Learn the Issues

Do ductless mini-split heat pumps filter fine particles out of indoor air?

Ductless heat pumps, or mini/multi split heat pumps, are an alternative to radiator or baseboard heating, as well as replacement for window units for cooling. A head unit, or multiple head units, are mounted on the interior wall or ceiling, with an accompanying unit outside. The outside unit extracts heat…

• Last published: July 6, 2026

Do ducted air source heat pumps filter fine particles out of indoor air?

A ducted air source heat pump (ASHP) provides heating and cooling by extracting heat from outside into your home in winter and pulling the heat out of your home in the summer. Ducted ASHP systems can be installed and connected to the conventional forced-air ductwork system that is typical of…

• Last published: July 6, 2026

Public Interest Waiver of the American Iron and Steel Requirements to Butte-Silver Bow County, Montana for Transition Couplings

Waiver to AIS Requirements.

Request for AIS Waiver for Flexible Sewer Tap Saddles with Tap Saddle Pressure Kit with Bentonite Seal for Pomona, Kansas (CWSRF)

AIS waiver request.

Butte-Silver Bow County, MT Waiver Request for Spring-Assisted Swing Check Valves

Denied waiver of the AIS requirements.

Project Waiver of AIS Requirements for Pressure Kits for Tap Saddles for the City of Pomona, Kansas (CWSRF)

AIS waiver approved.

Project Waiver of AIS Requirements for Butterfly Valves for Wolsey, South Dakota (DWSRF)

AIS waiver request approval.

Request for AIS Waiver for Ductile Iron Threaded Companion Flanges for Great Falls, Montana

AIS waiver request.

Project Waiver of American Iron and Steel Requirements to the Liberty Lake Water and Sewer District in Washington for Combination Wafer Swing Check Valves

Approval of AIS waiver request.

Project Waiver of the American Iron and Steel Requirements to the Metropolitan District in Connecticut for Mechanical Joint Adapter Bells

AIS project waiver.

Request for AIS Waiver for Type I Reinforcement Fibers in Precast Segment Tunnel Liners for Columbus, Ohio

AIS waiver request.

CWSRF Small Systems Waiver Requests

Request for waiver of AIS requirements.

The CWSRF: A Powerful Financial Tool to Support Brownfield and Superfund Assessment and Cleanup

Case studies that provide examples of how communities have leveraged brownfields grant and loan funding and CWSRF financing to clean up contaminated sites.

Public Interest Waiver of American Iron and Steel Requirements to the Northeast Ohio Regional Sewer District for Steel Fiber Reinforcement

Waiver of AIS requirements.

Project Waiver of AIS Requirements for Wafer-Style Check Valves for Wolsey, South Dakota (DWSRF)

AIS waiver request approval.

Request for AIS Waiver for Butterfly Valves for Wolsey, South Dakota (DWSRF)

AIS Waiver Request received

Lunch and Learn Webinar: AIS Certification Letters

Webinar presentation: AIS Compliance for Stainless Steel Nuts and Bolts Used in Couplings, Flanges, Restraints, Saddles, and Joints

Request for AIS Waiver for Wafer-Style Check Valves for Wolsey, South Dakota (DWSRF)

AIS Waiver Request

Project Waiver of AIS Requirements for 16-inch Plug Valves for Douglas, Georgia (CWSRF)

AIS waiver approved.

Request for AIS Waiver for 16-inch Plug Valves for Douglas, Georgia (CWSRF)

AIS waiver request.