Regen Media Filter & Filter Media Task Group Update

Current Issue Papers August 2008, Steve Andrews – Gapping of Elements and Use of Multiplier Could Lead to Bridging within Filter Design August 2011, Sung Choe – Precoat Filter Media Characteristics Can Adversely Effect Both Short Term and Long Term Filter Performance December 2011, Tom Vyles – Standard Change to Allow for Incidental Bridging within Tubular Precoat Filters, September 2012, Tom Vyles – Proposed Standard Change Balloted at 2012 Joint Committee Meeting and Failed to Pass September 2016, Steve Andrews - Proposed Change to Performance Based Standard Presented at 2016 Joint Committee Meeting

2016 Joint Committee Meeting Summary Excerpt Filter Media/Regenerative Filters – Steve Andrews Action: Lauren to distribute presentation/PDF to Joint Committee as this was a late submission (not included in meeting packet). Steve gave a detailed presentation on some issues related to filters. There was discussion following the presentation with a question regarding what the task group is asking the JC to do? The recommendation is that the standard needs to be changed; related to bridging. No solid data that supports there is no long term impact except for statements made by manufacturers; No validation testing done by NSF at this time. Performance criteria there, manufacturers to determine how they will operate filter to meet them. Cleanability needs to be verified over full length of elements, not just over 6 inch window. Tom opened the floor for a motion to charge the RWF Task Group on Filter Media with development of performance based standard and the required edits to standard 50. Action: Lauren to change the name of the task group to RWF Task Group on Filters in the NSF online workspace. Motion- Suzie Campbell (to charge RWF Task Group on Filter Media with development of performance based standard and the required edits to standard 50) Second- Alison Osinski Discussion- Alan Levin: What is the committee being asked to do? Alison: Don’t want to stifle innovative design because something doesn’t meet specific design criteria. Agree with direction for this committee as proposed. Crash: Particle size testing/turbidity reduction is a good idea, will these be included in testing process to define the micron of the material? Ron George: Yes have particle counters on inlets/outlets that can be set. Set for a range and count everything within that range. Crash: Can you incorporate a check valve there? Vote- All affirmative Outcome- Motion passes

Joint Committee Acceptance Allow Performance Based Testing Expansion of performance based testing criteria Allow for introduction of new technology without standards change

Current Performance Testing Required Physical Evaluation applicable to all filters Pressure Head Loss sand filter bed measures for flatness Regen Media Filter Cake consistency and stability not evaluated Filter Media Cleanability Turbidity Reduction Applicable to all filters Precoat Behavior precoating in a closed loop exempt from this test.

Regen Media Filter Critical Points of Testing Filter media behavior Confirmation of stable filter cake formation Initial Precoat and after each bump cycle Filter cleanability Regen Media Filter bump cycle Regen Media Filter cleanability inspection Finer filtration Micron removability easily confirmed Water savings Dirt retention capability vs. sand filters Water consumption when cleaning filter vs. sand filters

Simple Solution 5.2 Diatomite and other precoat media-type filters The requirements in this subsection apply only to pre-coat media-type filters utilizing diatomite or other pre-coat filter media (that conforms to 5.2.9) and their integral components designed for the filtration of swimming pool or spa/hot tub water. The design guide lines listed are meant for reference with some variance in operation such as reuse of filter media with a bump cycle and bridging of filter media during the filter cycle will be allowed. Filters seeking an operational variance shall be operated in accordance with the manufacture’s stated procedures while complying with all performance evaluation standards including filter media behavior before and after bumping as well as filter cleanability during media removal. The filter manufacturer shall provide product samples that allow for complete physical evaluation during all cycles of operation. Any claims of filter performance such as but not limited to finer filtration or water savings shall be validated during performance testing. Any reduction of filter cake stability that could result in an uncoated element active surface area during the precoat or filter cycle shall require immediate bumping or media replacement depending the status of filter operation.

Conclusion Allows Variance to Filter Operation Through Expansion of performance based testing criteria Allows for introduction of new technology without standards change Solves Regen Media Filter bridging issue now outstanding for 9 years