Tap and WellTreasure Valley water, from the public record

Culligan US-EZ-4 EZ-Change Level 4 Under-Sink Filter review

Under-sink carbon filter. DIY if you are comfortable with this install. Listed to IAPMO/ANSI 401, IAPMO/ANSI 42, IAPMO/ANSI 53, IAPMO/ANSI 372.

What it removes

ContaminantEvidenceStated reductionScope
TurbidityCertifiednot stated
Haloacetic Acids (HAA5)Certifiednot statedvoc surrogate
1,2-Dibromo-3-chloropropaneCertifiednot statedvoc surrogate
Chlorine (residual)Certifiednot statedchloramine
TrichloroethyleneCertifiednot statedvoc surrogate
PFOACertifiednot stated
BenzeneCertifiednot statedvoc surrogate
PFOSCertifiednot stated
Total ColiformCertifiednot statedcyst
Total TrihalomethanesCertifiednot statedvoc surrogate
LeadCertifiednot stated
TetrachloroethyleneCertifiednot statedvoc surrogate
Mercury (inorganic)Certifiednot stated

Certified is an NSF, WQA, or IAPMO listing for that claim.

Kitchen cold line. Does not soften the house.

Certifications

  • IAPMO/ANSI 401: Bisphenol A (listing checked 2026-09-14)
  • IAPMO/ANSI 42: Chlorine Taste and Odor Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 42: Chloramine Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 42: Nominal Particulate Reduction, Class I (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: Cyst Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: Lead Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: Mercury Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: MTBE Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: PFOA/PFOS Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: PFOA/PFOS Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: Turbidity Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: VOC Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: VOC Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: VOC Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: VOC Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: VOC Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 53: VOC Reduction (from the manufacturer's page, not yet checked against the certifier's database)
  • IAPMO/ANSI 372: (listed, no reduction claim text) (listing checked 2026-09-14)

Twist-off EZ-Change head with dedicated chrome faucet; RC-EZ-4 'Premium' cartridge (0.5 micron nominal, 500 gal / 6 mo, $54.99 on Amazon B000NNPVVW; annual cost est.). Culligan DIY page lists reduction of chlorine taste/odor, chloramine, sediment, lead, cysts, mercury, turbidity, Class I particulate, VOCs, MTBE, PFOA/PFOS and pharmaceuticals and states 'IAPMO R&T Tested and Certified' without naming the standards or giving percentages; the 42/53 standard numbers are from retailer listings, not confirmed on Culligan's page. Does NOT address arsenic, uranium, nitrate or fluoride. Amazon $86.45 (Culligan DIY $97.99).