| #Q001 | administrative | unknown | recommended | Implementation guidance source | 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 | corrective_action | health | recommended | Short-term exceedance mitigation plan | drinking water | For drinking water supplies that occasionally experience short-term exceedances above the guideline values, it is suggested that a plan be developed and implemented to address these situations. | For drinking water supplies that occasionally experience short-term exceedances above the guideline values | high |
| #Q003 | corrective_action | health | recommended | Long-term exceedance alternative water sources | drinking water | For more significant, long-term exceedances that cannot be addressed through treatment, it is suggested that alternative sources of water for drinking, showering, and bathing be considered. | For more significant, long-term exceedances that cannot be addressed through treatment | high |
| #Q004 | monitoring | health | recommended | Groundwater source characterization | drinking water | Groundwater sources should be characterized to determine if tetrachloroethylene is present, especially if the land use history is unknown. | Especially if the land use history is unknown | high |
| #Q005 | monitoring | health | recommended | Impacted groundwater quarterly monitoring | drinking water | Quarterly monitoring for tetrachloroethylene should be conducted for groundwater sources that are or may have been impacted by spills or other potential contamination with this compound. | For groundwater sources that are or may have been impacted by spills or other potential contamination with this compound | high |
| #Q006 | monitoring | operational | guidance | Reduced monitoring for remediated sites | drinking water | Authorities may consider reduced monitoring when it has been demonstrated that a previously contaminated site has been successfully remediated. | When it has been demonstrated that a previously contaminated site has been successfully remediated | high |
| #Q007 | design | health | mandatory | Distribution system component standards | drinking water | Although components and coatings for distribution system pipes are now required to meet standards that limit the leaching of contaminants, distribution pipes installed prior to the 1983 may leach tetrachloroethylene if a vinyl-toluene lining was used to rehabilitate the inside of asbestos-cement pipes. | | high |
| #Q008 | monitoring | health | recommended | Old asbestos-cement pipe quarterly monitoring | drinking water | Quarterly monitoring for tetrachloroethylene should be undertaken in the areas of the distribution system where old asbestos-cement pipes with vinyl-toluene lining are located, specifically at locations with the maximum residence time (e.g., dead ends). | In the areas of the distribution system where old asbestos-cement pipes with vinyl-toluene lining are located, specifically at locations with the maximum residence time (e.g., dead ends) | high |
| #Q009 | monitoring | operational | guidance | Less frequent monitoring based on baseline data | drinking water | Utilities that have baseline data indicating that tetrachloroethylene is not present within the distribution system may conduct less frequent monitoring. | If baseline data indicates that tetrachloroethylene is not present within the distribution system | high |
| #Q010 | monitoring | operational | guidance | Reduced sampling with flushing protocol | drinking water | Jurisdictions may consider reduced sampling if an appropriate flushing protocol is in place. | If an appropriate flushing protocol is in place | high |
| #Q011 | corrective_action | health | recommended | Elevated levels response plan | drinking water | In the event that monitoring data show elevated levels of tetrachloroethylene, it is suggested that a plan be developed and implemented to address these situations. | In the event that monitoring data show elevated levels of tetrachloroethylene | high |