NSF/ANSI 419: A New National Standard for Membrane Filtration Stefan Buck– NSF International NC AWWA-WEA Annual Conference Raleigh, NC November 16, 2015

NSF = National Sanitation Foundation Founded 1944 University of Michigan Today independent not-for profit Standards Development Food, Water, Public Health Product Certification Food Safety Drinking and Recreational Water Safety

ANSI ANSI = American National Standards Institute ANSI approves Standards NSF/ANSI 61 NSF/ANSI 419 ANSI accredits Certification Organizations

NSF/ANSI Standards Process NSF Joint Committees 30-36 members on each, equal balance of Regulators – EPA, Health Canada, States / Provinces Agencies Users – Utilities, Specifying Engineers Manufacturers Council of Public Health Consultants 25 Regulators/Users ANSI Public Review ANSI approval

NSF/ANSI Standards Public Drinking Water Systems NSF/ANSI 60 – treatment chemicals – health effects NSF/ANSI 61 – system components – health effects NSF/ANSI 419 – filtration performance NSF 420 – UV systems – under development

NSF/ANSI Standards Building Drinking Water Treatment Systems Point-of-Entry(in some cases used for small systems) NSF/ANSI 42 – contaminants w/ aesthetic effects NSF/ANSI 53 – contaminants w/ health effects NSF/ANSI 55 – UV systems NSF/ANSI 44 – residential water softeners Above standards have structural integrity and contaminant reduction tests. All reference NSF 61 for material health effects.

NSF/ANSI Standards Point-of-Use Drinking Water Treatment Systems NSF/ANSI 42 – contaminants w/ aesthetic effects NSF/ANSI 53 – contaminants w/ health effects NSF/ANSI 55 – UV systems NSF/ANSI 58 – RO systems NSF/ANSI 62 – Distillation systems NSF/ANSI 401 – Emerging Contaminants NSF P 231 – Microbiological Purifier

NSF/ANSI 419 Performance Validations and Certifications to support LT2 requirements for : Ultrafiltration Membrane Systems Microfiltration Membrane Systems Cartridge Filters Bag Filters

Transition from NSF EPA ETV NSF Managed US EPA Environmental Technology Verifications (ETV) Drinking Water Systems Center 1995 – 2013. Developed treatment equipment protocols with EPA & US States. One time, site specific, in field testing; Report of performance, operation and maintenance costs. Program ended September 2013 so there was a need to replace ETV with NSF Standards and Certifications.

ETV Protocols Focus on Compliance with the EPA’s LT2 Rules Filtration Ultrafiltration and Microfiltration Nanofiltration / Reverse Osmosis Bag and Cartridge Disinfection UV Chlorinators

Effect of LT2 Requirements Product specific challenge testing (PSCT) of membrane filters, UV disinfection units & Bag/ Cartridge filters. Testing by independent third party. Membranes: Confirming quality controls in place during manufacturing (section 3.2 MFGM). UV Systems Product retesting if modified (sec. 5.13 UVDGM). One time on-site testing is insufficient to address LT2 requirements.

Existing EPA ETV Protocols To Be Replaced by NSF/ ANSI Standards NSF /ANSI 419 (published Jan 2015) from: Generic Protocol for Product Specific Challenge Testing of Microfiltration or Ultrafiltration Membrane Modules. Protocol for Product Specific Challenge Testing of Bag / Cartridge Filters. NSF Standard 420 (TBD) from: ETV Generic Protocol for Development of Test/Quality Assurance Plans for Validation of Ultraviolet Reactors.

Performance Certification of Treatment Equipment Performance Testing to EPA ETV protocols then to NSF Standards when developed. Ongoing inspections of certified products at manufacturing facilities. Any changes must be reviewed prior to authorization. Any changes that might impact performance will require re-testing.

Performance Certification of Treatment Equipment NSF Report contains details of the validation tests. NSF Listing for products with performance results at www.nsf.org

NSF/ANSI 419 Standard and Certification

Development of NSF 419 In 2013, NSF elected to convert membrane and BCF ETV protocols into NSF/ANSI standard 419. JC for Public Drinking Water Equipment Performance Standards was formed and met in July 2013. The JC agreed on test procedures for all membrane technologies. NSF/ANSI 419 Standard published January 2015.

Scope of NSF/ANSI 419 Product specific microbial reduction testing for: Ultrafiltration membranes Microfiltration membranes Bag filters Cartridge filters Testing to obtain log removal values (LRV) for bacteria and viruses. Per EPA’s LT2ESWTR (40CFR141W). Procedures consistent with EPA Membrane Filtration Guidance Manual.

Scope of NSF/ANSI 419 Standard requires a review and re-publication within 5 years. NSF/ANSI 419 requires conformance to NSF/ANSI 61 for material safety.

