AWWA C655:2018 pdf download.Field Dechlorination
4.2.2.5 Discharge into storm sewers. Discharging chlorinated water into storm sewers may be an effective way to dissipate chlorine from some potable water releases. Storm sewers are usually discharged directly into receiving wetlands or streams bearing aquatic life, and the sewers may not have adequate dechlorinating capacity to complete dechlorination before release into such wetlands or streams. The discharged chlorinated water must be tested upstream of the receiving waters to confirm removal of chlorine.
4.2.2.6 Discharge to sanitary sewers. The release of chlorinated water into sanitary sewers is a very safe and effective means of disposing of chlorinated waters in most cases. Most utilities prefer this method as their first option for releasing chlorinated potable waters and prefer to discharge superchlorinated water into sanitary sewers. However, this requires close coordination with sanitation district officials to minimize any adverse impact to the wastewater treatment plant operations. The availability of a sanitary sewer near the point of chlorinated water release and the capacities of the sanitary sewer and the wastewater treatment plant to handle the additional load are the primary limitations in this method. Permission and coordination must also be obtained before releasing chlorinated water into sanitary sewers. Caution must be exercised in avoiding potential cross-connection during discharge to sanitary sewers. A backflow prevention device or an air gap method must be used to prevent cross-connection problems.
4.2.3 Chemical dechlorination. Chemical dechlorination is a faster and more predictable method of dechlorination and can be accomplished with little or no effect on the environment or personal safety. Solid, liquid, and gaseous dechlorination chemicals are commercially available and are widely used. The reactions of these chemicals with free and combined chlorine and descriptions of related water quality, ease of use, and other issues related to the application of these chemicals are presented in this section.
4.2.3.1 Safety data sheet (SDS). Regarding health and safety, the chemicals used for dechlorination can cause skin, eye, nose, throat, and lung irritation. The purchaser should refer to the corresponding safety data sheet for information and procedures on the proper handling of these chemicals.AWWA C655 pdf download.