Knowing the Chlorination Standard –
New Updates Change the Game for Contractors
With another construction season closing in on winter, now is a good time to take another look at AWWA’s C651 Field Chlorination Standard. Now at first you might think to yourself, “we know the standard, we have been installing water lines for X number of years.” Yes, that may be true however the times are a changing, as once stated in a popular song. And what is changing most in how you build systems is how you prepare them to be turned over to be put into service.
The key change will be in how you chlorinate the system before turning it over. Many of you have been loading the pipeline with calcium hypochlorite during construction, filling the line, pressure testing the line and then discharging the water at the end. You would normally over load the pipe with CalHypo to purify the line because it had dirt in the line that was not flushed prior to chlorination. In the old days before dechlorination was required this was the norm. With the increase in flushing rates set out in the newest update to the standard and the requirement of dechlorination of water discharged, this practice is being limited if not eliminated completely.
Reasons for Changing Your Methods
There are a few reasons for you to change your method of chlorination. First the updated standard now recommends high volume flushing before chlorination. Most equipment will not handle high volume flows at super chlorinated levels and still neutralize the chlorine being discharged. One piece of equipment, the 3M H2O Neutralizer, will handle flows of 1200+ GPM at 50 PPM and using No-Chlor CTS and still neutralize the chlorine. However, we are the only manufacturer that can legitimately claim this level of performance.
though the H2 H2O Neutralizer
handles this flow rate and CRL, is it still wise to keep installing your pipe
line using the method of loading the line during construction? The CLEAR ANSWER
because if you have a line failure during your pressure test you are in a world
of hurt with the high CRL of water that gets released. I will give you a real
life example, though the names have been changed to protect the innocent, the
facts are true and very painful.
What Can Go Wrong
A contractor in Northern California recently installed a pipe line with over 800,000 gallons of super chlorinated water, went to pressure test the line and had the line blow apart on them. What happened is that while the job was quoted and written up correctly by the distributor, when it was pulled from the shelves and shipped out to the jobsite, someone in the warehouse pulled the wrong type of pipe restrainers and shipped them out with the order. I remember having similar problems like this back in the 70s when I was running a small distributor operation back in Minnesota. I have heard this happening many more times over the years.
HELL, we have humans working in warehouse and production areas (manufacturing) and they make mistakes, which is why you always need to check your orders. And this applies to the distributor/manufacturer as well as the contractor. It’s important that you check the shipment you receive before installing those parts. It is way cheaper to do so before beginning of work than to dig up the project to repair a pipeline or replace wrong parts discovered to have been installed on the job. Nobody wins with back charges.
How do we know of this project problem? We have had to ship many containers of No-Chlor CTS to this distributor/contractor because the water is super chlorinated. The owner would only allow the contractor to discharge so much water each day until the line is drained and ready to be repaired. Then after all that the contractor has to re-chlorinate the system and once again dechlorinate that same volume of water again and hopefully pass all his B-Tac testing.
Avoiding Problems from the Outset
How do you prevent this from happening on your project? The simple answer is checking every shipment you receive to assure that you receive the proper fittings and connectors. And to be extra sure you are covered if any goes wrong change your chlorination method so if any parts do fail while pressure testing you won’t be caught with dangerously high chlorine levels in the line.
We tried to address this in the newly revised chlorination standard (I sit on the AWWA committee responsible for the standard) by adding the wording in the section ‘General Considerations for All Methods of Chlorination.’ This section states, potable water shall be used for pressure testing and high velocity flushing. It is also stated that high velocity flushing is to be completed prior to disinfection. The reasoning is being that most dechlorination equipment performance ranges are NOT capable of handling such water volume at high CRL needed for cooking the line. It is also covered again in the section ‘Basic Disinfection Procedure for New Mains’ - pressure test, flush than chlorinate.
What You’ll Avoid
By changing your construction procedures to comply with the updated standard you will prevent your crews from having a blow out with super chlorinated water and causing environmental issues that could result in fines and back charges.
How We Fit In
So how does the H2O Neutralizer fit in? We’ll make your life easier out on the jobsite because our equipment can be plumbed to work with any line size and just about any line pressure. With this one answer you can both chlorinate and dechlorinate with the only device in the industry offering the performance range needed to complete both jobs. For chlorinating you can use either sodium or calcium hypochlorite and then dechlorinate using any liquid dechlorination chemical.
Your Best Choice for Chlorination
Does Both Jobs
With the H2O Neutralizer and then chlorinate your system. Then complete your final flush with dechlorination to insure a complete and well done job. Just make sure your injection points for chlorination and discharge points for dechlorination are of the proper size and location. If you have any questions we can help you layout a plan for your chlorination and dechlorination requirements using the H2O Neutralizer.
To learn more about How the Device Works, visit http://www.h2oneutralizer.com/technical-assistance.html