Bag and Cartridge Filters A minimum of two filter units shall be tested. Microbial reduction measured At maximum designed flow rate Within 2 hours of start up At 45-55% maximum pressure drop After maximum pressure drop attained. Surrogate: Polystyrene latex fluorescent microspheres. 95% in range of 3.00 +/- 0.15um

Bag and Cartridge Filters Test rig is sanitized with sodium hypochlorite per AWWA C653. Units checked for any microbial contamination. Units are flushed and conditioned per manufacturers instructions. Negative control collected. Test dust is used to load the filter and create pressure drop. 10 NTU, 0-5 um.

Bag and Cartridge Filters Units are operated for at least 3 void volumes after microsphere challenge. Maximum feed concentration of microspheres is 1 x 104 times filtrate detection limit. Feed and filtrate samples are collected. Challenge and sampling after 3 void vols at 50+/-5% and 100% of max pressure drop. Log removal values calculated.

Micro and Ultrafiltration Membrane Modules A minimum of 5 modules shall be tested. B.atrophaeus shall be used as the surrogate for Cryptosporidium. 5x105 to 3.16x106 CFU/100mL MS-2 coliphage virus used for virus testing. 5x105 to 3.16x106 PFU/100mL

Micro and Ultrafiltration Tested at maximum design flux rate. Cross-flow units operated at max flux and max recovery. Units designed for both dead end and cross-flow are assigned LRV and max flux from the cross-flow tests.

Micro and Ultrafiltration Test rig is sanitized with sodium hypochlorite per AWWA C653. Units checked for any microbial contamination. Units are flushed and conditioned per manufacturer’s instructions. Negative control collected.

Micro and Ultrafiltration Each module subjected to non destructive performance test used in production QC before and after the test. Results establish a Quality Control Release Value. UF membranes are subject to pressure decay tests to evaluate membrane integrity. The lowest pressure decay represents the best membrane integrity.

Micro and Ultrafiltration In theory UF modules with the lowest pressure decay should have the highest LRV. QCRV would be selected from highest pressure decay results with a unit meeting or exceeding lowest LRV results.

Example QCRV and LRV Expected Module NDPT psi/min LRV 1 0.10 4.70 2 0.20 4.63 3 0.30 4.41 4 0.40 4.29 5 0.50 4.15 Choose QCRV = 0.50 psi/min at LRV of 4.15

Example QCRV and LRV However at low pressure decay rates you may not see a good correlation. Module NDPT psi/min LRV 1 0.09 4.7 2 0.10 4.75 3 0.12 4.8 4 0.18 5 0.22 Choose QCRV = 0.22 psi/min at LRV of 4.7

QCRV and NSF Certification Manufacturer performs pressure decay test on every new production unit. Products with results higher than QCRV are not Certified and cannot bear the NSF Certification Mark for 419. NSF verifies this during annual unannounced certification audits of manufacturing facility.

Log Removal Test Flushed and conditioned per manufacturer’s instructions. Each challenge test is 35 minutes. B.atrophaeus or MS-2 injected into feed stream at Startup After 15 minutes After 30 minutes Collect samples after 3 “hold up volumes” (huv) huv = unfiltered volume on feed side of membrane

Summary UF and MF Testing Membrane Modules operated at target flux rate. 5 modules tested. Pressure integrity testing prior to and after the test. Challenge products with: Endospores of bacteria Bacillus atrophaeus. MS2 coliphage virus is an OPTION. Log Removal Values (LRV) calculated from influent/effluent pairs over 35 minute test.

Summary UF and MF Testing A log removal value (LRV) established from performance testing. LRV is directly linked to the manufacturer’s QC of its modules or the Quality Control Release Value (QCRV). All modules used for drinking water shall meet the QCRV that is directly linked to the LRV. This is verified during NSF annual audits.

NSF audit of module parts The audit examines the wetted parts list for the NSF 61 audit. Looks for unauthorized changes in parts or suppliers. Reviews schematic of module for design or configuration changes. If in doubt, NSF conducts an engineering review of any changes in module design, part or supplier, e.g. potting resins, O rings or other seals; materials.

Benefits of NSF/ANSI 419 Standard is dynamic and can be updated annually by NSF Joint Committee. ANSI process ensures consensus must be reached by committee balanced with all stakeholders (regulators, manufacturers and users).

Benefits of NSF/ANSI 419 NSF Certification reports meet the need for independent third party requirements of US EPA. NSF Certification reports are identical to the high quality EPA ETV reports. NSF Certification audits will address: Whether the product tested is the same as that being produced and; Critical product / component changes affect performance and if so the amount of retesting.

Benefits of NSF/ANSI 419 Eliminates need to review reports at each state agency. State can refer to ANSI accredited Certification to NSF/ANSI 419. Should at some point reduce or eliminate need for extensive pilot testing.

Questions?? Dave Purkiss NSF International 734-827-6855 purkiss@nsf.org