| #Q001 | administrative | operational | recommended | Obtain Implementation Guidance | drinking water | Specific guidance related to the implementation of drinking water guidelines should be obtained from the appropriate drinking water authority in the affected jurisdiction. | | high |
| #Q002 | operational | treatment | recommended | Maintain Chlorine to Ammonia Ratio | drinking water | Utilities using ammonia as part of their disinfection strategy should ensure that the appropriate chlorine to ammonia ratio is maintained. | Utilities using ammonia as part of their disinfection strategy | high |
| #Q003 | monitoring | operational | recommended | General Ammonia Monitoring Locations | drinking water | Changes in free ammonia concentrations can be an indication that nitrification is occurring; thus, monitoring should be conducted both at the treatment plant and in the distribution system. | | high |
| #Q004 | monitoring | operational | recommended | Source Water Characterization | drinking water | Utilities should characterize their source water to assess the presence of ammonia and the variability of ammonia levels. | | high |
| #Q005 | monitoring | operational | recommended | Free Ammonia Monitoring in Distribution System | drinking water | Utilities that are chloraminating or that have ammonia in their source water should monitor for free ammonia, in addition to other parameters (e.g., total chlorine residual, nitrite, heterotrophic plate counts), at key locations in the distribution system. | Utilities that are chloraminating or that have ammonia in their source water | high |
| #Q006 | monitoring | operational | recommended | Daily Plant Effluent Monitoring | drinking water | It is recommended that free ammonia be monitored daily in the plant effluent. | | high |
| #Q007 | monitoring | operational | recommended | Weekly Source and Detention Monitoring | drinking water | In addition, it is recommended that source water, locations such as reservoir outlets and areas with long water detention times (e.g., dead ends) be monitored weekly. | | high |
| #Q008 | monitoring | operational | recommended | Triggered Increased Monitoring | drinking water | Changes in the trend of priority nitrification parameters in the distribution system, such as total chlorine residual, nitrite and nitrate, should trigger more frequent monitoring of free ammonia. | When changes in the trend of priority nitrification parameters occur | high |
| #Q009 | monitoring | operational | guidance | Reduced Monitoring Frequency Eligibility | drinking water | Utilities that undertake comprehensive preventive measures and have baseline data indicating that nitrification does not occur in the system may conduct less frequent monitoring of free ammonia. | Utilities that undertake comprehensive preventive measures and have baseline data indicating that nitrification does not occur in the system | high |
| #Q010 | operational | operational | guideline | Limiting Excess Free Ammonia | drinking water | Good operational practices will help prevent nitrification. These practices include limiting excess free ammonia entering the distribution system to concentrations below 0.1 mg/L (measured as ammonia-nitrogen), and preferably below 0.05 mg/L (measured as ammonia-nitrogen). | To prevent nitrification in the distribution system | high |