Division of Environmental Health Drinking Water Program

This is not a list of devices that are automatically approved and does not include all possible alternate filtration devices that could be acceptable for a particular water system.

This list contains only alternate filtration devices that are not currently certified by an ANSI accredited body to meet NSF/ANSI Standard 53, 58, or 419 for Cryptosporidium-sized cyst or particle removal. However, these devices have been third-party challenge tested to industry standard protocols such as those in the NSF/ANSI standards mentioned above to demonstrate greater than 2-log removal of Cryptosporidium -sized particles, including the 1-log buffer required under the Long Term 2 Enhanced Surface Water Treatment Rule (LT2) [ see 40 CFR 141.719(a)(1)]. These filters are also required to have up-to-date NSF/ANSI Standard 61 certifications to ensure their materials are compatible with drinking water applications. The filters in this list have been approved for use in Alaska for certain public water system (PWS) applications to meet the microbial filtration requirements of the Surface Water Treatment Rules for Giardia and Cryptosporidium. Their use for a particular PWS in the State needs to be evaluated by DEC on a case-by-case basis to determine their applicability to the quality of the water source.

Do not install a filter from this list in a PWS without prior DEC approval to construct. Devices on this list are not automatically approved for all PWSs.

Devices on this list can be proposed for use in PWSs. Approval by DEC is granted on a case-by-case basis. Before proposing a device on this list, closely evaluate the source’s water quality, filter efficiency, and economics of the treatment process for the PWS. These devices are approved for use based on site specific conditions through an engineering plan review process. To obtain removal credit from DEC, the filtration system must be properly designed and operated for treating the specific source water. For more information on the Drinking Water Program plan review process please visit our plan review webpage.

Filters on this list as well as other products not currently on the list may be approved based on supporting documentation to verify removal of at least 99.9 percent of Giardia- and Cryptosporidium-sized particles together with information on current NSF/ANSI Standard 61 certification status of the filter and housing. The request for approval to install a filtration device will require engineering documents submitted to DEC, which clearly identify the water quality parameters and other criteria considered in selecting the particular filtration technology, including the need for pre-treatment. Other considerations should include operation, maintenance, reliability, and technical requirements of the treatment process versus the level of operator expertise available. See our plan review checklists for additional information on what is need for review of a request to install treatment components.

Alternate filtration devices that are certified by an ANSI accredited body to meet NSF/ANSI Standard 53, 58, or 419 for Cryptosporidium-sized cyst or particle removal may be approved for use in Alaska for meeting microbial treatment requirements of the surface water treatment rules. Any filtration device installed in a PWS must first be approved by DEC through the engineering plan review process for site conditions unique to the PWS. Installation according to the manufacturer’s recommendations is usually required for design variables such as flow rate and differential pressure. Products or materials in contact with drinking water must also be certified to NSF/ANSI Standard 61. Please note that certification to NSF/ANSI Standards 53, 58 or 419 also includes certification to Standard 61. Lists of devices certified to the abovementioned NSF/ANSI Standards can be found on the websites of the following ANSI accredited bodies.

• NSF International
  • NSF Product and Service Listings
• UL, LLC
  • UL Product IQ (log in required; free to create account)
• CSA Group
• IAPMO Research and Testing, Inc.
• Water Quality Association (WQA)
• ICC Evaluation Service, LLC

This listing is not a guarantee of the availability of the product. These products may not be available from vendors in Alaska; consult with your local water treatment vendor regarding the availability of these devices. Contact the manufacturer directly to obtain the most current product information.

The approval of these devices for use in the State of Alaska requires the filtration system maintain the same product characteristics as those used during its performance testing as well as current NSF/ANSI Standard 61 certification. In the event compliance with these requirements is not maintained (e.g., change in filter manufacturing process or performance characteristics) the PWS may be required to upgrade or replace the filtration treatment system with one that meets current standards.

For further information on DEC requirements for proposing the installation of alternate filtration contact a Drinking Water Program engineer