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

2. 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

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

4. 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

5. 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

6. 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.

7. 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

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

9. 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.

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

11. 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 UVDGM).
One time on-site testing is insufficient to address LT2 requirements.

12. 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.

13. 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.

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

15. NSF/ANSI 419 Standard and Certification

16. 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.

17. 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.

18. 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.

19. 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 /- 0.15um

20. 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.

21. 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.

22. 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

23. 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.

24. 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.

25. 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.

26. 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.

27. 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

28. 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

29. 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.

30. 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

31. 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.

32. 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.

33. 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.

34. 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).

35. 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.

36. 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.

37. Questions?? Dave Purkiss NSF International 734-827-6855