Why is the H2O Neutralizer® the right product for all your
Field Dechlorination needs…
If you have been around the utility industry for any length of time you are probably seeing that field chlorination and NOW field dechlorination is changing the way you build your waterline projects.
When in Canada training contractors and utilities the other week due to a sale increases because issues with highly (super) chlorinated water discharges, that were not dechlorinated and caused property damage to many home owners.
The utility thought that they were doing the right process by having the contractors discharge the highly chlorinated water into the sanitary sewer system, seemed like a good idea at the time. But as the utility found out trying to cut corners can lead to big time problems and cost. The super chlorinated water flooded a lift station and shut down the pumps, the super chlorinated water then backed up into home owners basements. It’s bad enough to have sewage come into your basement but to have super chlorinated water as well, insures that damaged is caused.
You need to ask yourself, if we are allowing this practice will we be the next to pay for property damage because of our procedures? Or is the method that we are specifying the correct methods for the application? It seems like a good idea to have the super or even potable water placed into the sewer system as we all know that sewage will consume the chlorine, yes BUT, your wastewater treatment plant may not want additional clean water entering the plant as it only increases the treatment cost or harms the secondary treatment process and you may have a problem with lift stations that would cause problems for the home owners. The right way is to dechlorinate the water and discharge the water into the storm sewer system.
As owner (utility) of the project your specifications for new construction should take all field conditions into consideration.
- The proper dechlorination methods allowed to be used by the contractor. Dechlorination equipment is not the same for potable (low chlorinated water) water vs. super (highly chlorinated water) chlorinated water. Tablet style device are designed for potable water NOT super chlorinated water the reason is the binder in the tablet slows the dissolve rate of the tablet.
- Not all methods are equal, the C-655 standard lists 4 category’s of chemical method of field dechlorination:
- Drip-Style systems, mixes chemical with discharge flow in a mixing zone after you have lost control of the water. This method is best suited for potable water discharge, under 4 ppm.
- Passive devices that require discharge water make contact with dechlorination chemical (this type of device normally uses tablet form chemical for dechlorination). Tablet chemicals should only be used for low chlorinate water.
- Injection pumps are used to introduce dechlorination solution into the discharge flow and require additional mixing zone; however, if designed properly, it can handle highly chlorinated water.
- Vacuum-induced (drawing the solution into the device by means of a vacuum created within the device). These devices control dechlorination chemical entering the main flow of discharge water, has the widest performance range and can handle the highest levels of chlorine residual.
Because there is no standard for equipment the specifier’s specifications should make sure that chosen method will handle the chlorine residual level that needs to be neutralized.
- Proper dechlorination chemical allowed to be used by the contractor. There are many chemicals listed in the standard that will neutralize chlorine however, only two chemicals are safe for neutralizing chlorine in the environment and out of the these two chemical only one should be used for super chlorinated water.
- Determine how the water will be released into the environment or storm/sanitary sewer systems. You may have flow limitations that will affect either method of discharge.
As owner of the project you have to make sure that your contractors who are performing work on your behalf are following the requirements of all Federal, State and local requirements. If you are specifying methods and chemical make sure you have specified the correct equipment as you will sharing responsibility if any harm comes to the environment.
Robert J. Gordhamer
Measurement Technologies, Inc.