine residual low range.
Also, you should be carrying a small notebook or some type of a log sheet to record all of your data as you are doing the testing.
This is the colorimeter itself. It has a removable lid exposing the sample port for each time you do your testing.
Some of the points that I want to demonstrate here are some of the functional buttons.
We have an on off switch: lower black button. The upper black button is a menu selection button.
This is the button that allows you to toggle between the low and the high range.
We have a blue button, this is your zero button. This is used each time you have to zero off the machine prior to doing a test and the green button is your read button that is used to get your final reading when you are doing your chlorine residual test.
On-screen: HACH Meter Ranges Model 58700-00.
Low Range (LR): 0.02 to 2.00 mg/L. Use if residual is well below 2.00 mg/L.
High Range (HR): 0.1 to 8.0 mg/L. Use if residual is near or above 2.00 mg/L.
Common for systems using chloramines.
Switch to high range (HR) if you get a blinking 2.20.
Arriving at your sampling location, the first thing you want to do is remove any aerator devices that are on the sink tap.
You always want to start using cold water. Cold water should be used in all of the sampling that you conduct in your system.
We are now going to collect our water sample.
The first thing you want to remember is that you want to go to an approved sampling location and these locations are approved by the state and are part of your bacteria sampling site plan.
Once you get to your sampling location, you want to start the water running and
you should run the water for at least 5 minutes in order to get a representative sample and to ensure that you're getting a good chlorine residual.
While the water is running, you now want to get your colorimeter ready by determining what ranges you're going to be working in.
The first thing you want to do is turn your colorimeter on.
Going to the top black button, your menu select button.
You will select that button and you can now toggle using the green button between either the high range or the low range.
There will be a small arrow either in the upper left hand corner for the low range or a small arrow in the upper right corner for the high range.
Again as you move back and forth to determine your ranges.
Once you've determined the range, you can hit the menu select button again
and the arrow will become stationary either in the high range or in the low range.
Today we will be working in the high range.
Once you have a workable stream of water, you want to fill the low range glass
vials up to the 10ML line.
If you are using the high range on your meter,
you will want to use the plastic vials and you will fill those up to the 5ML line.
Once you have collected your sample, you want to now put the cap on the
sampling vial.
You want to wipe off any excess water or fingerprints that are on the sampling vial and getting your meter ready.
First of all, you want to turn the meter on.
Again, we will be working in the high range.
The upper right hand corner is our indicator to set the baseline.
You always zero your machine out using your sample only without any reagent
added to it.
Place the sampling vial into the sample port.
The bar indicator should be facing the display cover.
Hit the blue button to zero the machine.
It should now be reading 0. Zero in the high range.
After zeroing the colorimeter.
You will now add the reagent pillows to your water sample.
You want to make sure that you are using the total chlorine reagent pillows.
You always want to check the expiration date on these pillows.
You will be adding either 210ML sample pillows to your sample or 125ML sample packet to your pillow.
You want to be careful not to spill any of the reagent itself outside of the vial.
Once you've added the reagent, just gently swirl for about 20 seconds, and a pink color is a very good indicator for the presence of chlorine.
In reading your chlorine residual, you place the plastic vial into the sample port.
Again, the bar indicator should be facing the display.
Cover the sample and you will now hit the green button to get your final reading.
Again, you should wait for full color
development up to 3 to 6 minutes.
Hint: Use the timer on your smart phone to make sure that you are running the water for 5 minutes and the total chlorine sample is measured 3 to 6 minutes after adding the reagent (HACH METERS). Review your owners manual to determine the correct amount of time to wait before measuring the sample.
After you have obtained A chlorine residual result,
you always want to maintain a notebook or a log sheet for recording this
information.
You want to include sampler name, the date you took the sample,
the sampling site location, and the result that you got.
This information will be very valuable when you go back and try to report this
information to the state at the end of each quarter.
Now you can take your bacteria sample.
ATTENTION !!! Chlorine residual testing and bacteria sampling is conducted at an approved sampling location based on your system’s bacteria sampling site plan. Samples must be analyzed for total chlorine residual immediately on site. You want to test your total chlorine residual first... followed by your bacteria sampling !!
Data Reporting: Report chlorine residuals quarterly to the state. Data is retrieved from the notebook you have maintained for recording each compliance chlorine residual: Routine compliance samples, Repeat compliance samples, Replacement compliance samples. Print a copy for your system records. Print a copy to mail to the state.
The next step is the compliance reporting requirement.
Systems need to report their chlorine residuals to the state at the end of each
quarter.
There are currently 2 methods of reporting this data.
One method is the Electronic Reporting Information System, also known as ERIS. his is a completely paperless method and if your system is interested in learning more about ERIS, please contact the Drinking Water Program.
The other method is using the newly developed Bar coded Summary form, which is located on the North Dakota Department of Health's website.
In a few moments I will be demonstrating how this form needs to be completely and correctly filled out.
Our required fields for completing the quarterly summary form are public water
system name, public water system number, The type of water system this refers to your source water.
Are you a groundwater system or a surface water system?
Population of your system.
Type of disinfectant used.
Is your water treated with chlorine only, or are you receiving and producing water
that is a chloramine, which is chlorine plus added ammonia?
Select the appropriate box operator name.
This can be completed by the person filling out the form or the responsible
party for your system.
Next, you want to fill in the reporting year
followed by the appropriate reporting quarter.
Selecting the quarter.
The months for the quarter will automatically populate on the form.
You want to complete Section 1 by filling in the option, which is total chlorine.
Next you will refer to your notebook where you have maintained a monthly
record of all the compliance samples you've taken and fill in the total number
of samples for each particular month.
Now this total should include all routine, repeat and replacement compliance samples.
You then report and calculate the monthly average and as you are putting in these
monthly averages, the form is automatically calculating the
quarterly average for you.
The unique feature of this form is the bar code itself.
All of the information that you have inputted is being encrypted within this bar code.
Using this form has been very good as far as accuracy and efficiency in processing data.
Once the drinking water program receives a form, the bar code is simply scanned and the data is processed into our database.
If you should have any questions regarding chlorine residual testing or chlorine residual reporting, please contact the Drinking Water Program.
Following proper sample collection procedures can lead to Peace of Mind knowing that the test results are truly representative of what your water quality is like and what your customers are drinking.
After all, isn't it our goal to achieve good, safe drinking water?
