Multi-unit residential housing presents unique PFAS filtration challenges. Unlike single-family homes where the owner controls water infrastructure, multi-unit buildings distribute decision-making across owners, managers, HOAs, and residents — creating complexity that often leaves PFAS unaddressed even when residents want action.
The Governance Challenge
In rental apartments, the landlord controls building water infrastructure. Individual tenants typically cannot install whole-building systems, and even point-of-use filters require permission for any modifications to plumbing. In condominiums and co-ops, water infrastructure may be shared building property requiring board approval for modifications. This governance complexity means that PFAS protection in multi-unit housing often requires collective action rather than individual initiative.
Point-of-Entry (POE) Building Treatment
A point-of-entry system treats all water entering the building before it distributes to individual units. For PFAS specifically, building-level POE options include:
- Granular Activated Carbon (GAC) contactors: Large GAC vessels installed at the building water main; effective for long-chain PFAS; must be sized for the building’s total flow demand; media replacement is a building operational expense
- Ion Exchange systems: High-capacity PFAS-selective resins at the building entry; effective for both long and short-chain PFAS; higher capital cost but strong performance
- Large-format RO systems: Commercial RO for smaller buildings; higher capital and operating cost; generates significant concentrate waste that must be managed
Building-level treatment has the advantage of protecting all units simultaneously, including water used for showering and bathing in addition to drinking and cooking — reducing dermal exposure pathways that point-of-use drinking water filters don’t address.
Point-of-Use Options for Individual Units
For residents who cannot achieve building-level treatment, unit-level options include:
- Under-sink RO systems: Most effective PFAS removal; requires lease permission for installation in most buildings; wastewater goes to drain
- Countertop RO systems: Connects to faucet without permanent modification; no lease permission required; suitable for renters
- Countertop pitcher filters: NSF/ANSI 53 certified options for long-chain PFAS; no installation required; most accessible for renters
Advocacy Pathways for Residents
Residents who want building-level PFAS treatment can pursue:
- Formal request to building management with supporting water test data
- HOA or co-op board proposals with cost-benefit analysis including health risk reduction
- Organizing with other residents to present a collective request with broader support
- Engaging local health department to request building water testing if contamination is suspected
- In rental buildings with documented PFAS above MCLs, consulting a tenant’s rights attorney about landlord obligations to provide habitable water quality
Cost-Sharing Models
Building-level PFAS treatment costs can be shared among residents through HOA assessments, rent adjustments, or utility fee structures. A building-level GAC system for a 50-unit apartment building might cost $30,000–80,000 installed, plus $5,000–15,000 annually for media replacement — roughly $50–100 per unit per month when amortized. This compares favorably with each resident independently installing and maintaining individual filtration units, while providing more comprehensive whole-building protection.