(SW exceeded; (SW Inadequate Inadequate flowmeters filtration filtration and flow design restrictors or design or should be (Bags (Bags operation operation and and installed as needed if the In Adequate order to filters are not ensure microbial 99% Does designed for the Has removal removal of the the maximum flow requires that a PWS from the intake cartridge system as required pumps. keep filter by not the be used Long at daily or Pressure gauges conditions Term 1 should be Enhanced exceeding its of installed up and design Surface Water downstream of filter specifications Treatment Rule, the cartridges to the (flow final rate, inlet the allow daily pressure cartridge and filter monitoring and been must pressure be one drop), to recording of and two that micron the drop pressure drops absolute cartridge pore be across to and to trigger size, properly unless the the filter change installed in the manufacturer outs when filters, at can housing provide for and least manufacturer’s which challenge it was limits are close know 99.9% testing designed. results of when to being In showing order to 99.9% to reached. ensure that removal of these conditions out are met, the or a surrogate or of differential the same pressure size. According across to the the filter bags size should manufacturer, be monitored and the bag filter or recorded currently daily being have a and the filters used as the final 1 or 2 should filtration be barrier changed has not been out when certified the for manufacturer’s limits are close removal. The pore to PWS being should size reached. provide The system documentation is currently indicating not that monitoring and the existing / filter or recording meets the these values on above a requirements, daily basis. or use a different filter that does
exceeded; flowmeters and flow restrictors should be installed as needed if the filters are not designed for the maximum flow from the intake pumps. Pressure gauges should be installed up and downstream of the cartridges to allow daily monitoring and recording of pressure drops and to trigger filter change outs when manufacturer’s limits are close to being reached. (SW (Bags and Does the PWS keep daily of the drop across the filters, and know when to out Inadequate filtration design or operation Adequate microbial removal requires that a cartridge system not be used at conditions exceeding its design specifications (flow rate, inlet pressure and pressure drop), and that the cartridge be properly installed in the housing for which it was designed. In order to ensure that these conditions are met, the differential pressure across the filter bags should be monitored and recorded daily and the filters should be changed out when the manufacturer’s limits are close to being reached. The system is currently not monitoring and / or recording these values on a daily basis. (SW (Bags and Has the filter or filter been to at least 99.9% of or size or have a 1 or 2 pore size Inadequate filtration design or operation In order to ensure 99% removal of as required by the Long Term 1 Enhanced Surface Water Treatment Rule, the final cartridge filter must be one to two micron absolute pore size, unless the manufacturer can provide challenge testing results showing 99.9% removal of or a surrogate of the same size. According to the manufacturer, the bag filter currently being used as the final filtration barrier has not been certified for removal. The PWS should provide documentation indicating that the existing filter meets the above requirements, or use a different filter that does
ss_tribal_form.docx